中文摘要：

蛋白质的二级结构与其功能密切相关,错误的折叠将导致蛋白质生理功能的改变,甚至引起病变.以阿尔兹海默症的致病因子——淀粉样蛋白片段Aβ（16-21）为研究对象,开展分子动力学模拟,得到了Aβ（16-21）在水溶液中的全原子运动轨迹.统计结果表明,在纳秒的时间尺度上,水溶液中多肽链倾向于形成β和PPⅡ构型,进而易发生聚集,产生神经毒性.

英文摘要：

The function of protein is closely related to their secondary structure. Misfolding of the protein would cause malfunction, and even lead to disease. Molecular dynamics simulations were performed for Aβ（ 16-21 ） which is the pathogenic factor of Alzheimer＇s disease in aqueous solution. The all atom trajectories were obtained for statistical analysis. Results show that Aβ（ 16-21 ） tends to form fl and PPII conformations in aqueous solution during conformers could easily aggregate and yield neurotoxic effect. nanosecond time scale, and these