Computational And Experimental Approaches To Understand A Living Biotic-Abiotic Interface Using Gold Binding Peptides

Bio-abiotic hybrid materials have many potential applications in medicine, electronics, and nanotechnology. Peptides with predictable and controllable binding to inorganic surfaces are of great interest, in which bioengineered proteins can be introduced into bacterial cells to confer nonnative functionality and thereby alter whole-cell behavior. With this is mind, part of our work has been focused on engineering E. coli to display metal binding peptides using bacterial display system eCPX. Here, we present our efforts in understanding cell binding to Au(111) surfaces as well as gold nanoparticles (AuNPs) through a series of known and designed gold binding peptides (GBPs) that have been engineered into eCPX. First, we demonstrate that integration of specific GBPs into the E. coli outer membrane protein increases binding to both Au(111) surfaces and AuNPs. Second, from molecular dynamics (MD) simulations of select free GBPs in aqueous solution and on Au(111), we provide insights into the intermolecular interactions and dynamics driving peptide binding to gold that will be utilized to drive the rational design of inorganic-binding peptides. To conclude, we will discuss these findings in the greater context of our work in living materials, namely our efforts in fashioning sense and respond materials such as designer coatings and self-healing composites.