Zinc inhibition of pyruvate kinase of M-type isozyme.
Biometals
; 30(3): 335-340, 2017 06.
Article
em En
| MEDLINE
| ID: mdl-28293755
ABSTRACT
Inhibitory effect of Zn on the pyruvate kinase of M (muscle)-type isozyme was analyzed for the purpose of elucidating the cytotoxicity of Zn. Zn inhibited pyruvate kinase uncompetitively with respect to the substrate PEP, and competitively with respect to ADP. Quotient velocity plot calculated from the Zn-inhibition curves showed that Zn2+ as a ZnADP complex acted as competitive and uncompetitive inhibitors of the enzyme with respect to the substrate ADP and PEP, respectively Zn2+ forms a ZnADP complex, which may bind to the ADP-binding site of the free enzyme with the Ki value of 1.4 µM causing competitive inhibition, or to the ADP-site of the enzyme-PEP complex with 2.6 µM resulting in uncompetitive inhibition. The inhibition of pyruvate kinase by Zn2+ may be responsible for the cytotoxicity of this metal by decreasing glycolytic flux.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Piruvato Quinase
/
Zinco
/
Inibidores Enzimáticos
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article