Purification of norovirus-like particles (VLPs) by ion exchange chromatography

Recombinant expression of the norovirus capsid protein VP1 leads to self-assembly of non-infectious virus-like particles (VLPs), which are recognized as promising vaccine candidates against norovirus infections. To overcome the scalability issues connected to the ultracentrifugation-based purification strategies used in previous studies, an anion exchange-based purification method for norovirus VLPs was developed in this study. The method consists of precipitation by polyethylene glycol (PEG) and a single anion exchange chromatography step for purifying baculovirus-expressed GII.4 norovirus VLPs, which can be performed within one day. High product purity was obtained using chromatography. The purified material also contained fully assembled monodispersed VLPs, which were recognized by human sera containing polyclonal antibodies against norovirus GII.4.