Heme is in charge of PGG2 reduction into PGH2 , and the cyclooxygenase is responsible for the formation of hydroperoxy endoperoxide prostaglandin G2 from converting arachidonic acid .
The enzyme contains two active sites : a heme with peroxidase activity , responsible for the reduction of PGG2 to PGH2 , and a cyclooxygenase site , where arachidonic acid is converted into the hydroperoxy endoperoxide prostaglandin G2 ( PGG2 ) .