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From Citizendium, the Citizens' Compendium

Cyclooxygenase is an enzyme that is respondsible for the key step in prostaglandin biosynthesis. Other names for this enzyme include: Prostaglandin-endoperoxide synthase (the current official name), Prostaglandin H2 synthase, and Prostaglandin G/H synthase. The enzyme is most commonly abbreviated "COX," but may also be referred to as "PTGS" or "PGHS." This enzyme is the therapeutic target for the Nonsteroidal Anti-Inflammatory Drugs (NSAIDs). Research has also revealed that it is present in most organisms in two isoforms. A constitutive COX-1 and an inducible COX-2. This article will refer to both isoforms as a single enzyme where appropriate, and will distinguish one from the other when necessary. Also, all information will refer to the human cyclooxygenases except where noted.

Contents 1 Structure and Function 1.1 Genomics and Structure 1.1.1 COX-1 1.1.2 COX-2 1.2 Function

Structure and Function

Genomics and Structure

COX-1

The gene for COX-1 is located on the long arm of chromosome 9 at location 9q32-q33.3. After translation the enzyme contains 599 amino acids.

COX-2

The gene for COX-2 is located on the long arm of chromosome 1 at location 1q25.2-q25.3. After translation the enzyme contains 604 amino acids.

Function

Cyclooxygenase is responsible for the conversion of Arachidonic Acid to Prostaglandin H₂. Prostaglandin H₂ is the precursor to the series 2 prostanoids. Cyclooxygenase achieves this through the action of two active sites. First a cyclooxygenase active site (the source of the enzyme's common name) converts arachidonic acid to Prostaglandin G₂. Then a heme dependent peroxidase converts Prostaglandin G<sub2></sub> to Prostaglandin H₂