| Molecular motors are nanomachines responsible for cargo transportation in cell by converting chemical energy into mechanical energy. Liner molecular motors can be divided into three types:myosin, kinesin and dynein. This text mainly focuses on dynein and its mechanical property. Through experimental researches, Mallik et al. found that the force produced by a single dynein is closely related to the concentration of ATP. In a certain range, the force increases lineally with the concentration of ATP, and the force will reaches the max value of 1.1 pN when the ATP is above lmM. So far, there is still no reasonable theoretical explanation for this experimental result. Based on the ATP hydrolysis cycle and the mechanochemical coupling model of dynein, together with its movement characteristic and mechanical property, this paper proposes a chemical kinetic theory model to explain the relation between the force generated by dynein and the concentration of ATP. The numerical calculation results from our theory model are basically consistent with the experimental observations.This thesis includes four parts:Part one briefly introduces the structure and function of dynein. Part two elaborates the ATP working cycle of dynein and its mechanochemical coupling model. Part three describes the motion characteristic and mechanical property of dynein. Part four is the main part of this thesis, in which we make theoretical explanation as to the linear relationship between the force and the concentration of ATP. |
