Ornithine-δ-transaminase in the rat I. Assay and some general properties

Peraino, Carl; Pitot, H. C.

doi:10.1016/0006-3002(63)90306-8

Cited by 29 publications

(36 citation statements)

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“…In the past, metabolic studies of these biochemical pathways have not separated pericentral from other hepatocytes, leading to controversy concerning the role of OAT in the liver (22). We suggest that if pure pericentral cells were available it could be demonstrated that ornithine in those cells would mainly end up as glutamate and not be converted into other amino acids or into urea.…”

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confidence: 99%

Colocalization in pericentral hepatocytes in adult mice and similarity in developmental expression pattern of ornithine aminotransferase and glutamine synthetase mRNA.

Kuo

Hwu

Valle

et al. 1991

Proc. Natl. Acad. Sci. U.S.A.

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In situ hybridization showed that the mRNA for ornithine aminotransferase (OAT; ornithine-oxo-acid aminotransferase; L-ornithine:2-oxo-acid aminotransferase, EC 2.6.1.13) colocalized with glutamine synthetase [GS; glutamate-ammonia ligase; L-glutamate:ammonia ligase (ADPforming), EC 6.3.1.2] in pericentral hepatocytes of the adult mouse liver. In addition to an identical distribution in adult hepatocytes, OAT and GS have very similar expression patterns in fetal and neonatal liver. As was earlier described for GS, there is a low level of OAT mRNA in fetal cells and increasing pericentral levels in neonates that reach adult patterns within 2 weeks. These results suggest that the transcriptional regulation of the two genes is similar in the liver. However, there was a lack of colocalization of the mRNAs for the two enzymes in cells of the kidney, intestine, and brain, suggesting different regulatory decisions for the OAT and GS genes in the cells of these different tissues. The metabolic consequences of these localized expression patterns favor ammonia clearance from the blood by the liver and urea synthesis by the kidney.

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confidence: 99%

Colocalization in pericentral hepatocytes in adult mice and similarity in developmental expression pattern of ornithine aminotransferase and glutamine synthetase mRNA.

Kuo

Hwu

Valle

et al. 1991

Proc. Natl. Acad. Sci. U.S.A.

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“…The occurrence of these enzymes for the conversion of arginine into proline in the extramitochondrial fraction is consistent with the proposed role of proline penetrating the mitochondria to form precursors of oxaloacetate to bring about the complete oxidation ofpyruvate (Sacktor & Childress, 1967). Ornithine transaminase is a particulate enzyme in the rat (Peraino & Pitot, 1963), Tetrahymena (Hill & Chambers, 1967), the sunflower (J. E. Smith, 1962) and the chicken (Vecchio & Kalman, 1968). Only in Neuro8pora (Vogel & Kopac, 1960) has it previously been inferred to be a soluble enzyme.…”

Section: Resultsmentioning

confidence: 56%

“…of 01 M-KH2PO4, adjusted to pH8-0 with KOH, and containing 10mM-mercaptoethanol, in a TenBroeck tissue grinder kept cold in crushed ice. The reaction mixture was essentially as described by Peraino & Pitot (1963) and contained, in 3ml. : L-ornithine sodium salt, pH8-0, 300,tmoles; sodium a-oxoglutarate, pH7-4, 60,umoles; K2HPO4-KH2PO4 buffer, pH8-0, 750,umoles; pyridoxal 5'-phosphate, 1 mole; o-aminobenzaldehyde, 20-7,umoles [in 0-1ml.…”

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Arginine metabolism in insects. Role of arginase in proline formation during silkmoth development

Reddy

Campbell

1969

Biochemical Journal

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1. Ornithine 8-transaminase (L-ornithine-2-oxo acid aminotransferase, EC 2.6.1.13) and A'-pyrroline-5-carboxylate reductase [L-proline-NAD(P) 5-oxido. reductase, EC 1.5.1.2] were demonstrated in fat-body and flight-muscle tissues of the silkmoth Hyalophora gloveri. Arginase (L-arginine ureohydrolase, EC 3.5.3.1) is also present in these tissues. 2. Arginase, ornithine transaminase and pyrrolinecarboxylate reductase are generally considered to make up the catabolic pathway for the conversion of arginine into proline. The conversion of L-[U-14C]argirline into [14C]proline by intact fat-body tissue was used to show that the enzymes in insect fat body also function in this capacity. 3. Of the three enzymes of the catabolic pathway, only arginase increased during adult development and the increase coincided with the emergence of the winged adult moth. Since proline appears to be a major substrate utilized in insect flight metabolism, the increase in arginase activity at this stage suggests a major role for arginase in proline formation.

