Kranias E G, Schwartz A, Jungmann R A
Biochim Biophys Acta. 1982 Dec 6;709(1):28-37. doi: 10.1016/0167-4838(82)90417-4.
Canine cardiac sarcoplasmic reticulum vesicles contain intrinsic cAMP-dependent and Ca2+ -calmodulin-dependent protein kinase (EC 2.7.1.37) activities and a common substrate, phospholamban, for these enzymes. Cyclic AMP-dependent protein kinase associated with sarcoplasmic reticulum membranes was solubilized with Triton X-100. Solubilization of the sarcoplasmic reticulum protein kinase did not affect its dependency on cAMP or its substrate specificity. The solubilized cAMP-dependent protein kinase was purified by DEAE-cellulose chromatography and was characterized as a type II enzyme on the basis of its elution at high ionic strength. DEAE-purified cAMP-dependent protein kinase exhibited no Ca2+ -calmodulin-dependent protein kinase activity. Cytosol from canine cardiac muscle cells, chromatographed on DEAE-cellulose under conditions identical to those used with sarcoplasmic reticulum, exhibited the presence of both type I and type II cAMP-dependent protein kinase isozymes. The properties of the DEAE-cellulose purified type II protein kinases from sarcoplasmic reticulum and cytosol were similar. We conclude that cardiac sarcoplasmic reticulum contains primarily type II cAMP-dependent protein kinase and this is probably the enzyme which phosphorylates sarcoplasmic reticulum in vivo and regulates Ca2+ transport.
犬心肌肌浆网囊泡含有内在的环磷酸腺苷（cAMP）依赖性和钙离子-钙调蛋白依赖性蛋白激酶（EC 2.7.1.37）活性，以及这两种酶的共同底物受磷蛋白。与肌浆网膜相关的环磷酸腺苷依赖性蛋白激酶用曲拉通X-100进行了增溶。肌浆网蛋白激酶的增溶并不影响其对环磷酸腺苷的依赖性或其底物特异性。增溶后的环磷酸腺苷依赖性蛋白激酶通过二乙氨基乙基纤维素色谱法进行了纯化，并根据其在高离子强度下的洗脱情况被鉴定为II型酶。经二乙氨基乙基纤维素纯化的环磷酸腺苷依赖性蛋白激酶未表现出钙离子-钙调蛋白依赖性蛋白激酶活性。犬心肌细胞的胞质溶胶在与用于肌浆网相同的条件下进行二乙氨基乙基纤维素色谱分析，结果显示存在I型和II型环磷酸腺苷依赖性蛋白激酶同工酶。从肌浆网和胞质溶胶中经二乙氨基乙基纤维素纯化的II型蛋白激酶的性质相似。我们得出结论，心肌肌浆网主要含有II型环磷酸腺苷依赖性蛋白激酶，这可能就是在体内使肌浆网磷酸化并调节钙离子转运的酶。
