Structural determinants of oxidative folding in proteins

Details

Serval ID
serval:BIB_A82574779F55
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Structural determinants of oxidative folding in proteins
Journal
Proceedings of the National Academy of Sciences of the United States of America
Author(s)
Welker  E., Narayan  M., Wedemeyer  W. J., Scheraga  H. A.
ISSN
0027-8424 (Print)
Publication state
Published
Issued date
02/2001
Volume
98
Number
5
Pages
2312-6
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Feb 27
Abstract
A method for determining the kinetic fate of structured disulfide species (i.e., whether they are preferentially oxidized or reshuffle back to an unstructured disulfide species) is introduced. The method relies on the sensitivity of unstructured disulfide species to low concentrations of reducing agents. Because a structured des species that preferentially reshuffles generally first rearranges to an unstructured species, a small concentration of reduced DTT (e.g., 260 microM) suffices to distinguish on-pathway intermediates from dead-end species. We apply this method to the oxidative folding of bovine pancreatic ribonuclease A (RNase A) and show that des[40-95] and des[65-72] are productive intermediates, whereas des[26-84] and des[58-110] are metastable dead-end species that preferentially reshuffle. The key factor in determining the kinetic fate of these des species is the relative accessibility of both their thiol groups and disulfide bonds. Productive intermediates tend to be disulfide-secure, meaning that their structural fluctuations preferentially expose their thiol groups, while keeping their disulfide bonds buried. By contrast, dead-end species tend to be disulfide-insecure, in that their structural fluctuations expose their disulfide bonds in concert with their thiol groups. This distinction leads to four generic types of oxidative folding pathways. We combine these results with those of earlier studies to suggest a general three-stage model of oxidative folding of RNase A and other single-domain proteins with multiple disulfide bonds.
Keywords
Animals Cattle Kinetics Oxidation-Reduction *Protein Folding Ribonuclease, Pancreatic/*chemistry
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 14:40
Last modification date
20/08/2019 15:12
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