PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “AMINOTRANSFERASES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources

Effects of temperature on measurement of aspartate aminotransferase and alanine aminotransferase in commercial control sera.

The catalytic activity concentrations of aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) in several commercial control sera were determined at three different temperatures. Although these sera were of various biological origins, the temperature-conversion factors calculated are nearly identical to those for native human sera. The proportional increase of the activity concentration caused by adding pyridoxal-5'-phosphate to the reaction mixture is independent of the reaction temperature. Arrhenius plots and some thermodynamic activation parameters of both enzymes are independent of the presence of the coenzyme pyridoxal-5'-phosphate.

Alanine Transaminase↗

Milk fever in the cow--course of disease in relation to the serum activity of aspartate aminotransferase, alanine aminotransferase, creatine kinase and gamma-glutamyltransferase.

The serum activity of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), creatine kinase (CK), and gamma-glutamyltransferase (GGT) was determined at the time of first and subsequent treatments in milk fever cows which responded differently to treatment, and in a number of healthy, periparturient cows. Serum ASAT, ALAT and CK levels were lower in the healthy cows than in the milk fever cows at first treatment. Serum ASAT and serum CK were, at first treatment, higher in the milk fever cows which did not recover than in those which recovered. At second and subsequent treatments, serum ASAT and serum ALAT were higher in the cows which failed to recover, and these cows also showed the highest levels of serum CK up-to and including fourth treatment. After an overall assessment of serum activity of the various enzymes, it is concluded that muscle damage was a significant complication both in cows which recovered and in those which failed to recover, while liver damage was of little importance.

Alanine Transaminase↗

Studies on the influence of combustion exhaust gases and the products of their reaction with ammonia on the living organism. II. The influence on aspartate aminotransferase (AspAT) and alanine aminotransferase (AiAt) activities in the liver of guinea pig.

The behaviour of aspartate aminotransferase (AspAT) an alanine aminotransferase (AIAT) in the whole homogenate and subcellular liver fractions of guinea pigs exposed to combustion exhaust gases and the neutralization products of these gases is presented in this paper. In the liver of animals exposed to the chronic action of combustion exhaust gases a decrease of both enzyme activities in the whole homogenate as well as in the subcellular fractions could be noted. Statistically significant changes are shown by AspAT. In the group of animals subjected to the action of neutralization products an increase of AIAT activity was observed. The activity of AspAT still shows a decrease, but less distinct in comparison with group I. An exception here is the mitochondrial fraction in which the AspAT activity is distinctly increased.

Alanine Transaminase↗

Effects of mebendazole, albendazole and praziquantel on alanine aminotransferase and aspartate aminotransferase of Echinococcus granulosus cyst wall harbored in mice.

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of Echinococcus granulosus cyst wall harbored in mice for 10-12 months was measured. The activities of the 2 enzymes were 3,430 +/- 1,370-4,160 +/- 1,790 and 1,560 +/- 840-2,890 +/- 1,470, respectively. When infected mice were treated ig with mebendazole (Meb) 25 mg.kg-1.d-1 for 7-14 d, or 50 mg.kg-1.d-1 for 7 d, the ALT activities of cyst walls of both collapsed and full cysts were inhibited significantly with average inhibition rates of about 50%. Another benzimidazole derivative, albendazole (Alb), also inhibited ALT activity of the cyst wall with an inhibition rate of 40.7%, but this was not the case in the treatment with praziquantel 500 mg.kg-1.d-1 of the infected mice for 14 d. When the infected mice were treated ig with the above mentioned drugs at the same regimens, no apparent effect on AST activities of the cyst wall was seen except for the group treated ig with Meb at a higher daily dose, the inhibition rates being 26% (collapsed cyst) and 43.9% (full cyst). The significance of the results has been discussed briefly.

Alanine Transaminase↗

[Reestimation of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio based on JSCC consensus method--changes of criteria for a differential diagnosis of hepatic disorders following the alteration from Karmen method to JSCC method].

