Real-time biospecific interaction analysis of a natural human polyreactive monoclonal IgM antibody and its Fab and scFv fragments with several antigens.

Surface plasmon resonance (SPR) was used to investigate the kinetics of interactions between the human monoclonal polyreactive IgM antibody CB03, its Fab as well as its single-chain variable fragment (scFv) and different antigens. From these experiments apparent binding constants were determined and compared with binding constants obtained by ELISA experiments. In SPR studies with the complete antibody, the polyreactivity of the CB03 antibody as derived from ELISA experiments was confirmed. Interaction of scFv with κ casein and human myoglobin is strong evidence for the location of polyreactivity within the variable domains of the antibody