SEARCH · Search PubMed

Results for “TRANSAMINASES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

PubMed1974

Subcellular distribution and properties of kynurenine transaminase in rat liver.

Kynurenine transaminase activity in rat liver was found in both the mitochondrial and supernatant fractions. The mitochondrial and supernatant fractions contained (a) kynurenine-pyruvate transaminase, which showed a preference for pyruvate as amino acceptor and a pH optimum between 8.0 and 8.5, and (b) kynurenine-alpha-oxoglutarate transaminase, with a preference for alpha-oxoglutarate and a pH optimum between 6.0 and 6.5. Possible roles of these enzymes in tryptophan metabolism in the liver are discussed.

Alcohol Oxidoreductases↗

PubMed2001

Effect of alcohol withdrawal on liver transaminase levels and markers of liver fibrosis.

BACKGROUND AND AIM: Acute alcohol withdrawal causes changes in hepatic blood flow and metabolism that may result in liver damage. This study aims to assess liver function tests and markers of hepatic fibrogenesis following alcohol withdrawal in alcoholics with clinically compensated liver disease. METHODS: Serial liver function tests and clinical assessments were performed on 22 male alcoholics during alcohol withdrawal. Plasma tissue inhibitor of metalloproteinase 1 (TIMP1), an inhibitor of collagen degradation, and plasma amino-terminal procollagen III peptide (PIIINP), a collagen precursor molecule, were measured in these alcoholics and in 11 control subjects. RESULTS: Transaminase levels did not change significantly over 7 days when all subjects were analyzed together. However, 32% of subjects showed a marked transaminase rise. These subjects did not differ from the others in baseline characteristics or short-term outcome, but had a greater benzodiazepine requirement. Only one subject consumed paracetamol (acetaminophen; 1-2 g/day). He had the largest transaminase rise. By comparing PIIINP assays, intact PIIINP concentration appears to increase following alcohol withdrawal. The TIMP1 levels were elevated in alcoholic subjects, but did not change following withdrawal. CONCLUSIONS: Increasing PIIINP suggests that hepatic fibrogenesis increases, or hepatic clearance falls, during acute alcohol withdrawal. The TIMP1 elevation in these alcoholics suggests that the inhibition of collagen degradation occurs while liver disease is still compensated. The period following alcohol withdrawal may be a time of marked increased susceptibility to paracetamol. The biochemical changes we observed were not associated with adverse short-term outcome, but the cumulative effect after repeated episodes of abrupt withdrawal may be of concern.

Adult↗

PubMed1984

Gamma-aminobutyric acid-transaminase deficiency: a newly recognized inborn error of neurotransmitter metabolism.

Cerebrospinal fluid aminoacid analysis in a girl with severe psychomotor retardation, hypotonia, hyperreflexia and growth acceleration showed highly increased levels of free gamma-aminobutyric acid (4.8 mumol/l; range in twenty controls 0.04-0.12, median 0.08), homocarnosine, a dipeptide of gamma-aminobutyric acid and histidine (23.4 mumol/l; control range 4.0-8.7, median 7.6) and of beta-alanine, an alternative substrate for gamma-aminobutyric acid-transaminase (0.48 mumol/l; control range 0.02-0.06, median 0.05). Liver gamma-aminobutyric acid-transaminase activity was deficient (0.07 mumol/mg protein h; range in ten controls 0.31-0.69, median 0.38). Fasting plasma growth hormone levels were increased (7.9-38.4 ng/ml; nl less than 5). Brain evoked responses were suggestive of leukodystrophy. A brother of this patient, showing a similar clinical picture, had died at one year. Postmortem examination of his brain showed leukodystrophy of the type seen in amino acidopathies such as phenylketonuria. This appears to be the first report of gamma-aminobutyric acid-transaminase deficiency.

4-Aminobutyrate Transaminase↗

PubMed2000

Effects of vitamin B6 supplementation in rats during lactation on vitamin B6 concentration and transaminase activities in the offspring.

