Sok D E, Kim M R
Daejeon Machine Depot, Korea.
Biochem J. 1992 Jun 15;284 ( Pt 3)(Pt 3):641-3. doi: 10.1042/bj2840641.
A Zn(2+)-glycerophosphocholine cholinephosphodiesterase (EC 3.1.4.38) purified from mouse brain was found to be reversibly inhibited by tellurium tetrachloride. This effect was characterized by a competitive pattern of inhibition, with apparent Ki values of 0.7 microM and 1.5 microM for the hydrolysis of p-nitrophenylphosphocholine and glycerophosphocholine respectively. Interestingly, the inhibitory effect of tellurium tetrachloride was found to be greatly potentiated by tetramethylammonium salt, indicative of a synergistic interaction between the two compounds. Additionally, it was observed that the effect of tellurium tetrachloride was not affected by a number of other metal ions, and was more pronounced at neutral pH, suggesting that the inhibitory role of the tellurium tetrachloride may be of importance under physiological conditions. Thus Zn(2+)-glycerophosphocholine cholinephosphodiesterase is proposed to be one of the target enzymes which is susceptible to the inhibitory effect of tellurium tetrachloride.
从鼠脑中纯化得到的一种锌离子甘油磷酸胆碱胆碱磷酸二酯酶(EC 3.1.4.38)被发现可被四氯化碲可逆抑制。这种效应表现为竞争性抑制模式,对于对硝基苯基磷酸胆碱和甘油磷酸胆碱的水解,其表观抑制常数(Ki)分别为0.7微摩尔和1.5微摩尔。有趣的是,发现四氯化碲的抑制作用可被四甲基铵盐大大增强,这表明这两种化合物之间存在协同相互作用。此外,观察到四氯化碲的作用不受其他多种金属离子的影响,并且在中性pH条件下更为明显,这表明四氯化碲的抑制作用在生理条件下可能具有重要意义。因此,锌离子甘油磷酸胆碱胆碱磷酸二酯酶被认为是易受四氯化碲抑制作用影响的靶标酶之一。