ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two cyclic hexapeptides, cyclo[Ala1-D-Ala2-Ser3-Phe4-Gly5-Ser6] and cyclo[Ala1-Gly2-Ser3-Phe4-Gly5-Ser6], derived from the loop portion of the C′C″ ridge of CD4, were characterized by high-resolution nmr spectroscopy and simulated annealing studies. In DMSO-d6 both of these peptides display a single conformer on the nmr time scale with two intramolecular H-bond (1 ← 4) stabilized β-turns at positions 2-3 and 5-6. The nmr derived distance constraints were used in simulated annealing calculations to generate the solution structures. These structures adopt energetically comparable conformational substates that are not resolvable on the nmr time scale. In aqueous solution, the H-bond stabilized β-turn conformation for cyclo [Ala-D-Ala-Ser-Phe-Gly-Ser] is no longer the predominant structural form. Structures generated using molecular dynamics simulations with no experimental constraints were compared with those from nmr analysis. The correlation between these two sets of structures allows the use of molecular simulations as a predictive tool for the conformational analysis of small peptides. © 1994 John Wiley & Sons, Inc.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360340802
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