Additional info: |
Prostaglandin D synthase (PGD synthase) 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 PGD synthase have been identified, namely the lipocalin-type enzyme (.beta.-trace) and the hematopoietic enzyme. Lipocalin-type PGD synthase is localized in the central nervous system and male genital organs of various mammals and the human heart whereas the hematopoietic PGD synthase is widely distributed in the peripheral tissues and localized in the antigen-presenting cells, mast cells, and megakaryocytes. The lipocalin-type PGD synthase has been identified as .beta.-trace, which is a major protein in human cerebrospinal fluid. Human lipocalin-type PGD synthase is a 190 amino acid protein with a calculated molecular weight of 21,016. |