Determination of monoamine oxidase concentrations in rat liver by inhibitor binding.
Biochem Pharmacol
; 35(24): 4467-72, 1986 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-3790166
ABSTRACT
The concentrations of monoamine oxidase-A and -B have been determined in mitochondria, mitochondrial outer membranes and microsomes from Sprague-Dawley and Wistar rats by determining the binding of tritium-labelled pargyline. Although the amounts of each form present depended on the source and the preparation method, this was paralleled by the specific activity such that the molecular turnover number was found to remain constant. The catalytic constants, kcat/Km, which represents the apparent second-order rate constant for the combination of enzyme and substrate, were about 0.13 and 2.1 sec-1 X microM-1 for 5-hydroxytryptamine and 2-phenethylamine, respectively, regardless of the source. Estimations of the amounts of the two forms by determining the concentrations of the inhibitors clorgyline, (-)-deprenyl, J-508 or pargyline necessary to give complete inhibition were shown to give overestimates of the true values because of the non-specific binding of these inhibitors to sites other than the monoamine oxidase active site.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fígado
/
Monoaminoxidase
/
Inibidores da Monoaminoxidase
Limite:
Animals
Idioma:
En
Revista:
Biochem Pharmacol
Ano de publicação:
1986
Tipo de documento:
Article