title: On the mechanism of H+ translocation by mitochondrial H+ -ATPase. Studies with chemical modifier of tyrosine residues.
abstract: In this paper a detailed study of the effect of nitration of tyrosine residues by tetranitromethane on H+ conduction and other reactions catalyzed by the H+ -ATPase complex in phosphorylating submitochondrial particles, uncoupled particles, and the purified complex is presented. Tetranitromethane treatment of submitochondrial particles results in marked inhibition of ATP hydrolysis, ATP-33Pi exchange, and proton conduction by the H+ -ATPase complex. These effects are caused by nitration of tyrosine residues of H+ -ATPase complex as shown by the appearance of the absorption peak at 360 nm (specific for nitrotyrosine formation) and inhibition of ATP hydrolysis and ATP-33Pi exchange in the complex purified from tetranitromethane-treated particles. H+ conduction in phospholipid vesicles inlaid with F0 is also inhibited by tetranitromethane treatment. These observations indicate that tyrosine residue(s) of F0 are critically involved in energy-linked proton translocation in the ATP-ase complex.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D004734:Energy Metabolism; D066298:In Vitro Techniques; D008081:Liposomes; D008929:Mitochondria, Heart / Q000378:metabolism; D009840:Oligomycins / Q000494:pharmacology; D010710:Phosphates / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011522:Protons; D013367:Submitochondrial Particles / Q000378:metabolism*; D013774:Tetranitromethane / Q000494:pharmacology; D014443:Tyrosine
chemical_list: D008081:Liposomes; D009840:Oligomycins; D010710:Phosphates; D011522:Protons; D014443:Tyrosine; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D013774:Tetranitromethane