Cowpea mosaic virus

The Cowpea mosaic virus is a plant mosaic virus of the comovirus group. Infection of a cowpea leaf results in high virus yields (1-2 g/kg). Genomes consists of 2 molecules of positive-strand RNA (RNA-1 and RNA-2) which are separately encapsidated. Each is expressed by a polyprotein processing strategy. Particles are 28nm in diameter and contain 60 copies each of a Large (L) and Small (S) coat protein arranged pseudo T=3 (P=3) symmetry. The structure is well characterised to atomic resolution and the viral particles are thermostable.

It can infect the Black-eyed pea, as it displays a number of features that can be exploited for nanoscale biomaterial fabrication and because its genetic, biological and physical properties are well characterised. CPMV can be isolated readily from plants. It is possible to attach a number of different chemicals to the virus surface and to construct multilayer arrays of such nanoparticles on solid surfaces. This gives the natural nanoparticles a range of properties which could be useful in nanotechnological applications such as biosensors, catalysis and nanoelectronic devices.