The Stain-Dependent Myosin Work Cycle And Energy Conversion

Every movement of living organisms such as muscle contraction,beating of the flagella or cilia, chromosome copy and segregation and cell division,retrospect to molecular level,refers to molecular motors. Molecular motors use ATP or GTP as energy sources and execute diverse biological functions by changing the chemical energy deposited in ATP or GTP to mechanical energy. Owing to the improvement of the biological technique, more acquaintance to the muscular contraction property under different biochemistry conditions have been get. This paper is proposed to study the strain-dependent myosin work cycle and the energy conversion.The text is divided into two chapters. In chapter one, the strain effect on each step of myosin work cycle is mainly introduced,and some problem about spontaneous oscillation is explained. From the schematic mechanochemical single myosin ATPase cycle,the muscle contraction and spontaneous oscillation has been studied with the chemical kinetic method. The result indicates spontaneous oscillation steadily can be gained because the force produced by strain-dependent myosin counteracts the viscous drag force. In chapter two, based on the strain-dependent myosin ATPase cycle model,utilizing the chemical kinetic method and biochemical thermodynamic principle, Hill Characteristic Equation can be deduced. We gained energy released velocity constant in theory,understood deeply from the view of energy conduction. The significance of this work is that the information from the properties of myosin to the functions of muscular fibre has been conformitied.