Human rhinovirus capsid cationic surface site (HRV cationic sites)

Human rhinovirus (HRV) virions possess specific cationic (positively charged) surface sites on their icosahedral capsids, which are primarily composed of the structural proteins VP1, VP2, and VP3 (Blaas & Fuchs, 2014). These cationic patches are critical for the initial electrostatic interaction between the virus and the negatively charged cell surface, facilitating subsequent binding to specific receptors such as Intercellular Adhesion Molecule 1 (ICAM-1) or the Low-Density Lipoprotein Receptor (LDLR) (Grassauer et al., 2008). Therapeutic agents like iota-carrageenan, a polyanionic polysaccharide, target these sites by binding electrostatically to the positively charged regions of the viral capsid. This binding creates a physical barrier that prevents the virus from attaching to host cells and inhibits the uncoating process necessary for viral genome release (Koenighofer et al., 2014). By neutralizing the surface charge, these drugs effectively trap the virions in the mucus layer, where they can be cleared by mucociliary action. This target is particularly relevant for treating the common cold and preventing exacerbations of underlying respiratory conditions like asthma and COPD (Eccles, 2011). Unlike pocket-binding inhibitors, these agents act non-specifically across various HRV serotypes by exploiting the conserved electrostatic nature of the capsid surface. Clinical applications primarily involve topical administration via nasal sprays to limit viral replication at the primary site of infection.

Other names

HRV cationic patchesRhinovirus capsid surfaceHRV positively charged regions

Polyanionic compounds bind to the cationic surface sites of the rhinovirus capsid, creating a physical barrier that prevents viral attachment to host cell receptors and inhibits subsequent viral entry.