Conformational Analysis of Periodic Polypeptides Containing Pro Residue

合成了poly（Xaa- pro - pro - pro）、poly（Xaa- pro - pro）、poly（Xaa- pro）、poly（Xaa-Xaa- pro）、poly（Xaa-Xaa-Xaa- pro）、（Xaa=Ala、Leu、Val、Phe - Glu、Asp、Lys、Arg）等周期性多肽，并通过实验和理论方法分析了它们的构象。结果表明，它们具有新的螺旋结构，与已知的α-螺旋结构、β-链结构和聚脯氨酸- ii结构明显不同。这些构象的相对稳定性随溶剂和温度的变化而变化。实验结果得到了分子力学计算理论分析的支持。

Periodic polypeptides such as poly(Xaa-Pro-Pro-Pro), poly(Xaa-Pro-Pro), poly(Xaa-Pro), poly(Xaa-Xaa-Pro), poly(Xaa-Xaa-Xaa-Pro), (Xaa=Ala, Leu, Val, Phe Glu, Asp, Lys, Arg) were synthesized, and their conformations were analyzed by experimental and theoretical method. It was shown that they take new helical conformations which are clearly distinguished from the well-known secondary structures such as α-helix, β-strand, and polyproline-II structures. It was also shown that relative stabilities of those conformations are changed by solvents and temperature. The experimental results were supported by theoretical analysis using molecular-mechanics calculations.