Hepatic microsomal Ca2+-dependent ATPase. Calmodulin-dependence and partial purification.
Hepatic microsomal Ca2+-dependent ATPase. Calmodulin-dependence and partial purification.
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肝微粒体 Ca2 依赖性 ATP 酶。
DOI：
10.1042/bj2140069
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Kraus-Friedmann,N
中科院分区：
文献类型：
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作者：
Moore,PB;Kraus-Friedmann,N
亲和层析显示，肝微粒体部分含有紧密结合的钙调蛋白。当EGTA处理（0.5 mM-EGTA）部分去除该钙调素时，添加的钙调素刺激微粒体囊泡对45Ca2+的摄取，并被三氟拉嗪（TFP）抑制。Ca2+依赖性atp酶在钙调蛋白柱上部分纯化。当在添加钙调素的情况下测量时，这种部分纯化导致酶的比活性增加了500倍。针对钙调素制备的抗体阻止了这种刺激作用。从钙调素柱洗脱的部分含有几个蛋白质带，表明Ca2+依赖性atp酶的特定活性可能仍然被低估。肝微粒体部分可能存在其他钙调素敏感过程。
The hepatic microsomal fraction contains tightly bound calmodulin as demonstrated by affinity chromatography. When this calmodulin was partially removed by EGTA treatment (0.5 mM-EGTA), the uptake of 45Ca2+ by the microsomal vesicles was stimulated by added calmodulin and inhibited by trifluoperazine (TFP). The Ca2+-dependent ATPase was partially purified on a calmodulin column. This partial purification resulted in a 500-fold increase in the specific activity of the enzyme when measured in the presence of added calmodulin. Antibodies prepared against calmodulin prevented this stimulatory effect. The fraction eluted from the calmodulin column contained several protein bands indicating that the specific activity of the Ca2+-dependent ATPase is probably still underestimated. There are likely to be other calmodulin-sensitive processes present in the hepatic microsomal fraction.