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Mechanism of biosynthesis of 11 R ‐ and 12 R ‐hydroxyeicosatetraenoic acids by eggs of the sea urchin Strongylocentrotus purpuratus
Author(s) -
Hawkins Dan J.,
Brash Alan R.
Publication year - 1989
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 - 10.1016/0014-5793(89)81228-1
Subject(s) - sea urchin , biosynthesis , arachidonic acid , hydroxyeicosatetraenoic acid , strongylocentrotus purpuratus , biochemistry , monooxygenase , biology , lipoxygenase , stereochemistry , enzyme , chemistry , cytochrome p450 , microbiology and biotechnology
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( R )‐ and 12( R )‐hydroperoxy‐eicosanoids from incubations of the desalted 30–50% (NH 4 ) 2 SO 4 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 2 H 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.