Conformational study of an Aib-rich peptide in DMSO by NMR

被引:40
作者
Bellanda, M
Peggion, E
Bürgi, R
van Gunsteren, W
Mammi, S
机构
[1] Univ Padua, Dept Organ Chem, CNR, Biopolymer Res Ctr, I-35131 Padua, Italy
[2] ETH Zurich, Phys Chem Lab, CH-8092 Zurich, Switzerland
来源
JOURNAL OF PEPTIDE RESEARCH | 2001年 / 57卷 / 02期
关键词
3(10)-helix; Aib; DMSO; molecular dynamics; NMR; peptide folding;
D O I
10.1034/j.1399-3011.2001.00794.x
中图分类号
Q5 [生物化学];
学科分类号
071010 ; 081704 ;
摘要
The strong propensity of 2-amino-2-methyl propanoic acid (Aib)-rich peptides to form stable helical structures is well documented. NMR analysis of the short peptide Z-(Aib)(5)-L-Leu(Aib)(2)-OMe indicates the presence of a well-characterized 3(10)-helix even in dimethylsulfoxide (DMSO), a solvent known to disrupt helical structures. The structure remains stable at least up to 348 K. Stereospecific assignment of the diastereotopic methyls of Aib was achieved, with the assumption of a specific helical screw sense. The methyl more eclipsed with respect to the CO vector resonates at a higher field in the carbon dimension. Molecular dynamics simulations successfully predict the (3)J(CHNH) coupling constant of Leu(6) and most of the H-bonding pattern. Discrepancies were found for Aib(3) and Aib(7) amide protons which can be explained by a higher sensitivity of the simulations to the helix fraying at the end of the peptide and by the presence of extended conformations for Leu6 during most of the simulations.
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页码:97 / 106
页数:10
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