Mechanism of biosynthesis of 11R-and 12R-hydroxyeicosatetraenoic acids by eggs of the sea urchin Strongylocentrotus purpuratus.
11(R)-Hydroxyeicosatetraenoic acid [11(R)-HETE] and 12(R)-HETE are biosynthesized by eggs of the sea urchin S. purpuratus. We report here the isolation of the 11(4)- and 12(R)-hydroperoxy-eicosanoids from incubations of the desalted 30-50%(NH4)2SO4 fraction of the egg homogenate; biosynthesis required the addition of calcium but not NADPH. Egg 11- and 12-HETE were formed from octadeuterated arachidonic acid without loss of geminal 2H from C11 or C12, thus revealing that 11- or 12-keto intermediates are not involved in the biosynthesis. The results support the conclusion that egg 11(R)- and 12(R)-HETE are synthesized by a lipoxygenase and not by an NADPH-dependent cytochrome P450 monooxygenase mechanism.
Hawkins
D J
DJ
Division of Clinical Pharmacology, Vanderbilt University, School of Medicine, Nashville, Tn 37232.
Brash
A R
AR
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D006893:Hydroxyeicosatetraenoic Acids / Q000096:biosynthesis* / Q000302:isolation & purification; D008084:Lipoxygenase / Q000378:metabolism; D009249:NADP / Q000494:pharmacology; D010063:Ovum / Q000378:metabolism*; D012617:Sea Urchins; D013237:Stereoisomerism
D001095:Arachidonic Acids; D006893:Hydroxyeicosatetraenoic Acids; D009249:NADP; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C027356:11-hydroxy-5,8,12,14-eicosatetraenoic acid; D008084:Lipoxygenase; D002118:Calcium