The aim of the present investigation was to study the effect of a varying maternal vitamin B6 supplementation during lactation period on vitamin B6 levels in blood, liver and total body, and on the activity of two transaminase enzymes in the offspring. Therefore, eighty female Sprague-Dawley rats were fed a semi-synthetic diet (0.2 mg vitamin B6 per kg) which was supplemented during gravidity with 5 mg vitamin B6 per kg diet. During the following lactation period the rats were assigned to one of 10 vitamin B6 treatment groups (supplementation of 0, 3, 6, 9, 12, 15, 18, 36, 360, 3600 mg vitamin B6 per kg diet). At day 14 of lactation the pubs of all dams were decapitated and blood, liver, and carcass were used for analysis of vitamin B6 concentration, activities of two transaminases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in plasma, erythrocytes, and liver, and of haematological parameters. While the liver and total body wet weights as well as the haematological parameters (red blood cells, haemoglobin concentration, hematocrit, middle corpuscular cell volume, middle corpuscular haemoglobin, middle corpuscular haemoglobin concentration) did not differ within the experimental groups, the present data clearly show that in blood, liver and total body of the offspring exists a slight dose-response relationship between the maternal dietary vitamin B6 supplementation and the vitamin B6 concentration. Concerning the activities of the transaminases a dietary supplementation above 3 mg vitamin B6 per kg diet had no influence on the AST and ALT activities in offspring plasma. In the erythrocytes no statistical significant influence of the vitamin B6 supplementation during lactation on the activities of AST and ALT was found. The activities of ALT and AST in liver were not consistently altered by the vitamin B6 supplementation of the dams during lactation. In conclusion these results indicate that a minimal maternal dietary vitamin B6 supply of 3.1 mg per kg diet is necessary with regard to health and development of their offspring. But not all of the analysed parameters as the liver and total body weights, the activities of AST and ALT in the erythrocytes, and the haematological parameters were influenced by a deficient maternal dietary vitamin B6 supply.

Alanine Transaminase↗

PubMed1978

Apoenzyme activities of erythrocyte transketolase, glutathione reductase, and glutamic-pyruvic transaminase during pregnancy.

The erythrocyte apoenzyme activities of transketolase, glutathione reductase, and glutamic-pyruvic transaminase were determined in 236 pregnant women during the first or second trimester and again during the third trimester. There were no differences in erythrocyte glutathione reductase and erythrocyte glutamic-pyruvic transaminase activities during these two periods. In contrast, erythrocyte transketolase decreased significantly in the third trimester. No statistically significant correlations were found between levels of activity for the various enzymes and dietary intakes of protein, vitamins or calories. The percent of subjects with low erythrocyte transketolase activity (a value one standard deviation or more below the mean initial value) increased significantly during the third trimester. The percent of subjects with low erythrocyte glutamic-pyruvic transaminase activity was significantly reduced during the third trimester although the mean apoenzyme level did not change. Vitamin deficiencies as measured by enzyme stimulation tests tended to occur less frequently among subjects with low enzyme activities but in no instance was there a statistically significant difference. Hence, no association could be found between apoenzyme activity and the incidence of vitamin deficiencies.

Alanine Transaminase↗

PubMed1993

In vitro translocation of L-alanine:4,5-dioxovalerate transaminase into rat kidney mitochondria.

A specific rabbit antibody was prepared against rat kidney mitochondrial L-alanine: 4,5-dioxovalerate transaminase, which is one of the two enzymes catalyzing the synthesis of delta-aminolevulinic acid in the heme biosynthetic pathway. Total polyadenylated RNA isolated from rat kidney was translated in vitro using rabbit reticulocyte cell-free translation system, and L-alanine:4,5-dioxovalerate transaminase was estimated by indirect immunoprecipitation to represent 0.85% of the total translation product. When the total in vitro translated product was incubated with homologous kidney mitochondria, 59% of the [35S]methionine labeled enzyme was translocated into the mitochondria where it was no longer accessible to externally added protease. In relation to total protein translocation, the translocation of L-alanine:4,5-dioxovalerate transaminase remained unaltered by addition of hemin up to 50 microM. These results show that, unlike the other enzyme of the heme biosynthetic pathway (delta-aminolevulinic acid synthetase), this enzyme is not under tight control by heme, but nonetheless, functions as an important source to maintain a housekeeping level of delta-aminolevulinic acid.

