Application of C-Terminal 7-Azabicyclo[2.2.1]heptane to Stabilize β-Strand-like Extended Conformation of a Neighboring α-Amino Acid
作者:Luhan Zhai、Siyuan Wang、Masayuki Nara、Koh Takeuchi、Ichio Shimada、Yuko Otani、Tomohiko Ohwada
DOI:10.1021/acs.joc.8b01756
日期:2018.11.2
β-strand-like extended conformation of the adjacent α-amino acid on the N side. The bridgehead substitution of the Abh unit biases the amide cis–trans equilibrium of the adjacent α-amino acid residue to cis conformation. The proximity, specified by the presence of bond paths (such as H–H bond path) between the bridgehead proton of Abh and the α-proton of the α-amino acid provides a driving force favoring the extended
β链由延伸的线性肽链形成,该链通常通过链间氢键配对形成β-折叠结构。将结构化的有机分子与α-氨基酸连接可以增强或稳定连接氨基酸的β链状延伸结构。光谱和模拟研究表明,C末端7-氮杂双环[2.2.1]庚烷胺(Abh)的存在有利于N侧相邻α-氨基酸的β链状延伸构象。Abh单元的桥头取代将相邻的α-氨基酸残基的酰胺顺式-反式平衡偏向顺式构象。由Abh桥头质子和α-氨基酸的α-质子之间存在键路径(例如H–H键路径)所指定的接近度提供了有利于扩展构象的驱动力,与溶剂无关。这些结果为使用β-链增强剂/稳定剂甚至在不存在链间氢键的情况下从头设计β-链模拟延伸肽提供了基础。