Author: MIT News

Institute Professor Emeritus Mario Molina, environmental leader and Nobel laureate, dies at 77

by Kate S. Petersen | Jennifer Chu | MIT News Office | EAPS |

Renowned atmospheric chemist and MIT Institute Professor Emeritus Mario Molina, who discovered that chlorofluorocarbons (CFCs) had the potential to destroy the ozone layer in the Earth’s stratosphere, has died at the age of 77.

At MIT, Molina held joint appointments in the Department of Earth, Atmospheric and Planetary Sciences (EAPS) and the Department of Chemistry, from 1989 to 2004.

In the early 1970s, Molina demonstrated through computer modeling and laboratory work that compounds widely used in propellants and refrigerants could destroy ozone in the upper atmosphere, increasing the ultraviolet radiation reaching Earth. His theories were later confirmed by observation and helped support the ratification of the Montreal Protocol, the first global treaty to reduce CFC emissions.

In 1995, he shared the Nobel Prize in Chemistry with F. Sherwood Rowland of the University of California at Irvine, and Paul Crutzen, a scientist at the Max Planck Institute for Chemistry in Mainz, Germany, for discovering the depletion of the Earth’s thin, protective layer of ozone, which the Nobel committee referred to as the “Achilles heel of the universe.” Molina continued to advocate for environmental causes throughout his career.

“Mario Molina was the gentle giant of his age in environmental science, a wise mentor to his students, and respectful of others no matter their rank or status,” says Ronald Prinn, the TEPCO Professor of Atmospheric Science in EAPS, who led the search committee that originally brought Molina to MIT. “We are privileged to have had him on the faculty at MIT for 15 years, during the middle of which he was awarded the Nobel Prize, and from the proceeds of which he established the Molina Fellowships at MIT. His work on mitigating depletion of the ozone layer and air pollution in megacities is legendary. Most recently he founded the Centro Mario Molina devoted to the transition from fossil energy to clean energy in Mexico and beyond. He will be sorely missed, but never forgotten.”

Early scientific inquiry

Born on March 19, 1943 in Mexico City, Molina was enthralled by science from a young age. He used toy microscopes and chemistry sets to create his own “lab” in the bathroom of his childhood home. His aunt, a chemist, supported these early scientific interests by helping him conduct experiments more advanced than amateur chemistry sets would allow.

He attended school in Mexico City; later, his parents sent him abroad to the Institute Rosenberg in Switzerland, hoping to support his scientific proclivity. Molina attended the Universidad Nacional Autónoma de México (UNAM), where he completed his bachelor’s degree in chemical engineering in 1965, followed by a postgraduate degree in polymerization kinetics from the Albert Ludwig University of Freiburg, West Germany, in 1967. The University of California at Berkeley awarded him a PhD in physical chemistry in 1972.

Environmental reactions

In 1973, Molina began his CFC research as a postdoc at the University of California at Irvine, in the lab of F. Sherwood Rowland, who initially presented Molina with a list of research options. Molina latched quickly to one in particular: tracking the environmental fate of CFCs, the industrial chemicals that had been building up in the atmosphere and at the time were thought to have no adverse effects on the environment.

After simulating the chemicals’ reaction behavior and kinetics, Molina found that there was not much that could break down CFCs in the lower atmosphere. He suspected, however, that CFCs could be detrimental at higher altitudes, and hypothesized that high-energy photons from the sun available within the stratosphere could break the chemicals apart, generating free chlorine ions that would then react destructively with ozone molecules. Rowland and Molina published their work in the journal Nature in 1974.

That year, Molina and Rowland publicly called for a ban on CFCs at the American Chemical Society meeting. Molina also began teaching atmospheric science, holding positions at UC Irvine from 1975 to 1982 and conducting research at Caltech’s Jet Propulsion Laboratory from 1982 to 1989. Initially disputed by industry, Molina’s work began to gain traction, first when it was reviewed by the National Academy of Sciences in 1976, and then even more so when a hole in the Antarctic ozone later was first reported in 1985.

In 1987, his work, in part, inspired atmospheric chemist Susan Solomon to lead a scientific expedition to Antarctica, the results of which proved that the ozone hole was indeed caused by CFCs. The Montreal Protocol to phase out CFCs went into effect in 1989, the same year that Molina joined the faculty at MIT.

Molina was awarded the 1995 Nobel Prize in Chemistry with his colleagues for their work on CFCs and ozone depletion — the first time the Swedish Academy recognized environmental degradation from human-made substances. Molina donated a substantial portion of his share of the prize money to MIT in 1996 to create a fellowship program for scientists from developing countries to pursue environmental research.

“It’s clear to me that one of the important needs for global environment issues is the participation of scientists from all over the world,” Molina said in announcing the gift. “We have some very big challenges ahead if we are to preserve the environment, and it’s obvious that there are too few scientists from developing countries involved in the effort.”

Molina continued his work in atmospheric chemistry while at MIT, studying the atmosphere-biosphere interface, hoping to better understand global climate change.

“The signature feature of Mario Molina was that he was not only a great scientist and scholar, he was also a true gentlemen — always ready with a smile and focused on the person he was speaking with, whether it was an undergraduate student or a fellow Nobel laureate,” says Solomon, who is the Lee and Geraldine Martin Professor of Environmental Studies in EAPS and holds a secondary appointment in the Department of Chemistry.

“His humanity and his science”

In 1994 Molina was named by U.S. President Bill Clinton to serve on the 18-member President’s Committee of Advisors on Science and Technology (PCAST). Later, he also served on President Barack Obama’s Council of Advisors on Science and Technology in 2011, and received the Presidential Medal of Freedom from President Obama in 2016.

MIT appointed him an Institute Professor for his abilities as a “natural educator” and excellence in research in 1997.

Molina often traveled to Mexico to work on environmental projects. While at MIT, he collaborated with policymakers and researchers to reduce Mexico City’s severe air pollution and improve air quality. In 2004, he founded the Mario Molina Center for Strategic Studies in Energy and the Environment in Mexico City, an organization dedicated to bridging “practical solutions between science and public policy on energy and environment matters to promote sustainable development and vigorous economic growth.” That same year, he left MIT to join the Scripps Institution of Oceanography and the Department of Chemistry and Biochemistry at University of California at San Diego. In 2017, he was inducted into the California Hall of Fame.

“Mario Molina is unique in his ability to span from fundamental science to local and global policy for stewarding our environment. He towers in his humanity as well as his science,” said MIT President Charles M. Vest on Molina’s departure.

Molina was awarded numerous honorary degrees from institutions including Harvard University, Duke University, and Yale University, as well as institutions in Mexico. He was elected to the National Academy of Sciences in 1993, the United States Institute of Medicine in 1996, and The National College of Mexico in 2003. He was a member of the Mexican Academy of Sciences and a fellow of the American Association for the Advancement of Science (AAAS), and served on numerous advisory councils, including the National Science Foundation’s Advisory Committee for Geosciences.

In addition to his Nobel Prize, Molina received the Tyler Prize for Environmental Achievement, the UNEP-Sasakawa Environment Prize, and the United Nations Champion of the Earth Award. He was bestowed the Knight Medal of the Legion of Honor by French President Francois Hollande in 2014. He was awarded the Esselen Award of the Northeast section of the American Chemical Society in 1987, the Newcomb-Cleveland Prize from AAAS in 1988, as well as the NASA Medal for Exceptional Scientific Advancement and the United Nations Environmental Programme Global 500 Award in 1989.

