Some properties of membrane-bound, solubilized and reconstituted into liposomes H+-ATPase of vacuoles of Saccharomyces carlsbergensis.
Vacuoles of yeast grown in peptone medium possessed high ATPase activity (up to 1 mumol X mg protein-1 X min-1). Membrane-bound and solubilized ATPase activities were insensitive to vanadate and azide, but were inhibited by NO-3 . K+ and cyclic AMP stimulated both membrane-bound and solubilized ATPase activities. Dio-9 activated the membrane form of vacuolar ATPase 1.5-2-fold and did not affect the solubilized enzyme. Solubilized and partially purified vacuolar ATPase was reconstituted with soy-bean phospholipids by a freeze-thaw procedure. ATPase activities in native vacuoles and proteoliposomes were stimulated effectively by Dio-9, the protonophore FCCP and ionophores valinomycin and nigericin. ATP-dependent H+ transport into proteoliposomes was also shown by quenching of ACMA fluorescence. Vacuolar and partially purified ATPase preparations possessed also GTPase activity. Unlike ATPase, however, GTPase was not incorporated as a proton pump into liposomes.
D001693:Biological Transport, Active; D002462:Cell Membrane / Q000201:enzymology; D002463:Cell Membrane Permeability; D004563:Electrochemistry; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000378:metabolism; D008081:Liposomes; D009930:Organic Chemicals; D009940:Organoids / Q000201:enzymology*; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011522:Protons; D012440:Saccharomyces / Q000201:enzymology*; D014475:Uncoupling Agents / Q000494:pharmacology; D014617:Vacuoles / Q000201:enzymology*
D007473:Ion Channels; D008081:Liposomes; D009930:Organic Chemicals; D011522:Protons; D014475:Uncoupling Agents; C100056:DIO 9; D020558:GTP Phosphohydrolases; D006180:Proton-Translocating ATPases