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Identification of a lipoxygenase inhibitor in A431 cells as a phospholipid hydroperoxide glutathione peroxidase
Author(s) -
Huang Hei-Sheng,
Chen Ching-Jiunn,
Lu Hsieng S,
Chang Wen-Chang
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00130-6
Subject(s) - phospholipid hydroperoxide glutathione peroxidase , phospholipid , chemistry , biochemistry , trypsin , peroxidase , phospholipase a2 , peptide , phosphatidylcholine , lipoxygenase , glutathione peroxidase , glutathione , enzyme , microbiology and biotechnology , biology , membrane
An endogenous lipoxygenase inhibitor, purified from the cytosol of human epidermoid carcinoma A431 cells, was analyzed by N‐terminal microsequencing and mass spectrometric analysis. The inhibitor was purified by SDS‐PAGE, then subjected to in‐gel CNBr cleavage and trypsin digestion. The N‐terminal sequence data obtained from a 6–8 kDa band of in‐gel CNBr cleavage and the three isolated peptides of in‐gel trypsin digestion, and the C‐terminal peptide sequence from matrix‐assisted laser desorption ionization mass spectrometry matched the sequence of human phospholipid hydroperoxide glutathione peroxidase. The purified inhibitor exhibited peroxidase activity using phosphatidylcholine hydroperoxides as the substrate. We therefore concluded that the lipoxygenase inhibitor present in A431 cells was a phospholipid hydroperoxide glutathione peroxidase.