(713b) Surface Functionalization of Recombinant Barley Stripe Mosaic Virus-like Particles for Biomedical Applications & Nanomaterial Synthesis

Rod-shaped plant viruses are RNA-templated nanoparticles with densely packed surfaces that can be engineered for various nanotechnological and medical applications. While some rod-shaped plant viruses, such as tobacco mosaic virus (TMV), receive a great deal of research focus, barley stripe mosaic virus (BSMV) remains relatively unexplored. We recently used a bacterial host to prepare BSMV virus-like particles (VLPs) that demonstrated superior palladium-deposition capacity relative to TMV. The recombinantly expressed BSMV coat protein spontaneously self-assembled into disk multimers in vivo, which further formed helical nanorods upon expression of an RNA template containing the viral origin of assembly sequence for TMV. This heterologous expression platform circumvents the need for host plant infectivity, thus greatly expanding the achievable range genetically engineered variants. However, bacterial hosts cannot accommodate protein modifications and processes of interest, and their products suffer from toxic lipopolysaccharide contaminants that hinder medical applicability. We addressed these limitations by producing BSMV VLPs in yeast for the first time. We also leveraged the engineering flexibility granted by each recombinant expression platform to perform rapid design-test-build-learn cycles on various mutant VLPs. This accelerated engineering workflow guided the fusion of single residues, peptides, and proteins at the particle surface. I will discuss how these various modifications can be used to tune physicochemical and biological properties of BSMV VLPs and support particle stability, purification, immunogenicity, and cellular interactions.