Neurohypophyseal hormone-responsive renal adenylate cyclase. I. General characteristics of the neurohypophyseal hormone-sensitive adenylate cyclase in bovine renal medullary membranes prepared using a double phase polymer system.
Neurohypophyseal hormone-responsive renal adenylate cyclase. I. General characteristics of the neurohypophyseal hormone-sensitive adenylate cyclase in bovine renal medullary membranes prepared using a double phase polymer system.
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神经垂体激素反应性肾腺苷酸环化酶。
DOI：
10.1016/s0021-9258(17)40825-8
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
O. Hechter
中科院分区：
文献类型：
--
作者：
T. Nakahara;S. Terada;J. Pincus;G. Flouret;O. Hechter
采用聚乙二醇-葡聚糖双相聚合物体系制备了部分纯化的牛肾髓质膜组分。由此获得的膜颗粒在神经垂体激素（NHH）敏感腺苷酸环化酶活性上富集约低倍；从初始匀浆中恢复激素敏感环化酶活性从1.5%到35%不等。膜制剂不能检测到降解[“ HI [lysr -加压素（LVP）]或[”催产素COT]。实验条件设计为最大化NHH应答腺苷酸环化酶活性与基础活性之比（NHH/基础），最小化基础腺苷酸环化酶活性。发现腺苷酸环化酶对NHH的敏感性和反应性严重依赖于pH和EDTA，以及镁和ATP的浓度；添加电解质或GTP同样影响对NHH的敏感性和反应性。使用含有2.0 mM MgCI， 1.4 mM EDTA和100 FM ATP的标准检测培养基，在pH 8.0或8.5下获得最大的肽亲和力和高NHH/基础比率。在7种制剂中，平均NHH/基础比值为14.3 ~ 2.4 6。d .);nhh特异性腺苷酸环化酶的平均比活性为700 f 310 (SD.) pmol /IO min/mg膜蛋白。腺苷酸环化酶（K, 1）的半最大激活所需的乙酰氨基加压素（AVP）的浓度为7 × - 1 μ M；在一些牛膜制剂中，AVP在生理浓度为- 1 μ M时表现出明显的刺激作用。在标准试验中检查了一组NHH对牛肾髓质腺苷酸环化酶的激活的明显亲和力，发现具有这种亲和力
A partially purified plasma membrane fraction from bovine renal medulla was prepared using a polyethylene glycol (PEG)-dextran double phase polymer system. The membrane particles thus obtained are enriched about lo-fold in neurohypophyseal hormone (NHH)-sensitive adenylate cyclase activity; t, he recovery of hormone-sensitive cyclase activity from the initial homogenate varied from 1.5 to 35%. The membrane preparation does not detectably degrade [“HI [LysRlvasopressin (LVP) or [“Hloxytocin COT). Assay conditions were designed to maximize the ratio of NHH-responsive adenylate cyclase activity to basal activity (NHH/basal) and to minimize basal adenylate cyclase act, ivity. The sensitivity and responsiveness of adenylate cyclase to NHH was found to be critically dependent on pH and EDTA, as well as the concentrations of magnesium and ATP; addition of electrolytes or GTP likewise influenced sensitivity and responsiveness to NHH. Maximal peptide affinity and high NHH/basal ratios were obtained using a standard assay medium containing 2.0 mM MgCI,, 1.4 mM EDTA, and 100 FM ATP at pH 8.0 or 8.5. In seven preparations, the mean NHH/basal ratios were 14.3 f 2.4 6. D.); the mean specific activity of NHH-specific adenylate cyclase was 700 f 310 (SD.) pmol of CAMP/IO min/mg of membrane protein.The concentration of [ArgYlvasopressin(AVP) required for half-maximal activation of adenylate cyclase (K, 1 was 7 x lo-“’M; in some bovine membrane preparations, AVP exhibited clear stimulatory effects at physiological concentrations of lo-” M. The apparent affinities of a set of NHH for activation of bovine renal medullary adenylate cyclase were examined in the standard assay and found to have the