Extraction and purification of a High Mannose type oligosaccharide from Phaseolus lunatus beans by oxidative release with sodium hypochlorite

Abstract

High Mannose glycans (HM) are intermediates for the eukaryotic glycosylation pathway but are not commonly found on mature glycoproteins. HM, particularly Man9GlcNAc2 (M9), are present on the glycan shield of viral envelopes and have received attention as elements for semi-synthetic vaccines. The most common strategy to produce HM is extensive pronase digestion from soybean agglutinin (SBA) to obtain Asn-M9. Storage proteins from Phaseolus lunatus (butter beans) are abundant in M9 and could also be used for M9 production. Chemical alternatives to enzyme-based protocols such as sodium hypochlorite (NaClO) have been used effectively to release N-glycans. Here we present an application of the NaClO glycan release strategy to produce M9 from Phaseolus lunatus beans as an alternative to SBA and the characterisation of some of the release side products that support the release reaction mechanism.