平行或反平行β折叠片哪个更稳定？一项半经验研究。

Is the parallel or antiparallel beta-sheet more stable? A semiempirical study.

作者信息

Gailer C, Feigel M

机构信息

Department of Chemistry, University of Bochum, Germany.

出版信息

J Comput Aided Mol Des. 1997 May;11(3):273-7. doi: 10.1023/a:1007908728919.

DOI:10.1023/a:1007908728919

PMID:9263854

Abstract

The geometry and energy of parallel and antiparallel peptidic beta-sheets have been calculated using AM1. beta-Sheets composed of two peptide chains of up to 11 amino acid residues (Ala and Gly) and the dimers of cyclooctapeptides are used as model systems. The enthalpic difference between the parallel and the antiparallel arrangement is calculated to be very small, as it is found experimentally for the cyclic systems. The coordinates of the calculated structure of the cyclooctapeptide dimer 1 (cyclo-D,L-(Ala)8) have an rms deviation of only 0.223 A to the coordinates of the corresponding cyclopeptide obtained by X-ray analysis.

摘要

已使用AM1方法计算了平行和反平行肽β-折叠的几何结构和能量。由多达11个氨基酸残基（丙氨酸和甘氨酸）的两条肽链组成的β-折叠以及环八肽二聚体用作模型系统。计算得出平行排列和反平行排列之间的焓差非常小，正如在环状系统的实验中所发现的那样。环八肽二聚体1（环-D,L-（丙氨酸）8）的计算结构坐标与通过X射线分析获得的相应环肽坐标的均方根偏差仅为0.223埃。