Additionally, the Pew Charitable Trusts Scholars Program in Conservation and the Environment honored him as a leading environmental scientist in 1990. Molina was given the Golden Plate Award of the American Academy of Achievement in 1996. He won the Willard Gibbs Award from the Chicago Section of the American Chemical Society and the American Chemical Society Prize for Creative Advances in Environment Technology and Science in 1998. He was granted the 9th Annual Heinz Award in the Environment. He also had an asteroid named after him: 9680 Molina.

Molina is survived by his wife, Guadalupe Álvarez; his son, Felipe Jose Molina; and three stepsons, Joshua, Allan, and Asher Ginsburg. He was previously married to atmospheric chemist Luisa Tan Molina, an EAPS research affiliate.

MIT Alumni awarded 2020 “Genius Grants”

by Julie Fox | Alumni Association |

Three MIT alumni have won a 2020 MacArthur Fellowship, a prestigious honor unofficially known as the “Genius Grant.”

“In the midst of civil unrest, a global pandemic, natural disasters, and conflagrations, this group of 21 exceptionally creative individuals offers a moment for celebration,” says Cecilia Conrad, managing director of the 40-year-old fellowship program. Each recipient will receive a $625,000, no-strings-attached award.

Learn about the MIT-affiliated recipients:

Isaiah Andrews PhD ’14, professor of economics at Harvard University

As an econometrician, working in the subfield of economics that develops new statistical tools, Andrews is developing robust methods of statistical inference to address key challenges in economics, social science, and medicine.

From the MacArthur Foundation website:

“Much of Andrews’s work has focused on problems of weak identification, where information is limited and the validity of many standard inference procedures is thus called into question. The causal effect of one variable on another is said to be identified if it could be learned from a sufficiently large dataset. Weak identification arises when a small change in the distribution of the data would eliminate our ability to determine the causal effect. In an examination of nonlinear models, Andrews and a collaborator produced a pathbreaking analysis of the geometric structure of weak identification with applications in macroeconomic models.…” Read more.

Monika H. Schleier-Smith PhD ’11, associate professor of physics at Stanford University

As an experimental physicist in the field of quantum information science, Schleier-Smith focuses on the idea that information does not need to be encoded locally in individual particles but rather can be stored in correlations between different particles.

From the MacArthur Foundation website:

“Schleier-Smith devises and implements experimental set-ups and techniques involving laser-cooled atoms that allow her to isolate and manipulate physical phenomena that were not previously accessible in experiments. In collaboration with colleagues, she used light-mediated interactions between atoms trapped in an optical cavity to generate, detect, and measure quantum entanglement, a fragile and difficult-to-study phenomenon that occurs when a pair or group of particles interact in such a way that their behavior becomes correlated.…” Read more.

Mohammad R. Seyedsayamdost PhD ’08, associate professor of chemistry at Princeton University

A biological chemist, Seyedsayamdost seeks new therapeutic agents to combat infections.

From the MacArthur Foundation website:

“Seyedsayamdost is investigating the synthesis of new small molecules with bioactive or therapeutic properties. Leveraging commercially available libraries of small molecules (oftentimes known antibiotics), Seyedsayamdost developed a method called HiTES (High-Throughput Elicitor Screening) that can rapidly activate otherwise silent (or cryptic) secondary metabolic pathways and, therefore, production of the corresponding natural products. He then uses a range of methods, including nuclear magnetic resonance spectroscopy, computational and analytical chemistry, and imaging mass spectrometry to analyze and characterize the structure (and potential uses) of these complex natural products.…” Read more.

Learn about all of the 2020 MacArthur fellows, and read about the MIT alumni and faculty who were honored with a fellowship in 2018, 2016, 2012, and 2010.

This article originally appeared on the MIT Alumni Association’s Slice of MIT blog.

A step toward a universal flu vaccine

by Anne Trafton | MIT News Office |

Each year, the flu vaccine has to be redesigned to account for mutations that the virus accumulates, and even then, the vaccine is often not fully protective for everyone.

Researchers at MIT and the Ragon Institute of MIT, MGH, and Harvard are now working on strategies for designing a universal flu vaccine that could work against any flu strain. In a study appearing today, they describe a vaccine that triggers an immune response against an influenza protein segment that rarely mutates but is normally not targeted by the immune system.

The vaccine consists of nanoparticles coated with flu proteins that train the immune system to create the desired antibodies. In studies of mice with humanized immune systems, the researchers showed that their vaccine can elicit an antibody response targeting that elusive protein segment, raising the possibility that the vaccine could be effective against any flu strain.

“The reason we’re excited about this work is that it is a small step toward developing a flu shot that you just take once, or a few times, and the resulting antibody response is likely to protect against seasonal flu strains and pandemic strains as well,” says Arup K. Chakraborty, the Robert T. Haslam Professor in Chemical Engineering and professor of physics and chemistry at MIT, and a member of MIT’s Institute for Medical Engineering and Science and the Ragon Institute of MGH, MIT, and Harvard.

Chakraborty and Daniel Lingwood, an assistant professor at Harvard Medical School and a group leader at the Ragon Institute, are the senior authors of the study, which appears today in Cell Systems. MIT research scientist Assaf Amitai is the lead author of the paper.

Targeting flu

Most flu vaccines consist of inactivated flu viruses. These viruses are coated with a protein called hemagglutinin (HA), which helps them bind to host cells. After vaccination, the immune system generates squadrons of antibodies that target the HA protein. These antibodies almost always bind to the head of the HA protein, which is the part of the protein that mutates the most rapidly. Parts of the HA stem, on the other hand, very rarely mutate.

“We don’t understand the complete picture yet, but for many reasons, the immune system is intrinsically not good at seeing the conserved parts of these proteins, which if effectively targeted would elicit an antibody response that would neutralize multiple influenza types,” Lingwood says.

In their new study, the researchers set out to study why the immune system ends up targeting the HA head rather than the stem, and to find ways to refocus the immune system’s attention on the stem. Such a vaccine could elicit antibodies known as “broadly neutralizing antibodies,” which would respond to any flu strain. In principle, this kind of vaccine could end the arms race between vaccine designers and rapidly mutating flu viruses.

One factor that was already known to contribute to antibody preference for the HA head is that HA proteins are densely clustered on the surface of the virus, so it’s difficult for antibodies to access the stem region. The head region is much more accessible.

The researchers developed a computational model that helped them to further explore the “immunodominance” of the protein’s head region. “We hypothesized that the surface geometry of the virus could be key to its ability to survive by protecting its vulnerable parts from antibodies,” Amitai says.

The researchers explored the effects of geometry on immunodominance using a technique called molecular dynamics simulation. They further modeled a process called antibody affinity maturation. This process, which occurs after B cells encounter a virus (or a vaccine), determines which antibodies will predominate during the immune response.

Each B cell has on its surface proteins called B cell receptors, which bind to different foreign proteins. Once a particular B cell receptor binds strongly to the HA protein, that B cell becomes activated and starts to multiply rapidly. This process introduces new mutations into the B cell receptors, some of which bind more strongly. These better binders tend to survive, while the weaker binders die. At the end of this process, which takes one or two weeks, there is a population of B cells that is very good at binding strongly to the HA protein. These B cells secrete antibodies that bind to the HA protein.

“As time goes on, after infection, the antibodies get better and better at targeting this particular antigen,” Chakraborty says.

The researchers’ computer simulations of this process revealed that when a typical flu vaccine is given, B cell receptors that bind strongly to the HA stem are at a competitive disadvantage during the maturation process, because they can’t reach their targets as easily as B cell receptors that bind strongly to the HA head.

