Production of Well-Characterized Virus-like Particles in an Escherichia coli-Based Expression Platform for Preclinical Vaccine Assessments.

In this chapter we demonstrate a method to produce virus-like particles (VLPs) from Escherichia coli. Standard bacterial protocols are used for the cloning, transformation, and expression of the protein subunits. A two-step protein purification method is highlighted: one step based on separating soluble proteins with ion-exchange affinity chromatography and a second polishing step using size-exclusion columns to isolate VLP species. The ensuing VLPs can be characterized with a variety of biophysical techniques including ultraviolet (UV)-visible spectroscopy for protein quantification, dynamic light scattering for size distribution determination, and transmission electron microscopy to ascertain size and morphology.