大鼠组织中的多种环核苷酸磷酸二酯酶活性以及钙镁离子依赖性磷酸二酯酶及其蛋白质激活剂的存在情况。

Multiple cyclic nucleotide phosphodiesterase activities from rat tissues and occurrence of a calcium-plus-magnesium-ion-dependent phosphodiesterase and its protein activator.

Kakiuchi S, Yamazaki R, Teshima Y, Uenishi K, Miyamoto E

Biochem J. 1975 Jan;146(1):109-20. doi: 10.1042/bj1460109.

Abstract

Supernatant fluids from rat cerebral cortex, cerebellum, kidney, heart and liver contained more phosphodiesterase activity hydrolysing cyclic GMP than that hydrolysing cyclic AMP when assayed with sub-saturating concentrations of substrate. 2. These activities were resolved into several fractions by Sephadex G-200 gel filtration; no two tissues had similar activity profiles. 3. With every tissue examined, a fraction (fraction II) with a molecular weight of about 150,000 was obtained which hydrolysed cyclic GMP preferentially at sub-saturating substrate concentrations in the presence of micromolar concentration of Ca2+, millimolar concentration of Mg2+ and a protein activator. 4. The activity of fraction II accounted for about 60 percent in liver, more than 80 percent in heart and cerebellum, and almost 100 percent in cerebral cortex of the total activity for cyclic GMP hydrolysis, calculated from the activity profiles. 5. Km values of fraction II samples from kidney, heart and liver for cyclic GMP were 1.3, 1.7 and 5 muM respectively. 6. 3-Isobutyl-1-methylxanthine inhibited hydrolysis of cyclic GMP by fraction II with an I50 value of 3muM for heart and liver and 50 muM for cerebrum. 7. The activator protein, with an estimated molecular weight of about 30,000 was isolated from all the tissues listed in 1.8. The concentrations of activator protein and of the isolated enzyme, fraction II, did not correspond exactly.

摘要

当用亚饱和浓度的底物进行测定时，大鼠大脑皮层、小脑、肾脏、心脏和肝脏的上清液中，水解环鸟苷酸（cGMP）的磷酸二酯酶活性高于水解环腺苷酸（cAMP）的活性。2. 通过葡聚糖G - 200凝胶过滤将这些活性分离成几个组分；没有两个组织具有相似的活性谱。3. 在所检查的每个组织中，都获得了一个分子量约为150,000的组分（组分II），在微摩尔浓度的Ca2 +、毫摩尔浓度的Mg2 +和一种蛋白质激活剂存在下，该组分在亚饱和底物浓度下优先水解cGMP。4. 根据活性谱计算，组分II的活性在肝脏中约占总cGMP水解活性的60％，在心脏和小脑中超过80％，在大脑皮层中几乎占100％。5. 来自肾脏、心脏和肝脏的组分II样品对cGMP的Km值分别为1.3、1.7和5μM。6. 3 - 异丁基 - 1 - 甲基黄嘌呤抑制组分II对cGMP的水解，对心脏和肝脏的I50值为3μM，对大脑为50μM。7. 从1中列出的所有组织中分离出估计分子量约为30,000的激活蛋白。8. 激活蛋白和分离出的酶（组分II）的浓度并不完全对应。