Characterization of the fast-forming intermediate, des [30-75], in the reductive unfolding of onconase

Détails

ID Serval
serval:BIB_3823314B04F5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Characterization of the fast-forming intermediate, des [30-75], in the reductive unfolding of onconase
Périodique
Biochemistry
Auteur(s)
Xu  G., Narayan  M., Welker  E., Scheraga  H. A.
ISSN
0006-2960 (Print)
Statut éditorial
Publié
Date de publication
03/2004
Volume
43
Numéro
11
Pages
3246-54
Notes
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Mar 23
Résumé
A fast-forming intermediate in the reductive unfolding of frog onconase (ONC), des [30-75], analogous to the des [40-95] intermediate found in the reductive unfolding of its structural homologue, bovine pancreatic ribonuclease A (RNase A), has been isolated and characterized. The midpoints of the thermal transition and chemical denaturing curves (representing global unfolding) indicate that the conformation of des [30-75] is considerably less stable than that of the parent molecule, suggesting that the (30-75) disulfide bond plays a significant role in the conformational stability of ONC. While des [30-75] is formed very quickly by a partial reduction of the parent molecule in a local unfolding step, it is not as easily susceptible to further reduction, indicating that its three disulfides are much more buried compared to the (30-75) disulfide bond in the parent protein. The nature of des [30-75] is similar to that of des [40-95] RNase A, in that des [30-75] ONC is also a disulfide-secure species. In addition, based on the resistance to mild reducing conditions, structured des species appear to form in ONC from unstructured three-disulfide-containing ensembles. This step is key in the oxidative folding of RNaseA, and is much faster in ONC than the formation of the structured des [40-95] species in RNase A.
Mots-clé
Animals Cattle Chromatography, High Pressure Liquid Disulfides/chemistry Entropy Enzyme Stability Guanidine/chemistry Kinetics Models, Chemical Oxidation-Reduction Protein Denaturation *Protein Folding Rana pipiens Ribonuclease, Pancreatic/chemistry Ribonucleases/*chemistry Structural Homology, Protein
Pubmed
Web of science
Création de la notice
24/01/2008 15:40
Dernière modification de la notice
20/08/2019 14:26
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