Orientation of adsorbed myoglobin on (oxidized) polystyrene

The performance of protein biosensors is strongly determined by the conformation of proteins immobilized on the sensor surface. To improve protein reactivity and reduce non-specific binding, we are performing a fundamental study on the interaction between proteins and a polymeric biosensor surface. Both protein orientation and interaction energies are addressed. Experimental results are compared with molecular dynamics simulations. As a model system we study the adsorption of myoglobin on polystyrene surfaces with well-defined oxidation states. The focus of this poster is on determining the orientation of myoglobin on the polystyrene surface. We use six monoclonal antibodies that target different myoglobin epitopes. Using information on the affinities of these antibodies to myoglobin in solution, we can determine the myoglobin orientation on the surface by studying the binding of the different antibodies using total internal reflection fluorescence microscopy. In future we will quantify the interaction of single oriented myoglobin molecules with the surface using magnetic tweezers. The acquired knowledge will lead to a better understanding of protein-surface interactions and will set directions for biosensor optimizations.