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)

1. Isolated hepatocytes were used to establish the reasons for the accumulation of aspartate, previously observed when the isolated rat liver was perfused with ethanol in the presence of alanine or ammonium lactate. 2. The isolated cells did not form aspartate when incubated with alanine and ethanol, but much aspartate was formed on incubation with ammonium lactate and ethanol. 3. Urea was the main nitrogenous product on incubation with alanine, in contrast with the perfused liver, where major quantities of NH4+ are also formed. When the formation of urea was nullified by the addition of urease, alanine plus ethanol caused aspartate formation, indicating that aspartate formation depends on the presence of critical concentrations of NH4+. 4. The accumulated aspartate was present in the cytosol. Ethanol halved the content of 2-oxoglutarate in the cytosol and more than trebled that of glutamate in the mitochondria. 5. The findings support the assumption that 2-oxoglutarate formed by the mitochondrial aspartate aminotransferase is not translocated to the cytosol in the presence of ethanol and NH4+, because it is rapidly converted into glutamate, the dehydrogenation of ethanol providing the required NADH. Aspartate, however, is translocated to the cytosol and accumulates there because of the lack of stoicheiometric amounts of oxoglutarate.
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PMID:The accumulation of aspartate in the presence of ethanol in rat liver. 120 Oct 7

The hydrogen exchange at the Beta-carbon of L-alanine, L-glutamate and L-asparate with water has been examined during transamination catalyzed by glutamic-oxaloacetic transaminase and by glutamic-pyruvic transaminase. A significant hydrogen exchange at the Beta-carbon has been demonstrated during incubation of L-[3-3H]alanine + glutamic-pyruvic transaminase, L-[3-3H]alanine + alpha-oxo-glutarate + glutamic-pyruvic transaminase, L-[3-3H]glutamate + glutamic-oxaloacetic transaminase, L-[3-3H]glutamate + oxaloacetate +glutamic-oxaloacetic transaminase, and L-[3-3H]glutamate + pyruvate + glutamic-pyruvic transaminase as shown by the appearance of 3H2O. No hydrogen exchange at the Beta-carbon of L-glutamate occurred during incubation of L-[3-3H]-glutamate with glutamic-pyruvic transaminase alone. The hydrogen exchaned at the Beta-carbon of L-glutamate coincides with transamination as demonstrated by nuclear magnetic resonance studies of 2H2O-L-glutamate exchange during transamination by glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase. No hydrogen exchange at the Beta-carbon occurred during transamination of L-aspartate by glutamic-oxaloacetic transaminase as shown by nuclear magnetic resonance spectroscopy and confirmed by nuclear magnetic resonance simulation studies. The results are discussed with special reference to the different equilibria between the pyridoxal form and the pyridoxamine form of glutamic-oxaloacetic transaminase and of glutamic-pyruvic transaminase.
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PMID:Hydrogen exchane at the beta-carbon of amino acids during transamination. 120 22

The authors studied the activity of acid phosphatase (AP), lactic dehydrogenase (LDH), aspartic and alanine-aminotranspherases (AST and ALT) in the serum of rats with intact and removed adrenal glands after a severe multifocal trauma induced according to Noble-Collip (300 rpt of the drum with the rotation speed of 37 rpt/min). Adrenalectomy showed practically no influence on the dynamics of the LDH and AP activity. An increase in the activity of the AST and especially of the ALT in the serum of adrenalectomized rats after the trauma was considerably less than in the animals with the intact adrenal glands.
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PMID:[The role of the adrenals in the development of hyperenzymemia in experimental multiple injuries]. 121 54

In embryos of loach (Misgurnus fossilis) obtained from zygotes, which were incubated for 30 min in the D,L-aspartate solution the alanine aminotransferase activity is 2-4 times as high as in the control embryos. The most essential influence of this amino acid is found in the gastrula -- from 12 till 18 h after fertilization. The aspartate aminotransferase activity under these conditions does not undergo the essential changes. D,L-alanine and adenine do not affect the activity of the both enzymes during primary stages of development, but adenine as well as cytidine reduce the action of aspartate carbamoyltransferase of embryos 3, 6 and 3 h after the beginning of fertilizatio, respectively. The decrease in the aspartate carbamoyltransferase activity is revealed in the unfertilized eggs after 2 h of incubation in the solutions of estrone and thyroxine. Cytidine alone under these conditions has no definite influence, but removes the inhibitory effect of estrone. The regularities were established in changes of the activity of above mentioned enzymes of embryos under physiological conditions of development.
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PMID:[Activity of aspartate carbamoyltransferase, alanine and aspartate aminotransferases in loach embryos after incubation of zygotes in solutions of bioorganic compounds]. 124 Jun 68

