铃木青霉素（一种形成膜通道的多肽）14 残基和 16 残基片段的螺旋构象。

The helical conformations of 14- and 16-residue fragments of suzukacillin, a membrane channel-forming polypeptide.

作者信息

Iqbal M, Balaram P

出版信息

Biochim Biophys Acta. 1982 Sep 7;706(2):179-87. doi: 10.1016/0167-4838(82)90485-x.

Abstract

The suzukacillin fragments, Boc-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe (14), Boc-Ala-Aib-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe (16G) and the completely apolar 16-residue peptide in which the glutamine residue has been replaced by alanine (16A) have been studied by 270 MHz 1H-HMR, in C2HCl3 and (C2H3)2SO solution. Intramolecularly hydrogen-bonded NH groups have been identified by temperature and solvent dependence of chemical shifts. Peptides 14 and 16A adopt folded 3(1)) helical conformations stabilized by 11 and 13 hydrogen bonds, respectively. In peptide 16G there are 12 intramolecular hydrogen bonds, with the glycine NH being solvent-exposed, in contrast to 14 and 16A.

摘要

已通过在C2HCl3和（C2H3）2SO溶液中的270 MHz 1H-HMR对苏唑西林片段Boc-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe（14）、Boc-Ala-Aib-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe（16G）以及谷氨酰胺残基被丙氨酸取代的完全非极性16残基肽（16A）进行了研究。通过化学位移的温度和溶剂依赖性确定了分子内氢键结合的NH基团。肽14和16A分别采用由11个和13个氢键稳定的折叠3(1))螺旋构象。与14和16A相比，肽16G中有12个分子内氢键，其中甘氨酸NH暴露于溶剂中。