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| 003 | MX-MdCICY | ||
| 005 | 20250625140619.0 | ||
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| 090 | _aB-9771 | ||
| 245 | 1 | 0 | _aSome properties of glutamate dehydrogenase, glutamine synthetase and glutamate synthase from Corynebacterium callunae |
| 490 | 0 | _vArch. Microbiol., 158(1), p.35-41, 1992 | |
| 520 | 3 | _aCharacteristics of the three major ammonia assimilatory enzymes, glutamate dehydrogenase (GDH), glutamine synthetase (GS)and glutamate synthase (GOGAT)in Corynebacterium calhmae (NCIB 10338)were examined. The GDH of C. callunae specifically required NADPH and NADP + as coenzymes in the amination and deamination reactions, respectively. This enzyme showed a marked specificity for e-ketoglutarate and glutamate as substrates. The optimum pH was 7.2 for NADPH-GDH activity (amination)and 9.0 for NADP +- GDH activity (deamination). The results showed that NADPH-GDH and NADP+-GDH activities were controlled primarily by product inhibition and that the feedback effectors alanine and valine played a minor role in the control of NADPH-GDH activity. The transferase activity of GS was dependent on Mn +2 while the biosynthetic activity of the enzyme was dependent on Mg 2+ as essential activators. The pH optima for transferase and biosynthetic activities were 8.0 and 7.0, respectively. In the transfer reaction, the K m values were 15.2mM for glutamine, 1.46raM for hydroxylamine, 3.5x 10-3raM for ADP and 1.03raM for arsenate. Feedback inhibition by alanine, glycine and serine was also found to play an important role in controlling GS activity. In addition, the enzyme activity was sensitive to ATP. The transferase activity of the enzyme was responsive to ionic strength as well as the specific monovalent cation present. GOGAT of C. calhmae utilized either NADPH or NADH as coenzymes, although the latter was less effective. The enzyme specifically required ~- ketoglutarate and glutamine as substrates. In cells grown in a medium with glutamate as the nitrogen source, the optimum pH was 7.6 for NADPH-GOGAT activity and 6.8 for NADH-GOGAT activity. Findings showed that NADPH-GOGAT and NADH-GOGAT activities were controlled by product inhibition caused by NADP + and NAD +, respectively, and that ATP also had an important role in the control of NADPH-GOGAT activity. Both activities of GOGAT were found to be inhibited by azaserine. | |
| 650 | 1 | 4 | _aGDH |
| 650 | 1 | 4 | _aGLUTAMATE DEHYDROGENASE |
| 650 | 1 | 4 | _aGOGAT |
| 650 | 1 | 4 | _aGLUTAMATE SYNTHASE |
| 650 | 1 | 4 | _aGS |
| 650 | 1 | 4 | _aGLUTAMINE SYNTHETASE |
| 700 | 1 | 2 | _aHaluk Ertan |
| 856 | 4 | 0 |
_uhttps://drive.google.com/file/d/17if87Y5DKXym3dC65V8J2WOCjtBpJfvN/view?usp=drivesdk _zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx |
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