Aspartate: 2-Oxoglutarate Aminotransferase from Bakers' Yeast: Crystallization and Characterization1

Yagi, Toshiharu; Kagamiyama, H.; Nozaki, Mitsuhiro

doi:10.1093/oxfordjournals.jbchem.a133929

Cited by 22 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In micro-organisms, both enzymes have been extensively studied in Escherichia coli (Mavrides & Orr, 1975 ;Gelfand & Steinberg, 1977;Powell & Morrison, 1978) and to a lesser extent in Klebsiella aerogenes (Paris & Magasanik, 1981 a, b), Pseudomonas aeruginosa (Whitaker et al, 1982), Flavobacterium spp. (Beschle et al, 1982) and Saccharomyces cerevisiae (Kradolfer et al, 1982;Yagi et al, 1982). With the E. coli enzymes, considerable overlap of substrate specificity has been observed and they also share some similarities in their physical properties such as molecular weights and isoelectric points (Mavrides & Orr, 1975;Powell & Morrison, 1978).…”

Section: Introductionmentioning

confidence: 99%

Partial Purification and Some Properties of an Aromatic-amino-acid and an Aspartate Aminotransferase in Brevibacterium linens 47

Lee¹,

Desmazeaud²

1985

Microbiology

View full text Add to dashboard Cite

An L-aromatic-amino-acid aminotransferase (AT-IA) and an L-aspartate aminotransferase (AT-IB) were partially purified from Brevibacterium linens 47 grown on L-phenylalanine as sole nitrogen source and some properties were examined. Both enzymes were active with L-aromatic amino acids and L-aspartate. AT-IA showed 6 to 12 times higher affinity and slightly higher V,,, for the aromatic amino acids than for aspartate. AT-IB had higher affinity for tryptophan and tyrosine than for aspartate. However, this enzyme showed 6 to 10 times higher V,,, for the latter than for the aromatic amino acid substrates. Both enzymes had similar pH (8.5-9-0) and temperature (37-40 "C) optima, but they differed in their molecular weights (126000 for IA and 81 000 for IB) and markedly in their thermostability. At 50 "C, AT-IB was 14 times more rapidly inactivated and its inactivation rate also increased more rapidly (z-value, 7~9°C) as the temperature increased than AT-IA (z-value, 15-5 "C). The cofactor pyridoxal-5'-phosphate was tightly bound to both enzymes. Two enzymes co-eluted on DEAE-Trisacryl M column chromatography at pH 7.5 and could be separated by chromatography on a hydroxyapatite (HA-Ultrogel) column at the same pH. Chromatography on hydroxyapatite of AT-I from cells grown on L-phenylalanine and on ammonium sulphate revealed that AT-IA was present only in phenylalanine grown cells. AT-IB was present in both extracts at similar levels, suggesting that it is constitutive. The inducibility of IA suggested that it has an in vivo catabolic role. AT-IA is probably the key enzyme for the utilization of the aromatic amino acids as sole nitrogen sources in B. linens 47.

show abstract

Section: Introductionmentioning

confidence: 99%

Partial Purification and Some Properties of an Aromatic-amino-acid and an Aspartate Aminotransferase in Brevibacterium linens 47

Lee¹,

Desmazeaud²

1985

Microbiology

View full text Add to dashboard Cite

show abstract

“…Microbial AspATs have been purified from two mesophilic bacteria, E. coli (6,19,31) and Pseludomonas piutida (36), and from a yeast, Saccharomyces cerev'isiae (34), and characterized. The enzymic properties, including molecular weight, number of subunits, absorption spectra, and Mi-chaelis constants for the substrates of the microbial AspATs, are similar to those of the eucaryotic enzymes (35).…”

mentioning

confidence: 99%

Purification and characterization of thermostable aspartate aminotransferase from a thermophilic Bacillus species

et al. 1990

View full text Add to dashboard Cite

Aspartate aminotransferase (EC 2.6.1.1) was purified to homogeneity from cell extracts of a newly isolated thermophilic bacterium, Bacillus sp. strain YM-2. The enzyme consisted of two subunits identical in molecular weight (Mr, 42,000) and showed microheterogeneity, giving two bands with pls of 4.1 and 4.5 upon isoelectric focusing. The enzyme contained 1 mol of pyridoxal 5'-phosphate per mol of subunit and exhibited maxima at about 360 and 415 nm in absorption and circular dichroism spectra. The intensities of the two bands were dependent on the buffer pH; at neutral or slightly alkaline pH, where the enzyme showed its maximum activity, the absorption peak at 360 nm was prominent. The enzyme was specific for L-aspartate and L-cysteine sulfinate as amino donors and ax-ketoglutarate as an amino acceptor; the Kms were determined to be 3.0 mM for L-aspartate and 2.6 mM for ot-ketoglutarate. The enzyme was most active at 70°C and had a higher thermostability than the enzyme from Escherichia coli. The N-terminal amino acid sequence (24 residues) did not show any similarity with the sequences of mammalian and E. coli enzymes, but several residues were identical with those of the thermoacidophilic archaebacterial enzyme recently reported.

show abstract

“…An in vitro generation process has been described on storage of the a form from pig heart and has been assigned to hydrolysis of amide groups of asparagine or glutamine residues 23 …”

Section: Discussionmentioning

confidence: 99%

Cytosolic Aspartate Aminotransferases from different Chicken Tissues: Purification and Characterization of their Multiple Forms

Imperial

Busquets²,

Cortés³

et al. 1989

Preparative Biochemistry

View full text Add to dashboard Cite

Cytosolic aspartate aminotransferases from chicken heart, liver, spleen, skeletal muscle and breast muscle differed in number of their molecular forms, detected by polyacrylamide gel electrophoresis and specific staining. The number of molecular forms varied from tissue to tissue but the electrophoretic mobilities of a given form in all tissues were analogous. Within a single tissue most of the enzyme activity was present as the lowest-running band (alpha form) and the rest was distributed in minor bands termed (B,tau, alpha and epsilon forms). We report a method for the purification of cytosolic aspartate aminotransferases from various chicken tissues. The procedure can be carried out in one week and allows the obtention of isolated molecular forms of the enzyme, independently of the tissue under study. Separation of multiple forms was also achieved by chromatofocusing. The isoelectric points determined by this method for a given form in all five tissues were analogous and differed from those of the molecular forms of the enzyme from other origins. An Mr of 100,000 was obtained for all molecular forms of the five chicken tissues studied.

show abstract

Aspartate: 2-Oxoglutarate Aminotransferase from Bakers' Yeast: Crystallization and Characterization1

Cited by 22 publications

References 0 publications

Partial Purification and Some Properties of an Aromatic-amino-acid and an Aspartate Aminotransferase in Brevibacterium linens 47

Partial Purification and Some Properties of an Aromatic-amino-acid and an Aspartate Aminotransferase in Brevibacterium linens 47

Purification and characterization of thermostable aspartate aminotransferase from a thermophilic Bacillus species

Cytosolic Aspartate Aminotransferases from different Chicken Tissues: Purification and Characterization of their Multiple Forms

Contact Info

Product

Resources

About