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| {{distinguish|GGGT}}
| | I'm Boyce and I live with my husband and our 3 children in Sarn, in the south area. My hobbies are Vintage car, Home automation and Creative writing.<br><br>Also visit my page: [http://ihometaxsm.com/ihometaxshoppingmall_question/755453 Second Hand Cars in bangalore] |
| {{Pfam_box
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| | Symbol = G_glu_transpept
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| | Name = Gamma-glutamyltranspeptidase
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| | image =
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| | width =
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| | caption =
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| | Pfam= PF01019
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| | InterPro= IPR000101
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| | SMART=
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| | Prosite = PDOC00404
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| | SCOP =
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| | TCDB =
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| | OPM family=
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| | OPM protein=
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| | PDB=
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| }}
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| {{Infobox enzyme
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| | Name = gamma-glutamyltransferase
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| | EC_number = 2.3.2.2
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| | CAS_number = 9046-27-9
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| | IUBMB_EC_number = 2/3/2/2
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| | GO_code = 0003840
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| | image =
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| | width =
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| | caption =
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| }}
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| {{Infobox protein
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| | Name = [[GGT1|gamma-glutamyltransferase 1]]
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| | caption =
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| | image =
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| | width =
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| | HGNCid = 4250
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| | Symbol = [[GGT1]]
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| | AltSymbols = GGT
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| | EntrezGene = 2678
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| | OMIM = 231950
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| | RefSeq = NM_001032364
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| | UniProt = P19440
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| | PDB =
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| | ECnumber = 2.3.2.2
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| | Chromosome = 22
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| | Arm = q
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| | Band = 11.1-11.2
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| | LocusSupplementaryData =
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| }}
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| {{Infobox protein
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| | Name = gamma-glutamyltransferase 2
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| | caption =
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| | image =
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| | width =
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| | HGNCid = 4251
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| | Symbol = GGT2
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| | AltSymbols = GGT
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| | EntrezGene = 2679
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| | OMIM = 137181
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| | RefSeq = NM_002058
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| | UniProt = P36268
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| | PDB =
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| | ECnumber = 2.3.2.2
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| | Chromosome = 22
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| | Arm = q
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| | Band = 11.1-11.2
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| | LocusSupplementaryData =
