The hydrolytic and transferase action of alternanase on oligosaccharides
2001
Cote, G.L. | Ahlgren, J.A.
Alternanase is an enzyme which endo-hydrolytically cleaves the alpha-(1 leads to 3), alpha-(1 leads to 6)-linked D-glucan, alternan. The main products are isomaltose, alpha-D-Glcp-(1 leads to 3)-alpha-D-Glcp-(1 leads to 6)-D-Glc and the cyclic tetrasaccharide cyclo [leads to 6)-alpha-D-Glcp-(1 leads to 3)-alpha-D-Glcp-(1 leads to 6)-alpha-D-Glcp-(1 leads to 3)-alpha-D-Glcp-(1 leads to]. It is also capable of acting on oligosaccharide substrates. The cyclic tetrasaccharide is slowly hydrolyzed to isomaltose. Panose and the trisaccharide alpha-D-Glcp-(1 leads to 6)-alpha-D-Glcp-(1 leads to 3)-D-Glc both undergo transglycosylation reactions to give rise to the cyclic tetrasaccharide plus D-glucose, with panose being converted at a much faster rate. The tetrasaccharide alpha-D-Glcp-(1 leads to 3)-alpha-D-Glcp-(1 leads to 6)-alpha-D-Glcp-(1 leads to 4)-D-Glc is hydrolyzed to D-glucose plus the trisaccharide alpha-D-Glcp-(1 leads to 3)-alpha-D-Glcp-(1 leads to 6)-D-Glc. Alternanase does not act on isomaltotriose, theanderose (6Glc-O-alpha-D-Glcp sucrose), or alpha-D-Glcp-(1 leads to 6)-alpha-D-Glcp-(1 leads to 6)-alpha-D-Glcp-(1 leads to 4)-alpha-D-Glc. The enzyme releases 4-nitrophenol from 4-nitrophenyl alpha-isomaltoside, but not from 4-nitrophenyl alpha-D-glucopyranoside, 4-nitrophenyl alpha-isomaltotrioside, or 4-nitrophenyl alpha-isomaltotetraoside.
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