Arachidonate 12-lipoxygenase of platelet-type in human epidermal cells.

摘要: A homogenate of epidermal cells isolated from human skin converted arachidonic acid to 12S-hydroxy-5, 8,10,14-eicosatetraenoic and 15-hydroxy-5, 8,11,13-eicosatetraenoic as the main lipoxygenase products. The production these hydroxy acids was not stimulated by addition 1 mM NADPH required for cytochrome P-450 reaction, but inhibited 65-75% with 40 microM nordihydroguaiaretic acid, a nonspecific inhibitor. In products, cell prostaglandin E2 together minor amounts prostaglandins D2 F2a 12-hydroxy-5,8,10-heptadecatrienoic acid. Thromboxane B2 detected. This finding rules out possible contamination platelet 12-lipoxygenase in cells. After subcellular fractionation homogenate, activity found 164,000 x g supernatant, pellet, 10,000 pellet. cytosolic enzyme enzymes solubilized two pellets produced 12S-hydroperoxy-5,8,10,14-eicosatetraenoic primary product contrast which produces primarily acids. supernatant pellet were precipitable antibodies raised against 12-lipoxygenase, porcine leukocyte 12-lipoxygenase. immunoprecipitated each fraction almost inactive linoleic substrate, characteristic platelet-type. Furthermore, mRNA could be reverse-transcribed amplified polymerase chain reaction primers specific cDNA, those cDNA. Thus, is similar terms immunogenicity, catalytic property, structure, distinct