Portal de Periódicos da CAPES

C-2 Epimer Formation of Tetrose, Pentose and Hexose Sugars by Xylose Isomerase

2002; Taylor & Francis; Volume: 20; Issue: 4 Linguagem: Inglês

10.1080/10242420290029463

1029-2446

Antti Vuolanto, Ossi Pastinen, Hans E. Schoemaker, Matti Leisola,

Biofuel production and bioconversion

AbstractWe describe novel tetrose isomerizations and C-2 epimerizations by the industrially important d -xylose ketol-isomerase (E.C.5.3.1.5) with both the d - and l -forms of the sugars. We further show that in addition to isomerization to d -fructose, d -glucose is slowly C-2 epimerized to d -mannose. The formation rate of the C-2 epimer was 0.03 mg mg m 1 min m 1 from d -glucose, 0.56 mg mg m 1 min m 1 from d -arabinose and 3.0 mg mg m 1 min m 1 from d -erythrose. The equilibria of the reaction products as a function of temperature were measured for threose/erythrulose/erythrose, arabinose/ribulose/ ribose and glucose/fructose/mannose.KeywordsXylose IsomeraseGlucose IsomeraseC-2 EpimerizationTetrosesPentoses