Exploring the impact of nucleic acids on protein stability in bacterial cell lysate

-Addition of salt enhanced thermal stability of model substrate proteins by reducing electrostatic repulsion between protein molecules.-However, the opposite effect was observed with bacterial cell lysate, indicating that certain molecules within the lysate could enhance protein stability via electrostatic interactions.-Such molecules present in cell lysate were found to be nucleic acids known to have a potent anti-aggregation activity toward proteins involving electrostatic interactions.-Nucleic acids showed chaperone activity in physiological salt concentration within cells and in buffer or medium commonly used in experiments.-The chaperone activity of nucleic acids should be taken into account when performing various in vitro assays using cell lysate or samples containing nucleic acids.