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| }}
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| '''Gamma-glutamyltransferase''' or '''gamma-glutamyl transpeptidase''' (also '''γ-glutamyltransferase''', '''GGT''', '''GGTP''', '''gamma-GT''') ({{EC number|2.3.2.2}}) is an [[enzyme]] that transfers gamma-glutamyl [[functional group]]s. It is found in many tissues, the most notable one being the [[liver]], and has significance in [[medicine]] as a diagnostic marker.
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| GGT<ref name="PUB00003561">{{cite journal |author=Tate SS, Meister A |title=gamma-Glutamyl transpeptidase from kidney |journal=Meth. Enzymol. |volume=113 |issue= |pages=400–419 |year=1985 |pmid=2868390 |doi=10.1016/S0076-6879(85)13053-3 |series=Methods in Enzymology |isbn=978-0-12-182013-8}}</ref> catalyzes the transfer of the gamma-glutamyl moiety of [[glutathione]] to an acceptor that may be an amino acid, a peptide or water (forming [[glutamate]]). GGT plays a key role in the gamma-glutamyl cycle, a pathway for the synthesis and degradation of glutathione and drug and xenobiotic detoxification.<ref name="PUB00006169">{{cite journal |doi=10.1016/0006-2952(92)90140-E |author=Siest G, Courtay C, Oster T, Michelet F, Visvikis A, Diederich M, Wellman M |title=Gamma-glutamyltransferase: nucleotide sequence of the human pancreatic cDNA. Evidence for a ubiquitous gamma-glutamyltransferase polypeptide in human tissues |journal=Biochem. Pharmacol. |volume=43 |issue=12 |pages=2527–2533 |year=1992 |pmid=1378736}}</ref> Other lines of evidence indicate that GGT can also exert a prooxidant role, with regulatory effects at various levels in cellular signal transduction and cellular pathophysiology,<ref name = dominici />
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| == Function ==
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| GGT is present in the [[cell membrane]]s of many tissues, including the [[kidney]]s, [[bile duct]], [[pancreas]], [[gallbladder]], [[spleen]], [[heart]], [[brain]], and [[seminal vesicles]].<ref name = goldberg /> It is involved in the transfer of [[amino acid]]s across the [[cellular membrane]]<ref name = meister /> and [[leukotriene]] metabolism.<ref name = pmid2860060 /> It is also involved in [[glutathione]] [[metabolism]] by transferring the [[Glutamic acid|glutamyl]] [[Functional group|moiety]] to a variety of acceptor molecules including water, certain [[Levorotation|L]]-[[amino acid]]s, and [[peptides]], leaving the [[cysteine]] product to preserve [[intracellular]] [[homeostasis]] of [[oxidative stress]].<ref name = pmid238530 /><ref name = pmid17665541 /> This general reaction is:
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| :(5-L-glutamyl)-peptide + an amino acid <math>\rightleftharpoons</math> peptide + 5-L-glutamyl amino acid
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| ==Structural studies==
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| In prokaryotes and eukaryotes, it is an enzyme that consists of two polypeptide chains, a heavy and a light subunit, processed from a single chain precursor by an autocatalytic cleavage. The active site of GGT is known to be located in the light subunit.
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| ==Medical applications==
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| GGT is predominantly used as a diagnostic marker for liver disease in [[medicine]].
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| [[Blood test results interpretation#Liver function|Blood test results for GGT]] suggest that the normal value for men is 15-85 IU/L, whereas for women it is 5-55 IU/L.<ref>{{cite book |url=http://www.humc.com/lab_outreach/lab_services_10U.pdf |title=General Laboratory Manual |page=117 |publisher=Department of Pathology, Hackensack University Medical Centre |year=2010 |accessdate=20 November 2011}}</ref>
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| Elevated [[Serum (blood)|serum]] GGT activity can be found in diseases of the liver, biliary system, and pancreas. In this respect, it is similar to [[alkaline phosphatase]] (ALP) in detecting disease of the [[biliary tract]]. Indeed, the two markers correlate well, though there is conflicting data about whether GGT has better [[Sensitivity and specificity|sensitivity]].<ref name = betro /><ref name = lum /> In general, ALP is still the first test for biliary disease. The main value of GGT over ALP is in verifying that ALP elevations are, in fact, due to biliary disease; ALP can also be increased in certain bone diseases, but GGT is not.