Identification of a High‐Affinity‐Binding Oligosaccharide by (+) Nanoelectrospray Quadrupole Time‐of‐Flight Tandem Mass Spectrometry of a Noncovalent Enzyme–Ligand Complex

Sugar fix: A noncovalent enzyme–ligand complex in a mixture of aminoglucan heterooligosaccharides and a chitinase is analyzed by nanoelectrospray ionization collision-induced dissociation tandem mass spectrometry. The enzyme selectively binds a pentasaccharide composed of three N-acetylglucosamine (GlcNAc, A) and two glucosamine (GlcN, D) units (see picture).