Additional info: |
Prostaglandin D synthase (PGDS) catalyzes the isomerization of PGH2 to produce PGD2. PGD2 induces sleep, regulates nociception, inhibits platelet aggregation, and acts as an allergic mediator. Two distinct types of PGDS have been identified, namely the lipocalin type enzyme (.beta.-trace) and the hematopoietic enzyme. Lipocalin type PGDS is localized in the central nervous system and male genital organs of various mammals and the human heart. This enzyme has been identified as .beta.-trace, which is a major protein in human cerebrospinal fluid. Hematopoietic PGDS is widely distributed in the peripheral tissues and is localized in the antigen-presenting cells, mast cells, and megakaryocytes. This enzyme, which requires glutathione for activity, belongs to the sigma-class of glutathione-S-transferases and is approximately 23 kDa in size. |