Chemistry is truly the central science and underpins much of the efforts of scientists and engineers to improve life for humankind. TheMIT Department of Chemistryis taking a leading role in discovering new chemical synthesis, catalysis, creating sustainable energy, theoretical and experimental understanding of chemistry, improving the environment, detecting and curing disease, developing materials new properties, and nanoscience.
The Chemistry Education Office staff is responsible for administering the educational programs in the Department of Chemistry. Students can find answers to many questions about the undergraduate and graduate programs on the department website, and they are encouraged to stop by and see the staff in the office located in 6-205.
The student-run outreach programs in the Department of Chemistry aim to bring the excitement of chemical sciences to the community through lively demonstrations designed to illustrate a broad range of chemical principles. Graduate students visit science classes in high schools and middle schools in the Greater Boston area with a view to demystifying chemistry through hands-on experiments. ClubChem, an undergraduate chemistry organization, conducts Chemistry Magic Shows for elementary schools and youth programs in the Greater Boston area.
Chemistry is truly the central science and underpins much of the efforts of scientists and engineers to improve life for humankind. MIT Chemistry is taking a leading role in discovering new chemical synthesis, catalysis, creating sustainable energy, theoretical and experimental understanding of chemistry at its most fundamental level, unraveling the biochemical complexities of natural systems, improving the environment, detecting and curing disease, developing materials new properties, and nanoscience.
Research in the Hong laboratory lies at the interface of physical chemistry and biological chemistry. We develop and apply high-resolution solid-state NMR spectroscopy to determine the atomic structures and dynamics of biological macromolecules. On the methodological side, we develop new multidimensional correlation NMR experiments and analysis approaches to measure interatomic distances from angstroms to nanometers, elucidate the geometry of molecular motions from sub-nanoseconds to seconds, and determine intermolecular binding. We not only detect 1H, 13C and 15N NMR spectra but also observe 19F, 31P and 2H spins, which allow us to investigate a broad range of chemical and biophysical problems. Our solid-state NMR techniques increasingly integrate fast magic-angle-spinning (MAS), 1H detection, high magnetic fields, and dynamic nuclear polarization to enhance the sensitivity of structure determination.
Using these NMR approaches, we are studying three classes of biomolecular systems: virus membrane proteins, amyloid fibrils, and plant cell walls. In the membrane protein direction, we are investigating the influenza M2 protein family and viral fusion proteins. Influenza M2 is a proton channel as well as a membrane-scission protein: the first function initiates virus uncoating while the second function mediates virus budding and release. Antiviral drugs that target the M2 proton channel activity are currently limited by the circulation of resistant M2 mutants among influenza A viruses and the lack of effective blockers against influenza B M2. We are studying fundamental aspects of proton transport in these channels, especially how protein conformational dynamics and water mediate proton transfer, and how the amino acid sequence and the lipid environment affect proton-transfer equilibria and kinetics. To elucidate how M2 causes membrane scission, we are studying M2 interactions with cholesterol and other virus proteins. In a second membrane protein project, we investigate fusion proteins of enveloped viruses, including paramyxovirus and HIV. These fusion proteins merge the virus envelope with the target cell membrane to cause virus entry. Using solid-state NMR, we determine the protein structures at different stages of virus-cell fusion and couple the observed conformational changes with membrane curvature, which is detected by 31P NMR and other biophysical methods. Results from these studies are giving detailed insights into how these fusion proteins coordinate with lipids to cause membrane merger.
In the second direction, we are investigating the structures and assemblies of amyloid fibrils, including fibrils involved in Alzheimer’s disease, fibrils formed from peptide hormones, and fibrils designed for catalysis. We are particularly interested in understanding how the amino acid sequence dictates the three-dimensional folds of amyloid fibrils, the origin of molecular structural polymorphism, how water impacts fibril formation, and how metal ions stabilize amyloid fibrils.
In the third direction, we bring multidimensional solid-state NMR to bear on the energy-rich material of plant cell walls. Plant cell walls comprise of a complex mixture of polysaccharides and proteins. By 13C-enriching whole cell walls, we are able to employ a variety of 2D and 3D 13C and 1H correlation NMR techniques to determine the composition, conformation, intermolecular interaction, and mobilities of the polysaccharides. Intact cell walls of both dicot and grass families are being studied. Of particular interest are how the structures of cellulose microfibrils in plant cell walls differ from crystalline cellulose of bacteria and algae, and how the polysaccharide network is loosened during rapid plant growth. Our findings have implications for how to harvest energies from lignocellulose materials.