1887

Abstract

A cyclic pathway of NADPH generation involving interconversion of mannitol and fructose has been proposed to occur in fungi. In three enzymes of this proposed mannitol cycle (hexokinase, NADP-mannitol dehydrogenase and mannitol-1-phosphate phosphatase) were shown to be localized exclusively in the cytosol. Two isoenzymes of the fourth enzyme (mannitol-1-phosphate dehydrogenase) were detected and shown to be localized respectively in the mitochondrion and the cytosol. The mitochondrial isoenzyme appeared to be present on the outer face of the inner mitochondrial membrane. No evidence was found for a coordinated change in the maximal activities of the enzymes of the proposed mannitol cycle in extracts prepared from mycelia grown on six different carbon, and three different nitrogen sources nor for any increase in these activities induced by growth on NO . Studies of this type in which other NADP-linked dehydrogenases were measured showed that for most carbon sources tested growth on NO increased the maximal activity of NADP-isocitrate dehydrogenase as well as that of glucose-6-phosphate and 6-phosphogluconate dehydrogenases but had little effect on the maximal activity of NADP-malate dehydrogenase (decarboxylating). Our studies provide no support for the operation of the mannitol cycle, or for the proposed role of this cycle in NADPH generation in

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-134-3-643
1988-03-01
2024-12-08
Loading full text...

Full text loading...

/deliver/fulltext/micro/134/3/mic-134-3-643.html?itemId=/content/journal/micro/10.1099/00221287-134-3-643&mimeType=html&fmt=ahah

References

  1. Arst H. N., Bailey C. R. 1977; The regulation of carbon metabolism inAspergillus nidulans. In Genetics and Physiology of Aspergillus pp. 131–146 Smith J. E., Pateman J. A. Edited by New York: Academic Press;
    [Google Scholar]
  2. Beever R. E., Laracy E. P. 1986; Osmotic adjustment in the filamentous fungusAspergillus nidulans. Journal of Bacteriology 168:1358–1365
    [Google Scholar]
  3. Boonsaeng V., Sullivan P. A., Shepherd M. G. 1977; Mannitol production in fungi during glucose catabolism. Canadian Journal of Microbiology 22:808–816
    [Google Scholar]
  4. Comte J., Gautheron D. C. 1979; Preparation of outer membrane from pig heart mitochondria. Methods in Enzymology 55:98–104
    [Google Scholar]
  5. De Duve C., Pressman B. C., Gianetto R., Wattiaux R., Appelmans F. 1955; Tissue fractionation studies. 6. Intracellular distribution patterns of enzymes in rat liver tissue. Biochemical Journal 60:604–617
    [Google Scholar]
  6. Hankinson O., Cove D. J. 1974; Regulation of the pentose phosphate pathway in the fungus,Aspergillus nidulans. Journal of Biological Chemistry 249:2344–2353
    [Google Scholar]
  7. Hankinson O., Cove D. J. 1975; Regulation of mannitol-1-phosphate dehydrogenase inAspergillus nidulans. Canadian Journal of Microbiology 21:99–101
    [Google Scholar]
  8. Horecker B. L., Smyrmiotis P. Z. 1955; Glucose-6-phosphate dehydrogenase and 6-phosphogluconic dehydrogenase. Methods in Enzymology 1:323–327
    [Google Scholar]
  9. Hult K., Gatenbeck S. 1978; Production of NADPH in the mannitol cycle and its relation to polyketide formation inAlternaria alternata. European Journal of Biochemistry 88:607–612
    [Google Scholar]
  10. Hult K., Gatenbeck S. 1979; Enzyme activities of the mannitol cycle and some connected pathways inAlternaria alternata,with comments on the regulation of the cycle. Acta chemica scandinavica B 33:239–243
    [Google Scholar]
  11. Hult K., Veide A., Gatenbeck S. 1980; The distribution of NADPH regenerating mannitol cycle among fungi. Archives of Microbiology 128:253–255
    [Google Scholar]
  12. Jennings D. H., Austin S. 1973; The stimulatory effect of the non-metabolized sugar 3-O-methyl glucose on the conversion of mannitol and arabitol to polysaccharide and other insoluble compounds in the fungusDendryphiella salina. Journal of General Microbiology 75:287–294
    [Google Scholar]
  13. Joshi M. D., Jagannathan V. 1966; Hexokinase. I. Brain. Methods in Enzymology 9:371–375
    [Google Scholar]
  14. Kelly J. M., Hynes M. J. 1981; The regulation of phosphoenolpyruvate carboxykinase and the NADP-linked malic enzyme inAspergillus nidulans. Journal of General Microbiology 123:371–375
    [Google Scholar]
  15. Kelly J. M., Hynes M. J. 1982; The regulation of NADP-linked isocitrate dehydrogenase inAspergillus nidulans. Journal of General Microbiology 128:23–28
    [Google Scholar]
  16. Lehninger A. L. 1975 Biochemistry: the Molecular Basis of Cell Structure and Function, 2nd edn.. pp 722–723 New York: Worth;
    [Google Scholar]
  17. Mccorkindale N. J. 1976; The biosynthesis of terpenes and steroids. In The Filamentous Fungi 2: pp. 369–422
    [Google Scholar]
  18. Mccullough W., Roberts C. F. 1974; The role of malic enzyme inAspergillus nidulans. FEBS Letters 41:238–242
    [Google Scholar]
  19. Mccullough W., Roberts C. F., Osmani S. A., Scrutton M. C. 1986; Carbohydrate metabolism in filamentous fungi. In Carbohydrate Metabolism in Cultured Cells, pp 287–355 Morgan M. J. Edited by New York: Plenum Press;
    [Google Scholar]
  20. Niehaus W. G., Dilts R. P. 1982; Purification and characterisation of mannitol dehydrogenase fromAspergillus parasiticus. Journal of Bacteriology 151:243–250
    [Google Scholar]
  21. Osmani S. A., Scrutton M. C. 1983; The subcellular localisation of pyruvate carboxylase and of some other enzymes inAspergillus nidulans. European Journal of Biochemistry 133:551–560
    [Google Scholar]
  22. Osmani S. A., Marston F. A. O., Selmes I. P., Chapman A. G., Scrutton M. C. 1981; Pyruvate carboxylase fromAspergillus nidulans: regulatory properties. European Journal of Biochemistry 118:271–278
    [Google Scholar]
  23. Srere P. A. 1969; Citrate synthetase. Methods in Enzymology 13:3–10
    [Google Scholar]
  24. Strandberg G. W. 1969; d-Mannitol metabolism byAspergillus candidus. Journal of Bacteriology 97:1305–1309
    [Google Scholar]
  25. Walker P., Woodbine M. 1976; The biosynthesis of fatty acids. In The Filamentous Fungi, 26 pp 137–158 Smith J. E., Berry D. R. Edited by London: Edward Arnold;
    [Google Scholar]
  26. Watson K., Smith J. E. 1967; Oxidative phosphorylation and respiratory control in mitochondria fromAspergillus niger. Biochemical Journal 104:332–339
    [Google Scholar]
/content/journal/micro/10.1099/00221287-134-3-643
Loading
/content/journal/micro/10.1099/00221287-134-3-643
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