Mao Hui Z, Gray Wesley D, Weber Joachim
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA.
FEBS Lett. 2006 Jul 24;580(17):4131-5. doi: 10.1016/j.febslet.2006.06.059. Epub 2006 Jun 30.
During ATP synthesis, ATP synthase has to bind MgADP in the presence of an excess of MgATP. Thus, for efficient ATP synthesis it would be desirable if incoming substrate could be bound to a catalytic site with a preference for MgADP over MgATP. We tested three hypotheses predicting the existence of such a site. However, our results showed that, at least in absence of an electrochemical proton gradient, none of the three catalytic sites has a higher affinity for MgADP than for MgATP.
在ATP合成过程中,ATP合酶必须在过量的MgATP存在的情况下结合MgADP。因此,为了实现高效的ATP合成,如果进入的底物能够优先于MgATP结合到对MgADP具有偏好性的催化位点上,那将是很理想的。我们测试了三个预测此类位点存在的假设。然而,我们的结果表明,至少在没有电化学质子梯度的情况下,三个催化位点中没有一个对MgADP的亲和力高于对MgATP的亲和力。