Viral capsid mobility: A dynamic conduit for inactivation

Mass spectrometry and fluorescent probes have provided direct evidence that alkylating agents permeate the protein capsid of naked viruses and chemica lly inactivate the nucleic acid. N-acetylaziridine and a fluorescent alkyla ting agent, dansyl sulfonate aziridine, inactivated three different viruses , flock house virus, human rhinovirus-14 and foot and mouth disease virus. Mass spectral studies as well as fluorescent probes showed that alkylation of the genome was the mechanism of inactivation. Because particle integrity was not affected by selective alkylation (as shown by electron microscopy and sucrose gradient experiments), it was reasoned that the dynamic nature of the viral capsid acts as a conduit to the interior of the particle. Pote ntial applications include fluorescent labeling for imaging viral genomes i n living cells, the sterilization of blood products, vaccine development, a nd viral inactivation in vivo.