title: Dinitrophenol-stimulated adenosine triphosphatase activity in extracts of Desulfovibrio gigas.
abstract: A dinitrophenol (DNP)-stimulated adenosine triphosphatase (ATPase) has been found in both the soluble and particulate fractions of the anaerobic sulfate-reducing bacterium, Desulfovibrio gigas. As the soluble ATPase was labile to storage, only the particulate enzyme was studied in detail. It was optimally stimulated by DNP at 4 mm, and activity was insensitive to inhibition by ouabain. The ATPase was stimulated by both Ca(2+) and Mg(2+), but the magnitude of the stimulation was dependent upon pH. In the presence of Ca(2+) the optimum pH was 6.5, whereas, in the presence of Mg(2+) the pH optimum was 8.0. However, under optimal conditions the activity was the same with either Mg(2+) or Ca(2+). Both adenosine triphosphate and guanosine triphosphate were hydrolyzed, but activity toward guanosine triphosphate was only one-tenth that observed with adenosine triphosphate.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis; D002118:Calcium / Q000494:pharmacology; D002474:Cell-Free System; D002854:Chromatography, Paper; D003470:Culture Media; D003901:Desulfovibrio / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004140:Dinitrophenols / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008274:Magnesium / Q000494:pharmacology; D009705:Nucleosides / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D010085:Oxidative Phosphorylation; D013268:Stimulation, Chemical; D014461:Ultracentrifugation
chemical_list: D003470:Culture Media; D004140:Dinitrophenols; D009705:Nucleosides; D010042:Ouabain; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium