Crystal Structure and Proteomics Analysis of Empty Virus-like Particles of Cowpea Mosaic Virus

Abstract

SUMMARY Empty virus-like particles (eVLPs) of Cowpea mosaic virus (CPMV) are currently being utilized as reagents in various biomedical and nanotechnology applications. Here, we report the crystal structure of CPMV eVLPs determined using X-ray crystallography at 2.3 Å resolution and compare it with previously reported cryo-electron microscopy (cryo-EM) of eVLPs and virion crystal structures. Although the X-ray and cryo-EM structures of eVLPs are mostly similar, there exist significant differences at the C terminus of the small (S) subunit. The intact C terminus of the S subunit plays a critical role in enabling the efficient assembly of CPMV virions and eVLPs, but undergoes proteolysis after particle formation. In addition, we report the results of mass spectrometry-based proteomics analysis of coat protein subunits from CPMV eVLPs and virions that identify the C termini of S subunits undergo proteolytic cleavages at multiple sites instead of a single cleavage site as previously observed.

Stability of plant virus-based nanocarriers in gastrointestinal fluids

“…This is expected, because, although the capsid structure of CPMV and eVLPs is identical, eVLPs are less dense, as they are devoid of nucleic acid. 51 At pH 1.2 the L and S proteins banded mainly in the supernatant and in the 10% sucrose fractions, indicating that the capsid disassembled and the polypeptides denatured. At pH 1.2, followed by neutralisation, the L and S proteins could be found as a precipitate at the bottom.…”

Encapsidation of Viral RNA in Picornavirales : Studies on Cowpea Mosaic Virus Demonstrate Dependence on Viral Replication

“…In the case of members of the Picornavirales , CPMV and poliovirus (22, 23), the generation of VLPs requires the coexpression of both a coat protein precursor and the cognate protease needed for its processing. The coexpression of these components in the absence of RNA replication results in the production of large quantities of RNA-free VLPs in which the assembled protein shell is identical in structure to the natural, RNA-containing capsids (2, 4, 22, 24, 25) (Fig. 1b).…”

Virus‐like particles: Next‐generation nanoparticles for targeted therapeutic delivery

“…This review will focus on six of the most actively developed VLPs from: one animal virus, three bacteriophages, and two plant viruses (Figure ) . Table summarizes the properties of these VLPs.…”