Amino Acids↗

PubMedDate not supplied

Serum transaminase elevations in infants with rotavirus gastroenteritis.

Over a 6-week period, 35 (41%) of 86 infants admitted with diarrhea and dehydration were found to have human rotavirus (HRV) gastroenteritis, using the Rotazyme (RTZ) test. Serum transaminase levels were measured on 44 infants on admission and 72 infants during the first 3 days of hospitalization. On admission, RTZ-positive (RTZ+) infants had higher mean and median alanine aminotransferase (ALT) levels [mean 87.5 U/L in RTZ+ vs. 50.0 U/L in RTZ-negative (RTZ-), p = 0.001; medium 60 U/L in RTZ+ vs. 41 U/L in RTZ- infants, p = 0.002], and higher mean and median aspartate aminotransferase (AST) levels (mean 64.3 U/L in RTZ+ vs. 44.0 U/L in RTZ- infants, p = 0.008; median 67.5 U/L vs. 42.0 U/L, respectively, p = less than 0.05). On admission, 72% of RTZ+ vs. 19% of RTZ- infants had ALT levels greater than 50 U/L (p = 0.0004). Maximum ALT levels from the first 3 days were also higher in the RTZ+ group (67.7% of RTZ+ vs. 34.1% of RTZ- having levels greater than 50 U/L, p = 0.005). Transaminase elevations did not correlate with dehydration of any electrolyte abnormalities. These findings suggest that transaminase elevations are common in infants hospitalized with HRV enteritis.

Alanine Transaminase↗

PubMed2004

Serum transaminases in children with Wilson's disease.

OBJECTIVES: The response of serum transaminase levels to penicillamine and zinc treatment in Wilson's disease is poorly understood. The aim of this multicenter retrospective study was to evaluate transaminase levels after penicillamine and zinc treatment in children with Wilson's disease. PATIENTS AND METHODS: One hundred and nine patients with Wilson's disease (median age at diagnosis, 7.2 years; range, 1 to 18 years), treated for at least 12 months and observed in the last 20 years at 11 Paediatric Departments were studied. Clinical, laboratory and histologic features at diagnosis and initial treatment were recorded. Efficacy parameters were normalization of serum transaminase level and improved clinical and/or laboratory signs. One hundred and two patients had clinical or laboratory signs of liver disease. RESULTS: Fifty-six of 87 patients (64%) given penicillamine normalized serum alanine aminotransferase (ALT) levels within a median of 17 months (range, 2 to 96 months). Of the 29 patients with persistent hyper-ALT, 17 (59%) switched to zinc; only four of these normalized ALT on zinc within a median period of 38 months (range, 7 to 48 months). Eleven (50%) of the 22 patients given zinc alone normalized ALT within a median period of 6 months (range, 1 to 36 months). Of the 11 patients with persistent hyper-ALT, five switched to penicillamine. Three of the five normalized ALT within a median period of 6 months (range, 6 to 9 months). Overall, in penicillamine-treated and zinc-treated patients with persistent hypertransaminasemia, ALT decreased from a basal median of 236 IU/L (range, 54 to 640 IU/L) to a median of 78 (range, 46 to 960 IU/L) at the end of follow-up (P = 0.0245). Poor compliance was suspected in only 10% of cases. No predictive factor of persistent hypertransaminasemia was identified. Liver disease did not worsen in any patient during the study. CONCLUSIONS: Although the efficacy of penicillamine and zinc is well documented, it is notable that a subset of children with Wilson's disease-related liver disease (36%) had hypertransaminasemia despite appropriate treatment with penicillamine or zinc.

Adolescent↗

PubMed1989

An epidemiological and clinical study of transaminase levels and hepatitis B antibodies in 1,100 blood donors.

