In Vivo Packaging of Protein Cargo Inside of Virus-Like Particle P22

Protein cages are ubiquitous in nature and have been manipulated to encapsulate a range of nonnative cargos including organic, inorganic, and small molecules. Many protein cages are derived from virus capsids that have been rendered noninfectious through the preferential production and use of proteins that are solely involved in capsid assembly, but which do not encapsulate genetic material and therefore do not contribute to infectivity. Here, we describe the production of protein cargo(s) encapsulated inside of P22 virus-like particles (VLPs), derived from bacteriophage P22. This is achieved via genetic fusion of the cargo to a scaffolding protein, which becomes encapsulated in the P22 VLP during templated assembly of the protein cage.