Simantov R, Nadler H, Levy R
Eur J Biochem. 1982 Nov 15;128(2-3):461-6. doi: 10.1111/j.1432-1033.1982.tb06987.x.
Three clones of neuroblastoma-glioma cells that contain low amounts of calmodulin were selected from the NG108-15 cells after several treatments with high concentrations of chlorpromazine. Purified membranes of the three clones had decreased numbers of both alpha-adrenergic and opiate receptors, monitored with [3H]yohimbine and [3H,D-Ala2]methionine encephalinamide, respectively. No changes were observed in the affinity of these radioactive ligands to the receptors of the selected cells as compared to the parent cells. Addition of bovine brain calmodulin did not affect the binding of [3H,D-Ala2]methionine encephalinamide to the membranes of the selected cells and they had the same number of acetylcholine receptors, determined with 1-quinuclidinyl-[phenyl-4-3H]-benzilate, as the parent NG108-15 cells. The basal ATPase activity in the membranes of the selected cells was 35-50% of the parent cells, with a decreased V value and no significant change in the affinity constant Ka to ATP. Addition of Ca2+ to the purified membranes increased the V of the ATPase in the selected as well as the parent cells but the V of the selected cells remained lower than that of the parent cells. Ca2+ had no effect on the Ka to ATP in either cell type. The Ca2+-dependent ATPase activity of both the parent and the selected cells was also calmodulin-dependent dependent since it was blocked in vitro by chlorpromazine. The co-regulation of opiate and adrenergic receptors and their interaction with calmodulin and Ca2+-ATPase is discussed in view of recent observations indicating biochemical and physiological association between opiates, Ca2+ and adrenergic compounds.
在用高浓度氯丙嗪多次处理后，从NG108 - 15细胞中筛选出三个钙调蛋白含量低的神经母细胞瘤 - 胶质瘤细胞克隆。分别用[³H]育亨宾和[³H，D - Ala²]甲硫氨酸脑啡肽酰胺监测，这三个克隆的纯化膜中α - 肾上腺素能受体和阿片受体的数量均减少。与亲代细胞相比，未观察到这些放射性配体与所选细胞受体的亲和力有变化。添加牛脑钙调蛋白不影响[³H，D - Ala²]甲硫氨酸脑啡肽酰胺与所选细胞的膜结合，并且它们具有与亲代NG108 - 15细胞相同数量的乙酰胆碱受体，用1 - 喹核啶基 - [苯基 - 4 - ³H] - 苄酯测定。所选细胞的膜中基础ATP酶活性为亲代细胞的35 - 50%，V值降低，对ATP的亲和力常数Ka无显著变化。向纯化膜中添加Ca²⁺会增加所选细胞和亲代细胞中ATP酶的V，但所选细胞的V仍低于亲代细胞。Ca²⁺对两种细胞类型中ATP的Ka均无影响。亲代细胞和所选细胞的Ca²⁺依赖性ATP酶活性也依赖于钙调蛋白，因为它在体外被氯丙嗪阻断。鉴于最近的观察结果表明阿片类药物、Ca²⁺和肾上腺素能化合物之间存在生化和生理关联，讨论了阿片受体和肾上腺素能受体的共同调节及其与钙调蛋白和Ca²⁺ - ATP酶的相互作用。
