1887

Abstract

SUMMARY: The effects of purified oxyleghaemoglobin added to suspensions of bacteroids prepared anaerobically from soybean root nodules, were studied in terms of uptake of dissolved O nitrogenase activity and dissolved O concentration, in the absence of a gas phase. Leghaemoglobin allowed maximum rates of O uptake to continue to a much lower range of concentrations of free dissolved O than in the absence of the protein. This effect was diminished when the leghaemoglobin concentration was less than about 50 . Nitrogenase activity at a given O concentration was not increased by raising the leghaemoglobin concentration above about 50 . The fractional oxygenation of leghaemoglobin giving half the maximal O consumption rate by bacteroids was usually about 0·2; with limiting leghaemoglobin concentrations it was higher. Rates of nitrogenase activity were invariably greater during periods when the discharge of O from oxyleghaemoglobin was occurring at the maximum rate, than when similar maximum O uptake rates were being supported by higher concentrations of free dissolved O When myoglobin was used as the O carrier protein in similar experiments, enhanced nitrogenase activity also accompanied the maximum rate of discharge from the carrier. This occurred at about four times the concentration of free dissolved O at which it occurred when leghaemoglobin was the carrier. These results are discussed in relation to current theories about the mechanism of leghaemoglobin action.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-89-1-31
1975-07-01
2021-07-25
Loading full text...

Full text loading...

/deliver/fulltext/micro/89/1/mic-89-1-31.html?itemId=/content/journal/micro/10.1099/00221287-89-1-31&mimeType=html&fmt=ahah

References

  1. Antonini E., Brunori M. 1971; Hemoglobin and myoglobin in their reaction with ligands. Frontiers in Biology 21 p. 221 Amsterdam: North Holland.;
    [Google Scholar]
  2. Appleby C. A. 1969; Properties of leghaemoglobin in vivo and its isolation as ferrous oxyleghaemoglobin. Biochimica et biophysica acta 188:222–229
    [Google Scholar]
  3. Appleby C. A. 1974; Leghaemoglobin. In The Biology of Nitrogen Fixation pp. 521–554 Quispel A. Edited by Amsterdam; North Holland.:
    [Google Scholar]
  4. Appleby C. A., Dilworth M.J. 1975; Leghaemoglobin and rhizobium hemoproteins. In Dinitrogen Fixation Hardy R. W. F. Edited by New York: Wiley Interscience.; (In the Press.)
    [Google Scholar]
  5. Appleby C.A, bergersen F.J, Macnicol P.K, Turner G. L., Wittenberg B. A., Wittenberg J. B. 1975a; The role of leghaemoglobin in symbiotic N2-fixation. In Nitrogen Fixation: Interdisciplinary Discussions Newton W. E., Nyman J. C. Edited by Pullman: Washington State University Press.; (In the Press.)
    [Google Scholar]
  6. Appleby C.A, Turner G.L, Macnicol P.K. 1975b; Involvement of oxyleghaemoglobin and cytochrome P-450 in an efficient oxidative phosphorylation pathway which supports nitrogen fixation in rhizobium. Biochimica et biophysica acta (In the Press.)
    [Google Scholar]
  7. Bergersen F. J. 1971; Biochemistry of symbiotic nitrogen fixation in legumes. Annual Review of Plant Physiology 22:121–140
    [Google Scholar]
  8. Bergersen F. J. 1973; Symbiotic nitrogen fixation by legumes. In Chemistry and Biochemistry of Herbage 2 pp. 189–226 Butler G.W, Bailey R.W. Edited by London and New York:: Academic Press.;
    [Google Scholar]
  9. Bergersen F. J., Goodchild D. J. 1973; Cellular location and concentration of leghaemoglobin in soybean root nodules. Australian Journal of Biological Sciences 26:741–756
    [Google Scholar]
  10. Bergersen F. J., Turner G. L. 1973; Kinetic studies of nitrogenase from soya-bean root-nodule bacteroids. Biochemical Journal 131:61–75
    [Google Scholar]
  11. Bergersen F. J., Turner G. L., Appleby C. A. 1973; Studies of the physiological role of leghaemoglobin in soybean root nodules. Biochimica et biophysica acta 292:271–282
    [Google Scholar]
  12. Gourret J. P., Fernandez-Arias H. 1974; Étude ultrastructurale et cytochimique de la différenciation des bactéroides de Rhizobium trifolii Dangeard dans les nodules de Trifolium repens L. Canadian Journal of Microbiology 20:1169–1181
    [Google Scholar]
  13. Hugli T. E., Gurd F. R. N. 1970; Carboxymethylation of sperm whale myoglobin in the crystalline state. Journal of Biological Chemistry 245:1930–1938
    [Google Scholar]
  14. Stokes A. N. 1975; Facilitated diffusion; the elasticity of oxygen supply. Journal of Theoretical Biology (in the Press).
    [Google Scholar]
  15. Tjepkema J. D. 1971; Oxygen transport in the soybean nodule and the function of leghaemoglobin. Ph.D. thesis; University of Michigan, U.S.A.:
    [Google Scholar]
  16. Truchet G. 1972; Mise en évidence de l’activité peroxidasique dans les différentes zones des nodules radiculaires de pois (Pisum sativum L.). Localization de la leghemoglobine. Comptes rendus hebdoma-daire des séances de de l’Academie des sciences 274:1290–1293
    [Google Scholar]
  17. Wittenberg J. B. 1970; Myoglobin-facilitated oxygen diffusion; role of myoglobin in oxygen entry into muscle. Physiological Reviews 50:559–636
    [Google Scholar]
  18. Wittenberg J. B., Appleby C. A., Wittenberg B. A. 1972; The kinetics of the reactions of leghaemoglobin with oxygen and carbon monoxide. Journal of Biological Chemistry 247:527–531
    [Google Scholar]
  19. Wittenberg J. B., Bergersen F. J., Appleby C. A., Turner G. L. 1974; Facilitated diffusion of O2: the role of oxyleghemoglobin in nitrogen fixation by bacteroids isolated from soybean root nodules. Journal of Biological Chemistry 249:4057–4066
    [Google Scholar]
  20. Wong P. P., Burris R. H. 1972; Nature of oxygen inhibition of nitrogenase from Azotobacter vinelandii. Proceedings of the National Academy of Science of the United States of America 69:672–675
    [Google Scholar]
  21. Yocum C. S. 1964; Recent studies of symbiotic nitrogen fixation. Science; New York:146–432
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-89-1-31
Loading
/content/journal/micro/10.1099/00221287-89-1-31
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