Detection of serum antibodies to S-antigen by surface plasmon resonance (SPR).

Serum autoantibodies to visual arrestin, also termed S-antigen, have been shown to accompany several autoimmune-related diseases. However, they were also detected in sera of healthy individuals; there is lack of a sensitive and fast method for evaluation of putative differences between those two groups of antibodies. We show that, using biosensor technology based on surface plasmon resonance (SPR), it was possible to characterize real-time interactions of immune sera with immobilized arrestin. Binding characteristics revealed different interaction kinetics of antiarrestin antibodies present in two distinct rabbit sera and, thus, broadened results of immunoblotting analysis. Therefore, we suggest that SPR-based biosensor technology might be a valuable method for monitoring and evaluation of antiarrestin antibodies in patients' sera.