scholarly journals Methylation of 4-aminobutyrate aminotransferase (ABAT) by dnmy3b regulates chondrocytes metabolism and the development of osteoarthritis (OA)

2018 ◽  
Vol 26 ◽  
pp. S64-S65
Author(s):  
J. Shen ◽  
C. Wang ◽  
D. Li ◽  
T. Wang ◽  
A. McAlinden ◽  
...  
Keyword(s):  
Aminobutyrate Aminotransferase

Characterization of a novel moderate-substrate specificity amino acid racemase from the hyperthermophilic archaeon Thermococcus litoralis

2021 ◽  
Author(s):  
Ryushi Kawakami ◽  
Chinatsu Kinoshita ◽  
Tomoki Kawase ◽  
Mikio Sato ◽  
Junji Hayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Enzyme Stability ◽  
Hyperthermophilic Archaea ◽  
Thermococcus Litoralis ◽  
Hyperthermophilic Archaeon ◽  
Aminobutyrate Aminotransferase ◽  
Chaperone Protein ◽  
Amino Acid Racemase

Abstract The amino acid sequence of the OCC_10945 gene product from the hyperthermophilic archaeon Thermococcus litoralis DSM5473, originally annotated as γ-aminobutyrate aminotransferase, is highly similar to that of the uncharacterized pyridoxal 5ʹ-phosphate (PLP)-dependent amino acid racemase from Pyrococcus horikoshii. The OCC_10945 enzyme was successfully overexpressed in Escherichia coli by co-expression with a chaperone protein. The purified enzyme demonstrated PLP-dependent amino acid racemase activity primarily toward Met and Leu. Although PLP contributed to enzyme stability, it only loosely bound to this enzyme. Enzyme activity was strongly inhibited by several metal ions, including Co2+ and Zn2+, and non-substrate amino acids such as l-Arg and l-Lys. These results suggest that the underlying PLP-binding and substrate recognition mechanisms in this enzyme are significantly different from those of the other archaeal and bacterial amino acid racemases. This is the first description of a novel PLP-dependent amino acid racemase with moderate substrate specificity in hyperthermophilic archaea.

The reactions of aminobutyrate aminotransferase and ornithine aminotransferase with analogues of ethanolamine O-sulphate

1983 ◽  
Vol 32 (15) ◽  
pp. 2350-2353 ◽  
Author(s):  
Jennifer A. Williams ◽  
Michael J. Hewlins ◽  
Leslie J. Fowler ◽  
Roberta A. John
Keyword(s):  
Ornithine Aminotransferase ◽  
Aminobutyrate Aminotransferase

scholarly journals 4-Aminobutyrate Aminotransferase (ABAT): Genetic and Pharmacological Evidence for an Involvement in Gastro Esophageal Reflux Disease

PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e19095 ◽  
Author(s):  
Johan Jirholt ◽  
Bengt Åsling ◽  
Paul Hammond ◽  
Geoffrey Davidson ◽  
Mikael Knutsson ◽  
...  
Keyword(s):  
Reflux Disease ◽  
Esophageal Reflux ◽  
Aminobutyrate Aminotransferase

Kinetics of inactivation of 4-aminobutyrate aminotransferase by 3-bromopyruvate

1992 ◽  
Vol 70 (8) ◽  
pp. 716-719 ◽  
Author(s):  
K. J. Blessinger ◽  
G. Tunnicliff
Keyword(s):  
Pseudomonas Fluorescens ◽  
Maximum Rate ◽  
Enzyme Reaction ◽  
Reversible Inhibitor ◽  
Enzyme Complex ◽  
Inhibitor Concentration ◽  
Aminobutyrate Aminotransferase ◽  
Affinity Labelling ◽  
Sulphydryl Groups ◽  
Kinetics Of

3-Bromopyruvate inhibited 4-aminobutyrate aminotransferase (EC 2.6.1.19) from Pseudomonas fluorescens, apparently irreversibly. Kinetics of this inactivation were studied by continuously monitoring the enzyme reaction at 30 °C in the presence of inhibitor. Irrespective of how high an inhibitor concentration was present, a maximum rate of inactivation was eventually achieved (5.9 × 10−3 s−1), indicating the formation of a reversible inhibitor–enzyme complex before the final inactivation step. The dissociation constant of this complex was found to be 6.5 μM. This affinity labelling by 3-bromopyruvate suggests the presence of essential sulphydryl groups on the enzyme, since this compound is known to preferentially alkylate cysteinyl residues.Key words: 4-aminobutyrate, 4-aminobutyrate aminotransferase, inactivation, 3-bromopyruvate, affinity label, Pseudomonas fluorescens.

The mode of action of homocysteine on mouse brain glutamic decarboxylase and γ-aminobutyrate aminotransferase

1977 ◽  
Vol 55 (9) ◽  
pp. 1013-1018 ◽  
Author(s):  
G. Tunnicliff ◽  
T. T. Ngo
Keyword(s):  
Amino Acid ◽  
Mouse Brain ◽  
Mode Of Action ◽  
Acid Metabolism ◽  
Competitive Inhibition ◽  
The Other ◽  
Aminobutyric Acid ◽  
Aminobutyrate Aminotransferase ◽  
Dual Action

In the belief that homocysteine-induced convulsions might be related to alterations in brain γ-aminobutyric acid metabolism, we have studied the action of this amino acid on the activity of glutamic decarboxylase (GAD, EC 4.1.1.15) and γ-aminobutyrate aminotransferase (EC 2.6.1.19)of mouse brain in vitro. DL-homocysteine competitively inhibited GAD with respect to both L-glutamate and pyridoxal 5′-phosphate. The respective Ki's were 3.8 mM and 0.3 mM, The activity of GABA-T also was altered in the presence of DL-homocysteine. A competitive inhibition (Ki = 6 mM) was observed with γ-aminobutyric acid, and an uncompetitive inhibition with respect to pyridoxal 5′-phosphate and α-ketoglutarate. These results are explained in terms of a dual action of homocysteine on each of the enzymes: one involving a competition for substrate binding site and the other involving the formation of an inactive inhibitor – cofactor complex. The significance of the inhibition of these enzymes of γ-aminobutyric acid metabolism is discussed in relation to the convulsant action of homocysteine.

Reaction of Muscimol with 4-Aminobutyrate Aminotransferase

1983 ◽  
Vol 41 (6) ◽  
pp. 1751-1754 ◽  
Author(s):  
Leslie J. Fowler ◽  
David H. Lovell ◽  
Robert A. John
Keyword(s):  
Aminobutyrate Aminotransferase
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