title: Nitric oxide-dependent proton translocation in various denitrifiers.
abstract: Respiration of NO resulted in transient proton translocation in anaerobically grown cells of four physiologically diverse denitrifiers. Paracoccus denitrificans, Rhodopseudomonas sphaeroides subsp. denitrificans, "Achromobacter cycloclastes," and Rhizobium japonicum gave, respectively, H+/NO ratios of 3.65, 4.96, 1.94, and 1.12. Antimycin A completely inhibited NO-dependent proton translocation in P. denitrificans and severely restricted translocation in the R. sphaeroides strain. Proton uptake during NO respiration with antimycin A-inhibited cells supplied with an artificial electron source provided evidence for the periplasmic consumption of protons. Values obtained were consistent with the expected ratios of 0.5 mol of H+/mol of NO for reduction of NO to N2O and 1.0 mol of H+/mol of NO for reduction of NO to N2. These data are consistent with the presence of a unique NO reductase found only in anaerobically grown denitrifying cells.
mesh_terms: D000421:Alcaligenes / Q000378:metabolism*; D000693:Anaerobiosis; D000968:Antimycin A / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002256:Carbonic Anhydrases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009569:Nitric Oxide / Q000378:metabolism*; D010231:Paracoccus denitrificans / Q000378:metabolism*; D012231:Rhizobium / Q000378:metabolism*; D012242:Rhodobacter sphaeroides / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D009569:Nitric Oxide; D000968:Antimycin A; D002256:Carbonic Anhydrases