The Glc2Man2-fragment of the N-glycan precursor – a novel ligand for the glycan-binding proteinmalectin?

Abstract

The Glcα(1→3)Glcα(1→3)Manα(1→2)Man tetrasaccharide (Glc₂Man₂-fragment), a substructure of the natural N-glycan precursor, was synthesized. The interaction of this fragment with the protein malectin, a carbohydrate binding protein localized in the endoplasmatic reticulum, was investigated by ¹H¹⁵N HSQC experiments and isothermal calorimetry. The chemical shift perturbations of nuclei in the protein's backbone caused by the binding of the Glc₂Man₂-fragment to malectin suggest a binding mode like the known ligand nigerose.