Global analysis of a macromolecular interaction measured on BIAcore

We demonstrate that the interaction between myoglobin and an immobilized anti-myoglobin antibody measured on BIAcore 2000 can be described by a simple bimolecular reaction mechanism. We improved the quality of the sensor data by correcting for refractive index changes and nonspecific binding using a blank sensor surface. Applying nonlinear least squares analysis, we simultaneously fitted the association and dissociation phase data generated for a range of myoglobin concentrations injected across the antibody surface. The ability to globally fit these data to a simple binding model indicates that effects related to the sensor surface, like mass transport and the dextran matrix, did not complicate the observed binding responses. These results illustrate the potential of BIAcore to monitor macromolecular interactions in real-time and the utility of global analysis to resolve the reaction kinetics.