Accepted name: L-iditol 2-dehydrogenase
Reaction: L-iditol + NAD+ = L-sorbose + NADH + H+
Other name(s): polyol dehydrogenase; sorbitol dehydrogenase; L-iditol:NAD+ 5-oxidoreductase; L-iditol (sorbitol) dehydrogenase; glucitol dehydrogenase; L-iditol:NAD+ oxidoreductase; NAD+-dependent sorbitol dehydrogenase; NAD+-sorbitol dehydrogenase
Systematic name: L-iditol:NAD+ 2-oxidoreductase
Comments: This enzyme is widely distributed and has been described in archaea, bacteria, yeast, plants and animals. It acts on a number of sugar alcohols, including (but not limited to) L-iditol, D-glucitol, D-xylitol, and D-galactitol. Enzymes from different organisms or tissues display different substrate specificity. The enzyme is specific to NAD+ and can not use NADP+.
1.  Bailey, J.P., Renz, C. and McGuinness, E.T. Sorbitol dehydrogenase from horse liver: purification, characterization and comparative properties. Comp. Biochem. Physiol. 69B (1981) 909–914.
2.  Burnell, J.N. and Holmes, R.S. Purification and properties of sorbitol dehydrogenase from mouse liver. Int. J. Biochem. 15 (1983) 507–511. [PMID: 6852349]
3.  Leissing, N. and McGuinness, E.T. Rapid affinity purification and properties of rat liver sorbitol dehydrogenase. Biochim. Biophys. Acta 524 (1978) 254–261. [PMID: 667078]
4.  Negm, F.B. and Loescher, W.H. Detection and characterization of sorbitol dehydrogenase from apple callus tissue. Plant Physiol. 64 (1979) 69–73. [PMID: 16660917]
5.  O'Brien, M.M., Schofield, P.J. and Edwards, M.R. Polyol-pathway enzymes of human brain. Partial purification and properties of sorbitol dehydrogenase. Biochem. J. 211 (1983) 81–90. [PMID: 6870831]
6.  Ng, K., Ye, R., Wu, X.C. and Wong, S.L. Sorbitol dehydrogenase from Bacillus subtilis. Purification, characterization, and gene cloning. J. Biol. Chem. 267 (1992) 24989–24994. [PMID: 1460002]
[EC created 1961, modified 2011]
Accepted name: sorbose 5-dehydrogenase (NADP+)
Reaction: L-sorbose + NADP+ = 5-dehydro-D-fructose + NADPH + H+
Other name(s): 5-ketofructose reductase; 5-keto-D-fructose reductase; sorbose (nicotinamide adenine dinucleotide phosphate) dehydrogenase; reduced nicotinamide adenine dinucleotide phosphate-linked reductase; sorbose 5-dehydrogenase (NADP+)
Systematic name: L-sorbose:NADP+ 5-oxidoreductase
1.  Englard, S., Kaysen, G. and Avigad, G. 5-keto-D-Fructose. VI. A specific reduced nicotinamide adenine dinucleotide phosphate-linked reductase from yeast. J. Biol. Chem. 245 (1970) 1311–1318. [PMID: 4392628]
[EC created 1972, modified 1976]
Accepted name: sorbose reductase
Reaction: D-glucitol + NADP+ = L-sorbose + NADPH + H+
Glossary: L-sorbose = L-xylo-hex-2-ulose
Other name(s): Sou1p
Systematic name: D-glucitol:NADP+ oxidoreductase
Comments: The reaction occurs predominantly in the reverse direction. This enzyme can also convert D-fructose into D-mannitol, but more slowly. Belongs in the short-chain dehydrogenase family.
1.  Greenberg, J.R., Price, N.P., Oliver, R.P., Sherman, F. and Rustchenko, E. Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose utilization. Yeast 22 (2005) 957–969. [PMID: 16134116]
2.  Greenberg, J.R., Price, N.P., Oliver, R.P., Sherman, F. and Rustchenko, E. Erratum report: Candida albicans SOU1 encodes a sorbose reductase required for L-sorbose utilization. Yeast 22 (2005) 1171.
3.  Sugisawa, T., Hoshino, T. and Fujiwara, A. Purification and properties of NADPH-linked L-sorbose reductase from Gluconobacter melanogenus N44-1. Agric. Biol. Chem. 55 (1991) 2043–2049.
4.  Shinjoh, M., Tazoe, M. and Hoshino, T. NADPH-dependent L-sorbose reductase is responsible for L-sorbose assimilation in Gluconobacter suboxydans IFO 3291. J. Bacteriol. 184 (2002) 861–863. [PMID: 11790761]
[EC created 2006]
Accepted name: pyranose oxidase
Reaction: D-glucose + O2 = 2-dehydro-D-glucose + H2O2
Other name(s): glucose 2-oxidase; pyranose-2-oxidase
Systematic name: pyranose:oxygen 2-oxidoreductase
Comments: A flavoprotein (FAD). Also oxidizes D-xylose, L-sorbose and D-glucono-1,5-lactone, which have the same ring conformation and configuration at C-2, C-3 and C-4.
1.  Janssen, F.W. and Ruelius, H.W. Carbohydrate oxidase, a novel enzyme from Polyporus obtusus. II. Specificity and characterization of reaction products. Biochim. Biophys. Acta 167 (1968) 501–510. [PMID: 5722278]
2.  Machida, Y. and Nakanishi, T. Purification and properties of pyranose oxidase from Coriolus versicolor. Agric. Biol. Chem. 48 (1984) 2463–2470.
