摘要
用从头计算法优化了 2 0种天然氨基酸正、负、偶极离子 .计算结果表明 ,α- NH2 上的氮原子可以和羧基氧原子形成氢键 ,通过 N1— H2… O3氢键的生成 ,原子 N1、H3、O4、C4、C5形成了五元环 .从正离子、负离子到偶极离子 ,氢键强度逐渐减小 .侧链原子对氢键也有影响 :正离子的侧链除苏氨酸和丝氨酸外 ,其它氨基酸不对氢键构成影响 ;负离子氢键受侧链的影响较大 ;而偶极离子中氢键基本不受侧链的影响 .
The hydrogen bond structure is calculated by optimizing the 20 crude amino acids positive ions, negative ions and dipole ions with ab initio calculation.It is proved that hydrogen bond forms between the nitrogen atom of α-NH 2 and the oxygen atom of the carboxyl .With the N1-H2…O3 hydrogen bond , N1,H3,O4,C4,C5 form a five-numbered ring . The intensity of the hydrogen bonds become weak gradually from positive ions, negative ions to dipole ions. Apart from threonine and serine , the hydrogen bonds of the other positive ions are not affected by the side chain.The hydrogen bonds of the negative ions are mostly affected by the side chain, and the hydrogen bonds of the dipole ions are not affected by the side chain.
出处
《郑州大学学报（理学版）》
CAS
2004年第3期59-63,共5页
Journal of Zhengzhou University:Natural Science Edition
基金
国家自然科学基金资助项目
编号 2 0 2 72 0 5 4
