猪大脑皮层中钙调蛋白敏感的磷酸二酯酶：动力学行为、钙调蛋白激活及稳定性

Calmodulin sensitive phosphodiesterase of porcine cerebral cortex: kinetic behavior, calmodulin activation, and stability.

作者信息

Keravis T M, Duemler B H, Wells J N

出版信息

J Cyclic Nucleotide Protein Phosphor Res. 1986;11(5):365-72.

Abstract

The calmodulin sensitive phosphodiesterase of porcine cerebral cortex was characterized in terms of kinetic behavior, calmodulin activation, and stability. This enzyme displayed non-Michaelis-Menten kinetics in the presence or absence of calmodulin. The apparent affinity for cyclic GMP was higher than that for cyclic AMP but at saturating levels of substrate, this enzyme catalyzed the hydrolysis of cyclic AMP at a greater rate than it did cyclic GMP. The affinity of this enzyme for calmodulin was about 20-fold lower than usually reported. The apparent loss of phosphodiesterase activity after storage was found to be due to a strong association with container surfaces and could be prevented or reversed by the presence of 0.1% Triton X-100.

摘要

对猪大脑皮层中钙调蛋白敏感的磷酸二酯酶进行了动力学行为、钙调蛋白激活和稳定性方面的表征。无论有无钙调蛋白，该酶均表现出非米氏动力学。其对环鸟苷酸（cGMP）的表观亲和力高于对环腺苷酸（cAMP）的亲和力，但在底物饱和水平时，该酶催化cAMP水解的速率高于cGMP。该酶对钙调蛋白的亲和力比通常报道的低约20倍。发现储存后磷酸二酯酶活性的明显丧失是由于与容器表面的强烈结合，而0.1% Triton X-100的存在可防止或逆转这种情况。