Thromboxane-A synthase (TBXAS1) (TBXAS1)

Thromboxane-A synthase (TBXAS1) is a cytochrome P450 enzyme (CYP5A1) primarily located in the endoplasmic reticulum of platelets and macrophages [17, 21]. It catalyzes the final step in the biosynthesis of thromboxane A2 (TXA2) by converting the endoperoxide prostaglandin H2 (PGH2) into TXA2 [12, 17]. TXA2 is a potent mediator of platelet aggregation and a powerful vasoconstrictor, playing a central role in hemostasis and the pathogenesis of thrombotic disorders [8, 11]. In diseases such as atherosclerosis and myocardial infarction, overproduction of TXA2 contributes to vessel occlusion and tissue ischemia [1, 20]. Pharmacological inhibition of TXA2 synthase, using drugs like ozagrel or dazoxiben, aims to reduce prothrombotic activity while potentially shunting substrate toward anti-aggregatory prostaglandins like prostacyclin [5, 13]. However, the clinical utility of selective synthase inhibitors has been limited by the accumulation of PGH2, which can directly activate the thromboxane receptor, leading to the development of dual-action inhibitors and receptor antagonists [4, 13]. Beyond cardiovascular roles, the enzyme is also implicated in inflammatory processes and cancer progression [8, 21].

Other names

Thromboxane A synthase 1TXASTXSCYP5CYP5A1Cytochrome P450 5A1Thromboxane A2 synthetase

Inhibition of thromboxane-A synthase activity, preventing the conversion of prostaglandin H2 to thromboxane A2.