(5c) Engineering Protein Electrophoresis through Surfactant Design: The Role of Nanostructure

Protein electrophoresis is a common method for the analysis and identification of specific proteins within complex mixtures (e.g. cell lyses). The surfactant that is utilized in the electrophoresis system plays an integral role in determining the resulting separation. The two main roles of the surfactant are to provide a uniform charge and also to control the hydrodynamic interactions of the denatured protein complex and the gel sieve. Since the introduction of polyacrylamide gel electrophoresis (PAGE), sodium dodecyl sulfate (SDS) has been utilized as the standard surfactant for separations. In this work we utilize small angle scattering techniques (SANS and SAXS) to probe the nanometer scale structure of protein-surfactant complexes that are formed with anionic surfactants of the SDS family but having variable tail architectures. Our aim is to correlate the nanostructure of the protein-surfactant complex to the quality and performance of the macroscopic separation so that optimized surfactant chemistries can be engineered using rational design rules.