Phosphorylase-catalyzed N-formyl-alpha-glucosaminylation of maltooligosaccharides

Abstract

This paper describes the phosphorylase-catalyzed enzymatic N-formyl-alpha-glucosaminylation of maltooligosaccharides for direct incorporation of 2-deoxy-2-formamido-alpha-D-glucopyranose units into maltooligosaccharides. When the reaction of 2-deoxy-2-formamido-alpha-D-glucopyranose-1-phosphate (GlcNF-1-P) as the glycosyl donor and maltotetraose as a glycosyl acceptor was performed in the presence of phosphorylase, the N-formyl-alpha-D-glucosaminylated pentasaccharide was produced, as confirmed by MALDI-TOF MS. Furthermore, the glucoamylase-catalyzed reaction of the crude products supported that the 2-deoxy-2-formamido-alpha-D-glucopyranoside unit was positioned at the non-reducing end of the pentasaccharide. The pentasaccharide was isolated from the crude products and its structure was further determined by the (1)H NMR analysis. On the other hand, when the phosphorylase-catalyzed reactions of maltotriose and maltopentaose using GlcNF-1-P were conducted, no N-formyl-alpha-glucosaminylation took place in the former system, whereas the latter system gave N-formyl-alpha-D-glucosaminylated oligosaccharides with various degrees of polymerization. These results could be explained by the recognition behavior of phosphorylase toward maltooligosaccharides.