Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This article discusses the effects of Fructus Gardeniae extract on hepatic function. Fructus Gardeniae extract manifested no hepatotoxic effects on rats, as shown by alkaline phosphatase, aspartate aminotransferase, and lactate dehydrogenase studies. Fructus Gardeniae extract failed to activate the UDP-glucuronyltransferase system; whereas in hyperbilirubinemic state the enzyme was activated, presumably by substrate induction. Fructus Gardeniae extract increased the activity of UDP-glucose dehydrogenase, which would result in an increase in availability of UDP-glucuronic acid intracellularly, BSP clearance study showed an unexpected impairment of hepatic uptake of the dye after extract treatment. The action mechanism involved in lowering of serum bilirubin level by Fructus Gardeniae extract may well be complex; it is probably acting on a locus other than glucuronyl transferase.
Comp Med East West
PMID:Effects of Fructus gardeniae extract on hepatic function. 41 32

The serum gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), urate and triglyceride and mean cell volume (MCV) were determined in 60 total abstainers, 56 social drinkers and 100 alcoholics. Both enzymes and urate showed progressive rise with increasing alcohol intake. The mean cell volume was only moderately elevated. Gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), and urate are sensitive enough to detect people who take in alcohol regularly and yet may be regarded as normal and not alcohol dependent.
West Afr J Med
PMID:Biochemical and haematological markers of alcohol intake in Ghanaians. 136 76

Subacute intraperitoneal administration of the lipid portion of the unripe ackee arillus, referred to as "ackee oil", resulted in marked neutropenia (p less than 0.001) and increase in platelets (p less than 0.01) without anaemia, in rats. Blood urea, sodium and aspartate aminotransferase levels were significantly decreased but glucose and bilirubin levels were similar to those of controls. The lungs showed areas of petechial haemorrhages and a dose-related perivascular and peribronchial mononuclear cell infiltration. The pulmonary toxicity may be interpreted as a hypersensitive reaction to ackee oil. Further research is in progress on the neutropenic effects of ackee oil.
West Indian Med J 1992 Mar
PMID:Toxic effects of ackee oil (Blighia sapida L) following subacute administration to rats. 156 91

An improved understanding of medical problems of alcoholic patients can be gained from commonly encountered laboratory test results. Liver function tests--such as measures of alkaline phosphatase, gamma-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase--may provide evidence of altered hepatic activity of different types, such as obstruction and hepatocellular injury. Other test results may indicate impaired hepatic function, such as measurements of albumin, bilirubin, prothrombin time, and blood urea nitrogen. Alterations are also common in electrolytes, blood glucose, magnesium, phosphate, uric acid, and acid-base balance. Disturbances in hematologic function are not infrequent in alcoholic patients, including anemias from many causes, altered granulocyte responses, and thrombocytopenia.
West J Med 1992 Mar
PMID:Clinical significance in alcoholic patients of commonly encountered laboratory test results. 159 68

Monoclonal gammopathies can either be benign or more commonly malignant. The commonest disease associated with it is multiple myeloma. Over the seven-year period 1984-1990, two hundred and thirty-four monoclonal gammopathies were seen at the University Hospital, Jamaica. Multiple myeloma was diagnosed in one hundred and fifty-six cases (84 males and 72 females). The diagnoses of most of the others were not known as the samples came from other institutions. Of the patients with myeloma, the most common immunoglobulin type was IgG followed by IgA and then pure light chain disease. Only in about half of the cases where urine was analysed was Bence-Jones protein found. The majority of the cases had abnormal total serum protein, albumin and total globulin concentrations. Most of the cases also were in renal failure. Hypercalcaemia, hyperphosphataemia, elevated alkaline phosphatase, gammaglutamyl transferase and aspartate aminotransferase occurred in about one-third of them. These results were not much different from those reported in other countries.
West Indian Med J 1991 Dec
PMID:Biochemical abnormalities in multiple myeloma. 178 96

1. The single (cytosolic) aspartate aminotransferase was purified in high yield from baker's yeast (Saccharomyces cerevisiae). 2. Amino-acid-sequence analysis was carried out by digestion of the protein with trypsin and with CNBr; some of the peptides produced were further subdigested with Staphylococcus aureus V8 proteinase or with pepsin. Peptides were sequenced by the dansyl-Edman method and/or by automated gas-phase methods. The amino acid sequence obtained was complete except for a probable gap of two residues as indicated by comparison with the structures of counterpart proteins in other species. 3. The N-terminus of the enzyme is blocked. Fast-atom-bombardment m.s. was used to identify the blocking group as an acetyl one. 4. Alignment of the sequence of the enzyme with those of vertebrate cytosolic and mitochondrial aspartate aminotransferases and with the enzyme from Escherichia coli showed that about 25% of residues are conserved between these distantly related forms. 5. Experimental details and confirmatory data for the results presented here are given in a Supplementary Publication (SUP 50164, 25 pages) that has been deposited at the British Library Document Supply Centre, Boston Spa. Wetherby, West Yorkshire LS23 7 BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1991) 273, 5.
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PMID:The amino acid sequence of the aspartate aminotransferase from baker's yeast (Saccharomyces cerevisiae). 185 61

