Calcium-activated, phospholipid-dependent protein kinase in pancreatic acinar cells.
Calcium-activated, phospholipid-dependent protein kinase in pancreatic acinar cells.
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胰腺腺泡细胞中钙激活的磷脂依赖性蛋白激酶。
DOI：
10.1152/ajpgi.1985.248.6.g692
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
R. Jensen
中科院分区：
文献类型：
--
作者：
M. Noguchi;H. Adachi;J. Gardner;R. Jensen
在本研究中，我们用二乙氨基乙基纤维素和Sephadex G-150柱层析从豚鼠胰腺腺泡细胞中部分纯化了钙激活的磷脂依赖的蛋白激酶(蛋白激酶C)，并研究了该酶对钙、磷脂、二酰甘油(Diolin)和佛波酯12-O-十四烷基佛波酯(TPA)的依赖性。蛋白激酶C的浓缩制剂不含环核苷酸依赖或钙依赖、钙调蛋白依赖的蛋白激酶活性。H1-组蛋白和ATP的Km值分别为0.74+/-0.22和13.1+/-3.2微米。胰腺蛋白激酶C的激活需要绝对的钙和磷脂，而双甘油酯或TPA使酶对钙的亲和力增加了10倍。在磷脂酰丝氨酸作用下，引起半最大激活的钙浓度(Ka)为74+/-17微米，而在磷脂酰丝氨酸和双油酯或TPA作用下，钙的激活浓度分别为7.9+/-1.6微米和6.8+/-1.3微米。加入磷脂酰乙醇胺和磷脂酰丝氨酸使钙的Ka降低到2.0+/-0.9微米和0.7+/-0.4微米。当钙浓度大于1微米时，TPA和双油脂对蛋白激酶C的激活是相同的，但在磷脂存在的低钙浓度(小于1微米)下，最大有效浓度的双油脂仅引起TPA激活的55%。除了TPA，其他佛波酯，如佛波二丁酸酯和佛波二乙酸酯，但不是佛波酯本身，是激活的蛋白激酶C。
In the present study we partially purified calcium-activated, phospholipid-dependent protein kinase (protein kinase C) from pancreatic acinar cells of the guinea pig using diethylaminoethylcellulose and Sephadex G-150 chromatography and characterized the dependence of the enzyme on calcium, phospholipids, diacylglycerol (diolein), and the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). The enriched preparation of protein kinase C contained no cyclic nucleotide-dependent or calcium-dependent, calmodulin-dependent protein kinase activity. The values of Km for H1-histone and ATP were 0.74 +/- 0.22 and 13.1 +/- 3.2 microM, respectively. Pancreatic protein kinase C demonstrated an absolute requirement for calcium and phospholipid for its activation, and diolein or TPA increased the affinity of the enzyme for calcium by 10-fold. With phosphatidylserine the calcium concentration that caused a half-maximal activation (Ka) was 74 +/- 17 microM, whereas with phosphatidylserine and diolein or TPA the Ka for calcium was 7.9 +/- 1.6 or 6.8 +/- 1.3 microM, respectively. Adding phosphatidylethanolamine and phosphatidylserine decreased the Ka for calcium to 2.0 +/- 0.9 microM with diolein and to 0.7 +/- 0.4 microM with TPA. Activation of protein kinase C by TPA and diolein was identical with calcium concentrations greater than 1 microM, but at low calcium concentrations (less than 1 microM) in the presence of phospholipids, maximally effective concentrations of diolein caused only 55% of the activation seen with TPA. In addition to TPA, other phorbol esters such as phorbol dibutyrate and phorbol diacetate, but not phorbol itself, activated protein kinase C.(ABSTRACT TRUNCATED AT 250 WORDS)