title: Vanadate and dicyclohexylcarbodiimide insensitive proton extrusion from oxygen pulsed cells of the cyanobacterium Anacystis nidulans.
abstract: Oxygen pulses applied to dark anaerobic suspensions of Anacystis nidulans provoked immediate acidification of the external medium. The reaction was inhibited only 75% by dicyclohexylcarbodiimide and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole at concentrations which completely arrested all oxidative phosphorylation. Carbonyl cyanide m-chlorophenylhydrazone eliminated the acidification of oxygen pulsed cell suspensions while ortho-vanadate and diethylstilbestrol had no effect. No lag occurred between the onset of respiration and proton extrusion. H+/O ratios were 4.1 +/- 0.5 in the absence, and 1.9 +/- 0.4 in the presence, of dicyclohexylcarbodiimide. These results are consistent with a recently described proton-translocating aa3-type cytochrome c oxidase (H+/O = 1.6 +/- 0.4) in the cell membrane of A. nidulans (G.A. Peschek, J. Bacteriol. 153 (1983) 539-542).
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D002234:Carbodiimides / Q000494:pharmacology*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D000458:Cyanobacteria / Q000187:drug effects / Q000378:metabolism*; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010101:Oxygen Consumption / Q000187:drug effects*; D014638:Vanadates; D014639:Vanadium / Q000494:pharmacology*
chemical_list: D002234:Carbodiimides; D014639:Vanadium; D014638:Vanadates; D004024:Dicyclohexylcarbodiimide; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone