Quinine binds to mAb 314.1 with high affinity. mAb 314.1 and control antibody MOPC were immobilized by amine coupling to a CM5 chip for SPR analysis. Quinine at the indicated concentrations was flowed over the chip surfaces. Specific binding of quinine to mAb 314.1 was calculated as described in “Methods.” (A) Representative sensorgrams illustrating dose-dependent binding of quinine to mAb 314.1. (B) Binding isotherm derived from dose-response curves illustrated in (A). Values shown depict duplicate determinations that were nearly superimposable. (C) Scatchard plot analysis. Line shown is the linear fit for data points obtained in duplicate studies. In the experiment shown, KD for binding of quinine to mAb 314.1: 2.7 × 10−8 mol/L and molar ratio of quinine: mAb at saturation was 2.2. Qn, quinine; RU, resonance unit.
