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Activation by phospholipids of particulate mitochondrial ATPase from rat liver

Authors :
Federica Dabbeni-Sala
Alessandro Bruni
A. Pitotti
A.R. Contessa
Source :
Biochimica et Biophysica Acta (BBA) - Biomembranes. 274:528-535
Publication Year :
1972
Publisher :
Elsevier BV, 1972.

Abstract

1. 1. The activation by phospholipids of particulate mitochondrial ATPase from rat liver was studied on a preparation extracted from submitochondrial particles with cholate. 2. 2. Lysophosphatidylcholine and the highly acidic phospholipids diphosphatidylglycerol, phosphatidylinositol and phosphatidylserine stimulated the ATPase at low concentration (50–60 μg/mg protein); phosphatidylethanolamine was less effective whereas phosphatidylcholine exhibited the lowest activity. 3. 3. The saturation curves of phospholipids acting at low concentration showed in most cases a deviation from normal Michaelis-Menten kinetics. This devation was absent or less manifest with phosphatidylethanolamine and phosphatidylcholine. Competition between phospholipids and oligomycin was seen with acidic phospholipids or mixtures of neutral and acidic phospholipids. 4. 4. Similarly to oligomycin, dicyclohexylcarbodiimide, tributyltin and chlorpromazine competitively inhibited the activation produced by phosphatidylserine, phosphatidylinositol and diphosphatidylglycerol. 5. 5. It is concluded that both the hydrophobic-hydrophilic balance and the negative charge of phospholipids are important in the interaction between phospholipids and protein at the level of particulate mitochondrial ATPase. The competition between phospholipids and inhibitors of mitochondrial ATPase suggests that the activation induced by phospholipids is involved in the inhibitory effect.

Details

ISSN :
00052736
Volume :
274
Database :
OpenAIRE
Journal :
Biochimica et Biophysica Acta (BBA) - Biomembranes
Accession number :
edsair.doi.dedup.....3e41aa93923a7b19de75d78b6e41aa0d