(716b) Engineering of Barley Stripe Mosaic Virus Capsid Protein to Tune Morphology and Surface Functionality of Self-Assembled Viral-like Particles for Diverse Applications

Protein nanoparticles derived from plant virus capsid proteins offer tunable and modular self-assembly of diverse nanoscale architectures with applications in catalysis, sensing, consumer products, and medicine. Rod-shaped plant viruses, in particular, are attractive as they are non-infectious or safe in humans and are compelling for applications requiring high aspect ratios, such as nanowire templating and vaccine development. Despite the great diversity of rod-shaped plant viruses in nature, engineering efforts in this area have been largely limited to the tobacco mosaic virus (TMV), which has limited surface interactions for functionalization relative to emerging platforms such as barley stripe mosaic virus (BSMV). However, synthesis of BSMV relies on host infectivity, which greatly limits viral particle tunability. We addressed this limitation by expressing BSMV coat protein (CP) in E. coli for the first time. Despite their natural promiscuity for RNA, these proteins do not assemble around native RNA in E. coli, and they instead self-assemble into disks. Upon transcription of an RNA transcript containing a TMV encapsidation signal (OAS), however, they readily assemble into rod-shaped viral-like particles (VLPs). Similarly, we identify residues on BSMV CP involved in self-assembly and develop mutants that self-assemble into higher aspect ratio rods without the RNA transcript and exhibit stability over a broader pH range. Here, I will discuss our progress in engineering the morphology of BSMV VLPs as well as the functionalization of its surface with short peptide sequences for facile decoration with peptides, proteins, and other (bio)polymers. Our work establishes BSMV VLP as a highly tunable rod-shaped nanomaterial platform with broad engineering applications.