1. The cytosolic aspartate aminotransferase was purified from human liver. 2. The isoenzyme contains four cysteine residues, only one of which reacts with 5,5'-dithiobis-(2-nitrobenzoic acid) in the absence of denaturing agents. 3. The amino acid sequence of the isoenzyme is reported, as determined from peptides produced by digestion with trypsin and with CNBr, and from sub-digestion of some of these peptides with Staphylococcus aureus V8 proteinase. 4. The isoenzyme shares 48% identity of amino acid sequence with the mitochondrial form from human heart. 5. Comparisons of the amino acid sequences of all known mammalian cytosolic aspartate aminotransferases and of the same set of mitochondrial isoenzymes are reported. The results indicate that the cytosolic isoenzymes have evolved at about 1.3 times the rate of the mitochondrial forms. 6. The time elapsed since the cytosolic and mitochondrial isoenzymes diverged from a common ancestral protein is estimated to be 860 x 10(6) years. 7. Experimental details and confirmatory data for the results presented here are given in a supplementary paper that has been deposited as a Supplementary Publication SUP 50158 (25 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1990) 265, 5.
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PMID:The amino acid sequence of cytosolic aspartate aminotransferase from human liver. 224 99

The unfolding of the mitochondrial isoenzyme of aspartate aminotransferase from pig heart in solutions of guanidinium chloride (GdnHCl) has been studied. By a number of criteria (enzyme activity, protein fluorescence, c.d., thiol-group reactivity), the enzyme was judged to be almost completely unfolded in 2 M-GdnHCl. On dilution of the GdnHCl, no re-activation of the enzyme could be observed, whether or not pyridoxal 5'-phosphate and dithiothreitol were present. The behaviour of the mitochondrial isoenzyme is in marked contrast with that of the cytoplasmic isoenzyme [West & Price (1989) Biochem. J. 261, 189-196], despite the similarities in the amino acid sequences and tertiary structures of the two isoenzymes. The implications of these findings for the process of folding and assembly of the mitochondrial isoenzyme in vivo are discussed.
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PMID:The unfolding and attempted refolding of mitochondrial aspartate aminotransferase from pig heart. 230 72

In a study of Lassa fever in Sierra Leone, West Africa, we identified two variables associated with a high risk of death, and we evaluated the efficacy of ribavirin and Lassa virus-convalescent plasma for the treatment of Lassa fever. A serum aspartate aminotransferase level greater than or equal to 150 IU per liter at the time of hospital admission was associated with a case-fatality rate of 55 percent (33 of 60). Patients with the same risk factor who were treated for 10 days with intravenous ribavirin, begun within the first 6 days after the onset of fever, had a case-fatality rate of 5 percent (1 of 20) (P = 0.0002 by Fisher's exact test). Patients whose treatment began seven or more days after the onset of fever had a case-fatality rate of 26 percent (11 of 43) (P = 0.01). Viremia with levels greater than or equal to 10(3.6) TCID50 per milliliter on admission was associated with a case-fatality rate of 76 percent (35 of 46). Patients with this risk factor who were treated with intravenous ribavirin within the first six days after onset of fever had a case-fatality rate of 9 percent (1 of 11) (P = 0.006), whereas those treated after seven days or more of illness had a fatality rate of 47 percent (9 of 19) (P = 0.035). Oral ribavirin was also effective in patients at high risk of death. Lassa-convalescent plasma did not significantly reduce mortality in any of the high-risk groups. We conclude that ribavirin is effective in the treatment of Lassa fever and that it should be used at any point in the illness, as well as for postexposure prophylaxis.
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PMID:Lassa fever. Effective therapy with ribavirin. 394 Mar 12

The mitochondrial isozyme of aspartate aminotransferase (mAspAT), a dimeric pyridoxal phosphate (PLP)-dependent enzyme, is encoded by the nuclear genome and synthesized in the cytoplasm as a precursor protein (pmAspAT) containing a 29-residue amino-terminal signal peptide which is essential for its targeting and import into mitochondria. In the cytosolic-like environment of rabbit reticulocyte lysate, newly synthesized rat liver pmAspAT has been found to slowly fold and bind PLP (Mattingly, J. R., Jr., Youssef, J., Iriarte, A. and Martinez-Carrion, M. (1993) J. Biol. Chem. 268, 3925-3937). On the other hand, isolated mammalian (pig) mAspAT, when denatured with guanidine hydrochloride, seems unable to refold to a catalytically active state (West, S. M., and Price, N. C. (1990) Biochem. J. 265, 45-50). With the availability of rat liver recombinant precursor and mature forms of mAspAT as homogeneous, stable preparations, an assessment of the influence of the signal peptide on the in vitro refolding of this protein can be made. Following unfolding induced by guanidine hydrochloride, we have investigated the refolding process of this complex, dimeric coenzyme-dependent protein system by activity, fluorescence, and circular dichroism. Both mAspAT and pmAspAT can be efficiently renatured after rapid dilution of the denaturing agent at low protein concentrations. The equilibrium unfolding/refolding transitions and the kinetics of folding are protein concentration-independent and identical for both protein forms. Binding of coenzyme into the active site pocket seems to occur at a late step in the folding process of both mAspAT and pmAspAT, suggesting that in these proteins the coenzyme does not direct the folding of the polypeptide chain. These results indicate that the in vitro refolding of mAspAT is not regulated or influenced by the presence of the amino-terminal signal peptide. On the other hand, in vitro refolding in buffer is significantly faster than the folding of newly synthesized precursor protein in reticulocyte lysate examined in our previous report (reference above), pointing at the likely influence of cytosolic factors in modulating folding in the cell.
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PMID:Refolding of the precursor and mature forms of mitochondrial aspartate aminotransferase after guanidine hydrochloride denaturation. 822 37


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