Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/195247
Type: Artigo de periódico
Title: Inhibition Of Bovine Kidney Low Molecular Mass Phosphotyrosine Protein Phosphatase By Uric Acid.
Author: Granjeiro, José Mauro
Ferreira, Carmen Verissima
Granjeiro, Paulo Afonso
Da Silva, Cinthia Celestino
Taga, Eulázio Mikio
Volpe, Pedro Luiz Onofre
Aoyama, Hiroshi
Abstract: Uric acid inhibited 50% of the activity of bovine kidney low molecular mass phosphotyrosine protein phosphatase at concentrations of 1.0, 0.4, 1.3, and 0.2 mM, respectively for p-nitrophenyl phosphate (p-NPP), flavine mononucleotide, beta-naphthyl phosphate and tyrosine phosphate (Tyr-P) as substrates. The mixed type inhibition of p-NPP hydrolysis was fully reversible, with Kic and Kiu values of 0.4 and 1.1 mM, respectively; the inhibition by uric acid shifted the pH optimum from 5.0 to 6.5. When Tyr-P was the substrate, competitive inhibition was observed with a Ki value of 0.05 mM. Inhibition studies by uric acid in the presence of thiol compounds, and preincubation studies in the presence of inorganic phosphate suggest that the interaction of uric acid with the enzyme occurred at the active site, but did not involve SH residues, and that the mechanism of inhibition depended on the structure of the substrates.
Subject: Animals
Binding Sites
Binding, Competitive
Cattle
Enzyme Inhibitors
Flavin Mononucleotide
Kidney
Kinetics
Naphthalenes
Nitrophenols
Organophosphates
Organophosphorus Compounds
Phosphates
Protein Tyrosine Phosphatases
Substrate Specificity
Sulfhydryl Compounds
Tyrosine
Uric Acid
Rights: fechado
Identifier DOI: 10.1080/1475636021000013939
Address: http://www.ncbi.nlm.nih.gov/pubmed/12683751
Date Issue: 2002
Appears in Collections:Unicamp - Artigos e Outros Documentos

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