Prostaglandin E synthase isomerizes PGH2 to PGE2

Prostaglandin E2 (PGE2) is the most abundant prostanoid in the body and is a major mediator of inflammation in diseases such as osteoarthritis and rheumatoid arthritis. The product of arachidonate, prostaglandin H2 (PGH2) serves as the substrate for the isomerization to PGE2. The conversion is carried out by prostaglandin E synthases. Of the three forms, two are predominanly cytosolic. Prostaglandin E synthase 3 (PTGES3) is also called cytosolic prostaglandin E2 synthase (cPGES). Prostaglandin E synthase 2 (mPGES-2, PTGES2) is synthesized as a Golgi membrane-associated protein which undergoes a spontaneous cleavage of the N-terminal hydrophobic domain leading to a truncated mature cytosolic protein.

前列腺素E2（PGE2）是体内最丰富的前列腺素类物质，并在诸如骨关节炎和类风湿性关节炎等疾病中的炎症反应中发挥主要调节作用。花生四烯酸产物前列腺素H2（PGH2）作为PGE2异构化的底物。此转化过程由前列腺素E合成酶负责执行。在三种形式中，两种主要存在于细胞质中。前列腺素E合成酶3（PTGES3），亦称细胞质前列腺素E2合成酶（cPGES），以及前列腺素E合成酶2（mPGES-2，PTGES2），作为一种高尔基体膜相关蛋白被合成，其N端疏水域发生自发性切割，从而生成截断的成熟细胞质蛋白。