Nonfouling Coatings from Synthetic Intrinsically Disordered Proteins

Abstract The antifouling performance of a previously developed triblock protein, B‐M‐E is optimized, that self‐assembles on gold surfaces to form a nonfouling layer by modifying the sequence of its E block. In this protein, B is a gold‐binding domain, M is a trimerization domain, and E is a synthetic intrinsically disordered protein (IDP) that confers nonfouling behavior. To identify optimal sequences for the nonfouling E block, a few candidate IDPs are screened that provide a proxy for nonfouling behavior, such as extending the half‐life of their fusion partners in systemic circulation and sequences that promote soluble expression of their fusion partners in E coli. One IDP is identified with the sequence [(GAGAIP)₃‐(GAGEIP)]₄ as the E block in B‐M‐E brush on gold, forming a nonfouling coating with performance comparable to a self‐assembled monolayer (SAM) of a tetraethylene glycol‐terminated alkanethiol on gold. These B‐M‐E brushes also render gold surfaces resistant to E. coli attachment for at least seven days. The B‐M‐E protein can be synthesized at scale in bacterial expression systems using the upstream fermentation and downstream purification capabilities of the biotechnology industry. It may provide a useful and robust alternative to existing nonfouling coatings based on small molecules or synthetic polymers.