Making Conjugation-induced Fluorescent PEGylated Virus-like Particles by Dibromomaleimide-disulfide Chemistry

The recent rise in virus-like particles (VLPs) in biomedical and materials research can be attributed to their ease of biosynthesis, discrete size, genetic programmability, and biodegradability. While they're highly amenable to bioconjugation reactions for adding synthetic ligands onto their surface, the range in bioconjugation methodologies on these aqueous born capsids is relatively limited. To facilitate the direction of functional biomaterials research, non-traditional bioconjugation reactions must be considered. The reaction described in this protocol uses dibromomaleimides to introduce new functionality in the solvent exposed disulfide bonds of a VLP based upon Bacteriophage Qβ. Furthermore, the final product is fluorescent, which has the added benefit of generating a trackable in vitro probe using a commercially available filter set.