中文摘要：

利用从头算方法探索蛋白质模型分子——丙氨酸二肽在氯仿溶剂环境下的二级结构布居特征．借助对分子结构敏感的振动探针（酰胺振动吸收带）的光谱表象，寻求振动光谱参数与分子结构之间的联系．研究结果表明，丙氨酸二肽分子倾向于形成 β折叠、PPⅡ、C7eq和c，等构型．简正模式分析结果表明分子内酰胺振动带对分子骨架变化十分敏感，因此可以将酰胺振动吸收带作为结构探针研究蛋白质分子的二级结构信息．

英文摘要：

The population of the secondary structures of alanine dipeptide in chloroform was in- vestigated by means of ab initio calculation. The vibrational parameters of amide modes, which were known to be quite sensitive to the secondary structure of peptide, were calculated to reveal the correlation between the vibrational spectrum and the molecular structure. It was found that alanine dipeptide trends to form the conformations like β , PPⅡ, C7eq and C5. Normal mode analysis showed that the vibrational parameters of amide motions were very sensitive to the backbone confor- mation of alanine dipeptide, therefore, the amide vibrational modes can be used as structural probe in the determination for the secondary structure of the orotein and oolvoeotide.