Gamma-glutamyltransferase
Gamma-glutamyl transpeptidase | |||||||||
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Identifiers | |||||||||
Symbol | G_glu_transpept | ||||||||
Pfam | PF01019 | ||||||||
InterPro | IPR000101 | ||||||||
PROSITE | PDOC00404 | ||||||||
Membranome | 274 | ||||||||
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Gamma-glutamyltransferase | |||||||||
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ExPASy NiceZyme view | | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
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Chr. 22 q11.1-11.2 | |||||||
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gamma-glutamyltransferase 2 | |||||||
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Identifiers | |||||||
Symbol | GGT2 | ||||||
Alt. symbols | GGT | ||||||
Chr. 22 q11.1-11.2 | |||||||
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Gamma-glutamyltransferase (also γ-glutamyltransferase, GGT, gamma-GT, gamma-glutamyl transpeptidase;
Nomenclature
The name γ-glutamyltransferase is preferred by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.[5][2] The Expert Panel on Enzymes of the International Federation of Clinical Chemistry also used this name.[6][2] The older name is gamma-glutamyl transpeptidase (GGTP).[2]
Function
GGT is present in the
This general reaction is:- (5-L-glutamyl)-peptide + an amino acid ⇌ peptide + 5-L-glutamyl amino acid
Biochemistry
In prokaryotes and eukaryotes, GGT consists of two polypeptide chains, a heavy and a light subunit, processed from a single chain precursor by an autocatalytic cleavage.[12] The active site of GGT is known to be located in the light subunit.[citation needed]
Co-translational
Clinical significance
GGT is predominantly used as a diagnostic marker for liver disease.[citation needed] Elevated serum GGT activity can be found in diseases of the liver, biliary system, pancreas and kidneys.[13][14] Latent elevations in GGT are typically seen in patients with chronic viral hepatitis infections often taking 12 months or more to present.[citation needed]
Individual test results should always be interpreted using the reference range from the laboratory that performed the test, though example reference ranges are 15–85 IU/L for men, and 5–55 IU/L for women.[15] GGT is similar to alkaline phosphatase (ALP) in detecting disease of the biliary tract. Indeed, the two markers correlate well, though there are conflicting data about whether GGT has better sensitivity.[16][17] In general, ALP is still the first test for biliary disease. The main value of GGT 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.[17]
Alcohol use
GGT is elevated by ingestion of large quantities of alcohol (needs reference) However, determination of high levels of total serum GGT activity is not specific to alcohol intoxication,[18] and the measurement of selected serum forms of the enzyme offer more specific information.[19] Isolated elevation or disproportionate elevation compared to other liver enzymes (such as ALT or alanine transaminase) can indicate harmful alcohol use or alcoholic liver disease,[20] and can indicate excess alcohol consumption up to 3 or 4 weeks prior to the test.[citation needed] The mechanism for this elevation is unclear. Alcohol might increase GGT production by inducing hepatic microsomal production, or it might cause the leakage of GGT from hepatocytes.[21]
Xenobiotics
Numerous drugs can raise GGT levels, including
Cardiovascular disease
More recently, slightly elevated serum GGT has also been found to correlate with
Elevated levels of GGT can also be due to
Neoplasms
GGT is expressed in high levels in many different tumors. It is known to accelerate tumor growth and to increase resistance to cisplatin in tumors.[27]
Examples
Human proteins that belong to this family include
References
- ^ PMID 2868390.
- ^ S2CID 1070555.
- PMID 1378736.
- PMID 16399404.
- ^ "EC 2.3.2.2". International Union of Biochemistry and Molecular Biology. 2011. Retrieved 9 October 2016.
- PMID 6141014.
- PMID 6104563.
- PMID 4152527.
- PMID 2860060.
- PMID 238530.
- PMID 17665541.
- ^ PMID 21712391.
- S2CID 23177210.
- PMID 21307838.
- ^ Mannion CM (2012). General Laboratory Manual (PDF). Department of Pathology, Hackensack University Medical Centre. p. 129. Retrieved 20 February 2014.
- PMID 4148049.
- ^ PMID 5012259.
- PMID 4154814.
- ^ PMID 18023410.
- LCCN 84601128. Research Monograph No. 17.
- S2CID 84080031.
- PMID 4105075.
- ^ "Kava Uses, Benefits & Dosage". Herbal Database. Drugs.com.
- PMID 16203922.
- S2CID 4248204.
- PMID 16186419.
- PMID 10223181.
External links
- MedlinePlus Encyclopedia: Gamma-glutamyl transpeptidase (GGT) blood test
- gamma-Glutamyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- GGT - Lab Tests Online
- Overview of all the structural information available in the PDB for UniProt: P19440 (Gamma-glutamyltransferase 1) at the PDBe-KB.