Hinds T R, Raess B U, Vincenzi F F
J Membr Biol. 1981 Jan 30;58(1):57-65. doi: 10.1007/BF01871034.
Inside-out vesicles prepared from human red blood cells took up Ca2+ by an active transport process. Membranes from the same red blood cells displayed Ca2+-activated, Mg2+-dependent adenosine triphosphatase activity. Both the initial rate of Ca2+ transport and the (Ca2+ + Mg2+)-adenosine triphosphatase activity were increased approximately twofold by the calcium binding protein, calmodulin. Activities in the absence of added calmodulin were termed basal activities. Calmodulin-activated Ca2+ transport and adenosine triphosphatase activities could be antagonized in a relatively selective fashion by the phenothiazine tranquilizer drug, trifluoperazine. High concentrations of trifluoperazine also inhibited basal Ca2+ transport and adenosine triphosphatase activity. By contrast, calmodulin binding protein from beef brain selectively antagonized the effect of calmodulin on Ca2+ transport with no inhibition of basal activity. Ruthenium red antagonized calmodulin-activated and basal activity with equal potency. The results demonstrate that although phenothiazines can act as relatively selective antagonists of calmodulin-induced effects, other effects are possible and cannot be ignored. Calmodulin-binding protein may be a useful tool in the analysis of calmodulin functions. Ruthenium red probably interacts with Ca2+ pump adenosine triphosphatase at a site not related to calmodulin.
由人红细胞制备的外翻小泡通过主动转运过程摄取Ca2+。来自相同红细胞的膜显示出Ca2+激活的、Mg2+依赖的三磷酸腺苷酶活性。钙结合蛋白钙调蛋白使Ca2+转运的初始速率和（Ca2+ + Mg2+）-三磷酸腺苷酶活性均增加了约两倍。在不添加钙调蛋白的情况下的活性称为基础活性。钙调蛋白激活的Ca2+转运和三磷酸腺苷酶活性可被吩噻嗪类镇静药物三氟拉嗪以相对选择性的方式拮抗。高浓度的三氟拉嗪也抑制基础Ca2+转运和三磷酸腺苷酶活性。相比之下，来自牛脑的钙调蛋白结合蛋白选择性地拮抗钙调蛋白对Ca2+转运的作用，而不抑制基础活性。钌红以同等效力拮抗钙调蛋白激活的活性和基础活性。结果表明，尽管吩噻嗪类药物可作为钙调蛋白诱导效应的相对选择性拮抗剂，但其他效应也是可能的且不能被忽视。钙调蛋白结合蛋白可能是分析钙调蛋白功能的有用工具。钌红可能在与钙调蛋白无关的位点与Ca2+泵三磷酸腺苷酶相互作用。
