Reactivity of Enveloped Virus Genome, Proteins, and Lipids with Free Chlorine and UV₂₅₄

The survivability of viruses in natural and engineered systems impacts public health. Inactivation mechanisms in the environment have been described for nonenveloped viruses, but it remains unclear how the membrane layer of enveloped viruses influences inactivation. We applied molecular tools and high-resolution mass spectrometry to measure reactions in the genome, proteins, and lipids of enveloped Pseudomonas phage Phi6 during inactivation by free chlorine and UV₂₅₄. Free chlorine readily penetrated the lipid membrane to react with proteins in the nucleocapsid and polymerase complex. The most reactive Phi6 peptides were approximately 150 times more reactive with free chlorine than the most reactive peptides reported in nonenveloped coliphage MS2. The inactivation kinetics of Phi6 by UV₂₅₄ was comparable with those of nonenveloped adenovirus and coliphage MS2 and were driven by UV₂₅₄ reactions with viral genomes. Our research identifies molecular features of an enveloped virus that are susceptible to chemical oxidants or UV radiation. Finally, the framework developed in the manuscript for studying molecular reactivities of Phi6 can be adopted to investigate enveloped virus survivability under various environmental conditions.