肌巨蛋白PEVK多肽片段中模型分子EVPK的构象研究

Conformational study of EVPK in PEVK segment of titin

为探讨肌巨蛋白中PEVK多肽片段对肌巨蛋白的弹性贡献,本文采用分子力学随机构象搜索法、分子动力学模拟退火法和混合Monte Carlo方法,对PEVK多肽片段中的模型分子EVPK进行构象搜索和构象稳定性研究。结果表明,构象搜索所得低能构象集中,以分子动力学模拟退火所得的构象能量最低,构象中分子呈折叠式且稳定性较好。在拉力作用下构象被拉伸,在宏观上表现出弹性,为解释PEVK多肽片段是肌巨蛋白弹性的来源提供理论依据。

The conformational analysis of EVPK in PEVK segment of titin was carried out by stochastic search, simulated annealing and hybrid Monte Carlo method. The sampled multiple conformations resulting showed that the minimum energy conformation resulted from simulated annealing has the lowest energy of the three methods. And the folded conformations are the preferred backbone conformations. When resting muscle is stretched, the unfolding of the molecule may result in the extension of it and accompany the rise in passive tension moderately, which tells us the PErK segment of titin can contributes to the elasticity of titin.