Poliovirus type 1 capsid protein complex (None)

The Poliovirus type 1 capsid is the protein shell surrounding the viral RNA genome of poliovirus serotype 1. It is composed of 60 copies each of four proteins (VP1, VP2, VP3, and VP4), arranged in an icosahedral symmetry. This complex forms the external structure of the virus, mediating interactions with host cell receptors (CD155/PVR receptor). Upon receptor binding, the capsid undergoes a conformational change (from the native 160S particle to the cell entry intermediate 135S particle), facilitating the release of viral RNA into the host cell. The capsid contains antigenic sites important for immune recognition and is the primary target for neutralizing antibodies and vaccines. Small-molecule drugs may interact with a hydrophobic pocket in VP1, blocking the conformational transitions required for viral uncoating and infection. The structure, stability, and antigenicity of the capsid are determinants of viral infectivity, immune response, and the success of antiviral interventions. The capsid’s high mutation rate poses challenges for drug and vaccine effectiveness.

Other names

Poliovirus type 1 capsidPoliovirus type 1 virion capsidPV1 capsidPoliovirus coat protein complex

Drugs may bind to the capsid's hydrophobic pocket, stabilizing the virion and preventing conformational changes required for uncoating and genome release. Some molecules block receptor binding or prevent structural transitions triggered by host cell attachment.