Poliovirus type 2 capsid protein complex (PV2 capsid)

The Poliovirus type 2 capsid protein complex is the protective protein shell of the type 2 poliovirus, an enterovirus responsible for paralytic poliomyelitis. The capsid is composed of 60 copies each of four structural proteins—VP1, VP2, VP3, and VP4—arranged in an icosahedral symmetry (UniProt P03300). Its primary biological role is to protect the viral RNA genome and facilitate infection by binding to the host cell receptor, CD155, and mediating the subsequent uncoating process (PubMed: 11967304). In the context of therapeutics, the capsid is the primary target for both inactivated and oral vaccines, which elicit neutralizing antibodies to block viral entry (NIH: StatPearls). Additionally, small-molecule capsid inhibitors like V-073 target a hydrophobic pocket in the VP1 subunit to prevent the structural transitions required for genome release, serving as potential antiviral candidates for outbreak control and immunodeficient chronic shedders (PubMed: 22553327).

Other names

Poliovirus type 2 structural protein complexPoliovirus type 2 P1 polyproteinPoliovirus type 2 VP1-VP4 complexPoliovirus type 2 virion surface proteins

Capsid-binding inhibitors (e.g., V-073) bind to a hydrophobic pocket within the VP1 protein, which stabilizes the capsid and prevents the conformational changes necessary for the release of viral RNA into the host cell (uncoating). Vaccines induce neutralizing antibodies that bind to the capsid surface, preventing the virus from attaching to the host receptor (CD155).