文章基本信息

标题：13C-nuclear magnetic resonance study of [85% 13C-enriched proline]thyrotropin releasing factor: 13C-13C vicinal coupling constants and conformation of the proline residue
本地全文：下载
作者：W Haar ; S Fermandjian ; J Vicar 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1975
卷号：72
期号：12
页码：4948-4952
DOI：10.1073/pnas.72.12.4948
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：To understand fully interactions between peptides and cellular receptors, peptide side chain conformation must be defined. In many cases the complexity of proton nuclear magnetic resonance (NMR) prevents this but the present work demonstrates this problem can be solved by using 13C enrichment. Selective 13C enrichment of a natural peptide hormone has been achieved by preparing [85% 13C-enriched proline]thyrotropin releasing factor which was examined by 13C NMR spectroscopy at various pH values. Because of the 13C enrichment, one-bonded and three-bonded (vicinal) 13C-13C coupling constants have been determined. The latter vary from 0 to 5 Hz and show bond angle dependence. These data indicate that in this hormone the pyrrolidine ring is not free but fixed in the Cgamma-endo puckered conformation. It has also been possible to assign chemical shift values for a second order 13C NMR spectrum.