<ref name = lum /> More recently, slightly elevated serum GGT has also been found to correlate with [[cardiovascular diseases]] and is under active investigation as a cardiovascular risk marker. GGT in fact accumulates in [[atherosclerotic plaques]],<ref name = emdin /> suggesting a potential role in pathogenesis of cardiovascular diseases,<ref name = pompella /> and circulates in blood in the form of distinct protein aggregates,<ref name = franzini /> some of which appear to be related to specific pathologies such as [[metabolic syndrome]], [[alcohol addiction]] and [[chronic liver disease]]. High [[body mass index]] is associated with [[diabetes mellitus type 2|type 2 diabetes]] only in persons with high serum GGT.<ref>{{cite journal | author=Lim JS, Lee DH, Park JY, Jin SH, Jacobs DR Jr | title=A strong interaction between serum gamma-glutamyltransferase and obesity on the risk of prevalent type 2 diabetes: results from the Third National Health and Nutrition Examination Survey | journal=CLINICAL CHEMISTRY | volume=53 | issue=6 | year=2007 | pages=1092–1098 | url = http://www.clinchem.org/content/53/6/1092.long | pmid=17478563 | doi=10.1016/j.jacl.2011.05.004}}</ref>
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| GGT is elevated by large quantities of [[Ethanol|alcohol]] ingestion. Determination of total serum GGT activity is however not specific to alcohol intoxication,<ref name = lamy /> and the measurement of selected serum forms of the enzyme offer more specific information.<ref name = franzini /> Isolated elevation or disproportionate elevation compared to other liver enzymes (such as ALP or [[alanine aminotransferase|ALT]]) may indicate alcohol abuse or [[alcoholic liver disease]].<ref name = kaplan /> It may indicate excess alcohol consumption up to 3 or 4 weeks prior to the test. The mechanism for this elevation is unclear. Alcohol may increase GGT production by inducing hepatic microsomal production, or it may cause the leakage of GGT from [[hepatocyte]]s.<ref name = barouki />
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| Numerous drugs can raise GGT levels, including [[barbiturate]]s and [[phenytoin]].<ref name = rosalki /> GGT elevation has also been occasionally reported following [[nonsteroidal anti-inflammatory drug|NSAIDs]], [[St. John's wort]], and [[aspirin]]. Elevated levels of GGT may also be due to [[congestive heart failure]].<ref name = ruttmann />
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| ==Human proteins==
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| [[GGT1]]; [[GGT2]]; [[GGT6]]; [[GGTL3]]; [[GGTL4]]; [[GGTLA1]]; [[GGTLA4]];
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| == References ==
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| {{reflist | refs =
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| <ref name = meister>{{cite journal | author = Meister A | title = The gamma-glutamyl cycle. Diseases associated with specific enzyme deficiencies | journal = Ann. Intern. Med. | volume = 81 | issue = 2 | pages = 247–53 |date=August 1974 | pmid = 4152527 | doi = | url = }}</ref>
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| <ref name = dominici>{{cite journal | author = Dominici S, Paolicchi A, Corti A, Maellaro E, Pompella A | title = Prooxidant reactions promoted by soluble and cell-bound γ-glutamyltransferase activity | journal = Meth. Enzymol. | volume = 401 | pages = 483–500 | year = 2005 | pmid = 16399404 | url = | doi=10.1016/S0076-6879(05)01029-3}}</ref>
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| <ref name = goldberg>{{cite journal | title = Structural, functional, and clinical aspects of gamma-glutamyltransferase | last = Goldberg | first = DM | journal = Crit Rev Clin Lab Sci | year = 1980 | volume = 12 | pages = 1–58 | pmid = 6104563 | doi = 10.3109/10408368009108725 | issue = 1}}</ref>
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| <ref name = pmid17665541>{{cite journal | author = Yokoyama H | title = [Gamma glutamyl transpeptidase (gammaGTP) in the era of metabolic syndrome] | language = Japanese | journal = Nihon Arukoru Yakubutsu Igakkai Zasshi | volume = 42 | issue = 3 | pages = 110–24 |date=June 2007 | pmid = 17665541 | doi = | url = }}</ref>
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| <ref name = pmid238530>{{cite journal | author = Schulman JD, Goodman SI, Mace JW, Patrick AD, Tietze F, Butler EJ | title = Glutathionuria: inborn error of metabolism due to tissue deficiency of gamma-glutamyl transpeptidase | journal = Biochem. Biophys. Res. Commun. | volume = 65 | issue = 1 | pages = 68–74 |date=July 1975 | pmid = 238530 | doi = 10.1016/S0006-291X(75)80062-3 | url = }}</ref>
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| <ref name = lum>{{cite journal | author = Lum G, Gambino SR | title = Serum gamma-glutamyl transpeptidase activity as an indicator of disease of liver, pancreas, or bone | journal = Clin. Chem. | volume = 18 | issue = 4 | pages = 358–62 |date=April 1972 | pmid = 5012259 | doi = | url = }}</ref>
