Hepoxilin A3 formation in the rat pineal gland selectively utilizes (12S)-hydroperoxyeicosatetraenoic acid (HPETE), but not (12R)-HPETE.

摘要: Abstract Hepoxilins A3 and B3 have previously been shown to be formed from 12-hydroperoxyeicosatetraenoic acid (12-HPETE) through a heat-insensitive ferriheme catalysis as indicated by experiments with hemin or hemoglobin, typical of nonenzymatic rearrangement (Pace-Asciak, C. R. (1984) Biochim. Biophys. Acta 793, 485-488; Pace-Asciak, J. Biol. Chem. 259, 8332-8337). In this paper, we demonstrate use mixture (12S)- (12R)-HPETE that an enzyme system exists in the rat pineal gland selectively utilizes (12S)-HPETE for transformation into hepoxilin A3, while hemin-catalyzed is not selective, both being utilized. A new procedure was established rapidly extract (in absence acid) directly derivatize incubation products using 9-anthryldiazomethane reagent form derivatives hydroxyeicosatetraenoic acids (HETEs), hepoxilins trioxilins, which could detected high performance liquid chromatography flow-through fluorescence detector. The following observations were made: 1) showed preference formation minor amounts B3, heme A3; 2) chiral phase analysis HETEs recovered predominance (12R)-HETE experiments, indicating used up, whereas utilized experiments; 3) presence only 11S,12S-configuration (12S)-HPETE, contained native well unnative "bis-epi"-11R,12R-configuration epoxide group 4) reverse hydrolase product i.e. trioxilin enzymatic hydrolysis derived whose inhibited inhibitor, trichloropropene oxide. heat-sensitive, abolished tissue boiling, insensitive boiling. These exclusively, transformed "hepoxilin synthase" primarily A3.