The binding kinetics of the antibody-drug conjugate 1 and the antibody-drug conjugate 2 prepared in Example1 and the 900698 naked antibody with a human CD73 protein and a monkey CD73 protein. The human CD73 protein was diluted with the assay buffer to a series of concentrations of 50 nM, 25 nM,12.5 nM, 6.25 nM, 3.12 nM,and 1.57 nM,serving as analytes, and the assay buffer was used as a 0 concentration control. At a flow rate of 30 uL/min, association was conducted for 120 s, and dissociation was conducted for 600s. Glycine (10mM,pH1.5 was used for regeneration at a flow rate of 50 uL/min for 60s in a multi-cycle kinetic assay. A 1:1 binding model was used, and the Fit Local mode was selected to determine the association rate constant (ka), dissociation rate constant (kd), and equilibrium dissociation constant (KD).

The binding kinetics of the antibody-drug conjugate 1 and the antibody-drug conjugate 2 prepared in Example1 and the 900698 naked antibody with a human CD73 protein and a monkey CD73 protein. The human CD73 protein was diluted with the assay buffer to a series of concentrations of 50 nM, 25 nM,12.5 nM, 6.25 nM, 3.12 nM,and 1.57 nM,serving as analytes, and the assay buffer was used as a 0 concentration control. At a flow rate of 30 uL/min, association was conducted for 120 s, and dissociation was conducted for 600s. Glycine (10mM,pH1.5 was used for regeneration at a flow rate of 50 uL/min for 60s in a multi-cycle kinetic assay. A 1:1 binding model was used, and the Fit Local mode was selected to determine the association rate constant (ka), dissociation rate constant (kd), and equilibrium dissociation constant (KD).