Hydrolysis of phospholipids by a lysosomal enzyme

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...

Full description

Bibliographic Details
Main Authors: A. Mellors, A.L. Tappel
Format: Article
Language:English
Published: Elsevier 1967-09-01
Series:Journal of Lipid Research
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S0022227520389057
_version_ 1818941166279720960
author A. Mellors
A.L. Tappel
author_facet A. Mellors
A.L. Tappel
author_sort A. Mellors
collection DOAJ
description 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.
first_indexed 2024-12-20T06:51:13Z
format Article
id doaj.art-106608ffa93549bcaec0e54544b6ec95
institution Directory Open Access Journal
issn 0022-2275
language English
last_indexed 2024-12-20T06:51:13Z
publishDate 1967-09-01
publisher Elsevier
record_format Article
series Journal of Lipid Research
spelling doaj.art-106608ffa93549bcaec0e54544b6ec952022-12-21T19:49:31ZengElsevierJournal of Lipid Research0022-22751967-09-0185479485Hydrolysis of phospholipids by a lysosomal enzymeA. Mellors0A.L. Tappel1Department of Food Science and Technology, University of California, Davis, California 95616Department of Food Science and Technology, University of California, Davis, California 95616The 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.http://www.sciencedirect.com/science/article/pii/S0022227520389057lysosomesrat liverphospholipaselecithinphosphatidyl ethanolaminelysolecithin
spellingShingle A. Mellors
A.L. Tappel
Hydrolysis of phospholipids by a lysosomal enzyme
Journal of Lipid Research
lysosomes
rat liver
phospholipase
lecithin
phosphatidyl ethanolamine
lysolecithin
title Hydrolysis of phospholipids by a lysosomal enzyme
title_full Hydrolysis of phospholipids by a lysosomal enzyme
title_fullStr Hydrolysis of phospholipids by a lysosomal enzyme
title_full_unstemmed Hydrolysis of phospholipids by a lysosomal enzyme
title_short Hydrolysis of phospholipids by a lysosomal enzyme
title_sort hydrolysis of phospholipids by a lysosomal enzyme
topic lysosomes
rat liver
phospholipase
lecithin
phosphatidyl ethanolamine
lysolecithin
url http://www.sciencedirect.com/science/article/pii/S0022227520389057
work_keys_str_mv AT amellors hydrolysisofphospholipidsbyalysosomalenzyme
AT altappel hydrolysisofphospholipidsbyalysosomalenzyme