Physics Colloquium, October 30, 2007
Illuminating the Mechanistic Roles of Enzyme Conformational Dynamics and New Directions in Single-Molecule Spectroscopy Haw Yang

Department of Chemistry, University of California, Berkeley and Physical Biosciences Division, Lawrence Berkeley National Lab, Berkeley

It is often posited that conformational changes play an integral role in protein functions. To test this hypothesis, we apply the newly developed high-resolution fluorescence single-molecule techniques to study the structural fluctuations of individual adenylate kinase enzymes. By directly following the conformational changes of individual molecules, we show quantitatively how this enzyme has evolved to utilize thermal fluctuations to efficiently reconfigure its active site in order to achieve a balance between substrate recruitment, catalysis, and product release. These results highlight the prowess of high-resolution single-molecule spectroscopy in resolving the functional roles of nanoscale fluctuations. Future challenges in our fundamental understanding of biological structure-function dynamics lie in relating such in vitro knowledge to what is really happening in cellular environment. The second part of the presentation describes new experimental approaches, including 3D focus-tracking spectroscopy and guided confocal microscopy, which address this challenge and will allow us to directly follow the dynamics of individual nanoprobes as they move inside a cell.

Dr. Yang's Talk

Dr. Yang's Web Site

4:00 p.m., Physics Research Building (PRB), Room 1080

Reception at 3:45 p.m., Atrium, PRB