Methods for analysis of SSB-protein interactions by SPR.

Area of Science:

• Biochemistry
• Molecular Biology
• Biophysics

Background:

• Surface Plasmon Resonance (SPR) is a key technique for studying biomolecular interactions, particularly protein-protein binding.
• Traditional SPR methods face challenges with protein immobilization and sensor chip regeneration, hindering reproducible analysis.
• Single-stranded DNA binding proteins (SSBs) are crucial in DNA replication and repair, and understanding their interactions is vital.

Purpose of the Study:

• To develop an improved SPR method for analyzing interactions between single-stranded DNA binding proteins (SSBs) and other proteins.
• To overcome common limitations in SPR, such as protein immobilization difficulties and sensor chip regeneration.
• To enable both qualitative and quantitative assessment of SSB-heterologous protein binding kinetics and equilibrium.

Main Methods:

• Immobilization of a biotinylated single-stranded DNA (ssDNA) oligo onto an SPR sensor chip surface.
• Binding of the target SSB to the immobilized ssDNA oligo, creating an SSB-coated surface.
• Introduction of heterologous proteins (analytes) to the SSB-coated chip for interaction analysis using SPR.

Main Results:

• The developed method successfully immobilizes SSB via an ssDNA oligo, facilitating stable binding.
• The approach allows for efficient regeneration of the sensor chip surface after each experiment.
• SPR analysis provided both qualitative and quantitative data on SSB-heterologous protein binding, including equilibrium and kinetic parameters.

Conclusions:

• This novel SPR method offers a robust and efficient approach for studying SSB-protein interactions.
• The technique addresses critical limitations of traditional SPR, enhancing experimental reproducibility and data quality.
• The method facilitates detailed characterization of SSB binding partners, contributing to a better understanding of DNA-related cellular processes.