Conformational analysis of polypeptide chains with the aid of density of states calculations

✍ Scribed by Saul G. Jacchieri

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 321 KB
• Volume: 65
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)65:6<1115::aid-qua10>3.0.co;2-4

✦ Synopsis

A model system whose density of states is an analytical function of the potential energy is obtained by combining potential energy wells given by Lennard-Jones 6-12 potentials representing pairwise interactions between atoms and circular barriers. Structural aspects of polypeptide chains such as sharp and broad energy extremes and close-packed and loose-packed conformations are simulated. By changing Lennard-Jones parameters, the density of states is described as a function of topological features of the potential energy surface and rules used to interpret density of states calculations are derived. Important results are that the number of clusters of density of states maxima in a given energy range approaches the number of conformational families and very low density of states gaps indicate the existence of kinetic barriers. These conclusions are applied to the conformational analysis of ␣-MSH. Structural implications are discussed.