Yang H C, Farooqui A A, Horrocks L A
Department of Medical Biochemistry, Ohio State University, Columbus 43210.
Biochem J. 1994 Apr 1;299 ( Pt 1)(Pt 1):91-5. doi: 10.1042/bj2990091.
Two forms of Ca(2+)-independent cytosolic phospholipase A2 activity (110 kDa and 39 kDa) were found in bovine brain. They were separated by Sephadex G-75 column chromatography. The 110 kDa phospholipase A2 was much more active with phosphatidylethanolamine and was not affected by glycosaminoglycans, whereas the 39 kDa phospholipase A2 was much more active with ethanolamine plasmalogen and was markedly inhibited by glycosaminoglycans. Heparan sulphate was the most potent inhibitor, followed by chondroitin sulphate, hyaluronic acid and heparin. Gangliosides, especially the GM3 ganglioside, but not other glycosphingolipids, inhibited the activity of the 39 kDa phospholipase A2 in a dose-dependent manner. The heat-inactivation profiles of the 110 kDa and 39 kDa phospholipases A2 provide further evidence for the differences between these cytosolic enzymes. Interactions between glycosaminoglycans, gangliosides and phospholipases A2 may be involved in the maintenance of membrane function.
在牛脑中发现了两种不依赖钙离子的胞质磷脂酶A2活性形式（110 kDa和39 kDa）。它们通过葡聚糖G-75柱色谱法分离。110 kDa磷脂酶A2对磷脂酰乙醇胺的活性更高，且不受糖胺聚糖的影响，而39 kDa磷脂酶A2对乙醇胺缩醛磷脂的活性更高，并受到糖胺聚糖的显著抑制。硫酸乙酰肝素是最有效的抑制剂，其次是硫酸软骨素、透明质酸和肝素。神经节苷脂，尤其是GM3神经节苷脂，但其他糖鞘脂则不然，以剂量依赖的方式抑制39 kDa磷脂酶A2的活性。110 kDa和39 kDa磷脂酶A2的热失活曲线为这些胞质酶之间的差异提供了进一步的证据。糖胺聚糖、神经节苷脂和磷脂酶A2之间的相互作用可能参与维持膜功能。
