Hammes G G
Proc Natl Acad Sci U S A. 1982 Nov;79(22):6881-4. doi: 10.1073/pnas.79.22.6881.
A mechanism is proposed for the coupling between ion transport and enzyme catalysis. The basic concept is that enzymes associated with transport exist in two possible conformations. Each conformation has the potential of catalyzing the enzymatic reaction, and pumping is associated with the conversion of one conformational form to the other. The conformational transition is triggered by the kinetic blockage of specific mechanistic steps for each conformation. Such blockages can cause a cycling between the two conformations concomitant with catalysis. This mechanistic concept is consistent with a variety of results obtained with the Na+,K+-ATPase, the Ca2+,Mg2+-ATPase, and ATP synthesizing enzymes (coupling factors).
提出了一种离子转运与酶催化偶联的机制。基本概念是,与转运相关的酶存在两种可能的构象。每种构象都有催化酶促反应的潜力,而泵浦作用与一种构象形式向另一种构象形式的转变相关。构象转变由每种构象特定机制步骤的动力学阻碍触发。这种阻碍可导致两种构象之间伴随催化作用的循环。这一机制概念与通过钠钾ATP酶、钙镁ATP酶和ATP合成酶(偶联因子)获得的各种结果一致。