中文摘要：

Val55是鸡胱抑素（Chickeneystatin，cC）铰链环状区的重要位点。本文采用分子动力学模拟的方法研究了V55位点突变对cC典型的淀粉样突变体166Q结构稳定性的影响情况，并深入探讨了其分子机制。研究表明v55N和V55D对166Q突变体都有稳定其结构的作用，但V55N的稳定作用更显著。进一步研究发现V55N和V55D对166Q的这种稳定作用是由于突变后的55位残基与邻近残基形成了较多稳定的氢键，从而增加了自身位点及Loopl、β2-β3的稳定性，并进一步稳定了166Q的α-螺旋和疏水核心结构。这可能最终阻碍胱抑素淀粉样突变体166Q结构域交换的发生。

英文摘要：

Residue Val55 plays a significant role in the hinge loop of the chicken cystatin （cC）. In this study, mo- lecular dynamics simulations were preformed to investigate effect of Va155 mutation on the structural stability of a typical amyloidogenic cC mutant I66Q, and explored the possible mechanism. It was found that both V55N and V55D could enhance the structural stability of cC I66Q, especially in the case of V55N. Future research indicates that there were more hydrogen bonds related with position 55 in V55N and V55D mutants. This led to increasing the stability of Loopl and β2-β3, which stabilized the α - helix and hydrophobie core of cC I66Q. These listed factors might inhibit the process of domain swapping of cC I66Q.