Michael Chapman, Professor
Structural Biology: Viral-Host Interactions and Enzyme Dynamics
Michael Chapman, PhD, Professor, Interim Chair
Phone: 503-494-1025 Fax: 503-494-8393
Location: MRB 534A
Atomic structure, interactions and dynamics are core to understanding bio-molecular mechanism. The chapman group uses an array of physical and biological experiments to build and refine computational models of molecular structure-dynamics that explain function.
Using X-ray crystallography, we have determined the atomic structure of adeno-associated virus (AAV), a leading DNA-delivery vector for treating genetic diseases by gene therapy. We have recently screened the human genome for genes essential to AAV's cellular entry, identifying a recycling receptor in host cells that is needed for productive viral entry and trafficking towards the nucleus. Electron microscopy is now at the center of efforts to map, in atomic details, the interactions of host proteins with AAV as it enters the cell, preparing a foundation for modulating the specificity of the virus.
Protein motions are often overlooked, because they are difficult to characterize, but they are often critical to function. The rate-limiting millisecond dynamics of arginine kinase provide a window through which we are learning general principles. NMR measurements of local exchange rates are combined with crystallographic structure to model the mechanics of protein dynamics through the reaction cycle of an enzyme. It is providing the first experimental evidence in support of theories predicting heightened, rather than lessened protein dynamics in the transition state. We are now characterizing their nature and relation to intrinsic modes of motion that have evolved in enzymes.
Dr. Chapman's NIH Biosketch