Sheng X R, Li X, Pan X M
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing, 100101, China.
J Biol Chem. 1999 Aug 6;274(32):22238-42. doi: 10.1074/jbc.274.32.22238.
An iso-random Bi Bi mechanism has been proposed for adenylate kinase. In this mechanism, one of the enzyme forms can bind the substrates MgATP and AMP, whereas the other form can bind the products MgADP and ADP. In a catalytic cycle, the conformational changes of the free enzyme and the ternary complexes are the rate-limiting steps. The AP(5)A inhibition equations derived from this mechanism show theoretically that AP(5)A acts as a competitive inhibitor for the forward reaction and a mixed noncompetitive inhibitor for the backward reaction.
有人提出腺苷酸激酶存在一种等随机双双机制。在该机制中，一种酶形式可结合底物MgATP和AMP，而另一种形式可结合产物MgADP和ADP。在催化循环中，游离酶和三元复合物的构象变化是限速步骤。从该机制推导得出的AP(5)A抑制方程从理论上表明，AP(5)A对正向反应起竞争性抑制剂作用，对逆向反应起混合型非竞争性抑制剂作用。
