Characterization of a synaptosomal ATP diphosphohydrolase from the electric organ of Torpedo marmorata.
Brain Res Bull
; 26(6): 871-6, 1991 Jun.
Article
em En
| MEDLINE
| ID: mdl-1933407
ABSTRACT
A true ecto-apyrase (ATP diphosphohydrolase, EC 3.6.1.5) enzyme was found in the synaptosomal fraction from the electric organ of the electric ray Torpedo marmorata. The activity could not be attributed to the combined action of different enzymes. The pH requirement and calcium dependence were the same for hydrolysis of both substrates ADP and ATP. The enzyme had an apparent Km value of 117 microM for ATP and of 123 microM for ADP. The involvement of nonspecific phosphatases in the hydrolysis of both substrates was excluded. The enzyme hydrolyses almost equally well different nucleoside di- and triphosphates. ATP and ADP hydrolysis was not inhibited by seven ATPase inhibitors, i.e., sodium azide, dinitrophenol, ruthenium red, oligomycin, ouabain, sodium orthovanadate and lanthanum.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apirase
/
Sinaptossomos
/
Órgão Elétrico
Limite:
Animals
Idioma:
En
Revista:
Brain Res Bull
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
Brasil