Information accumulation in helical oligopeptide structures

If structural information is viewed in terms of entropy of the molecule, the folded and misfolded structures of a wild-type protein and its mutant contain different amounts of information. Here we present the strong side chain-dependence of the internal entropy of folding, and consequently of the relative information content for the simplest oligopeptides. It is found that during a conformational change from extended to 3(10)-helical structure, the (Gly)(10) oligomer accumulates 10(6) more information than the (Ala)(10) oligomer. It is argued that the difference in information accumulation is related to chirality. The role of Ala -> Gly point mutation is also examined. (C) 2007 Elsevier B.V. All rights reserved.