Yeast Hexokinase and Its Substrates d-Fructofuranose and d-Glucose

Abstract

ON solution in water, beta d-fructopyranose, the only crystalline form of d-fructose, exhibits mutarotation which mainly consists in a pyranose furanose interconversion1,2. In experiments at 0° C. and pH. = 4·5, under which conditions mutarotation proceeds the slowest, it was previously3 shown that beta d-fructopyranose added to a suspension of baker's yeast in 0·1 M KH2PO4 is unfermentable, whereas alpha d-glucose is fermented at the expected rate. Since in any quantitative consideration of the composition of a d-fructose solution at equilibrium (pH. = 4·5) open-chain forms (keto-form, enol-form) can be neglected, d-fructofuranose, chiefly present in the beta configuration, remains as the only fermentable isomer. The non-fermentability of d-fructopyranose—obviously due to lack of an OH-group at C6—rendered possible the determination of the proportion of the furanose form in an equilibrium mixture of d-fructose at 0° C.; this proportion was found4 to be 12 per cent. From this figure and the known differences in mutarotation of d-fructopyranose at 0° C. and at 25° C., it can be calculated that an equilibrated d-fructose solution at 25° C. contains approximately 22 per cent of the sugar in the furanose modification; it is in this way that the concentrations of fructofuranose given in this report have been derived.

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References

  1. 1

    Purves, C. B., and Hudson, C. S., J. Amer. Chem. Soc, 56, 702 (1934).

    CAS  Article  Google Scholar 

  2. 2

    Isbell, H. S., and Pigman, W. W., J. Res. Nat. Bur. Standards, 20, 773 (1938).

    CAS  Article  Google Scholar 

  3. 3

    Gottschalk, A., Austral J. Exp. Biol., 21, 133 (1943).

    Article  Google Scholar 

  4. 4

    Gottschalk, A., Austral. J. Exp. Biol, 21, 139 (1943).

    CAS  Article  Google Scholar 

  5. 5

    Hopkins, R. H., Biochem. J., 25, 245 (1931).

    CAS  Article  Google Scholar 

  6. 6

    Gottschalk, A., Austral. J. Exp. Biol., 22, 291 (1944).

    CAS  Article  Google Scholar 

  7. 7

    Sobotka, H., and Reimer, M., Biochem. J., 24, 1783 (1930).

    CAS  Article  Google Scholar 

  8. 8

    Fernbach, A., Schoen, M., and Mori, M., Ann. Inst. Pasteur, 42, 805 (1928).

    CAS  Google Scholar 

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GOTTSCHALK, A. Yeast Hexokinase and Its Substrates d-Fructofuranose and d-Glucose. Nature 156, 540–541 (1945). https://doi.org/10.1038/156540a0

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