The researchers also used their computer model to simulate this maturation process with a nanoparticle vaccine developed at the National Institutes of Health, which is now in a phase 1 clinical trial. This particle carries HA stem proteins spaced out at lower density. The model showed that this arrangement makes the proteins more accessible to antibodies, which are Y-shaped, allowing the antibodies to grab onto the proteins with both arms. The simulations revealed that those stem-targeting antibodies predominated at the end of the maturation process.

Refocused immunity

The researchers also used their computational model to predict the outcome of several possible vaccination strategies. One strategy that appears promising is to immunize with an HA stem from a virus that is similar to, but not the same as, strains that the recipient has previously been exposed to. In 2009, many people around the world were either infected with or vaccinated against a novel H1N1 strain. The modeling led the researchers to hypothesize that if they vaccinated with nanoparticles displaying HA-like proteins from a strain that is different from the 2009 version, it should elicit the kind of broadly neutralizing antibodies that may confer universal immunity.

Using mice with human immune cells, the researchers tested this strategy, first immunizing them against the 2009 H1N1 strain, followed by a nanoparticle vaccine carrying the HA stem protein from a different H1N1 strain. They found that this approach was much more successful at eliciting broadly neutralizing antibodies than any of the other strategies that they tested.

“We discovered that this particular event in our immune history can actually be harnessed with this particular nanoparticle to refocus the immune system’s attention on one of these so-called universal vaccine targets,” Lingwood says. “When there’s a refocusing event, that means we can swing the antibody response against that target, which under other conditions is simply not seen. We have shown in previous studies that when you’re able to elicit this kind of response, it’s protective against flu strains that mimic pandemic threats.”

The research was funded by the National Institutes of Health, the Harvard University Milton Award, the Gilead Research Scholars Program, and the National Science Foundation Research Fellowship Program.

Cancer researchers collaborate, target DNA damage repair pathways for cancer therapy

by Koch Institute |

Cancer therapies that target specific molecular defects arising from mutations in tumor cells are currently the focus of much anticancer drug development. However, due to the absence of good targets and to the genetic variation in tumors, platinum-based chemotherapies are still the mainstay in the treatment of many cancers, including those that have a mutated version of the tumor suppressor gene p53. P53 is mutated in a majority of cancers, which enables tumor cells to develop resistance to platinum-based chemotherapies. But these defects can still be exploited to selectively target tumor cells by targeting a second gene to take down the tumor cell, leveraging a phenomenon known as synthetic lethality.

Focused on understanding and targeting cell signaling in cancer, the laboratory of Michael Yaffe, the David H. Koch Professor Science and director of the MIT Center for Precision Cancer Medicine, seeks to identify pathways that are synthetic lethal with each other, and to develop therapeutic strategies that capitalize on that relationship. His group has already identified MK2 as a key signaling pathway in cancer and a partner to p53 in a synthetic lethal combination.

Now, working with a team of fellow researchers at MIT’s Koch Institute for Integrative Cancer Research, Yaffe’s lab added a new target, the gene XPA, to the combination. Appearing in Nature Communications, the work demonstrates the potential of “augmented synthetic lethality,” where depletion of a third gene product enhances a combination of targets already known to show synthetic lethality. Their work not only demonstrates the effectiveness of teaming up cancer targets, but also of the collaborative teamwork for which the Koch Institute is known.

P53 serves two functions: first, to give cells time to repair DNA damage by pausing cell division, and second, to induce cell death if DNA damage is too severe. Platinum-based chemotherapies work by inducing enough DNA damage to initiate the cell’s self-destruct mechanism. In their previous work, the Yaffe lab found that when cancer cells lose p53, they can re-wire their signaling circuitry to recruit MK2 as a backup pathway. However, MK2 only restores the ability to orchestrate DNA damage repair, but not to initiate cell death.

The Yaffe group reasoned that targeting MK2, which is only recruited when p53 function is absent, would be a unique way to create a synthetic lethality that specifically kills p53-defective tumors, by blocking their ability to coordinate DNA repair after chemotherapy. Indeed, the Yaffe Lab was able to show in pre-clinical models of non-small cell lung cancer tumors with mutations in p53, that silencing MK2 in combination with chemotherapy treatment caused the tumors to shrink significantly.

Although promising, MK2 has proven difficult to drug. Attempts to create target-specific, clinically viable small-molecule MK2 inhibitors have so far been unsuccessful. Researchers led by co-lead author Yi Wen Kong, then a postdoc in the Yaffe lab, have been exploring the use of RNA interference (siRNA) to stop expression of the MK2 gene, but siRNA’s tendency to degrade rapidly in the body presents new challenges.

Enter the potential of nanomaterials, and a team of nanotechnology experts in the laboratory of Paula Hammond, the David H. Koch Professor of Engineering, head of the MIT Department of Chemical Engineering, and the Yaffe group’s upstairs neighbor. There, Kong found a willing collaborator in then-postdoc Erik Dreaden, whose team had developed a delivery vehicle known as a nanoplex to protect siRNA until it gets to a cancer cell. In studies of non-small cell lung cancer models where mice were given the MK2-targeting nanocomplexes and standard chemotherapy, the combination clearly enhanced tumor cell response to chemotherapy. However, the overall increase in survival was significant, but relatively modest.

Meanwhile, Kong had identified XPA, a key protein involved in another DNA repair pathway called NER, as a potential addition to the MK2-p53 synthetic lethal combination. As with MK2, efforts to target XPA using traditional small-molecule drugs have not yet proven successful, and RNA interference emerged as the team’s tool of choice. The flexible and highly controllable nature of the Hammond group’s nanomaterials assembly technologies allowed Dreaden to incorporate siRNAs against both XPA and MK2 into the nanocomplexes.

Kong and Dreaden tested these dual-targeted nanocomplexes against established tumors in an immunocompetent, aggressive lung cancer model developed in collaboration between the laboratories of professor of biology Michael Hemann and Koch Institute Director Tyler Jacks. They let the tumors grow even larger before treatment than they had in their previous study, thus raising the bar for therapeutic intervention.

Tumors in mice treated with the dual-targeted nanocomplexes and chemotherapy were reduced by up to 20-fold over chemotherapy alone, and similarly improved over single-target nanocomplexes and chemotherapy. Mice treated with this regimen survived three times longer than with chemotherapy alone, and much longer than mice receiving nanocomplexes targeting MK2 or XPA alone.

Overall, these data demonstrate that identification and therapeutic targeting of augmented synthetic lethal relationships — in this case between p53, MK2 and XPA — can produce a safe and highly effective cancer therapy by re-wiring multiple DNA damage response pathways, the systemic inhibition of which may otherwise be toxic.

The nanocomplexes are modular and can be adapted to carry other siRNA combinations or for use against other cancers in which this augmented synthetic lethality combination is relevant. Beyond application in lung cancer, the researchers — including Kong, who is now a research scientist at the Koch Institute, and Dreaden, who is now an assistant professor at Georgia Tech and Emory School of Medicine — are working to test this strategy for use against ovarian and other cancers.

Additional collaborations and contributions were made to this project by the laboratories of Koch Institute members Stephen Lippard and Omer Yilmaz, the Eisen and Chang Career Development Professor.

This work was supported in part by a Mazumdar-Shaw International Oncology Fellowship, a postdoctoral fellowship from the S. Leslie Misrock (1949) Frontier Fund for Cancer Nanotechnology, and by the Charles and Marjorie Holloway Foundation, the Ovarian Cancer Research Foundation, and the Breast Cancer Alliance.