3.  Neidleman, S.L., Amon, W.F., Jr. and Geigert, J. Process for the production of fructose. Patent US4246347, Chem. Abstr. (1981), 94, 20737 (PDF).
4.  Ruelius, H.W., Kerwin, R.M. and Janssen, F.W. Carbohydrate oxidase, a novel enzyme from Polyporus obtusus. I. Isolation and purification. Biochim. Biophys. Acta 167 (1968) 493–500. [PMID: 5725162]
[EC created 1972]
Accepted name: L-sorbose oxidase
Reaction: L-sorbose + O2 = 5-dehydro-D-fructose + H2O2
Systematic name: L-sorbose:oxygen 5-oxidoreductase
Comments: Also acts on D-glucose, D-galactose and D-xylose, but not on D-fructose. 2,6-Dichloroindophenol can act as acceptor.
1.  Yamada, Y., Iizuka, K., Aida, K. and Uemura, T. Enzymatic studies on the oxidation of sugar and sugar alcohol. 3. Purification and properties of L-sorbose oxidase from Trametes sanguinea. J. Biochem. (Tokyo) 62 (1967) 223–229. [PMID: 5586487]
[EC created 1972]
Accepted name: sorbose dehydrogenase
Reaction: L-sorbose + acceptor = 5-dehydro-D-fructose + reduced acceptor
Other name(s): L-sorbose:(acceptor) 5-oxidoreductase
Systematic name: L-sorbose:acceptor 5-oxidoreductase
Comments: 2,6-Dichloroindophenol can act as acceptor.
1.  Sato, K., Yamada, Y., Aida, K. and Uemara, T. Enzymatic studies on the oxidation of sugar and sugar alcohol. 8. Particle-bound L-sorbose dehydrogenase from Gluconobacter suboxydans. J. Biochem. (Tokyo) 66 (1969) 521–527. [PMID: 5354025]
[EC created 1972]
Accepted name: D-sorbitol dehydrogenase (acceptor)
Reaction: D-sorbitol + acceptor = L-sorbose + reduced acceptor
Other name(s): D-sorbitol:(acceptor) 1-oxidoreductase
Systematic name: D-sorbitol:acceptor 1-oxidoreductase
Comments: A flavoprotein (FAD).
1.  Shinagawa, E. and Ameyama, M. Purification and characterization of D-sorbitol dehydrogenase from membrane of Gluconobacter suboxydans var-alpha. Agric. Biol. Chem. 46 (1982) 135–141.
[EC created 1989]
Accepted name: L-sorbose 1-dehydrogenase
Reaction: L-sorbose + acceptor = 1-dehydro-L-sorbose + reduced acceptor
Glossary: 1-dehydro-L-sorbose = L-sorbosone = 2-dehydro-L-gulose
Other name(s): SDH (ambiguous)
Systematic name: L-sorbose:acceptor 1-oxidoreductase
Comments: The product, L-sorbosone, is an intermediate in bacterial 2-keto-L-gulonic-acid formation. The activity of this membrane-bound enzyme is stimulated by Fe(III) or Co2+ but is inhibited by Cu2+. The enzyme is highly specific for L-sorbose as other sugars, such as glucose, mannitol and sorbitol, are not substrates. Phenazine methosulfate and DCIP can act as artificial acceptors.
1.  Sugisawa, T., Hoshino, T., Nomura, S. and Fujiwara, A. Isolation and characterization of membrane-bound L-sorbose dehydrogenase from Gluconobacter melanogenus UV10. Agric. Biol. Chem. 55 (1991) 363–370.
[EC created 2008]
Accepted name: protein-Nπ-phosphohistidine—L-sorbose phosphotransferase
Reaction: [protein]-Nπ-phospho-L-histidine + L-sorbose[side 1] = [protein]-L-histidine + L-sorbose 1-phosphate[side 2]
Other name(s): sorABFM (gene names); L-sorbose PTS permease; EIISor; Enzyme IISor
Systematic name: protein-Nπ-phospho-L-histidine:L-sorbose Nπ-phosphotransferase
Comments: This enzyme is a component (known as enzyme II) of a phosphoenolpyruvate (PEP)-dependent, sugar transporting phosphotransferase system (PTS). The system, which is found only in prokaryotes, simultaneously transports its substrate from the periplasm or extracellular space into the cytoplasm and phosphorylates it. The phosphate donor, which is shared among the different systems, is a phospho-carrier protein of low molecular mass that has been phosphorylated by EC (phosphoenolpyruvate—protein phosphotransferase). Enzyme II, on the other hand, is specific for a particular substrate, although in some cases alternative substrates can be transported with lower efficiency. The reaction involves a successive transfer of the phosphate group to several amino acids within the enzyme before the final transfer to the substrate.
1.  Wehmeier, U.F., Wohrl, B.M. and Lengeler, J.W. Molecular analysis of the phosphoenolpyruvate-dependent L-sorbose: phosphotransferase system from Klebsiella pneumoniae and of its multidomain structure. Mol. Gen. Genet. 246 (1995) 610–618. [PMID: 7700234]
2.  Yebra, M.J., Veyrat, A., Santos, M.A. and Perez-Martinez, G. Genetics of L-sorbose transport and metabolism in Lactobacillus casei. J. Bacteriol. 182 (2000) 155–163. [PMID: 10613875]
[EC created 1972 as EC, part transferred 2016 to EC]