Document Detail

Interchange reaction of disulfides and denaturation of oxytocin by copper(II)/ascorbic acid/O2 system.
MedLine Citation:
PMID:  3593355     Owner:  NLM     Status:  MEDLINE    
The interchange reaction of disulfides was caused by the copper(II)/ascorbic acid/O2 system. The incubation of two symmetric disulfides, L-cystinyl-bis-L-phenylalanine (PP) and L-cystinyl-bis-L-tyrosine (TT), with L-ascorbic acid and CuSO4 in potassium phosphate buffer (pH 7.2, 50 mM) resulted in the formation of an asymmetric disulfide, L-cystinyl-L-phenylalanine-L-tyrosine (PT), and the final ratio of PP:PT:TT was 1:2:1. As the reaction was inhibited by catalase and DMSO only at the initial time, hydroxyl radical generated by the copper(II)/ascorbic acid/O2 system seemed to be responsible for the initiation of the reaction. Oxytocin and insulin were denatured by this system, and catalase and DMSO similarly inhibited these denaturations. As the composition of amino acids was unchanged after the reaction, hydroxyl radical was thought to cause the cleavage and/or interchange reaction of disulfides to denature the peptides.
H Inoue; M Hirobe
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Biochemical and biophysical research communications     Volume:  145     ISSN:  0006-291X     ISO Abbreviation:  Biochem. Biophys. Res. Commun.     Publication Date:  1987 May 
Date Detail:
Created Date:  1987-07-15     Completed Date:  1987-07-15     Revised Date:  2000-12-18    
Medline Journal Info:
Nlm Unique ID:  0372516     Medline TA:  Biochem Biophys Res Commun     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  596-603     Citation Subset:  IM    
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MeSH Terms
Amino Acids / analysis
Ascorbic Acid / pharmacology*
Catalase / pharmacology
Copper / pharmacology*
Oxygen / pharmacology*
Oxytocin / metabolism*
Protein Denaturation
Superoxide Dismutase / pharmacology
Reg. No./Substance:
0/Amino Acids; 0/Disulfides; 50-56-6/Oxytocin; 50-81-7/Ascorbic Acid; 7440-50-8/Copper; 7782-44-7/Oxygen; EC; EC Dismutase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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