Pulsed Fourier transform proton magnetic resonance spectroscopy was used to study the glutamate-alanine transaminase-catalyzed incorporation of deuterium from solvent deuterium oxide into the alpha and beta positions of L-alanine. It was found that the beta proton resonance signal initially disappears slightly faster than the signal due to the alpha proton, but whereas the alpha proton signal decays exponentially, that due to the beta proton signal does not. Eventually, the rate of decrease of the alpha proton signal becomes greater than that for the beta proton. This change in the relative rates is ascribed to a deuterium isotope effect upon substitution of an alpha proton by a deuteron. Furthermore, as deuterium begins to replace hydrogen, two classes of alanine become distinguishable, i.e. alanine which contains deuterium in the alpha position and hydrogen in the beta position, and alanine which contains hydrogen in the alpha position and deuterium in the beta position. Thus, removal of all 3 beta protons is not contingent upon loss of an alpha proton from the same molecule. The two classes of deuterated alanine may conceivably arise by a scrambling mechanism in which protons are transferred from the alpha to the beta position and vice versa. Present evidence excludes this scramblong mechanism and leads to the conclusion that deuterium incorporation into L-alanine involves, (a) the reversible enzymatic conversion of the classical ketimine enzymes intermediate to an enaminetype structure, and (b) considerable conservation of label during the prototropic shift from the alpha carbon of L-alanine to the C4-position of pyridoxal 5'-phosphate. It is also postulated that alanine binds at the active site in such a way as to bring the beta protons into close contact with a basic group on the enzyme surface. This group is distinct from that used in abstraction of an alpha proton. The beta protons of glutamate are not enzymatically removed; presumably glutamate binds in such a way that the beta protons cannot effectively interact with an enzyme base. Similar studies were carried out on soluble glutamate-aspartate transaminase; no evidence was found for significant enzyme-catalyzed deuterium incorporation into the beta position of L-glutamate, L-aspartate, and L-alanine.
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PMID:Proton magnetic resonance studies of glutamate-alanine transaminase-catalyzed deuterium exchange. Evidence for proton conservation during prototropic transfer from the alpha carbon of L-alanine to the C4-position of pyridoxal 5'-phosphate. 124 68

In order to assess the functional state of the liver in 45 repair service workers of a chemical plant producing pesticides the serum concentration and electrophoretic pattern of proteins, the concentration of bilirubin and the activity of alkaline phosphatase, gamma-glutamyl- transpeptidase, alanine and aspartate aminotransferase, and lactic and malic dehydrogenase were determined. As compared to 35 healthy controls, not exposed to noxious chemicals, a significantly lower serum protein concentration with higher percentage of gamma-globulins and lower albumins and alpha 2-globulins were observed, the serum alanine and aspartate aminotransferase activities were significantly elevated. Ultrasound examination of the hepatic structure revealed liver steatosis in 11 (24.4%) workers. The results of our study point to a discrete lesion of the liver.
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PMID:[Biochemical indices of liver function in workers from repair brigades in chemical plants "Organika-Azot" in Jaworz]. 128 52

In glycogen storage disease type III (glycogen debranching enzyme (DE) deficiency), the activities of serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase may be strikingly elevated during childhood but are low during adult life. To determine the pattern of the elevated serum enzyme activities in relationship to diet, the biochemical subtype and clinical symptoms, 13 patients with DE deficiency were studied. Activities of serum aspartate and alanine transaminases, lactate dehydrogenase, and alkaline phosphatase were markedly elevated during infancy. Continued elevation of enzyme activities during childhood appeared to be related to DE deficiency in liver, but unrelated to DE deficiency in muscle. Activity elevations correlated inconsistently with diet and poorly with childhood growth rate or the presence of hypoglycaemia. The serum enzyme activities declined around puberty concomitantly with a decrease in liver size. Although periportal fibrosis and micronodular cirrhosis indicated the presence of hepatocellular damage during childhood, the decline in serum enzyme activities with age and the absence of overt hepatic dysfunction suggest that the fibrotic process may not always progress.
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PMID:Glycogen debranching enzyme deficiency: long-term study of serum enzyme activities and clinical features. 129 83

