Retention of bioactive ligand conformation in a gaseous protein-trisaccharide complex.

Arrhenius parameters, obtained with the blackbody infrared radiative dissociation technique, are reported for the dissociation of gaseous protonated complexes of a single-chain variable fragment (scFv) of the monoclonal antibody Se155-4 with structurally constrained trisaccharide ligands that resemble the bioactive conformer. The similarity in the dissociation activation energies measured for the +10 charge-state complexes of the constrained ligands and the native trisaccharide is evidence that the bioactive conformation of the native ligand is retained in the gas phase.