WikiMSK:Featured Article/1 March 2022
From WikiMSK
Featured Wiki Article for 1 March 2022
Prostaglandins and Cyclooxygenase Enzymes
Biosynthesis starts with membrane phospholipids, present in the lipid bilayer of the cell membrane. The biosynthesis pathway has three main steps. Initially arachidonic acid is liberated from membrane phospholipids, by hydrolysis, by phospholipase A2 enzyme (PLA2). The second step involves the COX enzyme, through its cyclooxygenase site, which results in prostaglandin G2 (PGG2). The same COX enzyme converts PGG2 to prostaglandin H2 (PGH2) through the COX peroxidase catalytic site. One end of the COX enzyme has a membrane binding domain along with an epithelial growth factor domain, and the other end is the active enzymatic site. PGH2 is converted to various kinds of prostanoids by tissue-specific isomerases. For example prostacyclin (PGI2), prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), prostaglandin F2a (PGF2a) and thromboxane A2 (TXA2). Arachidonic acid can also be converted to leukotrienes by the enzyme lipoxygenase. - Read More
