Hayashi Kumiko, Takano Mitsunori
Department of Physics, Waseda University, Tokyo, Japan.
Biophys J. 2007 Aug 1;93(3):895-901. doi: 10.1529/biophysj.106.100487. Epub 2007 May 11.
We report the results of molecular dynamics simulations of the protein myosin carried out with an elastic network model. Quenching the system, we observe glassy behavior of a density correlation function and a density response function that are often investigated in structure glasses and spin glasses. In the equilibrium, the fluctuation-response relation, a representative relation of the fluctuation-dissipation theorem, holds that the ratio of the density correlation function to the density response function is equal to the temperature of the environment. We show that, in the quenched system that we study, this relation can be violated. In the case that this relation does not hold, this ratio can be regarded as an effective temperature. We find that this effective temperature of myosin is higher than the temperature of the environment. We discuss the relation between this effective temperature and energy transduction that occurs after ATP hydrolysis in the myosin molecule.
我们报告了利用弹性网络模型对肌球蛋白进行分子动力学模拟的结果。通过对系统进行猝灭,我们观察到密度关联函数和密度响应函数的玻璃态行为,这两个函数常用于结构玻璃和自旋玻璃的研究。在平衡状态下,涨落-响应关系(涨落耗散定理的一个代表性关系)表明,密度关联函数与密度响应函数的比值等于环境温度。我们表明,在我们研究的猝灭系统中,这种关系可能会被违反。当这种关系不成立时,这个比值可被视为有效温度。我们发现肌球蛋白的这个有效温度高于环境温度。我们讨论了这个有效温度与肌球蛋白分子中ATP水解后发生的能量转换之间的关系。