Ahmad Zulfiqar, Senior Alan E
Department of Biochemistry and Biophysics, Box 712, University of Rochester Medical Center, Rochester, NY 14642, USA.
FEBS Lett. 2006 Jan 23;580(2):517-20. doi: 10.1016/j.febslet.2005.12.057. Epub 2005 Dec 28.
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.
研究了氟化镁（MgFx）对大肠杆菌ATP合酶ATP酶活性的抑制作用。野生型F(1)-ATP酶在与MgCl(2)、NaF和NaADP一起孵育时，尽管抑制作用缓慢，但受到了强烈抑制。这三种成分都需要同时存在。去除未结合的配体后，ATP酶活性的重新激活在22℃下的半衰期约为14小时，而在4℃下几乎是不可逆的。发现其中参与过渡态形成的催化位点残基被修饰的突变型F(1)-ATP酶对MgFx的抑制具有抗性。数据表明，MgFx与MgADP结合时在大肠杆菌ATP合酶中表现为紧密结合的过渡态类似物。
