Restructuring Biologically\nAssembled Binding Protein-Biopolymer\nConjugates toward Advanced Materials

Bacterial cell factories have been successfully engineered\nto efficiently\nassemble spherical polyhydroxybutyrate inclusions coated with functional\nproteins of interest. In these submicrometer-sized core–shell\nassemblies, proteins are bioconjugated to the polymer core, enabling\nbioengineering for uses as bioseparation resins, enzyme carriers,\ndiagnostic reagents, and particulate vaccines. Here, we explore whether\nthese functional protein–polymer assemblies could be restructured\nvia dissolution and subsequent precipitation while retaining the functionality\nof the conjugated protein. Polymer core-protein shell assemblies were\ncompletely dissolved in chloroform. Subsequent reconstitution into\ndifferent formats such as hollow spheres, fibers, and films was achieved.\nDifferent proteins such as the green fluorescent protein or IgG binding\ndomains GB1 or Z derived from protein G or protein A, respectively,\nwere implemented to monitor the retention of protein function upon\ngeneration of reformatted materials. Materials were characterized\nand the retention of protein functionality was studied by assessing\nthe fluorescence or IgG binding capacity. Since the Z domain protein\nfunctionality is retained, it suggests that protein refolding properties\nare critical parameters for restructuring these functional materials.\nThis study shows that bioengineered biologically assembled protein-coated\nbiopolymer particles can be completely dissolved and reformed into\nfibers, films, and hollow spheres retaining the original protein function.