COX-1 catalyzes the first step in the biosynthesis of prostaglandins (PGs), thromboxanes, and prostacyclins: the conversion of arachidonic acid to PGH2. COX-1 is constitutively expressed in almost all animal tissues and is involved in the homeostatic role of eicosanoids.1,2 COX-1 from ram seminal vesicles has an apparent Km value of 8.3 M for arachidonic acid.3 Technical Information Synonyms Constitutive Cyclooxygenase Cyclooxygenase 1 Prostaglandin H Synthase 1 (PGHS-1) Prostaglandin Endoperoxide Synthase MW 70 kDa Formulation 80 mM Tris-HCl, pH 8.0, containing 0.3 mM DDC, 0.1% polysorbate 20, and 10% glycerol Enzyme Commission 1.14.99.1 UniProt Accession P05979 Origin Animal/Ram