Versatile analysis of multiple macromolecular interactions by SPR imaging: application to p53 and DNA interaction

The greatest challenge in the postgenomic era is the description of proteome interactions, such as protein-protein or protein-DNA interactions. Surface plasmon resonance (SPR) is an optical technique in which binding of an analyte to the surface changes the refractive index at the surface/solution interface. Molecular interactions are analysed in real time without a labeling step. Currently, the limit to SPR imaging is the small number of reactions that can be simultaneously analysed. Using a novel grafting technology and a new imaging system, we increased the throughput of SPR imaging. The interaction between p53 and DNA was chosen as a paradigm for validation of this assay. Using a tagged DNA methodology, we simultaneously targeted multiple DNA sequences on a single chip. The interaction between p53 and these DNA sequences was monitored by SPR imaging. Qualitative and quantitative analysis provides results similar to those obtained with conventional technologies.