Fig 5.

Determination of ACE2-BA.5.5/BQ.1.1 RBD binding affinity by BLI. Recombinant human (A) or mouse (B) ACE2-Fc proteins were loaded onto biolayer interferometry (BLI) protein G pins at a concentration of 10 µg/mL and dipped into the indicated concentrations of BA.5.5 or BQ.1.1 RBDs. Samples were allowed to associate and dissociate for 300 and 600 s, respectively. Dashed black curves show fits to a 1:1 binding model with a drifting baseline. (C) Association rate (ka), dissociation rate (kd), and kinetic dissociation constant (K _D ) values were calculated and reported.