Cyclooxygenase peroxidase site

The **cyclooxygenase peroxidase site** refers to the peroxidase active site of prostaglandin-endoperoxide synthase enzymes, commonly known as **cyclooxygenases** (COX-1 and COX-2). This heme-containing enzymatic site is spatially distinct from, but functionally coupled to, the cyclooxygenase site within the same enzyme molecule[1][5][8]. The peroxidase site plays an essential role in the biosynthetic conversion of arachidonic acid to prostaglandins by catalyzing the reduction of hydroperoxide intermediates (such as PGG₂ to PGH₂), a critical step in the formation of bioactive lipids involved in inflammation, pain, cancer, and cardiovascular disease[1][2][8]. The peroxidase activity is required for full cyclooxygenase activation, as activation of the heme at the peroxidase site initiates the radical catalysis in the cyclooxygenase active site[1][3][5]. Both sites are targets of nonsteroidal anti-inflammatory drugs (NSAIDs), though most NSAIDs primarily act on the cyclooxygenase site, with some influence (depending on the drug) on peroxidase function as well[4][5]. The peroxidase site is also an area of interest for the development of drugs that modulate prostaglandin synthesis for anti-inflammatory, analgesic, and anti-cancer therapy, with notable therapeutic and safety considerations in chronic use[4][5][8].

Other names

Cyclooxygenase POX siteCOX peroxidase siteCOX POX sitePeroxidase site of prostaglandin-endoperoxide synthase

Inhibition of prostaglandin synthesis via interruption of peroxide reduction. Direct inhibition or covalent modification of the peroxidase or cyclooxygenase function (aspirin acetylates key serine in cyclooxygenase site, but both sites are functionally linked).