Mitochondrial H+-ATPase activation by an amine oxide detergent.
Lauryl dimethylamine oxide activates ATP hydrolysis by the mitochondrial H+-ATPase. Activation is observed in systems with a high content of inhibitor protein as described by Pullman and Monroy (Pullman, M.E., and Monroy, G.C. (1963) J. Biol. Chem. 238, 3762-3769), i.e. Mg-ATP submitochondrial particles and a Triton X-100-solubilized H+-ATPase from the same particles. Detergent activation of ATP hydrolysis is also present in inhibitor-reconstituted systems, i.e. submitochondrial particles, Triton extracts, and soluble F1-ATPase. In submitochondrial particles depleted of inhibitor protein, lauryl dimethylamine oxide induced a biphasic response which is characterized by a drop-in activity induced by relatively low concentrations of LDAO; at higher concentrations the detergent activates to an extent never greater than the initial activity. In inhibitor protein-depleted oligomycin-sensitive Triton extracts, lauryl dimethylamine oxide stimulates ATP hydrolysis to very high values (30 mumol min-1 mg-1). These findings suggest that in addition to the inhibitor protein ATP hydrolysis is controlled by other subunit interactions.
Vázquez-Laslop
N
N
Dreyfus
G
G
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D003902:Detergents / Q000494:pharmacology*; D004123:Dimethylamines / Q000494:pharmacology*; D004789:Enzyme Activation; D007700:Kinetics; D008929:Mitochondria, Heart / Q000201:enzymology*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D013367:Submitochondrial Particles / Q000201:enzymology; D013501:Surface-Active Agents / Q000494:pharmacology*
D003902:Detergents; D004123:Dimethylamines; D013501:Surface-Active Agents; C014518:dodecyldimethylamine oxide; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases