Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver necrosis was produced in rats by administering 3 doses of a mixture of carbon tetrachloride + olive oil, 2 ml/kg, ip. The liver damage was evidenced by the elevated levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (gamma-GT) and by histopathological observations of liver sections. Aspartate and glutamate administration (100 mg/kg, ip) significantly reduced these elevated levels of AST, ALT, and gamma-GT. Carbon tetrachloride induced liver necrosis was also found to be significantly reduced in aspartate and glutamate pretreated animals as observed macroscopically and histologically.
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PMID:Effect of aspartate and glutamate on carbon tetrachloride induced liver damage in rats. 209 35

The mechanism of expression of the overlapping genes that encode the alpha and beta subunits of aspartokinase II of Bacillus subtilis was studied by specific mutagenesis of the cloned coding sequence. Escherichia coli or B. subtilis VB31 (aspartokinase II-deficient), transformed with plasmids carrying either a deletion of the translation start site and about one-half of the coding region for the larger alpha subunit or a frameshift mutation early in the alpha subunit coding region, produced the smaller beta subunit in the absence of alpha subunit synthesis, indicating that beta subunit is not derived from alpha subunit and that its synthesis does not depend on the alpha subunit translation initiation site. The beta subunit translation start site was identified by oligonucleotide-directed mutagenesis of the putative translation start codon. Modification of the nucleotide sequence encoding methionine residue 247 of the alpha subunit from ATG to either TTA or AAT (but not GTG) abolished beta subunit synthesis but had no effect on the production of alpha subunit. This observation is consistent with peptide chain initiation by N-formylmethionine, which specifically requires an ATG or GTG sequence, and indicates that translation of the beta subunit starts at a site corresponding to Met247 of the alpha subunit. Initial studies on the function of the aspartokinase II subunits, using E. coli as a heterologous host, showed that beta subunit was not essential for the expression of the catalytic function of aspartokinase, measured in vitro and in vivo, nor for its allosteric regulation by L-lysine. Whether the beta subunit has a function specific to B. subtilis needs to be explored in a homologous expression system.
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PMID:Mechanism of expression of the overlapping genes of Bacillus subtilis aspartokinase II. 283 91

This study was prompted by the paradox of strong presence of mitochondria in an anaerobic protozoan, recently reclassified from the yeasts. Stemming from publication in 1911 to 1912, Blastocystis hominis has been generally accepted as a harmless intestinal yeast of humans, with short standardized textbook (parasitology) descriptions, even to the present day. Reports since 1967 have changed the classification of B. hominis from yeast to protozoan (Sarcodina), and this has been followed by interest in B. hominis-caused disease, resulting in documentation of disease in humans and other primates. In this study of B. hominis, the basic ultrastructure of the mitochondria was shown by thin-section electron microscopy to be identical to that of an archetypical mitochondrion. There were hundreds of them in large B. hominis cells (100 to 200 microns in diameter). Mitochondria were confined to a peripheral ring of cytoplasm bounded by the outer cell membrane (there is no cell wall) and the membrane of the large, spherical, organelle-free central body that constitutes 75% of the cell's volume. Mitochondria tended to surround the cell's usual two to four nuclei. Rhodamine 123 stained the mitochondria selectively, visualized by fluorescence microscopy. The cell was devoid of cytochromes. Addition of 0.1% cytochrome c to the growth medium increased utilization of glucose by 34% and that of lactate by 17%. Furthermore, it markedly increased the number of mitochondrion-filled cells. At higher concentrations, cytochrome c inhibited the growth of the cells. Despite the presence of large numbers of mitochondria, activities of the mitochondrial enzymes pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, isocitrate dehydrogenase, glutamate dehydrogenase, and cytochrome c oxidase were absent. Thus, the function of the mitochondria in B. hominis remains unknown. Considerable activities of aspartate aminotransferase and alanine aminotransferase were found. Aldolase activity was prominent. Pyruvate decarboxylase was present. Diaphorase and lactate dehydrogenase were detectable but in suspect quantities. Other missing enzymes were gamma glutamyl transpeptidase, alkaline phosphatase (a lysosomal marker), and creatine kinase isoenzymes.
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PMID:Biochemical and ultrastructural study of Blastocystis hominis. 283 9

Blood vessel walls are shown to contain creatine phosphokinase, lactate dehydrogenase, gamma glutamyl transpeptidase and aspartate transaminase activity. The activity of these enzymes in the serum may be enhanced by leakage from damaged blood vessels. The activity of the enzymes alanine transaminase and alkaline phosphatase as well as the content of triglycerides, cholesterol and lipoproteins are very low in the vascular tissue and are unlikely to be of diagnostic value in vascular tissue injury.
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PMID:The activity of diagnostic enzymes and the concentration of lipids in the blood vessels of cattle. 290 93

Male Sprague-Dawley rats were treated ip with beta-naphthoflavone (40 mg/kg/day) in corn oil or in DMSO for three days. Diphenaldehyde (90 mg/kg in DMSO) was injected ip 24 hr after pretreatment. The increase in the levels of aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase, gamma glutamyl transpeptidase, and lactate dehydrogenase was significantly lower in rats pretreated with BNF. This suggests that the BNF-induced P-450 isozyme systems have a protective effect against the acute hepatotoxicity of diphenaldehyde.
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PMID:Toxicity of polycyclic aromatic hydrocarbons. V. Protective effect of beta-naphthoflavone against hepatotoxicity induced by diphenaldehyde in rats. 345 82

In this paper we describe the cloning and sequence analysis of the tyrB and aspC genes from Escherichia coli K12, which encode the aromatic aminotransferase and aspartate aminotransferase respectively. The tyrB gene was isolated from a cosmid carrying the nearby dnaB gene, identified by its ability to complement a dnaB lesion. Deletion and linker insertion analysis located the tyrB gene to a 1.7-kilobase NruI-HindIII-digest fragment. Sequence analysis revealed a gene encoding a 43 000 Da polypeptide. The gene starts with a GTG codon and is closely followed by a structure resembling a rho independent terminator. The aspC gene was cloned by screening gene banks, prepared from a prototrophic E. coli K12 strain, for plasmids able to complement the aspC tyrB lesions in the aminotransferase-deficient strain HW225. Sub-cloning and deletion analysis located the aspC gene on a 1.8-kilobase HincII-StuI-digest fragment. Sequence analysis revealed the presence of a gene encoding a 43 000 Da protein, the sequence of which is identical with that previously obtained for the aspartate aminotransferase from E. coli B. Considerable overproduction of the two enzymes was demonstrated. We compared the deduced protein sequences with those of the pig mitochondrial and cytoplasmic aspartate aminotransferases. From the extensive homology observed we are able to propose that the two E. coli enzymes possess subunit structures, subunit interactions and coenzyme-binding and substrate-binding sites that are very similar both to each other and to those of the mammalian enzymes and therefore must also have very similar catalytic mechanisms. Comparison of the aspC and tyrB gene sequences reveals that they appear to have diverged as much as is possible within the constraints of functionality and codon usage.
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PMID:The cloning and sequence analysis of the aspC and tyrB genes from Escherichia coli K12. Comparison of the primary structures of the aspartate aminotransferase and aromatic aminotransferase of E. coli with those of the pig aspartate aminotransferase isoenzymes. 352 91

Anaesthesia was induced in 24 horses with xylazine and ketamine and maintained with halothane (12 cases) or enflurane (12 cases) in oxygen. Pulse rate, arterial blood pressure, arterial blood gas values, respiratory rate and tidal volume were measured at regular intervals during anaesthesia. Serial venous blood samples were taken for assay of glucose, urea, haemoglobin, packed cell volume, gamma glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase and creatine kinase. Operating conditions and the horses' behaviour in the recovery period were also recorded. In the case of the group of horses receiving enflurane, difficulty was experienced maintaining anaesthesia deep enough for surgery. This group also displayed greater respiratory depression. There were no significant differences between arterial blood pressure values, or any of the haematological or biochemical parameters recorded in each group. Recovery from anaesthesia was significantly faster in horses receiving enflurane but less smooth. It was concluded that, although enflurane appeared to be safe in the horse, the respiratory depression and the unpleasant recovery did not make it a desirable alternative to halothane.
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PMID:Clinical anaesthesia in the horse: comparison of enflurane and halothane. 397 74

Correlations have been calculated between high-density lipoprotein cholesterol and total plasma cholesterol, albumin, gamma-glutamyl transpeptidase, aspartate aminotransferase, alkaline phosphatase, triglyceride, urea, creatinine and uric acid for diphenylhydantoin (DPH) users and for subjects attending a multiphasic health screening centre. For women DPH users, high-density lipoprotein levels correlated significantly with gamma glutamyl transpeptidase, cholesterol and alkaline phosphatase. These correlations were significantly different from those found for male DPH users and from subjects attending the health screening centre. In male DPH users, high-density lipoprotein cholesterol correlates negatively with urea and uric acid levels, a relationship which is found neither in women DPH users nor in the health screening centre population.
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PMID:The effects of diphenylhydantoin on the relationship between high-density lipoprotein cholesterol and several biochemical assays. 610 46

A randomised double-blind trial of (+)-cyanidanol-3(Catechin), 2 g/day versus placebo, was carried out in 40 patients with pre-cirrhotic alcohol-related liver disease over a three month period. Twenty received the active drug and 20 placebo; one non-compliant patient in the treatment group was withdrawn. Forty-one per cent (16/39) abstained from alcohol and showed significant improvements (P < 0.005) in mean values for serum aspartate transaminase, serum gamma glutamyl transpeptidase, and mean corpuscular volume. Ten of the 16 showed overall histological improvement on liver biopsy. Fifty-nine pr cent (23/39) continued to drink, though significantly reducing their mean daily alcohol intake (P < 0.001). No significant changes occurred in this group in mean serum enzyme values, though the mean value for mean corpuscular volume improved significantly (P < 0.01) and 16 of the 23 showed overall histological improvement. Changes occurred irrespective of treatment with Catechin which suggests that, over a three month period, this drug did not influence the course of alcohol-related liver disease.
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PMID:Treatment of alcohol-related liver disease with (+)-cyanidanol-3: a randomised double-blind trial. 610 1

A randomised double-blind trial of thioctic acid (alpha-lipoic acid), 300 mg/day versus placebo was carried out in 40 patients with pre-cirrhotic alcohol-related liver disease over a six month period. Twenty patients received the active drug and 20 placebo. Twenty-two of the 40 patients (55%) abstained from alcohol and showed significant improvements (p less than 0.01) in mean values for serum aspartate transaminase, serum glutamyl transpeptidase, and mean corpuscular volume. Seventeen of the 22 (77%) showed overall histological improvement on liver biopsy. The remaining 18 patients (45%) continued to drink but significantly reduced their mean daily alcohol intake (p less than 0.001). No significant changes occurred in their laboratory indices, but five of the 18 (28%) showed overall histological improvement. Changes occurred irrespective of treatment with thioctic acid, which suggested that, over six months, this drug did not influence the course of alcohol-related liver disease.
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PMID:Treatment of alcohol-related liver disease with thioctic acid: a six month randomised double-blind trial. 612 79


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