Metalloslayer – Modular, Protein-Based Water Filtration Platform

Water contamination remains a critical global issue, impacting human health and ecosystems alike. As the world’s largest and most crucial resource, there’s a pressing need for accessible and sustainable innovations in water purification. We propose to develop MetalloSlayer, a modular, protein-based water filtration platform that aims to address heavy metal water pollution.S-layer proteins form highly ordered, two-dimensional arrays on the surface of many prokaryotic organisms and exhibit remarkable stability and are capable of self-assembling on a variety of supports and are easily purified. S-layer proteins in Bacillus sphaericus bacteria show a high capacity for bioadsorption of heavy metals like arsenic, lead, cadmium, chromium and mercury.Through synthetic biology, we can modify and improve these S-layers as a bioadsorbant by improving their binding and specificity for different metal ions. S-layer proteins are capable of tolerating fusions with other proteins while still retaining the ability to assemble into a lattice formation. We will combine the S-layers with specific metal-binding proteins for better capture and adsorption of heavy metals.To ensure a modular system that can be customized for different contaminants, we are taking advantage of the well-studied SpyTag/SpyCatcher conjugation system for effective protein-protein ligation. We aim to create a fusion protein combining B. sphaericus S-layer protein and the SpyCatcher protein, enabling a reliable system of swappable protein functionalization. Genetically encoding different metal-binding proteins with the SpyTag peptide chain allows them to bind to the S-layers through a spontaneous isopeptide bond formation. These conjugated S-layer proteins will then be reassembled on a porous membrane filter material, creating a cost-effective, filtration system functionalized with a potent and modular heavy metal bioadsorbant.