Peptide conformations. 28. Relayed heteronuclear correlation spectroscopy and conformational analysis of cyclic hexapeptides containing the active sequence of somatostatin
Peptide conformations. 28. Relayed heteronuclear correlation spectroscopy and conformational analysis of cyclic hexapeptides containing the active sequence of somatostatin
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肽构象。
DOI：
10.1021/ja00361a034
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发表时间：
1983
影响因子：
15
通讯作者：
R. R. Ernst
中科院分区：
文献类型：
--
作者：
H. Kessler;M. Bernd;H. Kogler;J. Zarbock;O. Soerensen;G. Bodenhausen;R. R. Ernst
Homo- and heteronuclear 2-dimensional NMR techniques were used to assign the 1H and 13C NMR spectra of title cyclic peptides cyclo[Phe7-D-Trp-Lys(COCH2Ph)-Thr-X11-Pro6] [X = Gly (I), Phe (II)] in Me2SO. Unequivocal assignments of C resonances of Trp and Phe in II could only be obtained by heteronuclear relayed spectroscopy. II has a bII' turn at Phe7...Thr and a bVI turn at Thr...Phe7 including a cis peptide bond between Phe11 and Pro6. Substitution of Phe11 by Gly to give I results in a dramatic change in the conformation; 2 species of I exist in a slow equil. (70:30) in which the major isomer has a trans Gly-Pro bond. The technique of relayed heteronuclear correlation spectroscopy and an improved pulse sequence are described. [on SciFinder (R)]
