A non-characterized gene, previously proposed as the d-tagatose-3-epimerase gene from Rhodobacter sphaeroides, was cloned and expressed in Escherichia coli. Its molecular mass was estimated to be 64 kDa with two identical subunits. The enzyme specificity was highest with d-fructose and decreased for other substrates in the order: d-tagatose, d-psicose, d-ribulose, d-xylulose and d-sorbose. Its activity was maximal at pH 9 and 40°C while being enhanced by Mn2+. At pH 9 and 40°C, 118 g d-psicose l−1 was produced from 700 g d-fructose l−1 after 3 h.
This is a preview of subscription content, log in to check access.
This research was supported financially by the National High Technology Research and Development Program of People’s Republic of China (2006AA10Z334) as well as the Research Program of State Key Laboratory of Food Science and Technology, Jiangnan University (SKLF-MB-200804 and SKLF-TS-200805).
Supplementary Fig. 1SDS-PAGE of purified R. sphaeroidesd-tagatose-3-epimerase. Lane 1, molecular mass markers (kDa); lane 2, purified R. sphaeroidesd-tagatose-3-epimerase (DOC 276 kb)
Deupree JD, Wood WA (1972) l-Ribulose-5-phosphate 4-epimerase from Aerobacter aerogenes. Evidence for a role of divalent metal ions in the epimerization reaction. J Biol Chem 247:3093–3097PubMedGoogle Scholar
Granström TB, Takata G, Tokuda M et al (2004) Izumoring: a novel and complete strategy for bioproduction of rare sugars. J Biosci Bioeng 97:89–94PubMedGoogle Scholar
Itoh H, Okaya H, Khan AR et al (1994) Purification and characterization of d-tagatose-3-epimerase from Pseudomonas sp. ST-24. Biosci Biotechnol Biochem 58:2168–2171Google Scholar
Kim HJ, Hyun EK, Kim YS et al (2006) Characterization of an Agrobacterium tumefaciensd-psicose-3-epimerase that converts d-fructose to d-psicose. Appl Environ Microbiol 72:981–985PubMedCrossRefGoogle Scholar
Leang K, Maekawa K, Menavuvu BT et al (2004) A novel enzymatic approach to the mass production of l-galactose from l-sorbose. J Biosci Bioeng 97:383–388PubMedGoogle Scholar
Lee LV, Poyner RR, Vu MV et al (2000) Role of metal ions in the reaction catalyzed by l-ribulose-5-phosphate 4-epimerase. Biochemistry 39:4821–4830PubMedCrossRefGoogle Scholar
Matsuo T, Izumori K (2006a) d-Psicose inhibits intestinal α-glucosidase and suppresses glycemic response after carbohydrate ingestion in rats. Tech Bull Fac Agric, Kagawa University 58:27–32Google Scholar
Matsuo T, Izumori K (2006b) Effects of dietary d-psicose on diurnal variation in plasma glucose and insulin concentrations of rats. Biosci Biotechnol Biochem 70:2081–2085PubMedCrossRefGoogle Scholar
Matsuo T, Baba Y, Hashiguchi M et al (2001) Dietary d-psicose, a C-3 epimer of d-fructose, suppresses the activity of hepatic lipogenic enzymes in rats. Asia Pac J Clin Nutr 10:233–237PubMedCrossRefGoogle Scholar
Matsuo T, Suzuki H, Hashiguchi M et al (2002a) d-Psicose is a rare sugar that provides no energy to growing rats. J Nutr Sci Vitaminol (Tokyo) 48:77–80Google Scholar
Matsuo T, Tanaka T, Hashiguchi M et al (2002b) Effects of oral acute administration and subchronic feeding of several levels of d-psicose in rats. J Nutr Sci Vitaminol (Tokyo) 48:512–516Google Scholar
Sun Y, Hayakawa S, Ogawa M et al (2007) Antioxidant properties of custard pudding dessert containing rare hexose, d-psicose. Food Control 18:220–227CrossRefGoogle Scholar
Sun Y, Hayakawa S, Ogawa M et al (2008) Influence of a rare sugar, d-psicose, on the physicochemical and functional properties of an aerated food system containing egg albumen. J Agric Food Chem 56:4789–4796PubMedCrossRefGoogle Scholar
Takeshita K, Suga A, Takada G et al (2000) Mass production of d-psicose from d-fructose by a continuous bioreactor system using immobilized d-tagatose-3-epimerase. J Biosci Bioeng 90:453–455PubMedGoogle Scholar
Yoshida H, Yamada M, Nishitani T et al (2007) Crystal structures of d-tagatose-3-epimerase from Pseudomonas cichorii and its complexes with d-tagatose and d-fructose. J Mol Biol 374:443–453PubMedCrossRefGoogle Scholar