Making tuberculosis more susceptible to antibiotics

by Anne Trafton | MIT News |

Every living cell is coated with a distinctive array of carbohydrates, which serves as a unique cellular “ID” and helps to manage the cell’s interactions with other cells.

MIT chemists have now discovered that changing the length of these carbohydrates can dramatically affect their function. In a study of mycobacteria, the type of bacteria that cause tuberculosis and other diseases, they found that shortening the length of a carbohydrate called galactan impairs some cell functions and makes the cells much more susceptible to certain antibiotics.

The findings suggest that drugs that interfere with galactan synthesis could be used along with existing antibiotics to create more effective treatments, says Laura Kiessling, the Novartis Professor of Chemistry at MIT and the senior author of the study.

“There are a lot of TB strains that are resistant to the current set of antibiotics,” Kiessling says. “TB kills over a million people every year and is the number one infectious disease killer.”

Former MIT graduate student Alexander Justen is the lead author of the paper, which appears today in Science Advances.

The long and short of it

Galactan, a polysaccharide, is a component of the cell wall of mycobacteria, but little is known about its function. Until now, its only known role was to form links between molecules called peptidoglycans, which make up most of the bacterial cell wall, and other sugars and lipids. However, the version of galactan found in mycobacteria is much longer than it needs to be to perform this linker function.

“What was so strange is that the galactan is about 30 sugar molecules long, but the branch points for the other sugars that it links to are at eight, 10, and 12. So, why is the cell expending so much energy to make galactan longer than 12 units?” Kiessling says.

That question led Kiessling and her research group to investigate what might happen if galactan were shorter. A team led by Justen genetically engineered a type of mycobacteria called Mycobacterium smegmatis (which is related to Mycobacterium tuberculosis but is not harmful to humans) so that their galactan chains would contain only 12 sugar molecules.

As a result of this shortening, cells lost their usual shape and developed “blebs,” or bulges from their cell membranes. Shortening galactan also shrank the size of a compartment called the periplasm, a space that is found between a bacterial cell’s inner and outer cell membranes. This compartment is involved in absorbing nutrients from the cell’s environment.

Truncating galactan also made the cells more susceptible to certain antibiotics — specifically, antibiotics that are hydrophobic. Mycobacteria cell walls are relatively impermeable to hydrophobic antibiotics, but the shortened galactan molecules make the cells more permeable, so these drugs can get inside more easily.

“This suggests that drugs that would lead to these truncated chains could be valuable in combination with hydrophobic antibiotics,” Kiessling says. “I think it validates this part of the cell as a good target.”

Her lab is currently working on developing drugs that could block galactan synthesis, which is not targeted by any existing TB drugs. Patients with TB are usually given drug combinations that have to be taken for six months, and some strains have developed resistance to the existing drugs.

Unexpected roles

Kiessling’s lab is also studying the question of why it is useful for bacteria to alter the length of their carbohydrate molecules. One hypothesis is that it helps them to shield themselves from the immune system, she says. Some studies have shown that a dense coating of longer carbohydrate chains could help to achieve a stealth effect by preventing host immune cells from interacting with proteins on the bacterial cell surface.

If that hypothesis is confirmed, then drugs that interfere with the length of galactan or other carbohydrates might also help the immune system fight off bacterial infection, Kiessling says. This could be useful for treating not only tuberculosis but also other diseases caused by mycobacteria, such as chronic obstructive pulmonary disease (COPD) and leprosy. Other strains of mycobacteria (known as “flesh-eating bacteria”) cause a potentially deadly infection called necrotizing fasciitis. All of these mycobacteria have galactan in their cell walls, and there are no good vaccines against any of them.

Although the research may end up helping scientists to develop better drugs, Kiessling first became interested in this topic as a basic science question.

“The reason I like this paper is because while it does have implications for treating tuberculosis, it also shows a fundamentally new role for carbohydrates, which I love. People are finding that they can have unexpected roles, and this is another unexpected result,” she says.

The research was funded by the National Institute of Allergy and Infectious Disease and the National Institutes of Health Common Fund.

School of Science appoints 12 faculty members to named professorships

by School of Science |

The School of Science has awarded chaired appointments to 12 faculty members. These faculty, who are members of the departments of Biology; Brain and Cognitive Sciences; Chemistry; Earth, Atmospheric and Planetary Sciences; and Physics, receive additional support to pursue their research and develop their careers.

Kristin Bergmann, an assistant professor in the Department of Earth, Atmospheric and Planetary Sciences, has been named a D. Reid Weedon, Jr. ’41 Career Development Professor. This is a three-year professorship. Bergmann’s research integrates across sedimentology and stratigraphy, geochemistry, and geobiology to reveal aspects of Earth’s ancient environments. She aims to better constrain Earth’s climate record and carbon cycle during the evolution of early eukaryotes, including animals. Most of her efforts involve reconstructing the details of carbonate rocks, which store much of Earth’s carbon, and thus, are an important component of Earth’s climate system over long timescales.

Joseph Checkelscky is an associate professor in the Department of Physics and has been named a Mitsui Career Development Professor in Contemporary Technology, an appointment he will hold until 2023. His research in quantum materials relies on experimental methods at the intersection of physics, chemistry, and nanoscience. This work is aimed toward synthesizing new crystalline systems that manifest their quantum nature on a macroscopic scale. He aims to realize and study these crystalline systems, which can then serve as platforms for next-generation quantum sensors, quantum communication, and quantum computers.

Mircea Dincă, appointed a W. M. Keck Professor of Energy, is a professor in the Department of Chemistry. This appointment has a five-year term. The topic of Dincă’s research falls largely under the umbrella of energy storage and conversion. His interest in applied energy usage involves creating new organic and inorganic materials that can improve the efficiency of energy collection, storage, and generation while decreasing environmental impacts. Recently, he has developed materials for efficient air-conditioning units and been collaborating with Automobili Lamborghini on electric vehicle design.

Matthew Evans has been appointed to a five-year Mathworks Physics Professorship. Evans, a professor in the Department of Physics, focuses on the instruments used to detect gravitational waves. A member of MIT’s Laser Interferometer Gravitational-Wave Observatory (LIGO) research group, he engineers ways to fine-tune the detection capabilities of the massive ground-based facilities that are being used to identify collisions between black holes and stars in deep space. By removing thermal and quantum limitations, he can increase the sensitivity of the device’s measurements and, thus, its scope of exploration. Evans is also a member of the MIT Kavli Institute for Astrophysics and Space Research.

Evelina Fedorenko is an associate professor in the Department of Brain and Cognitive Sciences and has been named a Frederick A. (1971) and Carole J. Middleton Career Development Professor of Neuroscience. Studying how the brain processes language, Fedorenko uses behavioral studies, brain imaging, neurosurgical recording and stimulation, and computational modelling to better grasp language comprehension and production. In her efforts to elucidate how and what parts of the brain support language processing, she evaluates both typical and atypical brains. Fedorenko is an associate member of the McGovern Institute for Brain Research.

Ankur Jain is an assistant professor in the Department of Biology and now a Thomas D. and Virginia W. Cabot Career Development Professor. He will hold this career development appointment for a term of three years. Jain studies how cells organize their contents. Within a cell, there are numerous compartments that form due to weak interactions between biomolecules and exist without an enclosing membrane. By analyzing the biochemistry and biophysics of these compartments, Jain deduces the principles of cellular organization and its dysfunction in human disease. Jain is also a member of the Whitehead Institute for Biomedical Research.

