title: Inhibition of the ATPase activity of Escherichia coli ATP synthase by magnesium fluoride.
abstract: Inhibition of ATPase activity of Escherichia coli ATP synthase by magnesium fluoride (MgFx) was studied. Wild-type F(1)-ATPase was inhibited potently, albeit slowly, when incubated with MgCl(2), NaF, and NaADP. The combination of all three components was required. Reactivation of ATPase activity, after removal of unbound ligands, occurred with half-time of approximately 14 h at 22 degrees C and was quasi-irreversible at 4 degrees C. Mutant F(1)-ATPases, in which catalytic site residues involved in transition state formation were modified, were found to be resistant to inhibition by MgFx. The data demonstrate that MgFx in combination with MgADP behaves as a tight-binding transition state analog in E. coli ATP synthase.
authors.affiliation: Department of Biochemistry and Biophysics, Box 712, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: Zulfiqar
authors.initials: Z
authors.lastname: Ahmad
authors.forename: Alan E
authors.initials: AE
authors.lastname: Senior
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D020134:Catalytic Domain; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005459:Fluorides / Q000378:metabolism*; D008024:Ligands; D015636:Magnesium Chloride / Q000378:metabolism*; D017616:Magnesium Compounds / Q000378:metabolism*; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D008024:Ligands; D017616:Magnesium Compounds; D015636:Magnesium Chloride; C031288:magnesium fluoride; D000244:Adenosine Diphosphate; D006180:Proton-Translocating ATPases; D005459:Fluorides