Inactivation of thromboxane synthase with hydroperoxy-fatty acids.
Bovine lung thromboxane synthase was immobilized on phenyl-Sepharose beads by adsorption. The immobilized enzyme was catalytically active and synthesized both TXA2 and HHT. The structure-activity relationship of several hydroperoxy fatty acids and their ability to inactivate thromboxane synthase was investigated. Millimolar quantities of hydrogen peroxide and tert-butylperoxide were required to inactivate the enzyme: whereas micromolar quantities of C18 and C20 hydroperoxy fatty acids inactivated the enzyme. Pretreatment of the enzyme with long chain hydroperoxy-fatty acids resulted in a decreased synthesis of both TXB2 and HHT.
Hall
E R
ER
Department of Internal Medicine, University of Texas Medical School, Houston.
Townsend
G
G
Frasier-Scott
K F
KF
D000818:Animals; D002417:Cattle; D004789:Enzyme Activation / Q000187:drug effects; D015289:Leukotrienes / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects / Q000201:enzymology*; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D011453:Prostaglandins / Q000096:biosynthesis; D013329:Structure-Activity Relationship; D013930:Thromboxane-A Synthase / Q000378:metabolism*
D015289:Leukotrienes; D011453:Prostaglandins; D013930:Thromboxane-A Synthase