Differences in the association of calmodulin with cyclic nucleotide phosphodiesterase in relaxed and contracted arterial strips.
Differences in the association of calmodulin with cyclic nucleotide phosphodiesterase in relaxed and contracted arterial strips.
复制标题
松弛和收缩动脉条中钙调蛋白与环核苷酸磷酸二酯酶的关联差异。
DOI：
10.1021/bi00328a007
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发表时间：
1985
期刊：
影响因子：
2.9
通讯作者：
Wells,JN
中科院分区：
文献类型：
--
作者：
Saitoh,Y;Hardman,JG;Wells,JN
田纳西州纳什维尔范德比尔特大学医学院药理系1984年8月27日收到摘要：细胞内钙离子浓度的变化被认为改变了完整细胞中钙调素敏感的环核苷酸磷酸二酯酶的活性。然而，这一假设是基于间接证据和对破碎细胞系统中酶活性的研究的类比。我们建立了一种方法来估计在完整的猪冠状动脉条中处于激活的乙二醇双(/3-氨基乙醚)-7V，Ar，7V，，7V‘-四乙酸(EGTA)状态的钙调素敏感的磷酸二酯酶的比例。实验方法包括将试条均质，并在延缓复合钙-钙调蛋白-磷酸二酯酶数量变化的条件下测定环鸟苷一磷酸(CGMP)磷酸二酯酶活性。我们的研究结果表明，不完整冠状动脉条中的环状GMP磷酸二酯酶确实与钙-钙调蛋白有关，改变完整冠状动脉条胞浆中钙离子浓度的干预措施改变了这种功能联系的程度。暴露于组胺(10或100ĩ)或50 mM KC1可引起收缩和EGTA敏感的环状GMP磷酸二酯酶活性增加。异丙肾上腺素引起的10ĩ组胺收缩的组织的松弛伴随着EGTA敏感的环状GMP磷酸二酯酶活性降低到收缩开始前的相同水平。
Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232 Received August 27, 1984 abstract: Changes in the concentration of cytosolic Ca2+ are assumed to alter the activity of Ca2+-calmodulin-sensitive cyclic nucleotide phosphodiesterase in intact cells. However, this assumption is based on indirect evidence and by analogy from studies of enzyme activitiesin broken cell systems. We have developed a procedure for estimating the fraction of Ca2+-calmodulin-sensitive phosphodiesterase that is in an activated, ethylene glycol bis (/3-aminoethyl ether)-7V, Ar, 7V,, 7V'-tetraacetic acid (EGTA) sensitive state in intact porcine coronary artery strips. The experimental approach involves homogenization of the strips and assay of cyclic guanosine monophosphate (cyclic GMP) phosphodiesterase activity under conditions that retard changes in the amount of the complex Ca2+-calmodulin-phosphodiesterase. Our findings indicate that cyclic GMP phosphodiesterase inintact coronary artery strips does associate with Ca2+-calmodulin and that interventions that change the concentration of Ca2+ in the cytosol of the intact strip change the extent of this functional association. Exposure to histamine (10 or 100 ĩ) or 50 mM KC1 caused contraction and an increase in EGTA-sensitive cyclic GMP phosphodiesterase activity. Isoproterenol-induced relaxation of tissues that had been caused to contract with 10 ĩ histamine was accompanied by a reduction in EGTA-sensitive cyclic GMP phosphodiesterase activity to the same level as that present before contraction was initiated.