Abstract
More than 20 types of carbohydrate epimerase have been reported to date. Distinctly different enzymes recognize the C1, C2, C3, C4, C5 or C6 position of carbohydrate substrates. They include, for instance, aldose 1-epimerase, N-acetyl-D-glucosamine 2-epimerase, UDP-N-acetylglucosamine 2-epimerase, cellobiose 2-epimerase, D-ribulose-5-phosphate 3-epimerase, L-ribulose-5-phosphate 4-epimerase, UDP-galactose 4-epimerase, dTDP-6-deoxy-D-xylo-4-hexulose 3,5-epimerase, GDP-mannose 3,5-epimerase and ADP-L-glycero-D-mannoheptose 6-epimerase. Their biological properties, catalytic mechanisms and tertiary structures are very diverse. This review focuses on the catalysis, structures and applications of carbohydrate epimerases that have recently been characterized in detail.
