Determining Substrate Specificities of β1,4-Endogalactanases Using Plant Arabinogalactan Oligosaccharides Synthesized by Automated Glycan Assembly.

Pectin is a structurally complex plant polysaccharide with many industrial applications in food products. The structural elucidation of pectin is aided by digestion assays with glycosyl hydrolases. We report the automated glycan assembly of oligosaccharides related to the arabinogalactan side chains of pectin as novel biochemical tools to determine the substrate specificities of endogalactanases. Analysis of the digestion products revealed different requirements for the lengths and arabinose substitution pattern of the oligosaccharides to be recognized and hydrolyzed by the galactanases.