摘要
提出一种计算多肽中N-H…O=C分子内氢键键能的新方法.并将新方法应用于计算甘氨酸和丙氨酸二肽、三肽中N-H…O=C分子内氢键键能.利用密度泛函理论B3LYP/6-31G(d)方法优化几何构型和计算频率.对全部结构计算MP2/6-311++G(3df,2p)水平上的单点能量.结果表明:在甘氨酸二肽中氢键键能为-6.38 kcal/mol,在丙氨酸二肽中氢键键能为-7.09-、6.25 kcal/mol;在甘氨酸三肽中氢键键能为-5.62 kcal/mol,在丙氨酸三肽中氢键键能为-5.37,-5.74 kcal/mol.
A new methodology was devised to predict the intramolecular N-H…O=C H-bond energy for ploypeptide. This methodology was applied to predict the intramolecular H-bond energies for glycine and alanine dipeptides and tripeptides. The geometries and vibrational frequencies were calculated using the densi- ty functional theory B3LYP/6-31G（d） method. The MP2/6-311 ＋ ＋ G（3df, 2p） calculation was preformed to obtain more accurate energies. The results show that the intramolecular H-bond energy is - 6.38 kcal/mol for glycine dipeptide and -7.09, -6.25 kcal/mol for alanine dipeptides; the intramolecular H-bond energy is - 5.62 kcal/mol for glycine tripeptide and - 5.37, - 5.74 kcal/mol for alanine tripeptides.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2007年第6期1166-1170,共5页
Journal of Atomic and Molecular Physics
基金
国家自然科学基金(20573049)
关键词
密度泛函理论
甘氨酸
丙氨酸
分子内氢键键能
density functional theory
glycine
alanine
intramolecular H-bond energy