We estimated clinical criteria of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio that is measured by the consensus method of JSCC (Japan Society of Clinical Chemistry) for serum AST and ALT. The JSCC consensus method is closely correlated with both IFCC (International Federation of Clinical Chemistry) recommended method without pyridoxal phosphate and Karmen method recommended by the expert panel of liver function tests in Japanese Society of Gastroenterology. The slopes of the regression line is estimated to be 1.00 and 0.87 respectively. We propose that the decision making value of AST/ALT ratio to differentiate several types of liver diseases should be set to 0.87 measured by JSCC consensus method, instead of 1.0 measured by Karmen method.

Alanine Transaminase↗

In vitro effects of the novel anti-epileptic agent vigabatrin on alanine aminotransferase and aspartate aminotransferase activities in rat serum.

The in vitro effects of vigabatrin (CAS 60643-86-9, MDL 71,754) on alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were examined in rat serum. Initially, vigabatrin (30-100 micrograms/ml) produced a concentration-dependent decrease in ALT activity at 100 micrograms/ml or more after 15 min incubation with the rat serum. AST activity, in contrast, was unaffected by concentrations up to 1,000 micrograms/ml. Next, treating the rat serum with vigabatrin (30-300 micrograms/ml) for up to 5 h produced a concentration- and time-dependent decrease in ALT activity. On the other hand, a decrease in AST activity was observed only after incubation with the highest concentration of vigabatrin for 3 h or more. Finally, an investigation was made on the antagonistic effect of L-alanine, a natural substrate for ALT, on the vigabatrin-induced decrease in ALT activity to elucidate possible mechanisms underlying the inhibitory effect of vigabatrin on ALT activity. L-alanine, depending on its concentration, countered the effects of vigabatrin (100 micrograms/ml) at a 10- or 100-fold higher molar ratio than vigabatrin. These findings suggest that vigabatrin favorably decreases ALT activity by blocking the L-alanine binding site of enzymes.

Alanine↗

Escherichia coli and Saccharomyces cerevisiae acetylornithine aminotransferase: evolutionary relationship with ornithine aminotransferase.

Genes argD and ARG8, encoding the acetylornithine aminotransferase (ACOAT) subunit in Escherichia coli and Saccharomyces cerevisiae, respectively, have been cloned and sequenced. The deduced amino acid sequences show substantial similarity. Moreover, they resemble ornithine aminotransferase (OAT) sequences (i.e., those from yeast, rat and man); the observed similarities are statistically significant, indicating that the enzymes are homologous. However, in contrast to OATs, which appear to be substrate (i.e., ornithine)-specific, S. cerevisiae ACOAT transaminates ornithine about as efficiently as E. coli does. The evolutionary relationship between ACOATs and OATs is discussed in terms of substrate ambiguity.

Amino Acid Sequence↗

Effect of pyridoxine deficiency and prednisolone on beta-alanine-oxoglutarate aminotransferase and D-3-aminoisobutyrate aminotransferase in rat liver and kidney.

beta-Alanine-oxoglutarate aminotransferase (beta-Ala-TI) was found to be distributed mainly in liver, brain, kidney, and testis (decreasing order of enzyme activity in the rat). D-3-Aminoisobutyrate aminotransferase (beta-Ala-T II) was distributed in kidney and liver. Both beta-Ala-T I and beta-Ala-T II were localized in the mitochondrial fraction in rat kidney. beta-Ala-T I in the liver of rats fed on pyridoxine-deficient or control diets was induced by injecting with prednisolone, while beta-Ala-T II in the liver of these rats was unaffected by prednisolone injection. The activities of beta-Ala-T I and beta-Ala-T II in the liver of rats fed on pyridoxine deficient diet did not change. However, in kidney, pyridoxine deficiency suppressed both enzyme activities, while treatment with prednisolone did not induce either enzyme. The ratios of the apo- to holo-enzyme for beta-Ala-T I and beta-Ala-T II in control rat kidney were 1.04 and 0.11, respectively. The values increased to 2.69 and 1.53, respectively, in pyridoxine-deficient rat kidney. These experiments indicate that pyridoxine deficiency and prednisolone affect the activities of beta-alanine degrading enzymes, but that the degree is different between liver and kidney.