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“…Ornithine aminotransferase (OATase; ornithine-oxo-acid aminotransferase; L-ornithine:2-oxo-acid aminotransferase, EC 2.6.1.13) is a nuclear-encoded pyridoxal phosphaterequiring mitochondrial matrix enzyme that catalyzes the interconversion of ornithine, glutamate, and proline (1). The enzyme is present in many mammalian tissues, including the liver (1, 2), kidney (1,2), and retina (3,4).…”

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confidence: 99%

“…The enzyme is present in many mammalian tissues, including the liver (1, 2), kidney (1,2), and retina (3,4). OATase is believed to be important in the intracellular production of glutamate and proline from ornithine (5) and in shuttling excess dietary amino acid carbons to the gluconeogenic pathway via the tricarboxylic acid cycle (6,7).…”

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confidence: 99%

Molecular cloning of human ornithine aminotransferase mRNA.

Inana

Totsuka

Redmond

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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The isolation and characterization of a cDNA clone for the mRNA of human ornithine aminotransferase (OATase; ornithine-oxo-acid aminotransferase; L-ornithine:2-oxo-acid aminotransferase, EC 2.6.1.13), a nonabundant mitochondrial matrix enzyme that is severely deficient in a hereditary chorioretinal degenerative disease (gyrate atrophy), is described. Human liver, retina, and retinoblastoma (Y79) mRNAs were prepared and tested for the OATase mRNA content by in vitro translation, immunoprecipitation, and NaDodSO4/PAGE. The retinoblastoma cells were found to be expressing this enzyme at a relatively high level. The primary translation product of the OATase mRNA is larger than the pure OATase protein on NaDodSO4/PAGE by =4 kDa, suggesting a precursor protein. Xgtll cDNA libraries were prepared from the human mRNAs, and the recombinant clones were immunoscreened as plaques with two different preparations of rabbit anti-human OATase antibodies. A clone (XgtRB315) was isolated from the retinoblastoma library that reacts with both of the antibody preparations, and the DNA sequence of its 2.1-kilobase-pair cDNA insert was obtained. An open reading frame consisting of 1371 nucleotides is present in the sequence, and a putative translational initiation methionine codon is identified at position 55. A putative leader sequence consisting of 32 amino acid residues is identified, resulting in a precursor protein of 439 amino acid residues and a molecular mass of 48,534 Da and a mature protein of 407 residues and 45,136 Da. The amino acid sequences of seven tryptic peptides (115 amino acid residues) of the pure human OATase were obtained by microsequencing. When the tryptic peptide and cDNA-derived amino acid sequences were compared, homologies in 111 of 115 residues, including a match of 20 consecutive residues, were observed. An RNA blot hybridization of 32P-labeled OATase cDNA to normal human retina and retinoblastoma mRNAs demonstrated an OATase mRNA species of "'2.2 kilobases. The level of OATase mRNA in the normal human retina is "1/100th the level of rhodopsin mRNA and 1/5th to 1/10th the level present in the retinoblastoma cells.

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Ornithine-δ-transaminase in the rat I. Assay and some general properties

Cited by 29 publications

References 0 publications

Colocalization in pericentral hepatocytes in adult mice and similarity in developmental expression pattern of ornithine aminotransferase and glutamine synthetase mRNA.

Colocalization in pericentral hepatocytes in adult mice and similarity in developmental expression pattern of ornithine aminotransferase and glutamine synthetase mRNA.

Arginine metabolism in insects. Role of arginase in proline formation during silkmoth development

Molecular cloning of human ornithine aminotransferase mRNA.

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