Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.44 (AGT)
 770 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A deficiency of activity of the peroxisomal enzyme alanine:glyoxylate aminotransferase (AGT,EC 2.6.1.44)has been found in the livers of six patients with primary hyperoxaluria type 1 (PH), including three in whom the tissue was obtained by percutaneous needle biopsy. AGT activity, assayed in unfractionated liver tissue, ranged from 11 to 47% of the mean control value, and appeared to be related to the clinical severity of PH and to several biochemical variables which indicate the degree of pathophysiological derangement. There was no difference between patients and controls in the activities of glutamate: glyoxylate aminotransferase (GGT, EC 2.6.1.4) or catalase (EC 1.11.1.6). In the five most severe cases residual AGT activity could be largely accounted for by the crossover from another enzyme, presumably GGT. PH can be diagnosed using percutaneous hepatic needle biopsy and assay of AGT, whose activity may be useful in determining the prognosis and likely severity of the disease.
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PMID:Enzymological diagnosis of primary hyperoxaluria type 1 by measurement of hepatic alanine: glyoxylate aminotransferase activity. 288 Jan 11

1. The activity of alanine:glyoxylate aminotransferase (AGT; EC 2.6.1.44) has been measured in the unfractionated livers of 20 patients with primary hyperoxaluria type 1 (PH1), three patients with other forms of primary hyperoxaluria and one PH1 heterozygote. The subcellular distribution of AGT activity was examined in four of the PH1 livers and in the liver of the PH1 heterozygote. 2. The mean AGT activity in the unfractionated PH1 livers was 12.6% of the mean control value. The activities of other aminotransferases and the peroxisomal marker enzymes were normal. When corrected for cross-over from glutamate:glyoxylate aminotransferase (GGT; EC 2.6.1.4), the mean AGT activity in the PH1 livers was reduced to 3.3% of the control values. 3. The livers from a patient with primary hyperoxaluria type 2 (D-glycerate dehydrogenase deficiency) and one with an undefined form of primary hyperoxaluria (possibly oxalate hyperabsorption) had normal AGT levels. The livers of a very mild PH1-type variant and a PH1 heterozygote had intermediate levels of AGT activity. 4. Subcellular fractionation of four PH1 livers by sucrose gradient isopycnic centrifugation demonstrated a complete absence of peroxisomal AGT activity. The subcellular distribution of the residual AGT activity was very similar to that of GGT activity (i.e. mainly cytosolic with a small amount mitochondrial). There were no alterations in the subcellular distributions of any of the peroxisomal marker enzymes. The subcellular distribution of AGT activity in the PH1 heterozygote liver was similar to that of the control (i.e. mainly peroxisomal).
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PMID:Further studies on the activity and subcellular distribution of alanine:glyoxylate aminotransferase in the livers of patients with primary hyperoxaluria type 1. 341 63

We have developed a sensitive assay for the measurement of alanine:glyoxylate aminotransferase (EC 2.6.1.44) activity in human liver. The assay is partly automated, and takes into consideration the sensitivity of the reaction to pH and to glyoxylate concentration. It is less subject to interference from other enzymes utilizing glyoxylate and to chemical interference from glyoxylate itself and can therefore be used without correction for cross-over by glutamate:glyoxylate aminotranferase (EC 2.6.1.4). The assay allows clear discrimination between normal and affected livers and is sufficiently sensitive to measure enzyme activity in fetal liver samples. Enzyme activity ranged from 17.9 to 38.5 mumol/h/mg protein in control livers (n = 9) and 0.8 to 9.5 mumol/h/mg protein in 30 of 39 hyperoxaluric patients studied. Normal alanine:glyoxylate aminotransferase activity (from 22.8 to 45.5 mumol/h/mg protein) allowed exclusion of primary hyperoxaluria type 1 in the other nine hyperoxaluric patients.
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PMID:A semiautomated alanine:glyoxylate aminotransferase assay for the tissue diagnosis of primary hyperoxaluria type 1. 924 73