Addressable Viral Nanobuilding Block

In 2002, for the first time, CPMV was regarded as an addressable nanobuilding block [79]. First, experiments were conducted in order to test selective chemical derivatization of wild-type virions later, several mutant particles were made, such as cysteine mutants [80] and histidine mutants [81]. Different bioconjugation strategies were applied and a set of biological and organic and inorganic chemical molecules have been attached to CPMV. 

CPMV-[NCD4]n CPMV CPMV-[NCD41n CPMV 

A further carboxylate is found in the carboxy-terminal domain of S however, owing to cleavage of 24 amino acids of the S subunit in the plant, the additional carboxylate is present in only a small proportion of the particles [85], 

Besides the reactive exterior, addressable groups have been found on the interior of the capsid as well. CPMV has at least two reactive interior cysteine residues [79], but no cysteines can be found on the solvent-exposed exterior [73], It was demonstrated that chemical derivatization of the internal cysteines can be achieved using small thiol reactive compounds, such as ethylmercury phosphane, 5-maleimidofluorescein [79], and thiol-selective shlbene derivatives [86]. 

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