Document Detail


A study of the supposed hydroxylation of tyrosine catalysed by peroxidase.
MedLine Citation:
PMID:  1275895     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The claim that peroxidase (rather than tyrosinase) is the enzyme responsible for the conversion of tyrosine into dopa (3,4-dihydroxyphenylalanine) in melanogenesis was investigated. The spectral changes that occurred during the action of horseradish peroxidase in the presence of H2O2 on dopa, tyrosine and mixtures of dopa with tyrosine or other phenolic compounds were studied. The effect of ascorbic acid or dihydroxyfumaric acid on some of these changes was also investigated. No evidence was found that tyrosine was hydroxylated by peroxidase in the presence of H2O2 and dopa as cofactor, although tyrosine or other phenolic compounds increased the rate of oxidation of dopa to dopachrome (indoline-5,6-quinone-2-carboxylic acid). Peroxidase was, however, effective in oxidizing tyrosine to dopa in the presence of dihydroxyfumaric acid and oxygen.
Authors:
P I Smith; G A Swan
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Biochemical journal     Volume:  153     ISSN:  0264-6021     ISO Abbreviation:  Biochem. J.     Publication Date:  1976 Feb 
Date Detail:
Created Date:  1976-08-02     Completed Date:  1976-08-02     Revised Date:  2010-09-07    
Medline Journal Info:
Nlm Unique ID:  2984726R     Medline TA:  Biochem J     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  403-8     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Ascorbic Acid
Dihydroxyphenylalanine
Fumarates
Horseradish Peroxidase / metabolism*
Hydrogen Peroxide
Hydroxylation
Peroxidases / metabolism*
Phenols
Tyrosine / metabolism*
Chemical
Reg. No./Substance:
0/Fumarates; 0/Phenols; 50-81-7/Ascorbic Acid; 55520-40-6/Tyrosine; 63-84-3/Dihydroxyphenylalanine; 7722-84-1/Hydrogen Peroxide; EC 1.11.1.-/Horseradish Peroxidase; EC 1.11.1.-/Peroxidases
Comments/Corrections

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


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