Aspartate
transaminase (AST) also called serum glutamic
oxaloacetic transaminase (SGOT) or aspartate
aminotransferase (ASAT/AAT) (EC
2.6.1.1) is similar to
alanine transaminase (ALT) in that it is another enzyme
associated with liver
parenchymal cells.
Function
It facilitates the conversion of
aspartate and
alpha-ketoglutarate to
oxaloacetate and
glutamate, and vice-versa.
Aspartate + α-ketoglutarate ⇌ oxaloacetate + glutamate
Isozymes
Two isoenzymes are present in humans. They have high
similarity.
Clinical
significance
It is raised in acute liver damage. It is also present in
red blood cells and
cardiac muscle, skeletal muscle, and kidney and brain
tissue, and may be elevated due to damage to those sources as
well.
AST was defined as a biochemical marker for the diagnosis of
acute myocardial infarction in 1954. However the use of AST for
such a diagnosis is now redundant and has been superseded by the
cardiac troponins.[2]
AST (SGOT) is commonly measured clinically as a part of
diagnostic
liver function tests, to determine
liver
health.
References
-
^
PDB
1AAMAlmo SC, Smith
DL, Danishefsky AT, Ringe D (March 1994). "The
structural basis for the altered substrate specificity
of the R292D active site mutant of aspartate
aminotransferase from E. coli". Protein Eng. 7
(3): 405–12.
PMID
7909946.
- ^
Gaze DC (2007). "The role
of existing and novel cardiac biomarkers for
cardioprotection". Curr. Opin. Invest. Drugs 8
(9): 711–717.
PMID
17729182.
-
^
GPnotebook > reference range (AST) Retrieved on Dec
7, 2009
Journal articles
- Kuramitsu S, Okuno S,
Ogawa T, Ogawa H, Kagamiyama H (1985). "Aspartate
aminotransferase of Escherichia coli: nucleotide sequence of
the aspC gene". J. Biochem. 97 (4): 1259–62.
PMID
3897210.
- Kondo K, Wakabayashi S,
Yagi T, Kagamiyama H (1984). "The complete amino acid
sequence of aspartate aminotransferase from Escherichia
coli: sequence comparison with pig isoenzymes". Biochem.
Biophys. Res. Commun. 122 (1): 62–7.
doi:10.1016/0006-291X(84)90439-X.
PMID
6378205.
- Inoue K, Kuramitsu S,
Okamoto A, Hirotsu K, Higuchi T, Kagamiyama H (1991).
"Site-directed mutagenesis of Escherichia coli aspartate
aminotransferase: role of Tyr70 in the catalytic processes".
Biochemistry 30 (31): 7796–801.
doi:10.1021/bi00245a019.
PMID
1868057.
See also
External links
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[hide]
Mitochondrial
enzymes and transporters |
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Outer membrane |
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Intermembrane space |
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Inner membrane |
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Matrix |
citric acid cycle (Citrate
synthase,
Aconitase,
Isocitrate dehydrogenase,
Oxoglutarate dehydrogenase,
Succinyl coenzyme A synthetase,
Fumarase,
Malate dehydrogenase)
anaplerotic reactions (Aspartate
transaminase,
Glutamate dehydrogenase,
Pyruvate dehydrogenase complex)
urea cycle (Carbamoyl
phosphate synthetase I,
Ornithine transcarbamylase,
N-Acetylglutamate synthase)
alcohol metabolism ( ALDH2)
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Other/to be sorted |
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Mitochondrial DNA |
Complex I (MT-ND1,
MT-ND2,
MT-ND3,
MT-ND4,
MT-ND4L,
MT-ND5,
MT-ND6) -
Complex III (MT-CYB)
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Complex IV (MT-CO1,
MT-CO2,
MT-CO3)
ATP synthase (MT-ATP6,
MT-ATP8)
tRNA ( MT-TA,
MT-TC,
MT-TD,
MT-TE,
MT-TF,
MT-TG,
MT-TH,
MT-TI,
MT-TK,
MT-TL1,
MT-TL2,
MT-TM,
MT-TN,
MT-TP,
MT-TQ,
MT-TR,
MT-TS1,
MT-TS2,
MT-TT,
MT-TV,
MT-TW,
MT-TY)
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