Stabilization of β-turn conformations in Pro-X sequences by disulphide bridging. Synthesis and solution conformations of five cyclic cystine peptides
作者:A. Ravi、P. Balaram
DOI:10.1016/s0040-4020(01)83512-2
日期:1984.1
Five cyclic peptidedisulphides of the type have been synthesized, where X = Gly (1), L-Ala (2), D-Ala (3), Aib (4) and L-Leu (5). 1H NMR studies at 270 MHz in CDCl3 and (CD3)2SO provide evidence of a Pro-X β-turn conformation, stabilized by a transannular 4→1 hydrogen bond involving the Cys(4) NH, in all the peptides. In addition peptides 2, 4 and 5 also possess a second intramolecular hydrogen bond
已经合成了五种类型的环状肽二硫化物,其中X = Gly(1),L-Ala(2),D-Ala(3),Aib(4)和L-Leu(5)。在270 MHz下的CDCl 3和(CD 3)2 SO中的1 H NMR研究提供了Pro-Xβ-turn构象的证据,该构象由涉及Cys(4)NH的跨环4→1氢键稳定,在所有肽中。另外,肽2、4和5还具有第二个涉及-NHMe基团的分子内氢键。光谱数据与肽2、4的连续III型β-转角构象一致和5,用于1的I(III)型β-转弯结构和用于3的II型转弯结构。