Sera from 209 dialysis patients were tested for antibodies to hepatitis C virus (anti-HCV) by a 2nd generation enzyme-linked immunoassay (ELISA 2) using nonstructural and core antigens. Confirmation of reactivity was obtained by a 2nd generation immunoblot assay (RIBA 2) for antibodies to 4 separate antigens (5-1-1, c100-3, c33c, c22-3). ELISA 2 was positive in 99 sera, 95 of which were confirmed by RIBA 2, thus accounting for an anti-HCV prevalence of 45.5%. Anti-HCV positivity was correlated to longer duration of dialysis therapy (p less than 0.001), higher number of transfusions (p less than 0.001), history of kidney transplant (p less than 0.001) and of serum alanine/aspartate aminotransferase (AST/ALT; p less than 0.001) or gamma-glutamyltransferase (GGT) (p less than 0.001) increments. The most frequent RIBA 2 patterns were: reactivity to all 4 antigens (34 patients) and to c33c and c22-3 (45 patients). The former patients, compared to the latter, had higher values of AST (p less than 0.08), ALT (p less than 0.02), GGT (p less than 0.005), IgG (p less than 0.05). It is possible that the reactivity to all 4 antigens of RIBA 2 is a clue of a greater activity of viral hepatic disease.
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PMID:Confirmation of high prevalence of hepatitis C antibodies in hemodialysis patients by second generation immunoblot assay. 132 87

Hepatitis A is an acute, necroinflammatory disease of the liver which results from infection by the hepatitis A virus (HAV). The mean incubation period is approximately 30 days. Although the disease is usually self-limited, the severity of illness is age-dependent. In children, hepatitis A is usually asymptomatic, while in adults, symptomatic infection is characteristic and jaundice is common. Fulminant hepatitis A is rare and is also age-dependent. The onset of hepatitis A is often abrupt and characteristic prodromal symptoms are followed, within a few days to a week, by dark urine and jaundice. Mild to moderate tenderness over an enlarged liver is usually detected. Serum alanine and aspartate aminotransferase levels usually both rise rapidly during the prodromal period, reach peak levels and then decrease by approximately 75% per week. Serum bilirubin concentrations reach peak levels later and decline less rapidly than serum aminotransferases. Nonetheless, the period of jaundice persists for < 2 weeks in approximately 85% of cases. Nearly all adult patients with clinically apparent disease experience complete clinical recovery with restoration of normal serum bilirubin and aminotransferase values by 6 months. Relapses and prolonged cholestasis are unusual manifestations of hepatitis A, and even in these circumstances, recovery is the rule and chronic hepatitis is not seen. The diagnosis of hepatitis A requires the detection of immunoglobulin M antibody to HAV in a patient who presents with, or has recently had, clinical features of hepatitis (icteric or anicteric disease) or in an individual with inapparent, asymptomatic infection in whom serum aminotransferase elevations may be detected.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical manifestations and diagnosis of hepatitis A virus infection. 133 49

The activities of aspartate and alanine aminotransferases in biological samples were assessed through a novel and sensitive procedure, based on the conversion of [U-14C]2-ketoglutarate to L-[U-14C]glutamate. In human plasma, the generation of L-[U-14C]glutamate was proportional to the volume of plasma (20-60 microL) and to the length of incubation (30-90 min). The reaction velocity was related to the temperature with a Q10 close to 1.7 for aspartate aminotransferase and 2.0 for alanine aminotransferase. At 37 degrees C, the 95% confidence interval in healthy subjects ranged from 5.1-18.8 U/mL (mean value 11.9 U/L) for aspartate aminotransferase and from zero to 20.1 U/L (mean value 9.9 U/L) for alanine aminotransferase. The intra-assay coefficient of variation did not exceed 2.5%. The present method was also applied to homogenates prepared from rat pancreatic islets, liver, heart, parotid glands, and erythrocytes, using no more than 40 micrograms wet weight of tissue per sample, and could thus be used in small biological samples, such as those obtained by needle biopsy.
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PMID:Radioisotopic assay of aspartate and alanine aminotransferase. 135 85


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