Pulin Li, an assistant professor in the Department of Biology and the Eugene Bell Career Development Professor of Tissue Engineering for the next three years, explores genetic circuitry in building and maintain a tissue. In particular, she investigates how communication circuitry between individual cells can extrapolate into multicellular behavior using both natural and synthetically generated tissues, for which she combines the fields of synthetic and systems biology, biophysics, and bioengineering. A stronger understanding of genetic circuitry could allow for progress in medicine involving embryonic development and tissue engineering. Li is a member of the Whitehead Institute for Biomedical Research.

Elizabeth Nolan, appointed an Ivan R. Cottrell Professor of Immunology, investigates innate immunity and infectious disease. The Department of Chemistry professor, who will hold this chaired professorship for five years, combines experimental chemistry and microbiology to learn about human immune responses to, and interactions with, microbial pathogens. This research includes elucidating the fight between host and pathogen for essential metal nutrients and the functions of host-defense peptides and proteins during infection. With this knowledge, Nolan contributes to fundamental understanding of the host’s ability to combat microbial infection, which may provide new strategies to treat infectious disease.

Leigh “Wiki” Royden is now a Cecil and Ida Green Professor of Geology and Geophysics. The five-year appointment supports her research on the large-scale dynamics and tectonics of the Earth as a professor in the Department of Earth, Atmospheric and Planetary Sciences. Fundamental to geoscience, the tectonics of regional and global systems are closely linked, particularly through the subduction of the plates into the mantle. Royden’s research adds to our understanding a of the structure and dynamics of the crust and the upper portion of the mantle through observation, theory and modeling. This progress has profound implications for global natural events, like mountain building and continental break-up.

Phiala Shanahan has been appointed a Class of 1957 Career Development Professor for three years. Shanahan is an assistant professor in the Department of Physics, where she specializes in theoretical and nuclear physics. Shanahan’s research uses supercomputers to provide insight into the structure of protons and nuclei in terms of their quark and gluon constituents. Her work also informs searches for new physics beyond the current Standard Model, such dark matter. She is a member of the MIT Center for Theoretical Physics.

Xiao Wang, an assistant professor, has also been named a new Thomas D. and Virginia W. Cabot Professor. In the Department of Chemistry, Wang designs and produces novel methods and tools for analyzing the brain. Integrating chemistry, biophysics, and genomics, her work provides higher-resolution imaging and sampling to explain how the brain functions across molecular to system-wide scales. Wang is also a core member of the Broad Institute of MIT and Harvard.

Bin Zhang has been appointed a Pfizer Inc-Gerald Laubach Career Development Professor for a three-year term. Zhang, an assistant professor in the Department of Chemistry, hopes to connect the framework of the human genome sequence with its various functions on various time and spatial scales. By developing theoretical and computational approaches to categorize information about dynamics, organization, and complexity of the genome, he aims to build a quantitative, predictive modelling tool. This tool could even produce 3D representations of details happening at a microscopic level within the body.

Winners of 2020 Teaching With Digital Technology Award recognized for their innovations

by MIT Open Learning |

On July 30, faculty and instructors across MIT were honored for their outstanding achievements in teaching with digital technology in an online ceremony hosted by Dean for Digital Learning Krishna Rajagopal and Vice Chancellor for Undergraduate and Graduate Education Ian A. Waitz.

The student-nominated Teaching with Digital Technology Awards, co-sponsored by MIT Open Learning and the Office of the Vice Chancellor, celebrate Institute faculty and instructors who have made innovative, effective use of technology for teaching and learning. Launched in 2016, the awards have a special significance this year, following the rapid transition to remote teaching due to Covid-19.

Says Waitz, “What’s special about the honorees is that they are great teachers. Moreover, they stepped up at an unusual time, adapting with new tools and practices on little notice. They demonstrated resilience, ingenuity, and creative problem-solving. But what fundamentally shone through was their unwavering dedication to student learning.”

This year’s 31 winners, selected from among the 232 people recognized in 487 student nominations, are:

  • Steve Banzaert — Mechanical Engineering
  • Kara Blackburn — Sloan School of Management
  • Amanda Bosh — Earth, Atmospheric and Planetary Sciences
  • Devin Michelle Bunten — Urban Studies and Planning
  • Semvon Dyatlov — Mathematics
  • Vivek Farias — Sloan School of Management
  • Malick Ghachem — History
  • Marah Gubar — Literature
  • Michelle Hanlon — Sloan School of Management
  • Adam Hartz — Computer Science
  • Stefan Helmreich — Anthropology
  • Barbara Hughey — Mechanical Engineering
  • Pei-Ken Hung — Mathematics
  • Alexandre Jacquillat — Sloan School of Management
  • Graham Jones — Anthropology
  • Miro Kazakoff — Sloan School of Management
  • Jonathan Kelner — Mathematics
  • Wolfgang Ketterle — Physics
  • Maria Khotimsky — Global Languages
  • James Magarian — Gordon Engineering Leadership Program
  • Karthish Manthiram — Chemical Engineering
  • Isadora Nicholas — Global Languages
  • Phiala Shanahan — Physics
  • Ben Shields — Sloan School of Management
  • Joe Steinmeyer — Electrical Engineering
  • Lawrence Susskind — Urban Studies and Planning
  • Clair Travis — Chemistry
  • Rodrigo Verdi — Sloan School of Management
  • Bruno Verdini — Urban Studies and Planning
  • David Wallace — Mechanical Engineering
  • Jacob White — Electrical Engineering

The original nomination period ended in mid-March, just as faculty and staff began the extraordinary process of moving all campus activity online. As MIT’s faculty and instructors began teaching in ways that none had planned for, all relying upon digital technology, the awards committee felt it only right to ask MIT’s students a second time whether they wished to recognize someone for outstanding teaching with digital technology.

As everyone — teachers and students alike — was scrambling to achieve a fraction of their learning goals during the pandemic, it was far from clear how MIT’s students would respond. The response was, in fact, both remarkable and heartening: While the original call garnered 157 nominations for 98 unique individuals, the call for nominations during the period when all teaching was remote garnered a total of 330 nominations for 163 instructors and faculty, including 29 who were nominated in both calls. With more than double the number of nominations as in a typical year, it seems clear that students were extraordinarily motivated to recognize their teachers’ ingenuity and dedication in 2020.

“We’ve read some remarkable testimonials from nominating students, speaking to their instructors’ flexibility, creativity, and compassion in this time of crisis,” says Sheryl Barnes, director of digital learning in residential education at Open Learning. “That combination of mind, hand, and heart is what makes MIT such a special place. We couldn’t miss the opportunity to celebrate our faculty’s dedication to keeping their students learning and growing, even under duress.”

Among the faculty honored, engineering Professor Jacob White, recognized for his 6.302 (Feedback System Design) course, exemplified this dedication. White made sure that his 140 students received hardware lab kits before they evacuated campus in March, and went to great lengths to make the online version of his course accessible and easy for his students to navigate. One of White’s nominators noted that the professor had been “working around the clock to be available to students.”

Other faculty were bent on providing their students with the hands-on learning opportunities they’d anticipated, Covid-19 notwithstanding. Although Amanda Bosh’s course, 12.409 (Hands-On Astronomy), seemed vulnerable to collapse in the transition to an online format, the Department of Earth, Atmospheric and Planetary Sciences lecturer was determined not to let her students be shortchanged. “Dr. Bosh and her team transformed a hands-on astronomy class that usually features visits to an observatory and rooftop telescope viewing sessions into an enjoyable virtual experience,” one of her nominators reports. “I submitted commands to have a telescope at Wallace Observatory virtually photograph a distant galaxy!”

