CD spectral analysis of chromophoric derivatives of tetrapeptides related to the β-turn part of [d-Val1,1′]-and [d-Val1,1′, l-Phe4,4′]-gramicidin S indicated that they had very low preference for β-turn formation. The results suggested that neither analog could take gramicidin S-like β-sheet conformation. It seems noteworthy that the side-chain bulkiness of the 4th amino acid of a tetrapeptide affects the stability of β-turn.
与[d-Val1,1']-和[d-Val1,1',l-Phe4,4']-
短杆菌肽S的β-转角部分相关的四肽发色衍
生物的CD光谱分析表明它们具有非常低的对β-转角形成的偏好。结果表明,两种类似物都不能采用
短杆菌肽 S 样 β-折叠构象。值得注意的是,四肽第 4 个
氨基酸的侧链体积会影响 β-转角的稳定性。