Folding of a disulfide-bonded protein species with free thiol(s): competition between conformational folding and disulfide reshuffling in an intermediate of bovine pancreatic ribonuclease A

Détails

ID Serval
serval:BIB_65827B84FF32
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Folding of a disulfide-bonded protein species with free thiol(s): competition between conformational folding and disulfide reshuffling in an intermediate of bovine pancreatic ribonuclease A
Périodique
Biochemistry
Auteur⸱e⸱s
Saito  K., Welker  E., Scheraga  H. A.
ISSN
0006-2960 (Print)
Statut éditorial
Publié
Date de publication
12/2001
Volume
40
Numéro
49
Pages
15002-8
Notes
Journal Article --- Old month value: Dec 11
Résumé
The conformational folding of the nativelike intermediate des-[40-95] on the major oxidative folding pathway of bovine pancreatic ribonuclease A (RNase A) has been examined at various pHs and temperatures in the absence of a redox reagent. Des-[40-95] has three of the four disulfide bonds of native RNase A and lacks the bond between Cys40 and Cys95. This three-disulfide species was unfolded at low pH to inhibit any disulfide reshuffling and was refolded at higher pH, allowing both conformational folding and disulfide-reshuffling reactions to take place. As a result of this competition, 15-85% of des-[40-95], depending on the experimental conditions, undergoes intramolecular disulfide-reshuffling reactions. That portion of the des-[40-95] population which has native isomers of essential proline residues appears to fold faster than the disulfide reaction can occur. However, when the folding is retarded, conceivably by the presence of non-native isomers of essential proline residues, des-[40-95] may reshuffle before completing the conformational folding process. These results enable us to distinguish among current models for the critical structure-forming step in oxidative folding and reveal a new model for coupling proline isomerization to disulfide-bond formation. These experiments also demonstrate that the reshuffling-folding competition assay is a useful tool for detecting structured populations in conformational folding intermediates.
Mots-clé
Animals Cattle Disulfides/*chemistry/metabolism Hydrogen-Ion Concentration Oxidation-Reduction Protein Denaturation Protein Folding Ribonuclease, Pancreatic/*chemistry/metabolism Sulfhydryl Compounds/chemistry Temperature
Pubmed
Web of science
Création de la notice
24/01/2008 15:40
Dernière modification de la notice
20/08/2019 15:21
Données d'usage