The Research Of Kinetics Of Continuous Motion In Molecular Motor

Molecular motors are nanomachines transporting cargoes and other functions in cell and they change the energy of the hydrolysis of ATP into the movement of motors. Continuous and directed movement of molecular motor is the basic condition to make the function of molecular motor come ture. Although we have already made lots of research on molecular motor, the mechanism of continous and directed movement of molecular motor is still not clear.There are two mechanism models for making research of molecular motor: mechanochemical cycle model and random motion model. Early research used 2-state random model. In the past decade, we mostly used polymorphic mechanochemical cycle model. For now, it has been becoming a new tendency to contruct polymorphic random motion model by combining these two models.Dynein, kinesin and myosin V are typical motors which make continuous motion. We summarize kinetics model for the continuous motion of these three motors. Therefore, we construct a 4 state random model of myosin V. we can use the master equation of probability density and its Fourier transform, with the chemical reaction rate corresponding to the ATP concentration being used as the variable of the model, to measure the dwell time of myosin V. the result shows that the probability density of lower dwell time is increasing with the rise of chemical reaction rate. We can get the conclusion that when the rate of chemical reaction increases in a certain range, the rate of movement of myosin V increases with the rise of the rate of chemical reaction.This paper includes four parts:Part one introduces the mechanochemical cycle model of dynein briefly. Part two introduces the mechanochemical cycle of myosin V. Part three introduces the random motion model of kinesin. Part four elaborates the probability distribution of dwell time of myosin V based on the random model. Theoretical curves are compared with the experimental data.