某些环肽及其相应线型肽在不同溶剂中构象的CD谱研究  

Study on the Conformation of Three Cyclic Peptides and Their Correspondent Linear Peptides with CD Spectroscopy

作　　者：蒋云[1] 苗振伟[1] 徐筱杰[1] 唐有祺[1] 

机构地区：[1]北京大学物理化学研究所,北京100871

出　　处：《物理化学学报》1996年第1期91-95,共5页Acta Physico-Chimica Sinica

基　　金：攀登计划"生命中重要化学问题"资助

摘　　要：We used CD spectroscopy to study the conformations of three cyclic peptides (CP10E: cyclo[Glu(OBz1)-Pro-Gly-Glu(OBzl), CP10K: cyclo[Lys(Z)-Pro Gly-Lys(Z)-Gly]2, CP12K: cyclo[Phe-Lys(Z)-Pro-Gly-Lys(Z)-Gly]2 and their correspon dent linear peptides (LP10E: Boc-[Glu(OBzl)-Pro-Gly-Glu(OBzl)-Gly]2-OPac, LP10K: Boc-[Lys(Z)-Pro-Lys(Z)-Pro]2-OMe, LP 12K: Bao- [-Lys(Z)-Pro-Gly-Lys(Z)-Gly]2- OMe) in three solvents of different polarity (chloroform, acetonitrile, 2,2,2-triliuroethanol), and it was found that all of linear and cyclicpeptides exist as γ-turn conformation in chloroform,however, in TFE & CH3CN solutions, the three linear peptides are in β Ⅱ-turn conformations. CP10E is β Ⅰ-turn conformation, CP10K & CP12K exist in more than one types of turn conformations. On the basis of our experiments, it was concluded: 1) In the presence of conformational constrained amino acids short linear peptides form obvious secondary structure, 2) The solvent polarity has influence on the peptide conformation and this influence on linear peptides is greater than that on cyclic peptides, 3) The backbone of cyclic peptide has constraint effect on its conformation and makes the secondary structure of cyclic peptide different from that of its relative linear peptide. This information might give some clues in the design of bioactive peptides with different receptor selectivity.We used CD spectroscopy to study the conformations of three cyclic peptides (CP10E: cyclo[Glu(OBz1)-Pro-Gly-Glu(OBzl), CP10K: cyclo[Lys(Z)-Pro Gly-Lys(Z)-Gly]2, CP12K: cyclo[Phe-Lys(Z)-Pro-Gly-Lys(Z)-Gly]2 and their correspon dent linear peptides (LP10E: Boc-[Glu(OBzl)-Pro-Gly-Glu(OBzl)-Gly]2-OPac, LP10K: Boc-[Lys(Z)-Pro-Lys(Z)-Pro]2-OMe, LP 12K: Bao- [-Lys(Z)-Pro-Gly-Lys(Z)-Gly]2- OMe) in three solvents of different polarity (chloroform, acetonitrile, 2,2,2-triliuroethanol), and it was found that all of linear and cyclicpeptides exist as γ-turn conformation in chloroform,however, in TFE & CH3CN solutions, the three linear peptides are in β Ⅱ-turn conformations. CP10E is β Ⅰ-turn conformation, CP10K & CP12K exist in more than one types of turn conformations. On the basis of our experiments, it was concluded: 1) In the presence of conformational constrained amino acids short linear peptides form obvious secondary structure, 2) The solvent polarity has influence on the peptide conformation and this influence on linear peptides is greater than that on cyclic peptides, 3) The backbone of cyclic peptide has constraint effect on its conformation and makes the secondary structure of cyclic peptide different from that of its relative linear peptide. This information might give some clues in the design of bioactive peptides with different receptor selectivity.

关 键 词：圆二色谱 环肽 线型肽 构象 CD谱 

分 类 号：Q516[生物学—生物化学]