类蛋白质分子扩散系数的模拟计算

蛋白质分子是一类比较特殊的高分子，一方面它的性质与氨基酸序列密切相关，另一方面其二级结构（如α螺旋以及β折叠等）极大地影响着它的性质．另外它的内部结构又非常紧密，与一般的高分子链完全不同．同时随着计算机技术的发展，计算机模拟日益作为一种有效的手段广泛应用于高分子科学的研究．但是由于蛋白质分子比一般的高分子结构更加复杂，如氨基酸之间有复杂的互相作用等，因此对蛋白质性质的研究往往建立在简化模型的基础上，如基于格点的HP紧密高分子模型等．虽然建立在格点模型上的蛋白质分子和真实的蛋白质分子存在着一定的差异，但基本上能体现蛋白质分子的主要特征，因此把这一类分子称为类蛋白质分子．

SIMULATION STUDIES ON THE DIFFUSION COEFFICIENT OF PROTEIN-LIKE CHAINS

Dynamics of protein-like chains are investigated by using Monte Carlo simulation method based on the modified orientation-dependent monomer-monomer interactions model (ODI). The diffusion coefficients for different chain length are calculated,and some comparisons with self-avoiding chains are also made. There exists a relationship between the diffusion coefficient D and chain length N for both protein-like chains and SAW chains,i.e D～N~-α . Here the value of α for SAW chains is 1.02,however,the value of α for protein-like chains is 4.75,which is 4～5 times larger than that of SAW chains. Therefore,dynamics of protein-like chains is different from SAW chains completely. These investigations may provide some insights into dynamics of proteins.