In order to provide epidemiological and clinical information on surrogate testing of blood donations, the respective prevalences of serum hepatitis B virus (HBV) markers and elevated transaminase levels were studied in 1,100 blood donors according to their geographic origin and socioeconomic level. The frequency of serum HBV markers varied as a function of HBV endemicity in the country of origin; however, it was inversely correlated (p less than 0.05) to the socioeconomic level of the donors, even in those originating from countries of low HBV endemicity. There was no association between serum HBV markers and the increased transaminase level which was observed in 48 (4.3%) donors. Twenty-five of these accepted further clinical evaluation. A diagnosis appeared probable in 12 of the 25: alcohol in 5; drugs in 6; non-A, non-B hepatitis in 1. Seven of the remaining 13 subjects were more than 25% above ideal body weight. Transaminase activities determined at the time of clinical assessment were normal in 14. In addition, serum HBV DNA was found in 5 of 247 donors, even in the absence of any usual HBV marker and/or hypertransaminasemia. This could account for the few cases of B and B-like posttransfusion hepatitis which are known to still occur despite careful HBsAg screening of blood donors.

Biomarkers↗

PubMed1986

The transamination of L-cystathionine, L-cystine and related compounds by a bovine kidney transaminase.

An enzyme which actively transaminates L-cystathionine, L-cystine, L-lanthionine and S-aminoethyl-L-cysteine has been purified from bovine kidney. The transaminase appears to be pure up to 90% and probably consists of two subunits of similar molecular mass of about 47 kDa. The enzymatic products arising from the transamination of L-cystathionine and related compounds spontaneously cyclize into ketiminic structures, which are the immediate precursors of unusual imino acids recovered in biological materials. The specificity towards other amino acid and oxo acid acceptors is similar to the specificity exhibited by rat kidney glutamine transaminase. This suggests that the sulfur amino acid transaminations that have been described could be performed by the bovine kidney glutamine transaminase.

Alanine↗

PubMed1980

Allele increasing susceptibility to human breast cancer may be linked to the glutamate-pyruvate transaminase locus.

The patterns of the occurrence of breast cancer in 11 high-risk families were evaluated by segregation and linkage analysis. These patterns were consistent with the hypothesis that increased susceptibility to breast cancer was inherited as an autosomal dominant allele with high penetrance in women. The postulated susceptibility allele in these families may be chromosomally linked to the glutamate-pyruvate transaminase (E.C. 2.6.1.2, alanine aminotransferase) locus. Confirmation of this linkage in other families would establish the existence of a gene increasing susceptibility to breast cancer. Since there is no association in the general population between a woman's glutamate-pyruvate transaminase genotype and her cancer risk, the glutamate-pyruvate transaminase linkage cannot be used as a screening test for breast cancer.

Alanine Transaminase↗

PubMed1990

Stereospecific production of the herbicide phosphinothricin (glufosinate) by transamination: isolation and characterization of a phosphinothricin-specific transaminase from Escherichia coli.

An aminotransferase capable of transaminating 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid to L-phosphinothricin [L-homoalanine-4-yl-(methyl)phosphinic acid], the active ingredient of the herbicide Basta (Hoechst AG), was purified to apparent homogeneity from Escherichia coli K-12. The enzyme catalyzes the transamination of L-phosphinothricin and various analogs with 2-ketoglutarate as the amino group acceptor. The transaminase has a molecular mass of 43 kilodaltons by sodium dodecyl sulfate-gel analysis and an isoelectric point of 4.35. The enzyme was most active in the high-pH region, with a maximum at pH 8.0 to 9.5, and had a temperature optimum of 55 degrees C. Heat stability was observed up to 70 degrees C. Substrate specificity studies suggested that the enzyme is identical with the 4-aminobutyrate:2-ketoglutarate transaminase (EC 2.6.1.19). The first 30 amino acids of the N terminus of the protein were determined by gas phase sequencing. The transaminase was immobilized by coupling to the epoxy-activated carrier VA-Biosynth (Riedel de Haen) and used in a column reactor for the continuous production of L-phosphinothricin. The enzyme reactor was operated for 7 weeks with only a slight loss of catalytic capacity. Production rates of more than 50 g of L-phosphinothricin per liter of column per h were obtained.

