The characterization of the interaction between a monoclonal antibody and its antigen is crucial for understanding the structural properties of an immuno-complex. Using chemical cross-linking and High-Mass MALDI mass spectrometry, it is possible to detemine with high-accuracy the mass of the antigen targeted by a monoclonal antibody. The stoechiometry of the interaction between the antigen and the antibody is also determined. This analysis is crucial when developing therapeutic antibodies.
Analysis of the complex formed by the bovine prion protein (bPrP) and a monoclonal antibody anti-bPrP (6H4). The complexes are analyzed before (Blue) and after cross-linking (red) with CovalX's K200 MALDI MS analysis kit. After cross-linking, the non covalent complex 6H4-bPrP and 6H4-2bPrP are easily detected with m=172.5 and 196.1 kDa using CovalX's High-Mass detection system HM1.
Bich et al. Anal. Biochem, 2008, 375:35-45.