Phosphatidylglycerol-modulated protein kinase activity from human spleen. II. Interaction with phospholipid vesicles.
Phosphatidylglycerol-modulated protein kinase activity from human spleen. II. Interaction with phospholipid vesicles.
复制标题
来自人脾脏的磷脂酰甘油调节的蛋白激酶活性。
DOI：
10.1016/0003-9861(88)90155-5
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发表时间：
1988
影响因子：
3.9
通讯作者：
Elias,L
中科院分区：
文献类型：
--
作者：
Klemm,DJ;Elias,L
磷脂酰肌醇或磷脂酰甘油刺激蛋白激酶P对内源性和人工蛋白底物的磷酸化（D. J. Klemm, and L. Elias, 1987）。医学杂志。Chem.262, 7580 - 7585;L. Elias和A. Davis（1985）。医学杂志。Chem.260, 7023 - 7028)。蛋白激酶P活性的刺激需要磷脂囊泡而不是游离磷脂分子。蛋白激酶P活性随卵泡磷脂酰肌醇含量从20%提高到100%而升高；低于20%的磷脂酰肌醇未检测到刺激。这表明酶的激活需要一个富含磷脂酰肌醇的囊泡表面。在内源和人工底物条件下，蛋白激酶P活性的最大激活值与磷脂浓度有关。产生最佳酶活性的磷脂浓度随蛋白质底物浓度而变化，但不随酶浓度而变化。因此，磷脂囊泡表面的底物分子密度是蛋白激酶P刺激的一个关键特征。蛋白激酶P与囊泡的结合与胶束组成无关，但人工底物组蛋白H2B的结合对含有磷脂酰肌醇或磷脂酰甘油的囊泡是特异性的，并且随着磷脂酰肌醇含量的增加而增加。因此，蛋白激酶P活化的一个重要特征似乎是蛋白质底物与磷脂囊泡的特异性结合。
Phosphorylation of endogenous and artificial protein substrates by protein kinase P is stimulated by phosphatidylinositol or phosphatidylglycerol (D. J. Klemm, and L. Elias (1987)J. Biol. Chem.262, 7580–7585; L. Elias and A. Davis (1985)J. Biol. Chem.260, 7023–7028). Stimulation of protein kinase P activity required phospholipid vesicles rather than free phospholipid molecules. Protein kinase P activity increased as the phosphatidylinositol content of the vesicles was raised from 20 to 100%; no stimulation was detected below 20% phosphatidylinositol. This suggests that a vesicle surface rich in phosphatidylinositol is required for enzyme activation. Maximum activation of protein kinase P activity showed an optimum value with respect to phospholipid concentration, with both endogenous and artificial protein substrates. The phospholipid concentration at which optimal enzyme activity occurred shifted in response to the concentration of protein substrate, but not enzyme concentration. Therefore, the density of substrate molecules on the surface of phospholipid vesicles is a critical feature of protein kinase P stimulation. Binding of protein kinase P to vesicles was independent of micelle composition, but the binding of the artificial substrate, histone H2B, was specific for vesicles containing phosphatidylinositol or phosphatidylglycerol, and increased as the content of phosphatidylinositol was increased. Thus, an important feature of protein kinase P activation appeared to be the specific binding of protein substrate to phospholipid vesicles.