DIACYLGLYCEROL KINASE IN PLASMA-MEMBRANES FROM WHEAT
DIACYLGLYCEROL KINASE IN PLASMA-MEMBRANES FROM WHEAT
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DOI：
10.1016/0005-2760(92)90109-9
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发表时间：
1992-01-24
期刊：
影响因子：
--
通讯作者：
SOMMARIN, M
中科院分区：
文献类型：
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作者：
LUNDBERG, GA;SOMMARIN, M
二酰基甘油激酶活性在从暗生长小麦（Triticum aestivum L.）通过含水聚合物两相分配。 二酰基甘油激酶的活性位点被定位到细胞膜的细胞质内表面使用隔离的内面向外和右侧出质膜囊泡从根。 从芽质膜囊泡中的酶活性表现出广泛的pH最适pH 7左右。 该反应是Mg2+和ATP依赖性的，并且在0.5 mM ATP和3 mM MgCl2附近观察到最大活性。 Mg 2+的需求只能部分地被Mn 2+取代，而不能被Ca 2+取代。 内源性二酰基甘油的磷酸化被洗涤剂强烈抑制，表明对脂质环境的极端依赖性。 肌醇磷脂刺激的活性二酰基甘油激酶质膜从芽和根，而活性抑制R59022，一个假定的抑制剂的几个二酰基甘油激酶同工酶参与解偶联二酰基甘油激活哺乳动物蛋白激酶C。
Diacylglycerol kinase activity was demonstrated in highly purified plasma membranes isolated from shoots and roots of dark-grown wheat (Triticum aestivum L.) by aqueous polymer two-phase partitioning. The active site of the diacylglycerol kinase was localized to the inner cytoplasmic surface of the plasma membrane using isolated inside-out and right-side-out plasma membrane vesicles from roots. The enzyme activity in plasma membrane vesicles from shoots showed a broad pH optimum around pH 7. The reaction was Mg2+ and ATP dependent, and maximal activity was observed around 0.5 mM ATP and 3 mM MgCl2. The Mg2+ requirement could be substituted only partially by Mn2+ and not at all by Ca2+. The phosphorylation of endogenous diacyglycerol was strongly inhibited by detergents indicating an extreme dependence of the lipid environment. Inositol phospholipids stimulated the activity of diacylglycerol kinase in plasma membranes from shoots and roots, whereas the activity was inhibited by R59022, a putative inhibitor of several diacylglycerol kinase isoenzymes involved in uncoupling diacylglycerol activation of mammalian protein kinase C.