Thromboxane-A synthase

Thromboxane-A synthase (TBXAS) is an enzyme that converts prostaglandin endoperoxide into thromboxane A2 (TXA2). TXA2 is a potent inducer of blood vessel constriction and platelet aggregation. It plays a key role in maintaining hemostasis.

TBXAS is a microsomal enzyme that is anchored to the endoplasmic reticulum. It is found in platelets, monocytes, and several other cell types.

TBXAS is a cytochrome P450 enzyme. It consists of a polypeptide chain of 60 kDa with no evidence of glycosylation. It utilizes arachidonic acid (5,8,11,14-eicosatetraenoic acid) as a preferred substrate.

TBXAS is encoded by the TBXAS1 gene. Non-synonymous polymorphisms in the TBXAS gene can alter TBXAS activity and affect TXA2 generation.

TBXAS may also be important for:

• Bone remodeling
• The production of red blood cells in bone marrow

The TBXAS1 gene polymorphism AA has been shown to affect the risk of clopidogrel resistance