In Vitro Studies of the Assembly of ssRNA Viruses and Virus-Like Particles

Chuck Knobler (Biochemistry, UCLA, USA)

Abstract: It is remarkable that the purified capsid protein and ssRNA genomes of several viruses are able to self-assemble in vitro into infectious viruses identical to those found in vivo. Moreover, the capsid protein can self-assemble around heterologous RNAs, dsDNA oligomers, anionic polymers, and functionalized gold nanoparticles into virus-like particles (VLP's) or, by itself into a variety of empty polymorphic structures. This capacity for in vitro self-assembly can be exploited to examine in detail the factors controlling the size and stability of viral assemblies, such as genome length, protein charge and spontaneous curvature. Head-to-head competition experiments allow the relative packaging efficiencies of RNAs to be precisely determined and provide insights into the kinetics of assembly.