Aminobutyrates↗

PubMed1983

Role of alanine-valine transaminase in Salmonella typhimurium and analysis of an avtA::Tn5 mutant.

In Salmonella typhimurium, as in Escherichia coli, mutations in avtA, the gene encoding the alanine-valine transaminase (transaminase C), are silent unless they are combined with mutations involved in isoleucine-valine biosynthesis. avtA is repressed by leucine or alanine but not by valine. Transaminase C is found at reduced levels upon starvation for any one of several amino acids. We hypothesize that this is due to repression of avtA by the elevated alanine and leucine pools found in amino acid-starved cells.

Culture Media↗

PubMed1985

beta-Chloro-L-alanine inhibition of the Escherichia coli alanine-valine transaminase.

beta-Chloro-L-alanine, an amino acid analog which inhibits a number of enzymes, reversibly inhibited the Escherichia coli K-12 alanine-valine transaminase, transaminase C. This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine.

Alanine↗

PubMed2002

The 2-aminoethylphosphonate-specific transaminase of the 2-aminoethylphosphonate degradation pathway.

The 2-aminoethylphosphonate transaminase (AEPT; the phnW gene product) of the Salmonella enterica serovar Typhimurium 2-aminoethylphosphonate (AEP) degradation pathway catalyzes the reversible reaction of AEP and pyruvate to form phosphonoacetaldehyde (P-Ald) and L-alanine (L-Ala). Here, we describe the purification and characterization of recombinant AEPT. pH rate profiles (log V(m) and log V(m)/K(m) versus pH) revealed a pH optimum of 8.5. At pH 8.5, K(eq) is equal to 0.5 and the k(cat) values of the forward and reverse reactions are 7 and 9 s(-1), respectively. The K(m) for AEP is 1.11 +/- 0.03 mM; for pyruvate it is 0.15 +/- 0.02 mM, for P-Ald it is 0.09 +/- 0.01 mM, and for L-Ala it is 1.4 +/- 0.03 mM. Substrate specificity tests revealed a high degree of discrimination, indicating a singular physiological role for the transaminase in AEP degradation. The 40-kDa subunit of the homodimeric enzyme is homologous to other members of the pyridoxalphosphate-dependent amino acid transaminase superfamily. Catalytic residues conserved within well-characterized members are also conserved within the seven known AEPT sequences. Site-directed mutagenesis demonstrated the importance of three selected residues (Asp168, Lys194, and Arg340) in AEPT catalysis.

Aminoethylphosphonic Acid↗

PubMed1971

Serum transaminases during salicylate therapy.

In 8 out of 32 juvenile patients suffering from chronic polyarthritis and in one patient with dermatomyositis, raised transaminase levels were found; the salicylate level was above 35 mg/100 ml in all except one. Reduction in the salicylate level led to a prompt fall in the serum transaminases. Despite a rise in alkaline phosphatase in three cases there was no other evidence of liver dysfunction in the children. Only one of the adults showed a rise in transaminase levels, and she had mild cirrhosis.

Adolescent↗

PubMed1964

SERUM ASPARTATE AND ALANINE TRANSAMINASE LEVELS IN WORKERS EXPOSED TO LEAD.

Serum aspartate and alanine transaminase levels were studied in a group of 46 workers exposed to lead. In none of them did the level of either enzyme vary from the values found in a group of 50 healthy persons with no industrial exposure to lead. No correlation was found between levels of aspartate transaminase or alanine transaminase and blood lead concentrations.

Alanine Transaminase↗

PubMed1975

Subcellular distribution and properties of kynurenine pyruvate transaminase in rat kidney.

Kynurenine transaminase activity in rat kidney was found in both the mitochondrial and supernatant fractions. These fractions contained (a) kynurenine pyruvate transaminase, which showed a preference for pyruvate as amino acceptor, and had a pH optimum between 8.0 and 8.5, and (b) kynurenine 2-oxoglutarate transaminase, with a preference for 2-oxoglutarate and a pH optimum between 6.0 and 6.5. The apparent Km value of the former enzyme for L-kynurenine was much lower than that of the latter enzyme.

Cytosol↗