University of Pittsburgh Department of Biological Sciences presents:
2019 Fall Seminar Series
Dr. Michael Gilson
University of California - San Diego
"Are All Enzymes Molecular Motors?"
Some enzymes, such as kinesin and F1FO ATPase, are highly evolved molecular motors. However, all enzymes release chemical energy catalytically and could in principle generate motion, including directional motion. This talk discusses two topics in this area. First, experimental studies suggest that many enzymes have a greater translational diffusion coefficient in the presence of their substrates. Various potential mechanisms have been suggested, but none have been proven. We offer a thermodynamic argument that enhanced diffusion of enzymes will not likely be explained by an active self-propulsion mechanism, as the power requirements are too high. A passive mechanism, such as increased dissociation of multi-subunit enzymes into faster-diffusing components, is more likely. Second, we offer a conjecture that all enzymes catalyzing a reaction that is out of equilibrium must generate directional motions, and we support this concept with a combination of simulation and theory. We show that the same reasoning implies that any chiral molecule driven between two energy surfaces should undergo directional motions. This result may have implications for the early evolution of molecular motors.
Monday, September 9, 2019
169 Crawford Hall
10:50 A.M. refreshments
Host: Dr. Jacob Durrant