Editing Cyclooxygenase (section)

{{cs1 config|name-list-style=vanc}}
{{Short description|Class of enzymes}}
{{redirect|COX||Cox (disambiguation)}}
{{infobox enzyme
| Name       = Prostaglandin-endoperoxide synthase
| EC_number  = 1.14.99.1
| CAS_number = 9055-65-6
| GO_code    = 0004666
| image      =
| width      = 
| caption    =  
}}
{{infobox protein
|Name= [[PTGS1|Cyclooxygenase 1]]
|caption=Crystallographic structure of prostaglandin H2 synthase-1 complex with [[flurbiprofen]]<ref name="pmid8121489">{{PDB|1CQE}}; {{cite journal | vauthors = Picot D, Loll PJ, Garavito RM | title = The X-ray crystal structure of the membrane protein prostaglandin H2 synthase-1 | journal = Nature | volume = 367 | issue = 6460 | pages = 243–9 | date = January 1994 | pmid = 8121489 | doi = 10.1038/367243a0 | bibcode = 1994Natur.367..243P | s2cid = 4340064 }}</ref>
|image= PROSTAGLANDIN H2 SYNTHASE-1 COMPLEX.png
|width=
|HGNCid=9604
|Symbol=[[PTGS1]]
|AltSymbols=COX-1
|EntrezGene=5742
|OMIM=176805
|RefSeq=NM_080591
|UniProt=P23219
|PDB=1CQE
|ECnumber=1.14.99.1
|Chromosome=9
|Arm=q
|Band=32
|LocusSupplementaryData=-q33.3
}}
{{infobox protein
|Name=[[PTGS2|Cyclooxygenase 2]]
|caption= Cyclooxygenase-2 (prostaglandin synthase-2) in complex with a COX-2 selective inhibitor<ref name="pmid8967954">{{PDB|6COX}}; {{cite journal | vauthors = Kurumbail RG, Stevens AM, Gierse JK, McDonald JJ, Stegeman RA, Pak JY, Gildehaus D, Miyashiro JM, Penning TD, Seibert K, Isakson PC, Stallings WC | title = Structural basis for selective inhibition of cyclooxygenase-2 by anti-inflammatory agents | journal = Nature | volume = 384 | issue = 6610 | pages = 644–8 | year = 1996 | pmid = 8967954 | doi = 10.1038/384644a0 | bibcode = 1996Natur.384..644K | s2cid = 4326310 }}</ref>
|image=Cyclooxygenase-2.png
|width=
|HGNCid=9605
|Symbol=[[PTGS2]]
|AltSymbols=COX-2
|EntrezGene=5743
|OMIM=600262
|RefSeq=NM_000963
|UniProt=P35354
|PDB=6COX
|ECnumber=1.14.99.1
|Chromosome=1
|Arm=q
|Band=25.2
|LocusSupplementaryData=-25.3
}}

'''Cyclooxygenase''' ('''COX'''), officially known as '''prostaglandin-endoperoxide synthase''' ('''PTGS'''), is an [[enzyme]] (specifically, a family of [[isozyme]]s, {{EC_number|1.14.99.1}}) that is responsible for biosynthesis of [[prostanoid]]s, including [[thromboxane]] and [[prostaglandin]]s such as [[prostacyclin]], from [[arachidonic acid]]. A member of the [[animal heme-dependent peroxidases|animal-type heme peroxidase]] family, it is also known as '''prostaglandin G/H synthase'''. The specific reaction catalyzed is the conversion from arachidonic acid to [[prostaglandin H2]] via a short-living [[prostaglandin G2]] intermediate.<ref name = "Litalien_2011">{{cite book | vauthors = Litalien C, Beaulieu P | chapter = Chapter 117 – Molecular Mechanisms of Drug Actions: From Receptors to Effectors | veditors = Fuhrman BP, Zimmerman JJ |title=Pediatric Critical Care | url = https://archive.org/details/pediatriccritica00mdbr | url-access = limited |date=2011 |publisher=Elsevier Saunders |location=Philadelphia, PA |isbn=978-0-323-07307-3 | doi = 10.1016/B978-0-323-07307-3.10117-X |pages=[https://archive.org/details/pediatriccritica00mdbr/page/n1557 1553]–1568 |edition=4th |quote=Arachidonic acid is a component of membrane phospholipids released either in a one-step process, after phospholipase A2 (PLA2) action, or a two-step process, after phospholipase C and DAG lipase actions. Arachidonic acid is then metabolized by cyclooxygenase (COX) and 5-lipoxygenase, resulting in the synthesis of prostaglandins and leukotrienes, respectively. These intracellular messengers play an important role in the regulation of signal transduction implicated in pain and inflammatory responses. }}</ref><ref>{{cite journal | vauthors = Liu J, Seibold SA, Rieke CJ, Song I, Cukier RI, Smith WL | title = Prostaglandin endoperoxide H synthases: peroxidase hydroperoxide specificity and cyclooxygenase activation | journal = The Journal of Biological Chemistry | volume = 282 | issue = 25 | pages = 18233–44 | date = June 2007 | pmid = 17462992 | doi = 10.1074/jbc.M701235200 | doi-access = free }}</ref>

[[Pharmaceutical drug|Pharmaceutical]] inhibition of COX can provide relief from the symptoms of [[inflammation]] and [[pain]].<ref name="Litalien_2011" /> [[Nonsteroidal anti-inflammatory drug]]s (NSAIDs), such as [[aspirin]] and [[ibuprofen]], exert their effects through inhibition of COX. Those that are specific to the [[COX-2]] isozyme are called [[COX-2 inhibitor]]s. The active metabolite ([[AM404]]) of [[paracetamol]] is a COX inhibitor, a fact to which some or all of its [[Analgesic|therapeutic effect]] has been attributed.<ref name="pmid15987694">{{cite journal | vauthors = Högestätt ED, Jönsson BA, Ermund A, Andersson DA, Björk H, Alexander JP, Cravatt BF, Basbaum AI, Zygmunt PM | title = Conversion of acetaminophen to the bioactive N-acylphenolamine AM404 via fatty acid amide hydrolase-dependent arachidonic acid conjugation in the nervous system | journal = The Journal of Biological Chemistry | volume = 280 | issue = 36 | pages = 31405–12 | date = September 2005 | pmid = 15987694 | doi = 10.1074/jbc.M501489200 | s2cid = 10837155 | url = http://www.jbc.org/content/280/36/31405.full.pdf | doi-access = free }}</ref>

In medicine, the [[gene nomenclature#Symbol and name|root symbol]] "COX" is encountered more often than "PTGS". In [[genetics]], "PTGS" is officially used for this family of [[gene]]s and [[protein]]s because the root symbol "COX" was already used for the [[cytochrome c oxidase]] family. Thus, the two isozymes found in humans, [[PTGS1]] and [[PTGS2]], are frequently called COX-1 and COX-2 in medical literature. The names "prostaglandin synthase (PHS)", "prostaglandin synthetase (PHS)", and "prostaglandin-endoperoxide synthetase (PES)" are older terms still sometimes used to refer to COX.