1887

Abstract

N kinetic labelling studies were done on liquid cultures of wild-type The labelling pattern of major amino acids under steady state conditions suggests that glutamate and glutamine-amide are the early products of ammonia assimilation in In the presence of phosphinothricin, an inhibitor or glutamine synthetase, N labelling of glutamate, alanine and aspartate was maintained whereas the labelling of glutamine was low. This pattern of labelling is consistent with ammonia assimilation into glutamate via the glutamate dehydrogenase pathway. In the presence of azaserine, an inhibitor of glutamate synthase, glutamate was initially more highly labelled than any other amino acid, whereas its concentration declined. Isotope also accumulated in glutamine. Observations with these two inhibitors suggest that ammonia assimilation can occur concurrently via the glutamine synthetase/glutamate synthase and the glutamate dehydrogenase pathways in low-ammonia-grown From a simple model it was estimated that about half of the glutamate was synthesized via the glutamate dehydrogenase pathway; the other half was formed from glutamine via the glutamate synthase pathway. The transfer coefficients of nine other amino acids were also determined.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-135-4-729
1989-04-01
2021-10-28
Loading full text...

Full text loading...

/deliver/fulltext/micro/135/4/mic-135-4-729.html?itemId=/content/journal/micro/10.1099/00221287-135-4-729&mimeType=html&fmt=ahah

References

  1. Berger M.G., Fock H.P. 1983; Effects of methionine sulfoximine and glycine on nitrogen metabolism of maize leaves in the light. Australian Journal of Plant Physiology 10: 187–194
    [Google Scholar]
  2. Brown C.M., Burn V.J., Johnson B. 1973; Presence of glutamate synthase in fission yeasts and its possible role in ammonia assimilation. Nature New Biology 246:115–116
    [Google Scholar]
  3. Casper P., Bode R., Birnbaum D. 1985; Untersuchungen zur Regulation der Ammoniumsas-similation von Candida maltosa . Journal of Basic Microbiology 25:95–101
    [Google Scholar]
  4. Dunn-Coleman N.S., Robey E.A., Tomsett A.B., Garrett R.H. 1981; Glutamate synthase levels in Neurospora crassa mutants altered with respect to nitrogen metabolism. Molecular and Cellular Biology 1:158–164
    [Google Scholar]
  5. Fentem A.P., Lea P.J., Stewart G.R. 1983; Ammonia assimilation in the roots of nitrate- and ammonia-grown Hordeum vulgare (cv Golden Promise). Plant Physiology 71:496–501
    [Google Scholar]
  6. Fincham J.R.S., Boulter A.B. 1956; Effects of amino acids on transaminase production in Neurospora crassa: evidence for four different enzymes. Biochemical Journal 62:72–77
    [Google Scholar]
  7. Folkes B.F., Sims A.P. 1974; The significance of amino acid inhibition of NADP-linked glutamate dehydrogenase in the physiological control of glutamate synthesis in Candida utilis . Journal of General Microbiology 82:77–95
    [Google Scholar]
  8. Galbraith J.C., Smith J.E. 1969; Changes in activity of certain enzymes of the tricarboxylic acid cycle and the glyoxylate cycle during the initiation of conidiation of Apergillus niger . Canadian Journal of Microbiology 15:1207–1212
    [Google Scholar]
  9. Genetet I., Martin F., Stewart G.R. 1984; Nitrogen assimilation in mycorrhizas. Ammonium assimilation in the N-starved ectomycorrhizal fungus Cenococcum graniforme . Plant Physiology 76:395–399
    [Google Scholar]
  10. Hummelt G., Mora J. 1980a; Regulation and function of glutamate synthase in Neurospora crassa . Biochemical and Biophysical Research Communications 96:1688–1694
    [Google Scholar]
  11. Hummelt G., Mora J. 1980b; NADH-dependent glutamate synthase and nitrogen metabolism in Neurospora crassa . Biochemical and Biophysical Research Communications 92:127–133
    [Google Scholar]
  12. Kusnan B.K., Berger M.G., Fock H.P. 1987; The involvement of glutamine synthetase/glutamate synthase in ammonia assimilation by Aspergillus nidulans . Journal of General Microbiology 133:1235–1242
    [Google Scholar]
  13. Lewis O.A.M., Chadwick S., Withers J. 1983; The assimilation of ammonium by barley roots. Planta 159:483–486
    [Google Scholar]
  14. Miflin B.J., Lea P.J. 1975; Glutamine and asparagine as nitrogen donors for reductant-depen- dent glutamate synthesis in pea roots. Biochemical Journal 149:403–409
    [Google Scholar]
  15. Miflin B.J., Lea P.J. 1980; Ammonia assimilation. In The Biochemistry of Plants 5 pp. 169–202 Miflin B. J. Edited by London: Academic Press;
    [Google Scholar]
  16. Monder C., Meister A. 1958; α-Ketoglutaramic acid as a product of enzymic transamination of glutamine in Neurospora . Biochimica et biophysica acta 28:202–203
    [Google Scholar]
  17. Pateman J.A. 1969; Regulation of synthesis of glutamate dehydrogenase and glutamine synthetase in micro-organisms. Biochemical Journal 115:769–775
    [Google Scholar]
  18. Pateman J.A., Kinghorn J.R. 1975; Nitrogen metabolism. In The Filamentous Fungi 2 pp. 159–237 Smith J. E., Berry D. R. Edited by London: Edward Arnold;
    [Google Scholar]
  19. Perham R.N. 1978; Techniques for determining the amino acid composition and sequence of proteins. Techniques in Protein and Enzyme Biochemistry B110:1–39
    [Google Scholar]
  20. Rhodes D., Sims A.P., Folkes B.F. 1980; Pathway of ammonia assimilation in illuminated Lemna minor . Phytochemistry 19:357–365
    [Google Scholar]
  21. Roon R.J., Even H.L., Larimore F. 1974; Glutamate synthase: properties of the reduced nicotinamide adenine dinucleotide-dependent enzyme from Saccharomyces cerevisiae . Journal of Bacteriology 118:89–95
    [Google Scholar]
  22. Sims A.P., Folkes B.F. 1964; A kinetic study of assimilation of 15N-ammonia and the synthesis of amino acids in an exponentially growing culture of Candida utilis . Proceedings of the Royal Society B 159:479–502
    [Google Scholar]
  23. Tempest D.W., Meers J.L., Brown C.M. 1970; Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route. Biochemical Journal 117:405–407
    [Google Scholar]
  24. Umbarger H.E. 1978; Amino acid biosynthesis and its regulation. Annual Review of Biochemistry 41:533–606
    [Google Scholar]
  25. Weiss R.L. 1973; Intracellular localization of ornithine and arginine pools in Neurospora . Journal of Biological Chemistry 248:5409–5413
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-135-4-729
Loading
/content/journal/micro/10.1099/00221287-135-4-729
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error