文章基本信息

标题：Hydrolysis of phospholipids by a lysosomal enzyme
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作者：A. Mellors ; A. L. Tappel
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：1967
卷号：8
期号：5
页码：479-485
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The phospholipid-hydrolyzing activity of rat liver lysosomes has been studied. These lysosomes contain a phospholipase that cleaves both fatty acid ester linkages of lecithin and of phosphatidyl ethanolamine and releases free fatty acids from both positional isomers of lysolecithin. The enzyme does not require calcium for maximum activity, and is inhibited by diethyl ether and sodium deoxycholate. Mercuric ions and cetyltrimethyl ammonium bromide also inhibit the hydrolysis. Compared with lipase activity, this enzyme is relatively stable to heat. The specific activity of the hydrolysis of lecithin by the lysosomal enzyme is considerably higher than those reported for mitochondrial and microsomal phospholipases. The enzyme resembles other hydrolases of the lysosome in that it has an acid pH optimum (pH 4.5). This enzymic activity is present in both the lysosomal soluble enzyme fraction and in the lysosomal membrane fraction. The enzyme may participate in the intracellular digestion of mitochondria that is carried out by the intact lysosome in vivo. Localized inflammation and changes in vascular permeability following tissue damage could be catalyzed by this phospholipase.
关键词：lysosomes ; rat liver ; phospholipase ; lecithin ; phosphatidyl ethanolamine ; lysolecithin ; phospholipid ; mitochondria ; uncoupling ; inflammation