Analysis of protein interactions on protein arrays by a novel spectral surface plasmon resonance imaging

We presented a novel surface plasmon resonance (SPR) imaging method for analysis of protein arrays based on a wavelength interrogation-based SPR biosensor. The spectral imaging was performed by the combination of position control and resonance wavelengths calculated from SPR reflectivity spectra. The imaging method was evaluated by analyzing interactions of glutathione S-transferase-fusion proteins with their antibodies. Antigen–antibody interactions were successfully analyzed on glutathione S-transferase-fusion protein arrays by using the spectral imaging method, and the results were confirmed by a parallel analysis using a previously used spectral SPR biosensor based on wavelength interrogation. Specific binding of anti-Rac1 and anti-RhoA to Rac1 and RhoA on the protein arrays was qualitatively and quantitatively analyzed by the spectral SPR imaging. Thus, it was suggested that the novel spectral SPR imaging was a useful tool for the high-throughput analysis of protein–protein interactions on protein arrays.