Cellular membranes house about a quarter of all proteins. These proteins serve a large variety of functions such as cell-cell signaling, selective ion permeation, and transporting metabolites between various cellular compartments. Our understanding of membrane proteins is however limited by the technical challenge of obtaining high resolution views of these molecules. X-ray and electron crystallography have in the past been the dominant biophysical tools for determining membrane protein structures, but they depend on the intrinsic property of proteins to form crystals. We demonstrate that Nuclear Magnetic Resonance is an emerging and versatile tool for determining membrane protein structures, and for revealing the dynamic events coupled to their function. Our examples include ion channels, transporters, and ligand-receptor signaling.

Dr. James J. Chou (周界文) is an Associate Professor of Biological Chemistry and Molecular Pharmacology at Harvard Medical School. He received his Ph.D. in Biophysics from Harvard, where he determined the atomic resolution structures of proteins involved in programmed cell death using Nuclear Magnetic Resonance (NMR) methods. As a post-doctoral fellow at the US National Institutes of Health, he developed a suite of powerful NMR tools for characterizing protein structure and dynamics in solution. Dr. Chou joined the faculty at Harvard Medical School in 2002. Since then, he has been pushing the envelope of NMR technology to study proteins in biological membranes. His research group has discovered a number of important mechanisms in biology, including the mechanism of proton conduction of the influenza virus proton channel and the mechanism of T cell receptor signaling across the membrane. Owing to his scientific contributions, Dr. Chou has received many prestigious awards such as the Pew Scholar Award in Biomedical Sciences, the Smith Family Award, and the Genzyme Outstanding Achievement in Biomedical Science Award. For more information about Professor James J. Chou, please visit http://chou.med.harvard.edu.