Entropic stabilization of isolated beta-sheets.

Philippe Dugourd; Rodolphe Antoine; Gary Breaux; Michel Broyer; Martin F Jarrold

doi:10.1021/ja0437499

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Entropic stabilization of isolated beta-sheets.

Philippe Dugourd·Rodolphe Antoine·Gary Breaux·Michel Broyer·Martin F Jarrold

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Abstract

Temperature-dependent electric deflection measurements have been performed for a series of unsolvated alanine-based peptides (Ac-WA(n)-NH(2), where Ac = acetyl, W = tryptophan, A = alanine, and n = 3, 5, 10, 13, and 15). The measurements are interpreted using Monte Carlo simulations performed with a parallel tempering algorithm. Despite alanine's high helix propensity in solution, the results suggest that unsolvated Ac-WA(n)-NH(2) peptides with n > 10 adopt beta-sheet conformations at room temperature. Previous studies have shown that protonated alanine-based peptides adopt helical or globular conformations in the gas phase, depending on the location of the charge. Thus, the charge more than anything else controls the structure.

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Alanine Algorithms Computer Simulation Models, Molecular Monte Carlo Method Peptides Protein Structure, Secondary Thermodynamics Tryptophan Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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Philippe Dugourd, Rodolphe Antoine, Gary Breaux, Michel Broyer, Martin F Jarrold. 2005-04-06. Entropic stabilization of isolated beta-sheets.. https://doi.org/10.1021/ja0437499

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