Skip to main content
PMC home page
Plant Physiology logoLink to Plant Physiology
. 1987 Jul;84(3):830–834. doi: 10.1104/pp.84.3.830

Ketose Reductase Activity in Developing Maize Endosperm

Douglas C Doehlert 1
PMCID: PMC1056678  PMID: 16665530

Abstract

Ketose reductase (NAD-dependent polyol dehydrogenase EC 1.1.1.14) activity, which catalyzes the NADH-dependent reduction of fructose to sorbitol (d-glucitol), was detected in developing maize (Zea mays L.) endosperm, purified 104-fold from this tissue, and partially characterized. Product analysis by high performance liquid chromatography confirmed that the enzyme-catalyzed reaction was freely reversible. In maize endosperm, 15 days after pollination, ketose reductase activity was of the same order of magnitude as sucrose synthase activity, which produces fructose during sucrose degradation. Other enzymes of hexose metabolism detected in maize endosperm were present in activities of only 1 to 3% of the sucrose synthase activity. CaCl2, MgCl2, and MnCl2 stimulated ketose reductase activity 7-, 6-, and 2-fold, respectively, but had little effect on NAD-dependent polyol dehydrogenation (the reverse reaction). The pH optimums for ketose reductase and polyol dehydrogenase reactions were 6.0 and 9.0, respectively. Km values were 136 millimolar fructose and 8.4 millimolar sorbitol. The molecular mass of ketose reductase was estimated to be 78 kilodaltons by gel filtration. It is postulated that ketose reductase may function to metabolize some of the fructose produced during sucrose degradation in maize endosperm, but the metabolic fate of sorbitol produced by this reaction is not known.

Full text

PDF
831

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BLAKLEY R. L. The metabolism and antiketogenic effects of sorbitol; sorbitol dehydrogenase. Biochem J. 1951 Aug;49(3):257–271. doi: 10.1042/bj0490257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. CHAKRAVORTY M., VEIGA L. A., BACILA M., HORECKER B. L. Pentose metabolism in Candida. II. The diphosphopyridine nucleotide-specific polyol dehydrogenase of Candida utilis. J Biol Chem. 1962 Apr;237:1014–1020. [PubMed] [Google Scholar]
  3. Cox E. L., Dickinson D. B. Hexokinase from maize endosperm and scutellum. Plant Physiol. 1973 May;51(5):960–966. doi: 10.1104/pp.51.5.960. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. HORWITZ S. B., KAPLAN N. O. HEXITOL DEHYDROGENASES OF BACILLUS SUBTILIS. J Biol Chem. 1964 Mar;239:830–838. [PubMed] [Google Scholar]
  5. Huber S. C., Akazawa T. A novel sucrose synthase pathway for sucrose degradation in cultured sycamore cells. Plant Physiol. 1986 Aug;81(4):1008–1013. doi: 10.1104/pp.81.4.1008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Loescher W. H., Marlow G. C., Kennedy R. A. Sorbitol metabolism and sink-source interconversions in developing apple leaves. Plant Physiol. 1982 Aug;70(2):335–339. doi: 10.1104/pp.70.2.335. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. McCORKINDALE J., EDSON N. L. Polyol dehydrogenases. I. The specificity of rat-liver polyol dehydrogenase. Biochem J. 1954 Jul;57(3):518–523. doi: 10.1042/bj0570518. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Negm F. B., Loescher W. H. Characterization and Partial Purification of Aldose-6-phosphate Reductase (Alditol-6-Phosphate:NADP 1-Oxidoreductase) from Apple Leaves. Plant Physiol. 1981 Jan;67(1):139–142. doi: 10.1104/pp.67.1.139. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Negm F. B., Loescher W. H. Detection and characterization of sorbitol dehydrogenase from apple callus tissue. Plant Physiol. 1979 Jul;64(1):69–73. doi: 10.1104/pp.64.1.69. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. SMITH M. G. Polyol dehydrogenases. 4. Crystallization of the L-iditol dehydrogenase of sheep liver. Biochem J. 1962 Apr;83:135–144. doi: 10.1042/bj0830135. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Shaw J. R., Dickinson D. B. Studies of sugars and sorbitol in developing corn kernels. Plant Physiol. 1984 May;75(1):207–211. doi: 10.1104/pp.75.1.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Su J. C., Preiss J. Purification and properties of sucrose synthase from maize kernels. Plant Physiol. 1978 Mar;61(3):389–393. doi: 10.1104/pp.61.3.389. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Tsai C. Y., Salamini F., Nelson O. E. Enzymes of carbohydrate metabolism in the developing endosperm of maize. Plant Physiol. 1970 Aug;46(2):299–306. doi: 10.1104/pp.46.2.299. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. WILLIAMS-ASHMAN H. G., BANKS J., WOLFSON S. K., Jr Oxidation of polyhydric alcohols by the prostate gland and seminal vesicle. Arch Biochem Biophys. 1957 Dec;72(2):485–494. doi: 10.1016/0003-9861(57)90224-2. [DOI] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES