Evidence for the preservation of specific intermolecular interactions in gaseous protein-oligosaccharide complexes

Arrhenius parameters, obtained with the blackbody infrared radiative dissociation technique, are reported for the dissociation of a series of gaseous protonated complexes composed of mutants of a single chain variable fragment (scFv) of the monoclonal antibody Se155-4 and three trisaccharide ligands. Hydrogen bonding between a ligand and a particular amino acid residue is identified from a comparison of activation energies measured for the complex of the unmodified scFv and the corresponding mutant. It is shown that the specific hydrogen bond between His(101H) and Man C-4 OH is preserved in the gaseous complex.