4-Aminobutyrate Transaminase↗

Serum versus heparinized plasma for alanine aminotransferase and aspartate aminotransferase of normal individuals.

The influence of heparin on the estimation of aminotransferases was investigated in a reaction medium containing phosphate or Tris buffer. Heparin scarcely affects the ASAT determination, but the ALAT activity in plasma is about 70% of the activity in serum, when the enzyme determination is carried out in Tris buffer. There exists a lag phase due to which the decrease in absorbance with the incubation time is nonlinear. When the Tris buffer is omitted, the same lag phase is observed in the ALAT determination. This lag phase is not caused by the indicator enzyme LDH. Addition of phosphate to the incubation medium without any buffer abolishes this lag phase. The possibility exists that heparin influences the structure of the proteins present in plasma and that these proteins, in their turn, decrease the enzymatic activity of ALAT.

Alanine Transaminase↗

Molecular cloning and nucleotide sequence analysis of mRNA for human kidney ornithine aminotransferase. An examination of ornithine aminotransferase isozymes between liver and kidney.

The cDNA encoding ornithine aminotransferase (EC 2.6.1.13; OAT) was isolated from a human kidney cDNA library. The isolated cDNA contained the entire protein coding region and partial 3'- and 5'-untranslated regions. The nucleotide sequences of human kidney OAT cDNA were absolutely homologous with those of human liver OAT cDNA, and human kidney and liver OAT fused completely against the antibody to human kidney OAT in an Ouchterlony double diffusion test. These findings settled the controversy as to which characteristics of liver and kidney OAT isozymes are different. An N-terminal sequence analysis of purified mature human kidney OAT clarified that the leader peptide was cleaved between Gln-35 and Gly-36.

Amino Acid Sequence↗

Complete amino acid sequence of rat kidney ornithine aminotransferase: identity with liver ornithine aminotransferase.

The complete amino acid sequence of rat kidney ornithine aminotransferase [EC 2.6.1.13] is presented. The 404-residue sequence was determined by analysis of peptides generated by digestion of the S-carboxyamidomethylated protein with CNBr, Achromobacter protease I, arginylendopeptidase, or Staphylococcus aureus V8 protease. Mueckler and Pitot have reported the amino acid sequence of the rat liver enzyme (440 residues) as predicted from the nucleotide sequence of the cDNA [Mueckler, M.M. & Pitot, H.C. (1985) J. Biol. Chem. 260, 12993-12997]. The amino acid sequence of the rat kidney enzyme presented herein coincides with residue 36 (Gly) through 440 (Phe) of the predicted precursor protein, indicating that the liver and kidney enzymes are identical, and that the enzyme is processed at the amino-terminal region after translation.

Alcaligenes↗

Aspartate Aminotransferase in Alfalfa Root Nodules : III. Genotypic and Tissue Expression of Aspartate Aminotransferase in Alfalfa and Other Species.

Aspartate aminotransferase (AAT) plays an important role in nitrogen metabolism in all plants and is particularly important in the assimilation of fixed N derived from the legume-Rhizoblum symbiosis. Two isozymes of AAT (AAT-1 and AAT-2) occur in alfalfa (Medicago sativa L.). Antibodies against alfalfa nodule AAT-2 do not recognize AAT-1, and these antibodies were used to study AAT-2 expression in different tissues and genotypes of alfalfa and also in other legume and nonlegume species. Rocket immunoelectrophoresis indicated that nodules of 38-day-old alfalfa plants contained about eight times more AAT-2 than did nodules of 7-day-old plants, confirming the nodule-enhanced nature of this isozyme. AAT-2 was estimated to make up 16, 15, 5, and 8 milligrams per gram of total soluble protein in mature nodules, roots, stems, and leaves, respectively, of effective N(2)-fixing alfalfa. The concentration of AAT-2 in nodules of ineffective non-N(2)-fixing alafalfa genotypes was about 70% less than that of effective nodules. Western blots of soluble protein from nodules of nine legume species indicated that a 40-kilodalton polypeptide that reacts strongly with AAT-2 antibodies is conserved in legumes. Nodule AAT-2 immunoprecipitation data suggested that amide- and ureide-type legumes may differ in expression and regulation of the enzyme. In addition, Western blotting and immunoprecipitations of AAT activity demonstrated that antibodies against alfalfa AAT-2 are highly cross-reactive with AAT enzyme protein in leaves of soybean (Glycine max L.), wheat (Triticum aestivum L.), and maize (Zea mays L.) and in roots of maize, but not with AAT in soybean and wheat roots. Results from this study indicate that AAT-2 is structurally conserved and localized in similar tissues among diverse species.

