학술논문
Lifetimes of Intermediates in the β-Sheet to α-Helix Transition of β-Lactoglobulin by Using a Diffusional IR Mixer
Document Type
research-article
Source
Proceedings of the National Academy of Sciences of the United States of America, 2001 Jun 01. 98(12), 6646-6649.
Subject
Language
English
ISSN
00278424
Abstract
The extremely slow α-helix/β-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-µs time resolution to show that the trifluoroethanol driven β-sheet to α-helix transition of β-lactoglobulin proceeds via a compact β-sheet intermediate with a lifetime of 7 ms, small compared with the overall folding time of β-lactoglobulin.