Figure 4.

BLI sensorgrams of kinetic analyses of rhTNF binding to immobilized adalimumab and pH-dependent binding variants (PSV#1, PSV#2 and PSV#3). Association with rhTNF at indicated concentrations was measured for 300 s at pH 7.4. Dissociation was performed for 1800 s at pH 7.4 (left panel) or at pH 6.0 (right panel). Dissociation times at pH 6.0 varied between 400 s (PSV#1, PSV#2 and PSV#3) and 900 s (adalimumab). Binding curves (colored lines) were fitted with a 1:1 interaction model (red lines). In contrast to the applied global fitting analysis, binding curves of PSV#1, PSV#2 and PSV#3 were fitted using the local partial model when dissociation was carried out at pH 6.0. Representative experiments from triplicate measurements are shown (except: adalimumab at pH 6.0 in duplicates).