Demonstration of the simultaneous activation of Ca2+-independent and Ca2+-dependent ATPases from rat skeletal muscle microsomes.
Biochim Biophys Acta
; 939(2): 409-15, 1988 Apr 07.
Article
em En
| MEDLINE
| ID: mdl-2965600
The activation of the Ca2+-independent (basal) ATPase from rat skeletal muscle microsomes is demonstrated in the presence of enough Ca2+ to provide the simultaneous activation of the (Ca2+ + Mg2+)-ATPase. It was achieved taking advantage of the delayed inorganic phosphate (Pi) release due to the formation of a phosphoenzyme complex during the Ca2+-dependent enzymatic cycle, which is evidenced in fast experiments. The microsomes were immobilized on a filter and perfused at constant flow with an incubation medium which was briefly interrupted with a pulse of appropriate reactants to activate the ATPases, at 2 degrees C. Successive samples were collected after passing through the filter, at approx. 0.1 s intervals. The Pi effluent profile coincides with the pattern of the pulse when it activates only the Ca2+-independent ATPase, it appears delayed when the pulse activates only extra Pi production by the (Ca2+ + Mg2+)-ATPase, and it includes a rapid and a delayed component when both Ca2+-independent and Ca2+-dependent ATPases are activated simultaneously by the pulse.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cálcio
/
ATPase de Ca(2/) e Mg(2/)
/
ATPases Transportadoras de Cálcio
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Adenosina Trifosfatases
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Músculos
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1988
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda