PGH synthase is the enzyme that converts arachidonic acid to PGH2, the precursor of the other prostaglandins (Figure 19.31). The reaction mechanism by which PGH synthase works is shown in Figure 19.32.
Mammalian cells contain two forms of PGH synthase called PGHS-1 and PGHS-2 (or Cox-1 and Cox-2, respectively). This enzyme catalyzes the conversion of arachidonic acid to PGH2, an essential step in prostaglandin biosynthesis.
Aspirin and other non-steroidal compounds, which target the PGH synthases, are called non-steroidal anti-inflammatory drugs (NSAIDs) because they help prevent formation of prostaglandins and thromboxanes, thus reducing pain and inflammation in the body.
1. Eicosanoids