Ciclooxigenase 1 also known as Prostaglandin Endoperoxide H Synthase-1. Prostaglandin endoperoxide H synthases (PGHSs) catalyze the committed step in the biosynthesis of prostaglandins and thromboxane, the conversion of arachidonic acid, two molecules of O2, and two electrons to prostaglandin endoperoxide H2 (PGH2).
PTGS1 (COX-1) and PTGS2 (COX-2) are bifunctional enzymes that carry out two consecutive chemical reactions in spatially distinct but mechanistically coupled active sites. Both the cyclooxigenase and the peroxidase active sites are located in the catalytic domain, which accounts for approximately 80% of the protein. The catalytic domain is homologous to mammalian peroxidases such as myeloperoxidase.
Myeloperoxidase (MPO) also is a peroxidase enzyme. MPO is most abundantly expressed in neutrophil granulocytes (a subtype of white blood cells), and produces hypohalous acids to carry out their antimicrobial activity.It is a lysosomal protein stored in azurophilic granules of the neutrophil and released into the extracellular space during degranulation. Neutrophil myeloperoxidase has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus. The green color contributed to its outdated name verdoperoxidase.
Non-steroidal anti-inflamatory drugs (NSAIDs) inhibit prostaglandin production by PTGS1 (COX-1) and PTGS2 (COX-2).
REFERENCES
PDB:1igx
Prostaglandin Endoperoxide H Synthase-1.
THE FUNCTIONS OF CYCLOOXYGENASE ACTIVE SITE RESIDUES IN THE BINDING, POSITIONING, AND OXYGENATION OF ARACHIDONIC ACID. Elizabeth D. Thuresson, Karen M. Lakkides, Caroline Jill Rieke , Michael G. Malkowski. ENZYME CATALYSIS AND REGULATION| Volume 276, ISSUE 13, P10347-10357, March 30, 200
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