Transition state and ground state properties of the helix-coil transition in peptides deduced from high-pressure studies.

ABSTRACT: Volume changes associated with protein folding reactions contain valuable information about the folding mechanism and the nature of the transition state. However, meaningful interpretation of such data requires that overall volume changes be deconvoluted into individual contributions from different structural components. Here we focus on one type of structural element, the α-helix, and measure triplet-triplet energy transfer at high pressure to determine volume changes associated with the helix-coil transition. Our results reveal that the volume of a 21-amino-acid alanine-based peptide shrinks upon helix formation. Thus, helices, in contrast with native proteins, become more stable with increasing pressure, explaining the frequently observed helical structures in pressure-unfolded proteins

SUBMITTER: Neumaier S 

PROVIDER: S-EPMC3876207 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature