Strategy for Structural Elucidation of Polysaccharides: Elucidation of a Maize Mucilage that Harbors Diazotrophic Bacteria

Polysaccharides are the most abundant biomolecule in nature and are ubiquitously found in every kingdom of life. Despite their natural abundance, methods for the characterization of their complicated structures have lagged behind both proteins and DNA. Polysaccharides can reach up to one million daltons and may contain many different monosaccharides, glycosidic linkages, and branching patterns, all of which add additional analytical challenges. A lack of robust and rapid structural characterization strategies has resulted in a limited understanding of their bioactivity. We present a general approach for the characterization of polysaccharides by employing the first liquid chromatography-mass spectrometry platform. This strategy was applied to elucidate the structure of a maize mucilage polysaccharide that is known to harbor a diazotrophic microbiota and employed several new analytical methods that include chemical depolymerization, oligosaccharide sequencing, and monosaccharide and glycosidic linkage quan...