Publication Type Journal Article
Title Role of glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase in the reduction of lysophospholipid hydroperoxides
Authors H. Susana Marinho F. J. N. Antunes RE Pinto
Groups
Journal FREE RADICAL BIOLOGY AND MEDICINE
Year 1997
Month
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Volume 22
Number 5
Pages 871-883
Abstract 1-linoleoyl lysophosphatidylcholine hydroperoxide is a substrate of GSH peroxidase (GPx) both purified from bovine erythrocytes and nonpurified from rat liver. The initial reaction rate for bovine erythrocyte GPx with l-linoleoyl lysophosphatidylcholine hydroperoxide is about 76 and 95\% of the reaction rate for hydrogen peroxide and linoleic acid hydroperoxide respectively. For rat liver GPx these initial reaction rates are about 66 and 75\%, respectively. The rate constants for the reaction of GPx with 1-linoleoyl lysophosphatidylcholine hydroperoxide were calculated to be similar to 3 x 10(7) M(-1)s(-1) and similar to 2 x 10(6) M(-1)s(-1) for the bovine erythrocyte and the rat liver enzymes, respectively. By using kinetic models of lipid peroxidation we found by simulation that: (1) the main source of lysophospholipid hydroperoxides in vivo is the peroxidation of lysophospholipids, both in mitochondrial inner membranes and in endoplasmic reticulum; (2) a specialized enzyme able to reduce directly lysophospholipid hydroperoxides is important for the reduction of these hydroperoxides, because the detoxification of these species mediated by the action of acyl ester bond cleaving enzymes is not efficient; (3) the reduction through GPx predominates over phospholipid hydroperoxide glutathione peroxidase (PHGPx) in mitochondrial inner membranes and in the cytosolic phase of the endoplasmic reticulum; (4) in the luminal phase of endoplasmic reticulum PHGPx is predominant. Copyright (C) 1997 Elsevier Science Inc.
DOI http://dx.doi.org/10.1016/S0891-5849(96)00468-6
ISBN
Publisher
Book Title
ISSN 0891-5849
EISSN
Conference Name
Bibtex ID ISI:A1997WD84200015
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