1887

Abstract

SUMMARY: Ammonia-limited and synthesized glutamate from NH and 2-oxoglutarate by a process that involved first the synthesis of glutamine and then the reductive transfer of the glutamine amide-nitrogen to the 2-position of 2-oxoglutarate. The latter step required the recently reported enzyme ‘glutamine(amide): 2-oxoglutarate amino-transferase oxido-reductase (NADP)', some further properties of which are described here. This enzyme, from different organisms, always had a well-defined maximum activity at a pH value between 7·5 and 8·0; it had an apparent for 2-oxoglutarate between 0·1 and 2·0 m and an apparent for glutamine between 0·2 and 1·8 m. Glutamate (the metabolic end-product) and Mg strongly inhibited the enzyme from Gram-negative bacteria but less so that from Gram-positive species. Synthesis of glutamate by this enzyme required NADPH, and NADH was inactive; pyruvate, oxaloacetate, 2-oxobutyrate and 2-oxoisovalerate could not substitute for 2-oxoglutarate, nor could the requirement for glutamine be met by asparagine, citrulline, arginine or urea. Although conditions that favoured the synthesis of this enzyme generally also favoured synthesis of glutamine synthetase and caused suppression of glutamate dehydrogenase formation, a close correlation between the bacterial contents of these different enzymes was not apparent.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-64-2-187
1970-12-01
2021-10-18
Loading full text...

Full text loading...

/deliver/fulltext/micro/64/2/mic-64-2-187.html?itemId=/content/journal/micro/10.1099/00221287-64-2-187&mimeType=html&fmt=ahah

References

  1. Dixon M., Webb E. C. 1964 Enzymes 2nd edn. London: Longmans Green.;
    [Google Scholar]
  2. Evans C. G. T., Herbert D., Tempest D. W. 1970; The continuous cultivation of micro-organisms. II. Construction of a chemostat.. Methods in Microbiology 2277–328 London and New York: Academic Press.;
    [Google Scholar]
  3. Herbert D., Phipps P. J., Tempest D. W. 1965; The chemostat: design and construction.. Laboratory Practice 14:1150–1161
    [Google Scholar]
  4. Hughes D. E. 1951; A press for disrupting bacteria and other micro-organisms.. British Journal of Experimental Pathology 32:97–109
    [Google Scholar]
  5. Meers J. L., Tempest D. W., Brown C. M. 1970; A novel pathway of glutamic acid synthesis in Aerobacter aerogenes.. Journal of General Microbiology 60:x
    [Google Scholar]
  6. Pateman J. A. 1969; Regulation of synthesis of glutamate dehydrogenase and glutamine synthetase in micro-organisms.. Biochemical Journal 115:769–775
    [Google Scholar]
  7. Stickland L. H. 1951; The determination of small quantities of bacteria by means of the biuret reaction.. Journal of General Microbiology 5:698–703
    [Google Scholar]
  8. Tempest D. W., Meers J. L., Brown C. M. 1970a; Synthesis of glutamate in Aerobacter aerogenes by a hitherto unknown route.. Biochemical Journal 117:405–407
    [Google Scholar]
  9. Tempest D. W., Meers J. L., Brown C. M. 1970b; Influence of environment on the content and composition of bacterial free amino acid pools.. Journal of General Microbiology 64:171–185
    [Google Scholar]
  10. Umbarger H. E. 1969; Regulation of amino acid metabolism.. Annual Review of Biochemistry 38:323–370
    [Google Scholar]
  11. Woolfolk C. A., Shapiro B., Stadtman E. R. 1966; Regulation of glutamine synthetase. I. Purification and properties of glutamine synthetase from Escherichia coli.. Archives of Biochemistry and Biophysics 116:177–192
    [Google Scholar]
  12. Wu C., Yuan L. H. 1968; Regulation of synthesis of glutamine synthetase in Escherichia coli.. Journal of General Microbiology 51:57–66
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-64-2-187
Loading
/content/journal/micro/10.1099/00221287-64-2-187
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