Leukotriene A4. Enzymatic conversion into 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid by mouse liver cytosolic epoxide hydrolase.
J Haeggström, J Meijer, O Rådmark
Index: J. Biol. Chem. 261(14) , 6332-7, (1986)
Full Text: HTML
Abstract
Mouse liver homogenates transformed leukotriene A4 into a 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acid. This novel enzymatic metabolite of leukotriene A4 was characterized by physical means including ultraviolet spectroscopy, high performance liquid chromatography, and gas chromatography-mass spectrometry. After subcellular fractionation, the enzymatic activity was mostly recovered in the 105,000 X g supernatant and 20,000 X g pellet. Heat treatment (80 degrees C, 10 min) or digestion with a proteolytic enzyme abolished the enzymatic activity in the high speed supernatant. A purified cytosolic epoxide hydrolase from mouse liver also transformed leukotriene A4 into a 5,6-dihydroxyeicosatetraenoic acid with the same physico-chemical characteristics as the compound formed in crude cytosol, but not into leukotriene B4, a compound previously reported to be formed in liver cytosol (Haeggström, J., Rådmark, O., and Fitzpatrick, F.A. (1985) Biochim. Biophys. Acta 835, 378-384). These findings suggest a role for leukotriene A4 as an endogenous substrate for cytosolic epoxide hydrolase, an enzyme earlier characterized by xenobiotic substrates. Furthermore, they indicate that leukotriene A4 hydrolase in liver cytosol is a distinct enzyme, separate from previously described forms of epoxide hydrolases in liver.
Related Compounds
Related Articles:
2016-04-01
[Mol. Pharmacol. 89 , 413-24, (2016)]
2010-05-01
[Am. J. Respir. Crit. Care Med. 181 , 899-907, (2010)]
Role of leukotriene A4 hydrolase aminopeptidase in the pathogenesis of emphysema.
2014-06-01
[J. Immunol. 192(11) , 5059-68, (2014)]
1987-10-15
[J. Biol. Chem. 262(29) , 13873-6, (1987)]
Leukotriene A4 hydrolase in the human lung. Inactivation of the enzyme with leukotriene A4 isomers.
1987-07-25
[J. Biol. Chem. 262(21) , 10200-5, (1987)]