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)

The subcellular location of aspartate aminotransferase isozymes (EC 2.6.1.1) in the genus Capsella (Brassicaceae) was studied. The diploid species C. grandiflora and C. rubella have three AAT isozymes, including one located in the plastids. Each locus is duplicated in the tetraploid Capsella bursa-pastoris. Variation at the plastid-coding locus exceeded that at the other loci. C. bursa-pastoris had some unique alleles not detected in the diploid species. Segregation in open-pollinated families revealed that Capsella grandiflora was outcrossing, whereas C. rubella was highly inbred, with most populations homozygous or uniform at all three loci. Inheritance in the tetraploid colonizer C. bursa-pastoris is disomic. This species was also predominantly selfing with outcrossing rates between 2% and 10%.
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PMID:Aspartate aminotransferase isozymes in the genus Capsella (Brassicaceae): subcellular location, gene duplication, and polymorphism. 271 24

Working up great test series to determine chloroform-extractive substances and tensides, increased trichlormethane concentrations can appear in the laboratory air-inspite of realization of numerous precautionary measures. As a rule the MAKD rate will be exceeded than. Various precautions failed to fulfill their purpose so that the solvent trichlormethane had been replaced by other solvents. Two demands mainly influenced on this replacement. The risk to health must be decreased so far that the work with solvents can be performed without any difficulties. The correlation between methods of determination must-on the other hand-be a reliable one. Trichlortrifluorethane is especially suited for the determination of extractive substances, dichlormethane for those of AAT (MBAS). The MAK rates can be observed with utilization of both the solvents. The reliable correlation of the concentration ascertained could be proved.
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PMID:[Decreasing the emission of pollutants in laboratory waste water by substitution of trichloromethane]. 274 1

To survey the genetic resources of Atlantic salmon (Salmo salar L.) stocks in Finland, an electrophoretic study was made of natural and hatchery stocks. The stocks were compared with the nearest stocks in the USSR, and the effects of hatchery rearing were evaluated. The genetic variation within and between stocks was measured from 20 samples, of which three (Kola, Neva and Onega) were from the USSR. Twenty-five enzyme loci were examined, of which six were polymorphic: AAT-4, IDH-3, ME-3, MDH-3, PGM-1, and SDH-1. The mean heterozygosity of all the populations was 4.2% (1.0-7.2). For the natural salmon stocks of the Arctic Ocean, the mean heterozygosity was 6.3%, for the natural stocks of Atlantic salmon in the Baltic 4.8%, for the hatchery stocks 3.6%, and for the lake salmon (Salmo salar m. sebago Girard) 1.8%. The results are in agreement with the hypothesis that the amount of variation depends on the effective population size and that culture diminishes variation by decreasing the effective population size. All the stocks originating from different rivers differed from each other with statistical significance. The most unique stocks were the River Kola stock and the lake salmon stock from Lake Saimaa. The genetic distances were consistent with the geographic distance between the rivers from which the stocks originated. Stress is laid on the importance in fish culture of maintaining separate stocks and using larger brood stocks.
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PMID:Electrophoretically detectable genetic variation in natural and hatchery stocks of Atlantic salmon in Finland. 277 27

Recently we reported that the contractile agonist angiotensin II induces hypertrophy, not hyperplasia, in cultured rat aortic smooth muscle cells (Geisterfer AAT, Peach MJ, Owens GK: Angiotensin II induces hypertrophy, not hyperplasia, of cultured rat aortic smooth muscle cells. Circ Res 1988;62:749-756). We have further explored the hypothesis that contractile agonists are important regulators of smooth muscle cell growth by examining the effects of another contractile agonist, arginine vasopressin, on growth of cultured rat aortic smooth muscle cells. Autoradiographic analysis as well as cell number determinations showed that arginine vasopressin (1 microM) did not stimulate proliferation in cells made quiescent in a defined serum-free media nor did it augment proliferation in 0.4% fetal bovine serum. However, flow cytometric analysis of cellular protein content demonstrated that arginine vasopressin (1 microM) did induce cellular hypertrophy in quiescent cultures after 4 days of treatment, increasing smooth muscle cell protein content by 35% as compared with vehicle-treated controls. The increase in protein content showed a concentration dependence. Cellular hypertrophy was accompanied by an increase in [35S]methionine incorporation, which was elevated 45% by 24 hours. Both the increase in [35S]methionine incorporation and the increase in protein content could be prevented by the specific arginine vasopressin receptor antagonist. [1-beta-mercapto-beta,beta-cyclopentamethylene propionic acid), 2-(O-methyl)tyrosine] arginine vasopressin. An increase in [35S]methionine incorporation was observed between 12 and 24 hours after treatment of quiescent smooth muscle cells for only 5 minutes with arginine vasopressin (1 microM). Arginine vasopressin-induced increases in [35S]methionine incorporation was increased within 6 hours after treatment. These studies show that arginine vasopressin, like angiotensin II, induces hypertrophy but not hyperplasia of cultured rat aortic smooth muscle cells.
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PMID:Arginine vasopressin-induced hypertrophy of cultured rat aortic smooth muscle cells. 279 15

