二肽分子内氢键键能的计算

Calculation of the Intramolecular Hydrogen-bonding Energies of Dipeptide

以含甲基侧链和无甲基侧链的二肽结构为研究对象,在保持其他位置原子和结构不变的情况下,用C原子取代形成氢键的N原子,并以全铺展结构作为基准,C原子取代后,视原有构象中库仑作用和空间位阻不发生变化,初步估算了“氢键键能”,与经验结果相近.在估算氢键键能上具有一定的参考价值.

In this paper, α-dipeptide with and without the side chain methyl group were studied. We replaced the motif NH which is involved in the hydrogen-bonding by a fragment CH2, at the same time keeping the position of other atoms fixed. The coulomb interactions and the steric repulsive interactions are constant during replacing. Taking the full extended structure as the ＂reference＂, the hydrogen-bonding energies were calculated. The results are similar with experimental parameters.