Raghavendra K, Sasisekharan V
Int J Pept Protein Res. 1979 Oct;14(4):326-38. doi: 10.1111/j.1399-3011.1979.tb01940.x.
The conformational analysis of a pair of two-linked peptide units in the anti-parallel arrangement is reported here with a view to study the effect of association of one chain with the other. The pair of two-linked peptide units were fixed in space through the hydrogen bonds between them, in accordance with certain hydrogen bond criteria. Model building was undertaken to ascertain whether the proximity of the side-chains could be used to eliminate any one of the right-hand twisted, left-hand twisted or regular beta-structures. Stereochemically, it was found possible with all of them. The preference for a right-hand twisted beta-structure, however, was indicated by the classical energy calculations. The relevance of the results thus obtained is discussed in the context of the preferential right-hand twist of the beta-pleated sheets present in globular proteins. The agreement between the minimum energy conformations obtained for the pair of two-linked peptide units and the globular protein data is also indicated.
本文报道了一对以反平行排列的双连接肽单元的构象分析，旨在研究一条链与另一条链缔合的影响。根据某些氢键标准，这对双连接肽单元通过它们之间的氢键在空间中固定。进行模型构建以确定侧链的接近度是否可用于排除右手扭曲、左手扭曲或规则β结构中的任何一种。从立体化学角度来看，发现所有这些结构都是可能的。然而，经典能量计算表明更倾向于右手扭曲的β结构。本文在球状蛋白质中存在的β折叠片优先右手扭曲的背景下讨论了由此获得的结果的相关性。还指出了双连接肽单元对获得的最低能量构象与球状蛋白质数据之间的一致性。