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

The mitochondrial acetyl-CoA acetyltransferase (acetyl-CoA:acetyl-CoA C-acetyltransferase, EC 2.3.1.9), which is involved in the biosynthesis or degradation of ketone bodies, was directly demonstrated in organ extracts applying a two-step chromatography-immunoelectrophoresis method. In liver, the enzyme can be shown in at least three forms: in an unmodified state, designated as AAT, and in the CoASH-modified forms A1 and A2, in amounts of 51.5 +/- 5.0%, 39.4 +/- 4.8% and 9.1 +/- 2.7% (areas of immunoprecipitation), respectively. This pattern, which could not be altered by a treatment with glutathione, resembles that of mitochondrial acetyl-CoA acetyltransferase in extrahepatic tissues. However, the proportion of the unmodified enzyme (AAT) is lower as compared to those in other tissues such as brain (81.5 +/- 4.4%). CoASH-modification and transformation into modified forms, which equal naturally occurring forms, can be demonstrated in vitro with acetyl-CoA acetyltransferase from both liver and brain. Thus CoASH-modification of mitochondrial acetyl-CoA acetyltransferase seems to be a process of general importance.
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PMID:Mitochondrial acetyl-CoA acetyltransferase in various organs from rat: form patterns and coenzyme-A-mediated modification. 286 16

The activities of the enzymes SD, GD, AAT, 5'NT, GGT, LDH and CPK were determined weekly in sera of two calves each infected with 10,000 S. bovis cercariae and in two controls. In infected animals, LDH activity increased from the first week of exposure and remained high throughout the experiment (22 weeks). GGT activity increased nine weeks after exposure and remained high. CPK activity was elevated during weeks 8-15 of infection. No change was detected in the activity of the other enzymes, nor in any enzymes of the controls.
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PMID:Serum enzyme changes in calves experimentally infected with Schistosoma bovis. 288 18

Human alpha-L-fucosidase, a lysosomal enzyme, hydrolyzes alpha-L-fucose from glycolipids and glycoproteins. Its activity is deficient in human fucosidosis an autosomal recessive disease. In order to understand the molecular basis of this lysosomal storage disorder we have cloned several cDNAs coding for human alpha-L-fucosidase from a human hepatoma and a human liver cDNA library constructed in lambda gt11. Compiling the cDNA sequences of these clones we have identified 1,829 base pairs (bp) encoding human alpha-L-fucosidase. This includes an open reading frame of 1,172 bp, a consensus polyadenylation signal AAT AAA and a poly(A)+ tail. The sequence is incomplete at the 5'-end, and clones encoding the amino terminus of the native protein, the propeptide and leader signal have not yet been isolated. The open reading frame encodes for 390 amino acids with a calculated Mr of 45,557. This represents 78-95% of the mature processed alpha-L-fucosidase. The availability of these cDNA clones has enabled us to map the structural gene for alpha-L-fucosidase to chromosome 1p34.1-1p36.1 by Southern blot analysis of DNA from human-rodent somatic cell hybrids and by in situ hybridization. Furthermore, a Pvu II restriction fragment length polymorphism (RFLP) has been identified at the human alpha-L-fucosidase gene locus. Analysis of mRNA by Northern blotting gives a major species of 2.25 kb. In 4 patients with fucosidosis no mRNA signal was detected and Western blots gave no immunoreactive enzyme. Southern blotting after Eco RI digestion in two fucosidosis families revealed a banding abnormality (extra 6-kb band).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular biology of the alpha-L-fucosidase gene and fucosidosis. 289 6

The potential of nucleosome assembly along the sequence of a plasmid carrying the long terminal repeat (LTR) and its flanking region of Moloney murine leukemia virus was analyzed by in vitro reconstitution experiments with histones from chicken erythrocytes. The results of electrophoretic mobility-shift and micrococcal nuclease-digestion assays indicated that the plasmid DNA contained four preferred sites for nucleosome formation. However, all of these sites were mapped on the vector moiety but not on the LTR moiety. Computer analysis of the sequences in the four preferred sites, each spanning about 150 bp, indicated that short runs of (dA,dT) containing two kinds of triplets, AAA/TTT and AAT/ATT, occurred frequently. Furthermore, many of these triplets tended to occur in the same side of the DNA helix, suggesting that DNA curvature was involved in the preferred sites for nucleosome assembly. Consistent was the observation that DNA fragments carrying these preferred sites showed anomalous electrophoretic mobilities at a low temperature.
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PMID:Reconstitution of nucleosomes in vitro with a plasmid carrying the long terminal repeat of Moloney murine leukemia virus. 293 Jul 79

A novel family of micronuclear elements termed telomere-bearing elements (TBEs) is described. All 1900 family members are eliminated during macronuclear development. We conclude that they are transposons, first because the members are moderately conserved in sequence and probably dispersed in the genome. Second, in two cases, sequence comparison of the termini and flanks of the element with the corresponding empty site indicate that elements cause 3 bp target duplications (AAT) upon insertion; the 3 bp are part of the 5 bp target sequence, AATGA. Lastly, both elements carry 77 or 78 bp inverted terminal repeats. The tip of each inverted terminal repeat is the 17 bp telomere-like sequence 5' C1A4C4A4C4. At least half of the elements have these 17 bp or an extremely similar sequence. One possible pathway for transposition into new micronuclear sites starts in the developing macronucleus with excision to create a free linear form to which telomeres are added, followed by a low frequency of movement to the micronucleus, and insertion into the germ-line micronuclear DNA.
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PMID:Mobile elements bounded by C4A4 telomeric repeats in Oxytricha fallax. 300 Jun 14


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