The main goal of electrophoretic separation is to use electric fields to separate proteins out of complex biological mixtures (e.g. serum, saliva or cell lysates). The proposed work uses the principles of nanoscience to rationally improve reproducibility, resolution, and sensitivity.. It focuses on the structure of the protein-surfactant complex and employs a multi-scale experimental approach based on the fundamentals of colloid and polymer science to decipher the intricate relationship between the nano-structure of protein-surfactant complexes, the mechanism of electrophoretic transport (e.g. reptation) and the effectiveness of the macroscopic separation.
Light, x-ray and neutron scattering experiments will systematically evaluate the structure of protein complexes that are made from "non traditional" anionic surfactants. These experiments will probe nanometer scale structural transitions occurring in the protein-surfactant complex. The changes are triggered by specific alterations in the hydrophobic moiety of the surfactant (e.g. linear and branched alkyl chains) or through the use of mixed surfactant and co-surfactant formulations. In addition, the structure and conformation of the proteins will be monitored in-situ, using on-line neutron scattering experiments carried out in polymeric gels and with the application of electric fields. This should lead to the development of an accurate physical understanding of the true structural parameters that govern electrophoretic transport. The long term goal is to extend these studies into other areas, such as the use of nano-structured sieving matrices, so that we can develop a complete understanding of the separation.
Educationally the results of this work will be incorporated into existing courses to demonstrate the use of surfactants in high-technology applications. It will immediately impact the research experience of graduate and undergraduate students from under-represented groups. This will help to increase their participation in STEM graduate programs. Finally, the proposal will allow the PI to continue serving as a liaison between the NIST Center for Neutron Research and faculty and students from under-represented groups. This will increase awareness of these and other valuable resources among groups that have historically been unable to take advantage of their availability.
