Figure 2. Quantitative kinetic analysis of XMetD binding to the hINSR. (A) Kinetic analysis of XMetD binding to the INSR solubilized from CHO-hINSR cells in the absence of insulin by SPR. (B) Kinetic analysis of XMetD binding to the INSR solubilized from CHO-hINSR cells in the presence of 1 μg/ml insulin (in running buffer) by SPR. For (A) and (B), the INSR was solubilized from CHO cells expressing the B isoform of the receptor and captured on the sensor surface via an immobilized monoclonal anti-INSR β subunit antibody (clone CT-3). XMetD concentrations ranging from 1.64‒133 nM were injected over the captured receptor to obtain association and dissociation kinetics. Residuals from the curve fit are shown adjacent to each SPR sensorgram.