Still others gave new meaning to the term “agility,” adapting their courses to the specific rhythms of life during the pandemic. Anthropology professors Graham Jones and Stefan Helmreich, who taught their 21A.157 (Meaning of Life) course — always popular, and now more important than ever — this past spring, incorporated the cultural, ethical, and political considerations of the crisis into the class: They altered the syllabus to include discussions of new common behaviors such as social distancing, and changed the final assignment to an analysis of the pandemic.

The honorees’ work offers a unique view into the possibilities of digital education, both as a planned curricular element and as an effective alternative to in-person instruction. But it also reveals a community defined by resilience, ingenuity, creative problem-solving, and most importantly, care for one another and a passionate dedication to teaching and learning. In short: it reveals the MIT community at its best.

Says Rajagopal, “Hearing from these award winners as we did today is always one of my favorite occasions of the year. We are celebrating the creativity and ingenuity of MIT’s best and most dedicated teachers; ‘Teaching With’ in the name of the award is more important than ‘Digital Technology.’ Great teachers find and create new ways to shape great learning experiences for their students by hook or by crook, including via new technologies deployed by choice or necessity. It is so gratifying to hear from MIT’s students that so many of MIT’s teachers were able to find within themselves the wellsprings of energy and creativity to pull this off, with agility and aplomb, during the first weeks of the Covid-19 pandemic. Their deep commitment to MIT’s students is worthy of celebration.”

School of Science grows by 10

by School of Science |

Despite the upheaval caused by the coronavirus pandemic, 10 new faculty members have joined MIT in the departments of Biology; Chemistry; Earth, Atmospheric and Planetary Sciences; Mathematics; and Physics. The School of Science welcomes these new faculty, most of whom began their appointment July 1, amidst efforts to update education and research plans for the fall semester. They bring exciting and valuable new areas of strength and expertise to the Institute.

Camilla Cattania is an earthquake scientist. She uses continuum mechanics, numerical simulations, and statistics to study fault mechanics and earthquake physics at different scales, from small repeating events to fault interaction on regional and global scales. The models she has developed can help forecast earthquake sequences caused by seismic or aseismic events, such as aftershocks and swarms induced by forcing mechanisms like magma moving under the Earth’s surface. She has also developed theoretical models to explain why certain faults rupture in predictable patterns while others do not. Cattania’s research plans include widening her focus to other tectonic settings and geometrically complex fault structures.

Cattania earned her bachelor’s and master’s degrees from Cambridge University in experimental and theoretical physics in 2011, after which she completed a PhD in Germany at the GFZ German Research Center for Geosciences and the University of Potsdam in 2015. Subsequently, she spent a few months as a researcher at Woods Hole Oceanographic Institution and as a postdoc at Stanford University and her doctoral institution. She joins the Department of Earth, Atmospheric and Planetary Sciences as an assistant professor.

Richard Fletcher researches quantum physics using atomic vapors one-millionth the density of air and one-millionth the temperature of deep space. By manipulating the gas with intricately sculpted laser beams and magnetic fields, he can engineer custom-made quantum worlds, which provide both a powerful test bed for theory and a wonderful playground for discovering new phenomena. The goal is to understand how interesting collective behaviors emerge from the underlying microscopic complexity of many interacting particles. Fletcher’s interests include superfluidity in two-dimensional gases, methods to probe the correlations between individual atoms, and how the interplay of interactions and magnetic fields leads to novel physics.

Fletcher is a graduate of Cambridge University, where he completed his bachelor’s in 2010. Before returning to Cambridge University to earn his PhD in 2015, he was a research fellow at Harvard University. He originally came to MIT as a postdoc in 2016 and now joins the Department of Physics as an assistant professor. Fletcher is a member of the MIT-Harvard Center for Ultracold Atoms.

William Frank investigates deformation of the Earth’s crust. He combines seismology and geodesy to explore the physical mechanisms that control the broad continuum of rupture modes and fault instabilities within the Earth. His research has illuminated the cascading rupture dynamics of slow fault slip and how the aftershocks that follow a large earthquake can reveal the underlying behavior of the host fault. Frank considers shallow shifts that cause earthquakes down to deep creep that is all-but-invisible at the surface. His insights work to improve estimates of seismic hazards induced by tectonic dynamics, volcanic processes, and human activity, which can then inform risk prediction and mitigation.

Frank holds a bachelor’s degree from the University of Michigan in earth systems science, which he received in 2009. The Institut de Physique du Globe de Paris awarded him a master’s degree in geophysics in 2011 and a PhD in 2014. He first joined MIT as a postdoc in 2015 before moving to the University of Southern California as an assistant professor in 2018. He now returns as an assistant professor in the Department of Earth, Atmospheric and Planetary Sciences.

Ronald Fernando Garcia Ruiz advances research on fundamental physics and nuclear structure largely through the development of novel laser spectroscopy techniques. He investigates the properties of subatomic particles using atoms and molecules made up of short-lived radioactive nuclei. Garcia Ruiz’s experimental work provides unique information about the fundamental forces of nature and offers new opportunities in the search beyond the Standard Model of particle physics. His previous research at CERN focused on the study of the emergence of nuclear phenomena and the properties of nuclear matter at the limits of existence.

Garcia Ruiz’s bachelor’s degree in physics was achieved in 2009 at Universidad Nacional de Colombia. After earning a master’s in physics in 2011 at Universidad Nacional Autónoma de México, he completed a doctoral degree in radiation and nuclear physics at KU Leuven in 2015. Prior to joining MIT, he was first a research associate at the University of Manchester from 2016-17 and then a research fellow at CERN. Garcia Ruiz has now joined the Department of Physics as an assistant professor. He began his appointment Jan. 1. He is also affiliated with the Laboratory for Nuclear Science.

Ruth Lehmann studies germ cells. The only cells in the body capable of producing an entire organism on their own, germ cells pass genomic information from one generation to the next via egg cells. By analyzing the organization of their informational material as well as the mechanics they regulate, such as the production of eggs and sperm, Lehmann hopes to expose germ cells’ unique ability to enable procreation. Her work in cellular and developmental biology is renowned for identifying how germ cells migrate and lead to the continuation of life. An advocate for fundamental research in science, Lehmann studies fruit flies as a model to unveil vital aspects of early embryonic development that have important implications for stem cell research, lipid biology, and DNA repair.

Lehmann earned her bachelor’s degree in biology from the University of Tubingen in Germany. She took an interlude from her education to carry out research at the University of Washington in the United States before returning to Germany. There, she earned a master’s equivalent from the University of Freiburg and a PhD from the University of Tubingen. Lehmann was subsequently a postdoc at the Medical Research Council Laboratory of Molecular Biology in the UK, after which she joined MIT. A faculty member and Whitehead Institute for Biomedical Research member from 1988 to 1996, she now returns after 23 years at New York University. Lehmann joins as a full professor in the Department of Biology and is the new director of the Whitehead Institute for Biomedical Research.

As an astrochemist, Brett McGuire is interested in the chemical origins of life and its evolution. He combines physical chemistry experiments and analyses with molecular spectroscopy in a lab, the results of which he then compares against astrophysics observation. His work ties together questions about the formation of planets and a planet’s ability to host and create life. McGuire does this by investigating the generation, presence, and fate of new molecules in space, which is vast and mostly empty, providing unique physical challenges on top of chemical specifications that can impact molecular formation. He has discovered several complex molecules already, including benzonitrile, a marker of carbon-based reactions occurring in an interstellar medium.