Journal Article↗

Localization of the lysine epsilon-aminotransferase (lat) and delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (pcbAB) genes from Streptomyces clavuligerus and production of lysine epsilon-aminotransferase activity in Escherichia coli.

Lysine epsilon-aminotransferase (LAT) in the beta-lactam-producing actinomycetes is considered to be the first step in the antibiotic biosynthetic pathway. Cloning of restriction fragments from Streptomyces clavuligerus, a beta-lactam producer, into Streptomyces lividans, a nonproducer that lacks LAT activity, led to the production of LAT in the host. DNA sequencing of restriction fragments containing the putative lat gene revealed a single open reading frame encoding a polypeptide with an approximately Mr 49,000. Expression of this coding sequence in Escherichia coli led to the production of LAT activity. Hence, LAT activity in S. clavuligerus is derived from a single polypeptide. A second open reading frame began immediately downstream from lat. Comparison of this partial sequence with the sequences of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D valine (ACV) synthetases from Penicillium chrysogenum and Cephalosporium acremonium and with nonribosomal peptide synthetases (gramicidin S and tyrocidine synthetases) found similarities among the open reading frames. Since mapping of the putative N and C termini of S. clavuligerus pcbAB suggests that the coding region occupies approximately 12 kbp and codes for a polypeptide related in size to the fungal ACV synthetases, the molecular characterization of the beta-lactam biosynthetic cluster between pcbC and cefE (approximately 25 kbp) is nearly complete.

Amino Acid Sequence↗

Influence of proline on rat brain activities of alanine aminotransferase, aspartate aminotransferase and acid phosphatase.

Hyperprolinemia type II (HPII) is an autosomal recessive disorder caused by the severe deficiency of enzyme delta1-pyrroline-5-carboxylic acid dehydrogenase leading to tissue accumulation of proline. Chronic administration of Pro led to significant reduction of cytosolic ALT activity of olfactory lobes (50.57%), cerebrum (40%) and medulla oblongata (13.71%) only. Whereas mitochondrial ALT activity was reduced significantly in, all brain regions such as olfactory lobes (73.23%), cerebrum (70.26%), cerebellum (65.39%) and medulla oblongata (65.18%). The effect of chronic Pro administration on cytosolic AST activity was also determined. The cytosolic AST activity from olfactory lobes, cerebrum and medulla oblongata reduced by 75.71, 67.53 and 76.13%, respectively while cytosolic AST activity from cerebellum increased by 28.05%. The mitochondrial AST activity lowered in olfactory lobes (by 72.45%), cerebrum (by 78%), cerebellum (by 49.56%) and medulla oblongata (by 69.30%). In vitro studies also showed increase in brain tissue proline and decrease in glutamate levels. In vitro studies indicated that proline has direct inhibitory effect on these enzymes and glutamate levels in brain tissue showed positive correlation with AST and ALT activities. Acid phosphatase (ACP) activity reduced significantly in olfactory lobes (40.33%) and cerebrum (20.82%) whereas it elevated in cerebellum (97.32%) and medulla oblongata (76.33%). The histological studies showed degenerative changes in brain. Following proline treatment, the animals became sluggish and showed low responses to tail pricks and lifting by tails and showed impaired balancing. These observations indicate influence of proline on AST, ALT and ACP activities of different brain regions leading to lesser synthesis of glutamate thereby causing neurological dysfunctions.

Acid Phosphatase↗