Biacore assays

Biacore assays were used to detect the in vitro binding affinity of SHR-A1403 and SHR-A1403 mAb to c-Met protein derived from human, cynomolgus monkey, and mouse. After SHR-A1403 or SHR-A1403 mAb was captured by the Protein A sensor chip, c-Met protein diluted to different concentrations was injected and allowed to flow over the chip surface. The real-time signals of association and dissociation were measured. The data were fitted by a Langmuir model (BIA evaluation version 4.1, GE), and the affinity to c-Met protein, as measured by the K_D, was obtained.

To measure the binding affinity of SHR-A1403 and SHR-A1403 mAb to human Fcγ receptors (FcγRs), FcRn, or C1q, His-tagged FcγRs, FcRn, or C1q proteins were immobilized to the CM5 sensor chip surface, and SHR-A1403 or SHR-A1403 mAb was injected and allowed to flow over the chip surface. The real-time signals of association and dissociation were measured. The data were fitted by a steady-state affinity model (Biacore T200 Evaluation Software version 3.0, GE), and the affinity to FcγRs, FcRn, or C1q was obtained.