Skeletal muscle is the source of human body motion.Many scholars have been studying in this field to reveal its contraction mechanism,and relevant achievements have been awarded the Nobel Prize.This paper reviewed the current researches on biomechanics of skeletal muscle,and concluded two strategies(top-down and bottom-up methods) for the biomechanical research of skeletal muscle.Moreover,this paper generalized two major aspects of muscle research:(1) the multi-force coupling mechanism and the collective operation mechanism of molecular motors;(2) the bioelectrochemical driving and control principium of muscle contraction.We discussed the solution for experimental verification and induced a novel idea to study the biomechanics of skeletal muscle based on the microscopic working mechanism of molecular motor,which is the origin of muscle contraction.Finally we analyzed the disadvantages in existent researches and explored future directions that need further studies.
The dynamics of the myosin molecular motor as it binds to actin filaments during muscle contraction are still not clearly understood.In this paper,we focus on the coupling mechanism of multi-force interactions in the myosin molecule during its interaction with actin.These forces include the electrostatic force,the van der Waals force and the Casimir force in molecular dynamic simulations of the molecules in solvent with thermal fluctuations.Based on the Hamaker approach,van der Waals and Casimir potentials and forces are calculated between myosin and actin.We have developed a Monte Carlo method to simulate the dynamic activity of the molecular motor.We have shown that because of the retardation effect,the van der Waals force falls into the Casimir force when the distance between the surfaces is larger than 3 nm.When the distance is smaller than 3 nm,the electrostatic force and the van der Waals force increase until the myosin becomes attached to the actin.Over the distances studied in the present work,the electrostatic force dominates the attractive interactions.Our calculations are in good agreement with recently reported experimental results.
