Random, Amphiphilic, Charged Copolymers for Protein Encapsulation in Solution and at Interfaces

Random copolymers with hydrophobic, hydrophilic, and charged groups are investigated using simulation and experiments for their ability to encapsulate a proteins in aqueous solution and at interfaces. Experiments are performed on a protein known as PETase, which depolymerizes polyethylene terephthalate (PET). In aqueous solution, we show the formation of complexes slightly larger than the protein itself. In the presence of PET film substrate, an increase in activity is observed in response to thermal challenge. MARTINI simulations show the formation of protein-polymer complexes and are used to optimize these complexes by changing the relative amounts of the 3 different types of monomers. These simulations also show the formation of complexes at elevated temperature and that the polymer can stabilize the conformation of the protein at high temperature. Simulations using cytochrome P450 show that the ability of our random copolymers to form complexes is general. Finally, we show the behavior of these protein-polymer complexes in the presence of interfaces (PETase in the presence of a PET film, P450 in the presence of an oil water interface).