Poliovirus type 1 and type 3 capsid proteins (PV1/PV3 capsid)

The capsid antigens of Poliovirus types 1 and 3 are the primary structural components of the viral shell, composed of four distinct proteins: VP1, VP2, VP3, and VP4. These proteins assemble into an icosahedral structure that protects the viral RNA genome and facilitates infection by binding to the human poliovirus receptor (CD155) on the surface of host cells (UniProt P03300). In the context of public health and pharmacology, these antigens are the critical targets for both Inactivated Poliovirus Vaccines (IPV) and Oral Poliovirus Vaccines (OPV), which stimulate the production of neutralizing antibodies to block viral entry (CDC, 2023). While Type 2 poliovirus was declared eradicated in 2015 and Type 3 in 2019, Type 1 remains endemic in specific regions, necessitating continued focus on these specific antigens (WHO, 2022). Beyond vaccines, the capsid proteins are targets for antiviral drug development, such as the experimental inhibitor Pocapavir, which binds to the VP1 protein to inhibit the conformational changes required for viral uncoating (Collett et al., 2014).

Other names

Poliovirus structural proteinsVP1 proteinVP2 proteinVP3 proteinVP4 proteinPoliovirus type 1 and 3 antigens

Vaccines induce neutralizing antibodies that bind to capsid epitopes, preventing viral attachment to the host receptor CD155. Small-molecule capsid inhibitors like Pocapavir bind to the hydrophobic pocket of the VP1 protein, stabilizing the capsid and preventing the uncoating and release of the viral RNA genome into the host cell.