Effect of mutation of proline 93 on redox unfolding/folding of bovine pancreatic ribonuclease A

Details

Serval ID
serval:BIB_266A7A5947E0
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Effect of mutation of proline 93 on redox unfolding/folding of bovine pancreatic ribonuclease A
Journal
Biochemistry
Author(s)
Cao  A., Welker  E., Scheraga  H. A.
ISSN
0006-2960 (Print)
Publication state
Published
Issued date
07/2001
Volume
40
Number
29
Pages
8536-41
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Jul 24
Abstract
Both the reductive unfolding and oxidative regeneration of a P93A mutant and wild-type RNase A have been studied at 15 degrees C and pH 8.0. The rate of reduction of the 40--95 disulfide bond is accelerated about 120-fold by the P93A mutation, while the reduction of the 65--72 disulfide bond is not accelerated by this mutation (within the experimental error). Moreover, the reduction of native P93A to des[40--95] is about 10 times faster than the further reduction of the same des[40--95] species. These results demonstrate that the reduction of the mutant proceeds through a local unfolding event and provides strong support for our model in which the reduction of wild-type RNase A to the des species proceeds through two independent local conformational unfolding events. The oxidative regeneration rate of the P93A mutant is comparable to that of wild-type RNase A, suggesting that a cis 92--93 peptide group that is present in native wild-type RNase A and in native des[40--95], is not obligatory for the formation of the third (final) native disulfide bond of des[40--95] by reshuffling from an unstructured 3S precursor. Thus, the trans to cis isomerization of the Tyr92-Pro93 peptide group during the regeneration of wild-type RNase A may occur after the formation of the third native disulfide bond.
Keywords
Alanine/genetics Amino Acid Substitution/genetics Animals Cattle Chromatography, Ion Exchange Disulfides/metabolism Kinetics Oxidation-Reduction *Point Mutation Proline/*genetics Protein Conformation *Protein Folding Ribonuclease, Pancreatic/*genetics/*metabolism
Pubmed
Web of science
Create date
24/01/2008 14:40
Last modification date
20/08/2019 13:05
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