McGuire’s BS degree was awarded by the University of Illinois at Urbana-Champaign in 2009. He completed a master’s in physical chemistry in 2011 at Emory University and a PhD in 2015 at Caltech. He then pursued a postdoc at the National Radio Astronomy Observatory and the Harvard-Smithsonian Center for Astrophysics. He joins the Department of Chemistry as an assistant professor.

Dor Minzer works in the fields of mathematics and theoretical computer science. His interests revolve around computational complexity theory, or — more explicitly — probabilistically checkable proofs, Boolean function analysis, and combinatorics. With collaborators, he has proved the 2-to-2 Games Conjecture, a central problem in complexity theory closely related to the Unique-Games Conjecture. This work significantly advances our understanding of approximation problems and, in particular, our ability to draw the border between computationally feasible and infeasible approximation problems.

Minzer is not new to online education. After earning his bachelor’s degree in mathematics in 2014 and a PhD in 2018, both from Tel-Aviv University, he became a postdoc at the Institute for Advanced Study at Princeton University. He joins the Department of Mathematics as an assistant professor.

Lisa Piccirillo is a mathematician specializing in the study of three- and four-dimensional spaces. Her work in four-manifold topology has surprising applications to the study of mathematical knots. Perhaps most notably, Piccirillo proved that the Conway knot is not “slice.” For all other small knots, “sliceness” is readily determined, but this particular knot had remained a mystery since John Conway presented it in the mid-1900s. After hearing about the problem at a conference, Piccirillo took only a week to formulate a proof. She is broadly interested in low-dimensional topology and knot theory, and employs constructive techniques in four-manifolds.

Piccirillo earned her BS in mathematics in 2013 from Boston College. Her PhD in mathematics was earned from the University of Texas at Austin in 2019, and from 2019-20 she was a postdoc at Brandeis University. She joins the Department of Mathematics as an assistant professor.

Jonathan Weissman’s research interest is protein folding and structure, an integral function of life. His purview encompasses the expression of human genes and the lineage of cells, as well as protein misfolding, which can cause diseases and other physiological issues. He has made discoveries surrounding protein folding mechanisms, the development of CRISPR gene-editing tools, and other new therapeutics and drugs, and in the process generated innovative experimental and analytical methods and technologies. One of his novel methods is the ribosome profiling approach, which allows researchers to observe in vivo molecular translation, the process by which a protein is created according to code provided by RNA, a major advancement for health care.

Weissman earned a bachelor’s degree in physics from Harvard University in 1998 and a PhD from MIT in 1993. After completing his doctoral degree, he left MIT to become a postdoc at Yale University for three years, and then a faculty member at the University of California at San Francisco in 1996. He returns to MIT to join the Department of Biology as a full professor and a member of the Whitehead Institute for Biomedical Research. He is also a Howard Hughes Medical Institute investigator.

Yukiko Yamashita, a stem cell biologist, delves into the origins of multicellular organisms, asking questions about how genetic information is passed from one generation to the next, essentially in perpetuity, via germ cells (eggs and sperm), and how a single cell (fertilized egg) becomes an organism containing many different types of cells. The results of her work on stem cell division and gene transmission has implications for medicine and long-term human health. Using fruit flies as a model in the lab, she has revealed new areas of knowledge. For example, Yamashita has identified the mechanisms that enable a stem cell to produce two daughter cells with distinct fates, one a stem cell and one a differentiating cell, as well as the functions of satellite DNA, which she found to be crucial, unlike the “waste” they were previously thought to be.

Yamashita received her bachelor’s degree in biology in 1994 and her PhD in biophysics in 1999, both from Kyoto University. After being a postdoc at Stanford University for five years, she was appointed a faculty member at the University of Michigan in 2007. She joined the Department of Biology as a full professor with a July 1 start. She also became a member of the Whitehead Institute of Biomedical Research and is a standing investigator at the Howard Hughes Medical Institute.

A chemist who plays with space

by Fernanda Ferreira |

Much of the earthy taste of rye bread is due to caraway seeds. These seeds get their flavor from carvone, a molecule made up of 10 carbon atoms, 14 hydrogen atoms, and one oxygen atom. But earthy isn’t the only taste that exact collection of atoms can create. The minty taste of spearmint is also due to carvone. Which flavor you get depends on the spatial distribution of the atoms in the molecule; if you placed both carvones side by side, you’d see them as mirror images of each other.

The study of the spatial distribution of atoms in a molecule is called stereochemistry. Alison Wendlandt, the Green Career Development Assistant Professor of Chemistry at MIT, explains that when it comes to molecules, it’s not only the atoms that determine molecular properties, but also the very three-dimensional arrangement of the similarly connected atoms.

This spatial distribution of atoms doesn’t just impact flavor. It can also determine the effectiveness of a drug molecule. Wendlandt’s work focuses on finding strategies for fine-tuning the stereochemistry of molecules and, in doing so, how quickly and thoroughly a drug treatment can work in patients.

Mirror images

When Wendlandt entered college, she wasn’t planning on majoring in chemistry; she was a math major. “But I ended up taking organic chemistry, and it just clicked as a language,” she says. Many students approach chemistry via memorization, but for Wendlandt the logic of chemistry innately made sense. “There was no memorizing, just understanding the rules,” she remembers. “And then at that point, there was nothing else I could do.”

Wendlandt’s training is in catalysis, which involves designing a catalyst to get a desired reaction. “A catalyst is any kind of reagent that can promote a reaction but isn’t consumed in that reaction,” says Wendlandt. This can be a reaction that is hard to perform, or one that leads to a specific product or outcome. During her postdoc at Harvard University, she focused on enantioselective catalysis, where a specific enantiomer, one of a pair of mirror image molecules, is generated.

There are a number of aspects of enantioselective catalysis that attract Wendlandt to the work, but two stand out. “One is the importance of chiral drug molecules,” she says. With drug molecules, it’s often the case that only one enantiomer has the drug properties of interest, while the other has no effect or, in some cases, a negative effect. “There are some famous catastrophes where our failure to control or acknowledge the off-target effects of enantiomers led to disasters.” Thalidomide, which was taken by pregnant women in the 1950s, is one such example. “One enantiomer was fine and treated morning sickness effectively, and the other enantiomer was a teratogen and led to birth defect issues,” says Wendlandt. “It was totally a stereochemistry problem.”

Wendlandt is also attracted to the molecular design aspect of the work. “It allows us to make a very small energetic change to reaction coordinates,” she says. In terms of energy, Wendlandt explains, 1,000-2,000 calories — like the ones you consume and use for energy — can determine whether a product is a balanced mix of two enantiomers or whether it’s a pure mix of just the one enantiomer of interest. With catalysis, Wendlandt says, you can actually control the reaction’s path.

Sugar rush

Many molecules have stereochemistry, but the class of molecules Wendlandt is particularly interested in are sugars. She explains that, for molecules like amino acids and proteins, their properties are often determined by their functional groups, groupings of atoms on the molecule that give it a specific nature. This is not the case with sugars. “Many of the biological and physical properties of sugars are stereochemistry-related,” Wendlandt says. With some important exceptions, all sugars are isomers, meaning they share the same basic chemical formula. “They just differ in terms of their spatial connectivity.”

