期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2001
卷号：98
期号：12
页码：6646-6649
DOI：10.1073/pnas.101122898
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The extremely slow -helix/{beta}-sheet transition of proteins is a crucial step in amylogenic diseases and represents an internal rearrangement of local contacts in an already folded protein. These internal structural rearrangements within an already folded protein are a critical aspect of biological action and are a product of conformational flow along unknown metastable local minima of the energy landscape of the compact protein. We use a diffusional IR mixer with time-resolved Fourier transform IR spectroscopy capable of 400-{micro}s time resolution to show that the trifluoroethanol driven {beta}-sheet to -helix transition of {beta}-lactoglobulin proceeds via a compact {beta}-sheet intermediate with a lifetime of 7 ms, small compared with the overall folding time of {beta}-lactoglobulin.
