Catalyzes the conversion of prostaglandin H2 (PGH2) to thromboxane A2 (TXA2), a potent inducer of blood vessel constriction and platelet aggregation (PubMed:11097184, PubMed:11297515, PubMed:22735388, PubMed:24009185, PubMed:8436233, PubMed:9873013). Cleaves also PGH2 to 12-hydroxy-heptadecatrienoicacid (12-HHT) and malondialdehyde, which is known to act as a mediator of DNA damage. 12-HHT and malondialdehyde are formed stoichiometrically in the same amounts as TXA2 (PubMed:11297515, PubMed:22735388, PubMed:9873013). Additionally, displays dehydratase activity, toward (15S)-hydroperoxy-(5Z,8Z,11Z,13E)-eicosatetraenoate (15(S)-HPETE) producing 15-KETE and 15-HETE (PubMed:17459323).
