基于分子动力学模拟研究温度致Aβ42蛋白构象变化

Abstract

基于分子动力学模拟方法研究了不同温度对Aβ42蛋白结构的影响。模拟选用GROMACS软件包和GROMOS 43A1分子力场，在300 K、340 K和380 K下分别进行60 ns的分子动力学模拟。通过计算原子均方根涨落、回旋半径、二级结构形成几率等参数，分析了Aβ42蛋白结构的稳定性、二级结构及三级结构形成。研究发现：该蛋白在三种不同温度下，都没有稳定结构，表现出固有无序特征，温度会导致结构特征发生显著变化；在高温(380 K)时，会产生α螺旋向β折叠转换的趋势。 The temperature-induced conformation changes of Aβ42 protein were studied by molecular dynamics simu-lation. The three independent molecular dynamics simulations of Aβ42 protein at different temperatures 300 K, 340 K and 380 K, were performed using the GROMACS software package and GROMOS 43A1 force field, respectively. Each simulation was run for 60 ns. Based on the simulations, we analyzed the conformation changes of Aβ42 protein and the formation of its secondary structure and tertiary structure. The results indicated that Aβ42 protein has no stable structure and it has the characters of intrinsically disorder proteins at the different temperatures. It also shows that the structure of Aβ42 protein change obviously with different temperature. In addition, there is a change tendency from α-helix to β-sheet at 380 K.