Theoretical Approach to Actin-Myosin System as an Example of Complex System

抄録

Stochastic Inclined Rods Model (SIRM) is proposed for understanding the movement of actin-myosin system in muscle. SIRM has many inclined rods stood out from its body like myosin, and it moves always forward to one direction whenever those rods are independently vibrating. SIRAM can convert the thermal noise to the one directional motion by using stochastic resonance and inclined rods in random open fields. We estimate concretely the physical characteristics of SIRM as a conceptual model of actin-myosin system. If SIRM have the radius γ=5nm and mass 10^<-21> kg like a myosin molecule, the estimated frequency of stochastic resonance which is nearly phonon frequency 10^<11>rad / s. The amplitude of stochastic resonance is 2×10^<-11>m. Moreover, 10^<-18> joules, which is nearly equal to energy of 1ATP hydrolysis, and output is physical work of this machine is about 10^<-10>N / head. As a conclusion we point out that actomyosin system in muscle utilizes the random motion of water molecules for its movement.