In Vitro Assembly of Bacteriophage Lambda Procapsid to Enable Payload Encapsulation For Targeted Drug Delivery

The ability to structurally engineer viral nanoparticles makes them a useful platform for targeted drug delivery. The procapsid of bacteriophage lambda is one such structure. This hollow icosahedral structure can be made from multiple copies of three major capsid proteins: gpE (structural), gpNu3 (scaffolding), and gpD (stabilizing), and is amenable to payload encapsulation to allow transportation and delivery of therapeutics. An effective method for encapsulation must be found, because expression of gpE, gpD, and gpNu3 in bacterial cells results in self-assembly of the fully-formed procapsid. Therefore, if bacteriophage lambda procapsid can be assembled in vitro, the structure may be able to form around a payload in solution. In this study the preliminary steps to in vitro assembly were completed by expressing and purifying gpE. Via western blot analysis, it was found that gpE-GST can be expressed via induction of an inducible plasmid, and purified via GST-affinity chromatography.