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| <ref name = emdin>{{cite journal | author = Emdin M, Pompella A, Paolicchi A | title = Editorial - Gamma-glutamyltransferase, atherosclerosis, and cardiovascular disease: triggering oxidative stress within the plaque | journal = Circulation | volume = 112 | pages = 2078–80 | year = 2005 | pmid = 16203922 | doi = 10.1161/CIRCULATIONAHA.105.571919| url = | issue=14}}</ref>
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| <ref name = pompella>{{cite journal | author = Pompella A, Emdin M, Passino C, Paolicchi A | title = The significance of serum gamma-glutamyltransferase in cardiovascular diseases | journal = Clin. Chem. Lab. Med. | volume = 42 | pages = 1085–91 | year = 2004 | pmid = 15552264 | doi = 10.1515/CCLM.2004.224| url = | issue=10}}</ref>
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| <ref name = franzini>{{cite journal | author = Franzini M, Bramanti E, Ottaviano V, Ghiri E, Scatena F, Pompella A, Donato L, Emdin M, Paolicchi A | title = A high performance gel filtration chromatography method for gamma-glutamyltransferase fraction analysis | journal = Anal. Biochem. | volume = 374 | pages = 1–8 | year = 2006 | pmid = 18023410 | doi = 10.1016/j.ab.2007.10.025| url = }}</ref>
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| <ref name = betro>{{cite journal | author = Betro MG, Oon RC, Edwards JB | title = Gamma-glutamyl transpeptidase in diseases of the liver and bone | journal = Am. J. Clin. Pathol. | volume = 60 | issue = 5 | pages = 672–8 |date=November 1973 | pmid = 4148049 | doi = | url = }}</ref>
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| <ref name = rosalki>{{cite journal | author = Rosalki SB, Tarlow D, Rau D | title = Plasma gamma-glutamyl transpeptidase elevation in patients receiving enzyme-inducing drugs | journal = Lancet | volume = 2 | issue = 7720 | pages = 376–7 |date=August 1971 | pmid = 4105075 | doi = 10.1016/S0140-6736(71)90093-6| url = http://www.sciencedirect.com/science/article/pii/S0140673671900936 }}</ref>
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| <ref name = pmid2860060>{{cite journal |author=Raulf M, Stüning M, König W |title=Metabolism of leukotrienes by L-gamma-glutamyl-transpeptidase and dipeptidase from human polymorphonuclear granulocytes |journal=Immunology |volume=55 |issue=1 |pages=135–47 |date=May 1985 |pmid=2860060 |pmc=1453575 |doi= |url=}}</ref>
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| <ref name = kaplan>{{Cite book | author = Kaplan MM, '''et al.''' | title = Biochemical basis for serum enzyme abnormalities in alcoholic liver disease | in = Early identification of alcohol abuse | editor = Chang NC, Chan NM | work = Research Monograph No. 17 | publisher = NIAAA | year = 1985 | page = 186}}</ref>
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| <ref name = barouki>{{cite journal | author = Barouki R, Chobert MN, Finidori J, Aggerbeck M, Nalpas B, Hanoune J | title = Ethanol effects in a rat hepatoma cell line: induction of gamma-glutamyltransferase | journal = Hepatology | volume = 3 | issue = 3 | pages = 323–9 | year = 1983 | pmid = 6132864 | doi = 10.1002/hep.1840030308 }}</ref>
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| <ref name = lamy>{{cite journal | author = Lamy J, Baglin MC, Ferrant JP, Weill J | title = Determination de la gamma-glutamyl transpeptidase senque des ethyliques a la suite du sevrage | journal = Clin Chim Acta | year = 1974 | volume = 56 | page = 169}}</ref>
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| <ref name = ruttmann>{{cite journal | author = Ruttmann E, Brant LJ, Concin H, Diem G, Rapp K, Ulmer H | title = Gamma-glutamyltransferase as a risk factor for cardiovascular disease mortality: an epidemiological investigation in a cohort of 163,944 Austrian adults | journal = Circulation | volume = 112 | issue = 14 | pages = 2130–7 |date=October 2005 | pmid = 16186419 | doi = 10.1161/CIRCULATIONAHA.105.552547 | url = }}</ref>
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| ==External links==
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| * {{MedlinePlusEncyclopedia|003458}}
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| * {{MeshName|gamma-Glutamyltransferase}}
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| {{Acyltransferases}}
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| {{Amino acid metabolism enzymes}}
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| {{Eicosanoid metabolism enzymes}}
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| {{Clinical biochemistry blood tests}}
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| [[Category:Chemical pathology]]
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| [[Category:EC 2.3.2]]
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