Theortical Study On The Hill Characteristic Equation On Muscle Contraction And The Energy Conversional Efficiency Of Myosin

The myosin of skeletal muscle is a crucial component of muscle contractrction that accomplishes the transformation of the chemical energy stored in ATP into mechanical energy. Motor proteins exist in animals and plants. They are the essential agents of movement at the molecular level. Studying the molecular motors is the hotspots in biophysics. The myosin of skeleton muscle is studied more widely than other molecular motors; the structure, cyclical working mechanism and the dynamics of single molecule have been investigated thoroughly. Meantime many tests for the muscular contraction property under different biochemical conditions have been done. This paper is proposed to study the relationship between external force and contractive velocity on muscle contraction and to study the directed motion and the energy conversional efficiency of myosin.The text was divided 3 chapters: In the first chapter, sliding filament theory of muscle contraction, structure of myosin and the mechanochemical actin-actived myosin ATPase cycle are introduced, study of experiment about muscle contraction is reviewed.In the second chapter, based on the mechanochemical actin-activated myosin ATPase cycle model, utilizing the chemical kinetic method and biochemical thermodynamic principle, taking the experimental results of single myosin into account, Hill Characteristic Equation on Muscle Contraction can be deduced and understood deeply from the view of energy conduction. The significance of this paper is that the information from the properties of myosin to the functions of muscular fibre has been conformitied.In the third chapter, a stochastic transitional two-state model of myosin is proposed, the probability current and effective potential are calculated with the equation of Fokker-Planck. The slope of the effective potential was defined in general.. The efficiency was discussed qualitatively which is switched from the energy in the system. It is found that there exists the relationship between the efficiency and the external load.