Stimulation of the catalytic cycle of the Ca2+ pump of porcine plasma-membranes by negatively charged phospholipids.
Biochim Biophys Acta
; 1105(1): 118-24, 1992 Mar 23.
Article
em En
| MEDLINE
| ID: mdl-1314667
ABSTRACT
The (Ca(2+)+Mg2+)-ATPase of the plasma membrane is activated by negatively charged phospholipids. The mechanism of this activation was investigated by studying the effect of negatively charged phospholipids on the steady-state phosphointermediate level and on the p-nitrophenylphosphatase activity. Both parameters were differentially affected by different acidic phospholipids. The level of phosphoprotein intermediate was not affected by phosphatidylserine (20% of total phospholipid), but it was increased by 60% by phosphatidylinositol 4-phosphate. Phosphatidylserine increased the p-nitrophenylphosphatase activity, whereas phosphatidylinositol 4-phosphate had no significant effect. It is suggested that phosphatidylinositol 4-phosphate mainly affects a reaction step which leads to accelerated formation of the phosphointermediate, whereas the action of phosphatidylserine would affect two reaction steps, one upstream and one downstream of the phosphointermediate.
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Base de dados:
MEDLINE
Assunto principal:
Fosfolipídeos
/
ATPases Transportadoras de Cálcio
/
Membrana Eritrocítica
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
Bélgica