Simbios Talk by Jung-Chi Liao, Stanford University, October 18, 2005

Title: Identifying the Mechanical Step of a Walking Myosin

Abstract: Myosin is a motor protein that converts chemical energy into mechanical work. Although it has been studied extensively, when the mechanical step happens in the chemical cycle remains an open question. Specifically, it is difficult to resolve the sequence of the mechanical power stroke step and the phosphate release step since they occur so rapidly. Single molecule laser trap experiment, however, can accelerate or decelerate the power stroke step so that it is possible to distinguish these steps. I have developed a novel computational algorithm that can exactly predict single molecule dwell-time distributions of any complex kinetics. Using this new algorithm, the possible mechanochemical mechanism of one head of myosin V was simulated, and the timing of the mechanical step in the chemical cycle was identified.