收缩蛋白质分子的光学特性及其在蛋白质分子运动过程中的变化规律

Study on the Optical Property of Contracting Protein Molecules and Its Change During the Movement of Protein Molecules

本文用具有各向异性的光学晶体模拟肌肉收缩蛋白质分子，给出了描述收缩蛋白质光学特性的极化率张量表示，并讨论了在蛋白质分子运动过程中极化率张量的变化规律。基于这一理论分析，根据用光的椭圆偏振技术测得的单根青蛙肌纤维在僵直状态和松弛状态及在不同温度下的实验结果，我们认为，当肌纤维处于僵直状态时，其内部肌球蛋白分子（横桥部分）与肌动蛋白分子空间距离近，相互作用力强；而在松弛状态时，两种收缩蛋白分子空间距离远，相互作用力弱；当改变肌纤维所处溶液温度时，横桥与肌动蛋白分子的相对空间取向和相互作用力受到影响，较高温度时分子热运动会削弱肌球蛋白分子和肌动蛋白分子之间的作用，使横桥向粗肌丝骨架靠拢．

The authors model the contracting protein molecules using a crystal with anisotropyt give the tensor representation of polarizability of the contrasting proteins and analyze the change of tensor representationduring the movement of protein molecules.According to the theroetical model and optical ellipsometric measurement from single frog skeletal muscle fibers,we propose such an idea that crossbridges(part of myosin protein molecules) might be in closer vicinity to and have stronger interaction with actin protein molecules in rigor state than in relaxed state and that the change of temperature could effect the crossbridge orientation with respective to the thick filament backbone and thermal motion of molecules under higher temperature condition could weaken the interaction between two kinds of contracting Protein molecules and cause crossbridges move away from actin protein molecule.