Methods for analysis of SSB-protein interactions by SPR.

Surface plasmon resonance (SPR) is a widely employed technique for studying protein-protein interactions. Here, we describe a method for the analysis of single-stranded DNA binding protein (SSB)-heterologous protein interactions by SPR. This method avoids several pitfalls often associated with SPR, particularly difficulties in immobilizing the protein while still allowing for facile regeneration of the sensor chip surface for subsequent experiments. Essentially, the method entails immobilizing a biotinylated single-stranded DNA oligo onto the chip surface, which is then bound by SSB prior to analyte addition to the SSB-coated chip. This allows for rapid qualitative and detailed quantitative analysis of both equilibrium and kinetic parameters of the SSB-protein interaction.