Single-Particle Tracking Shows that a Point Mutation in the Carnivore Parvovirus Capsid Switches Binding between Host-Specific Transferrin Receptors

ABSTRACT Determining how viruses infect new hosts via receptor-binding mechanisms is important for understanding virus emergence. We studied the binding kinetics of canine parvovirus (CPV) variants isolated from raccoons—a newly recognized CPV host—to different carnivore transferrin receptors (TfRs) using single-particle tracking. Our data suggest that CPV may utilize adhesion-strengthening mechanisms during TfR binding and that a single mutation in the viral capsid at VP2 position 300 can profoundly alter receptor binding and infectivity.