Efficient disulfide bond formation in virus-like particles.

Virus-like particles (VLPs) consist of a virus's outer shell but without the genome. Similar to the virus, VLPs are monodisperse nano-capsules which have a known morphology, maintain a high degree of symmetry, and can be engineered to encapsidate the desired cargo. VLPs are of great interest for vaccination, drug/gene delivery, imaging, sensing, and material science applications. Here we demonstrate the ability to control the disulfide bond formation in VLPs by directly controlling the redox potential during or after production and assembly of VLPs. The open cell-free protein synthesis environment, which has been reported to produce VLPs at yields comparable or greater than traditional in vivo technologies, was employed. Optimal conditions for disulfide bond formation were found to be VLP dependent, and a cooperative effect in the formation of such bonds was observed.