Submitted to: Journal of Virological Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 15, 2011
Publication Date: September 22, 2011
Citation: Natilla, A., Hammond, R. 2011. Maize rayado fino virus-like particles expressed in tobacco plants: a new platform for cysteine selective bioconjugation peptide display. Journal of Virological Methods. 178:209-215. Interpretive Summary: Agricultural losses due to plant and animal diseases necessitate the development of reagents for detection and control of the pathogens that cause the disease. Plant viruses and virus-like particles are able to assemble themselves in unique ways. In the present study, we studied the ability of one particular virus to reassemble into different types of virus-like particles. These particles can be used to generate reagents which have multiple uses for applications in pathogen detection and vaccine production. We demonstrated that these chemically-modified particles can serve as platforms for the display of diverse molecules. These results will be of interest to plant and animal virologists who are studying virus particle assembly and disease specialists who are developing methods for disease control.
Technical Abstract: The ability of plant virus coat proteins to self-assemble into virus-like particles (VLPs), coupled with unique properties including three-dimensional structures, orthogonal reactivities, suitability for genetic manipulation and chemical bio-conjugation, provide potential utility in nanotechnology applications. Maize rayado fino virus (MRFV), the type member of the genus Marafivirus, family Tymoviridae, is a small spherical plant virus characterized by isometric particles of approximately 30 nm in diameter and containing 180 copies of the virus-encoded capsid protein (CP), which form a T=3 lattice that is stabilized by protein-protein interactions. The virus capsid is composed of two serologically related CPs of 21-22kDa (CP2) and 24-28kDa (CP1) containing common peptide sequences and that are found in molar ratios of 3:1, respectively. In this report we examined the ability of plant-produced MRFV-VLPs to serve as a novel platform to which a variety of peptides can be covalently displayed. In order to provide an anchor for chemical modifications, three Cys-MRFV-VLPs mutants were created by substituting several of the amino acids present on the shell of the wild-type MRFV-VLPs with cysteine residues. One Cys-MRFV-VLP mutant exhibited, under native conditions, cysteine thiol reactivity in bioconiugation reactions with a fluorescent dye. In addition this Cys-MRFV-VLP was cross-linked by NHS-PEG4-Maleimide to 17 (F) and 8 (HN) amino acid long peptides, corresponding to neutralizing epitopes of Newcastle disease virus (NDV). The resulting Cys-VLPs-F and Cys-VLPs-HN were recognized in Western blots by antibodies to MRFV as well as to F and HN. This report demonstrates the ability of plant-produced MRFV-VLPs to function as a novel platform for the multivalent display of surface ligands.