Thermophoresis of Molecules and Structures of different Sizes in Self-assembled Biomatrices

Abstract

Upon subjecting biomolecules to non-equilibrium conditions, many biochemical and biophysical features such as biomolecular diffusion, protein folding, interaction kinetics, as well as enzyme-catalyzed reactions can be characterized in an aqueous solution. However, most assays under non-equilibrium conditions cannot be performed in complex self-assembled biomatrices (e.g. extracellular matrices) due to the limitations associated with sample handling, reaction design, and optical detection. Herein, we report the study of biomolecular thermodiffusion in non-covalently assembled synthetic or naturally derived hydrogels. This approach has been demonstrated with a large variety of analytes, including small molecules, polysaccharides, DNAs, DNA origami, and proteins in various polymer networks. The in-biomatrix method has also shown advantages over in-solution measurements: First, it allows us to analyze biomolecules in 3D matrices in a high-throughput fashion. Second, the aggregation of analytes can be remarkably prevented. Although the underlying physics of thermodiffusion is still not well-understood, we demonstrated that the thermodiffusion of surrounding networks will enhance the thermodiffusion of the analyte, an effect counteracting the hindered movement by the polymer network.