Correlation between BTK inhibitor IC50 values measured on the BTK kinase domain (residues 389–659) versus the full-length BTK enzyme.
Binding curves of fenebrutinib on activated and non-activated BTK fitted with the 1:1 binding model using the Biacore T200 Evaluation software (left), and immunoblot analysis of the phosphorylation state of the BTK preparations (right).
Alternative binding model for fenebrutinib on activated BTK, assuming that the enzyme preparation is heterogeneous in phosphorylation state.
Comparison of the association (ka) and dissociation (kd) rates of BTK inhibitors on activated and non-activated BTK. The dotted lines indicate equilibrium dissociation constants (KD) calculated from the on- and off rates.