Evidence for a latent form of protein phosphatase 1 associated with cardiac myofibrils.
Evidence for a latent form of protein phosphatase 1 associated with cardiac myofibrils.
复制标题
潜在形式的蛋白磷酸酶 1 与心肌原纤维相关的证据。
DOI：
10.1016/0006-291x(89)92406-6
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发表时间：
1989
影响因子：
3.1
通讯作者：
Wilson,SE
中科院分区：
文献类型：
--
作者：
Schlender,KK;Wang,W;Wilson,SE
用清洁剂纯化的牛心脏肌原纤维含有很少的自发活性蛋白磷酸酶1活性。从肌原纤维中提取的磷酸酶1，在500 mM氯化钾存在下冷冻解冻，钴/胰蛋白酶处理显著激活。用肝素- sepharose层析法将肌原纤维磷酸酶1与磷酸酶2A分离。以潜伏形式分离出磷酸酶1。胰蛋白酶预处理可释放游离催化亚基，使活性提高约25倍。在胰蛋白酶中加入钴后，活性又增加了2倍。潜伏的肌原纤维磷酸酶1似乎与先前表征的蛋白磷酸酶1不同。我们认为心肌肌原纤维磷酸酶1含有一个独特的抑制亚基，该亚基将酶导向肌原纤维并调节肌原纤维磷酸化蛋白的去磷酸化。
Detergent-purified myofibrils from bovine heart contained very little spontaneously active protein phosphatase 1 activity. Phosphatase 1, extracted from the myofibrils by freeze-thawing in the presence of 500 mM KCl, was markedly activated by cobalt/trypsin treatment. Myofibril phosphatase 1 was separated from phosphatase 2A by chromatography on heparin-Sepharose. The phosphatase 1 was isolated in a latent form. Pretreatment with trypsin released free catalytic subunit and increased activity about 25-fold. Addition of cobalt with the trypsin increased activity another 2-fold. The latent myofibril phosphatase 1 did not appear to be the same as previously characterized forms of protein phosphatase 1. We suggest that cardiac myofibril phosphatase 1 contains a unique inhibitory subunit which directs the enzyme to the myofibril and regulates the dephosphorylation of myofibril phosphoproteins.