Vasopressin conformational fluctuations: A molecular dynamics study

✍ Scribed by J. R. Somoza; J. W. Brady

• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 870 KB
• Volume: 27
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360270605

✦ Synopsis

Molecular dynamics simulations have been used to study the conformational fluctuations of the oligopeptide hormone vasopressin. Starting coordinates for these simulations were built upon the crystal structure of pressinoic acid, the cyclic ring moiety of vasopressin, recently determined by x-ray diffraction. Coordinates for the additional tripeptide "tail" of vasopressin were selected by arbitrary positioning of this segment using interactive computer graphics. Two such starting configurations were minimized to relax strains, and long dynamics simulations (20 and 40 ps) in vacuo were then conducted following extensive heating and equilibration sequences (36 ps). In these studies, vasopressin was found to undergo few substantial conformational changes at 300 K on the time scale simulated, in contrast to the results of a shorter previous simulation, but comparable structural transitions were observed during the equilibration periods. The pressinoic acid structure was found to be a reasonably stable possible conformation for vasopressin in vacuum on this time scale.