Terasaki W L, Appleman M M
Metabolism. 1975 Mar;24(3):311-9. doi: 10.1016/0026-0495(75)90112-2.
A rat-heart cyclic nucleotide phosphodiesterase has been chromatographically separated from related enzymes and its kinetic properties have been studied. The enzyme can hydrolyze both cyclic AMP and cyclic GMP and has about the same maximum velocity and apparent KM (greater than 10-5 M) for the two nucleotides. Kinetic plots indicate positive cooperative behavior for both substrates. Cyclic GMP at low concentrations is a potent activator of cyclic AMP hydrolysis and this activation, as well as the cooperativity, can be abolished by treatment with solvents or sulfydryl reagents under conditions which do not destroy the catalytic function. A kinetic model for this enzyme is porposed and the physiologic role is discussed.
一种大鼠心脏环核苷酸磷酸二酯酶已通过色谱法与相关酶分离，并对其动力学特性进行了研究。该酶能水解环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP），对这两种核苷酸的最大反应速度和表观米氏常数（大于10⁻⁵M）大致相同。动力学曲线表明两种底物均呈现正协同行为。低浓度的cGMP是cAMP水解的有效激活剂，在不破坏催化功能的条件下，用溶剂或巯基试剂处理可消除这种激活作用以及协同性。提出了该酶的动力学模型并讨论了其生理作用。
