Figure 4

Dynamic and thermodynamic behavior of different glycoforms of IgG-Fc. (a) The peptide where each glycoform of IgG-Fc produced differences in deuterium uptake is depicted in magenta. The terminal galactose units are depicted with yellow sticks. (b) Sequence of the peptide of IgG-Fc showing differential deuterium exchange rates. (c) Relative deuterium uptake for each glycoform. (d) Representation of the van’t Hoff plot corresponding to the binding of each glycoform to a surface decorated with Mut FcγRIIIa. Temperature dependence of the dissociation constant KD yields the van’t Hoff enthalpy (ΔH°), entropy (−TΔS°) and free energy (ΔG°). (e) Comparison of the values of the thermodynamic parameters determined from panel d.