1887

Abstract

SUMMARY

The pyruvate carboxylase of had a pH optimum of 7·8 and a specific requirement for ATP. At the optimum pH, magnesium ions were required for maximum activity, while at pH 6·8 manganese was more effective than magnesium. Potassium was stimulatory while sodium was ineffective. Avidin and -chloromercuribenzoate strongly inhibited the enzyme while biotin and dithio- threitol, respectively, reversed the effect of the inhibitors. Aspartate and oxalacetate were inhibitory while acetyl-CoA and CoA reversed the inhibition by aspartate. These cofactors were ineffective in the absence of aspartate. None of the tested metabolic intermediates was stimulatory to pyruvate carboxylase activity while NADP and 2,3-diphosphoglycerate were the most effective inhibitors (75 %) at a concentration of 6·7 m. Levels of pyruvate carboxylase in cells grown on glucose, acetate, malate, xylose, glycerol or aspartate differed only slightly. The data indicated that the physiological role of pyruvate carboxylase in is the anaplerotic biosynthesis of C Krebs-cycle intermediates from pyruvate.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-81-1-15
1974-03-01
2024-04-20
Loading full text...

Full text loading...

/deliver/fulltext/micro/81/1/mic-81-1-15.html?itemId=/content/journal/micro/10.1099/00221287-81-1-15&mimeType=html&fmt=ahah

References

  1. Feir H. A., Suzuki I. 1969; Pyruvate carboxylase of Aspergillus niger: kinetic study of a biotin- containing carboxylase. Canadian Journal of Biochemistry 47:697–710
    [Google Scholar]
  2. Hartman R. E., Keen N. T. 1973; Enzymes capable of anaplerotic carbon dioxide fixation in Verticillium albo-atrum. Phytopathology 63:947–953
    [Google Scholar]
  3. Hartman R. E., Keen N. T., Long M. 1972; Carbon dioxide fixation by Verticillium albo-atrum. Journal of General Microbiology 73:29–34
    [Google Scholar]
  4. Lowry O. H., Rosebrough N. J., Farr A. L., Randall R. J. 1951; Protein measurements with the Folin phenol reagent. Journal of Biological Chemistry 193:265–275
    [Google Scholar]
  5. Payne J., Morris J. G. 1969; Pyruvate carboxylase in Rhodopseudomonas spheroides. Journal of General Microbiology 59:97–101
    [Google Scholar]
  6. Renner E. D., Bernlohr R. W. 1972; Characterization and regulation of pyruvate carboxylase of Bacillus licheniformis. Journal of Bacteriology 109:764–772
    [Google Scholar]
  7. Ruiz-Amil M., de Torrontegui G., Palacian E., Cataline L., Losada M. 1965; Properties and function of yeast pyruvate carboxylase. Journal of Biological Chemistry 240:3485–3492
    [Google Scholar]
  8. Scrutton M. C., Young M. R. 1970; Pyruvate carboxylase. In The Enzymes 6, 3rd edn. pp. 1–35 Boyer P. D. Edited by New York: Academic Press;
    [Google Scholar]
  9. Utter M. F., Scrutton M. C. 1969; Pyruvate carboxylase. Current Topics in Cellular Regulation 1:253–296
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-81-1-15
Loading
/content/journal/micro/10.1099/00221287-81-1-15
Loading

Data & Media loading...

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