A proteomics approach to survey the antigenicity of the influenza virus by mass spectrometry.

A proteomics-based approach is described that combines gel electrophoresis and MS in order to identify protein interactions and the nature of the interaction interface with high-sample throughput and sensitivity. Results for protein antigens of the influenza virus have demonstrated that the approach can be successfully employed to detect determinants within the hemagglutinin antigen of two divergent type A forms of the virus in present circulation. The determinants are localised to residues 206-224 following tryptic digestion of the hemagglutinin antigen. Specific peptide-antibody complexes formed after treatment of gel-recovered antigen are shown to be able to be preserved on the MALDI target array as has been previously demonstrated in this laboratory for whole virus. The approach has broad applicability for the analysis of a wide array of protein complexes with identification of the interaction interface in a single step with high-sample throughput and at low sample levels.