The present invention aims to provide a method for producing a
polysaccharide with high efficiency using a
polysaccharide synthase. The present invention provides a method for producing a
polysaccharide, including allowing polysaccharide synthase (B) to act on
ribonucleoside diphosphate-
monosaccharide (A) shown below to produce a polysaccharide, wherein in 10 to 100% of the duration in which (B) acts on (A), the concentration of
ribonucleoside diphosphate in a reaction solution is lower than 100 times an inhibitory concentration IC50 described below against polysaccharide synthase (B).Inhibitory concentration IC50: a concentration of
ribonucleoside diphosphate at which an
enzyme activity of polysaccharide synthase (B) is reduced by half while under a condition where (B) has a concentration at which (B) acts on ribonucleoside diphosphate-
monosaccharide (A), wherein ribonucleoside diphosphate-
monosaccharide (A) is used as a substrate and ribonucleoside diphosphate is used as an inhibitor.
Ribonucleoside diphosphate-monosaccharide (A): a
sugar nucleotide in which a
proton of at least one hydroxyl group of at least one monosaccharide (a) selected from the group consisting of triose (a-1), tetrose (a-2),
pentose (a-3),
hexose (a-4), heptose (a-5), and monosaccharide (a-6) described below is substituted with a functional group represented by any one of chemical formulae (1) to (5) below.
Monosaccharide (a-6): a monosaccharide selected from the group consisting of (a-1), (a-2), (a-3), (a-4), and (a-5), in which at least one member selected from the group consisting of a
proton, a hydroxyl group, and a
hydroxymethyl group of the monosaccharide is substituted with
substituent (E) described below.
Substituent (E) is at least one
substituent selected from the group consisting of carboxyl, amino, N-acetylamino,
sulfate, methylester, N-glycolyl, methyl, 1,2,3-trihydroxypropyl,
phosphate, and 2-carboxy-2-hydroxyethyl groups.