In the body, sugars serve a number of functions, from energy and information storage to structure, and they’re also common components in pharmaceutical drugs. Some sugars, such as glucose and cellulose, are easy to come by, but others, particularly those that can be active ingredients in drugs, are harder to produce. These rare sugars “have to be made by chemical synthesis,” says Wendlandt.

Despite the importance of sugars, studying them is hampered by subpar methods for producing rare sugars, says Wendlandt. “And the reason these methods are poor has to do with our inability to manage issues of selectivity,” she says. Because the property of sugars are determined by their stereochemistry, making a rare sugar often comes down to moving a specific atom from one location on the molecule to another. It’s a major challenge, but one Wendlandt is drawn to.

In a January 2020 paper in Nature, Wendlandt and her lab made allose, a rare sugar, by modifying the spatial distribution of atoms in a glucose molecule. The process involved breaking a chemical bond in one spot and reforming it in another spot on the molecule, which goes against a chemical principle called microscopic reversibility. “It dictates that the way the bond is broken is the same way that the bond is formed,” explains Wendlandt. To get around this, the lab decoupled the bond-breaking and bond-forming process by using two catalysts: one to break the bond and another to form it. With these two separate catalysts and some blue light to drive catalysis, a hydrogen atom is removed from a specific spot on the sugar molecule while a new hydrogen atom is added to another stereochemical position on that same molecule. With this switch, common glucose became rare allose.

Making allose is just the start. What drives the site selectivity of the reaction is not yet clear, and it’s a question Wendlandt and her lab are continuing to probe. “If we can understand why these reactions are selective, we can, in principle, design them to do other things,” says Wendlandt, such as breaking bonds at other sites on the molecule. Once predictability and stability is honed, this method can become a powerful tool in pharmaceuticals, including many FDA-approved antiviral, antibacterial, anti-cancer, and cardiac drugs. “A medicinal chemist can come in and say ‘OK, I want to edit this bond or that bond,’” imagines Wendlandt, letting them fine-tune sugars into potent pharmaceutical ingredients. This tinkering of atoms in a molecule can mean the difference between tragedy and safe, effective drugs.

MIT hosts seven distinguished MLK Professors and Scholars for 2020-21

by MIT News |

In light of the Covid-19 pandemic, MIT has been charged with reimagining its campus, classes, and programs, including the Dr. Martin Luther King, Jr. (MLK) Visiting Professors and Scholars Program (VPSP).

Founded in 1990, MLK VPSP honors the life and legacy of Martin Luther King, Jr. by increasing the presence of and recognizing the contributions of scholars from underrepresented groups at MIT. MLK Visiting Professors and Scholars enhance their scholarship through intellectual engagement with the MIT community and enrich the cultural, academic, and professional experience of students. The program hosts between four and eight scholars each year. But what does a virtual year mean for a visiting scholar?

Even with the challenge of remote learning and limited in-person contact, MLK VPSP faculty hosts have articulated innovative ways to engage with the MIT community. Moya Bailey, for instance, will be a content contributor for the Program in Women’s and Gender Studies’ website and social media accounts. Charles Senteio will continue to collaborate with the Office of Minority Education on curriculum development that reflects a diverse student population with a focus on health and well-being, and he will also explore remote learning and its impact on curriculum.

With Provost Martin Schmidt’s steadfast institutional support, and with active oversight from Institute Community and Equity Officer John Dozier and Associate Provost Tim Jamison, the MLK VPSP continues to honor King’s legacy and be an institutional priority on campus and online. For Academic Year 2020-2021, MIT is hosting seven accomplished scholars representing different areas of interest from all over the United States and Canada.

2020-2021 MLK Visiting Professors and Scholars

Moya Bailey is an assistant professor at Northeastern University in the Department of Cultures, Societies, and Global Studies and in the program in Women’s, Gender, and Sexuality Studies. In 2010, Bailey coined the term “misogynoir,” widely adopted by scholars, which describes the anti-Black racist misogyny that Black women experience. In the spring, she will teach a course in the MIT Program in Women’s and Gender Studies called Black Feminist Health Science Studies. In April 2021, she will organize and host a daylong Black Feminist Health Science symposium.

Jamie Macbeth joins the program for another year in MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) as a valuable member of the Genesis group, a research team mainly focused on building computer systems and computational models of human intelligence based on humans’ capability for understanding natural language. One of Macbeth’s research collaborations involves using computer systems in understanding natural language to detect aggressive language on social media with the eventual goal of violence prevention. He will continue to mentor and collaborate with women and underrepresented groups at the undergraduate, MS, and PhD levels.

Ben McDonald is returning for a second year as a postdoc in the Department of Chemistry. His research focuses on developing designer polymers for chemical warfare-responsive membranes and surfactants to control the function of dynamic, complex soft colloids. His role as a mentor will expand to include both undergraduate and graduate students in the Swager Lab. McDonald will continue to collaborate with Chemistry Alliance for Diversity and Inclusion at MIT to organize and host virtual seminars showcasing the work of underrepresented scholars of color in the fields of chemistry and chemical engineering.

Luis Gilberto Murillo-Urrutia, a research fellow hosted by the Environmental Solutions Initiative (ESI), joins us from the Center for Latin America and Latino Studies at American University. His research focuses on the intersection of peace and security with environmental conservation, particularly in Afro-Colombian territories. During his visit, Murillo-Urrutia will hold mentorship sessions at ESI for students conducting research on environmental planning and policy or with a minor in environment and sustainability.

Thomas Searles, recently promoted to associate professor with tenure, is visiting from the Department of Physics at Howard University. While at MIT, he will pursue numerical studies of topological materials for photonic and quantum technological applications. He will mentor students from his lab, the Black Students Union, National Society of Black Engineers, and the Black Graduate Student Association. Searles plans to meet with the MIT physics graduate admissions committee to formulate recruitment strategies with his home and other historically Black colleges and universities.

Charles Senteio joins the program from Rutgers University School of Communication and Information, where he is an assistant professor in library and information science. As a visiting scholar at the MIT Sloan School of Management, he will collaborate with the Operations Management Group to expand on his community health informatics research and investigate health equity barriers. He recently facilitated a workshop, “Healthcare, Technology, and Social Justice Converge — Applied Equity Research and Why It Matters to All of Us” at the MIT Day of Dialogue event in August.

Patricia Saulis is Wolastoqey (Maliseet) from Wolastoq Negotkuk (Tobique First Nation in New Brunswick, Canada). As an MLK Visiting Scholar, Saulis will collaborate with her faculty host, Professor James Paradis from Comparative Media Studies/Writing, on a course titled, “Transmedia Art, Extraction and Environmental Justice” and engage with MIT Center for Environmental Health Sciences on their EPA Superfund-related work in the Northeastern United States. She will work closely with the American Indian Science and Engineering Society (AISES) and the Native American Students Association in raising awareness of the challenges impacting our Indigenous students. Through dialogue and presentations, she will help promote the understanding of Indigenous Peoples’ culture and help identify strategies to create a more inclusive campus for our Indigenous community.

Community engagement

This year’s scholars are eager to join our community and embark on a mutually rewarding journey of learning and engagement — wherever in the world we may be.

MIT community members are invited to join the Institute Community and Equity Office in engaging the MLK Professors and Scholars through a signature monthly speaker series, where each scholar will present their research and hold discussions via Zoom. The first welcome event will be held on Sept. 16 from 12 to 1 p.m. Contact Rachel Ornitz rornitz@mit.edu for event details.

For more information about this year’s and previous scholars and the program, visit the newly redesigned MLK Visiting Professors and Scholars website.