【作者】 王潇伟；

【导师】 王长生；

【作者基本信息】 辽宁师范大学 ， 无机化学， 2006， 硕士

【摘要】 本文定义了丙氨酸多肽中的特殊氢原子并提出了特殊氢方法，采用密度泛函理论B3LYP方法，对丙氨酸-α-二肽、三肽、四肽、五肽和六肽分子进行了计算，对构象中与特殊氢原子有关的主要非键相互作用进行分析，确定了相应的参数。使用特殊氢方法得到的参数来快速预测多肽构象的相对稳定性，得到了满意的结果。本文结果进一步证明了特殊氢原子在决定丙氨酸-α-多肽构象稳定性方面的重要地位。 1)以丙氨酸-α-多肽的稳定构象为研究对象，明确提出了特殊氢方法，在已有参数的基础上，引入了新参数并确定了相互作用参数的数值。 2)使用特殊氢方法及相应参数来预测丙氨酸-α-二肽、三肽、四肽、五肽和六肽分子共239个稳定构象的稳定性，进而将之应用于预测丙氨酸-α-多肽分子构象稳定性，得到了满意的结果。更多还原

【Abstract】 The features of the conformers’ structures have been analyzed and a new method has been proposed based on the density functional theory to determine the conformer’s relative stability of the alanine-a-polypeptide. The special hydrogen atom was defined in this paper and the special hydrogen method was then proposed to predict the conformer’s relative stability of the alanine-a-polypeptide. Total 239 conformers of alanine di-, tri-, tetra- , penta- and hexa- peptide molecules have been completely optimized at B3LYP/6-31G~* level. The parameters of twelve non-bonded interactions have been determined from 28 conformers of alanine polypeptides.In this work, comparing with the relative energies of total 239 alanine-a-polypeptide conformers obtained by B3LYP/6-31G~* method, it can be concluded that the special hydrogen method is quite reasonable for prediction of the conformation stability of alanine-α-polypeptides. The linear correlation equation between the relative energies Y(kJ/mol) obtained by the special hydrogen method and the relative energies X(kJ/mol) obtained by the B3LYP/6-31G~* is Y=0.9365X+1.7298. The correlation coefficient is R=0.9608. The standard deviation is 4.3kJ/mol. The population of the conformations with deviation smaller than 2kcal/mol is up to 95.0%. Through comparing the 239 conformers’ relative energies obtained by the new scheme and B3LYP/6-31G~* ones, it can be concluded that the new method and the interaction parameters are reasonable for the determination of the conformation stability of alanine polypeptides.更多还原