Poliovirus type 1 capsid antigen

The **Poliovirus type 1 capsid antigen** is the structural protein shell (capsid) of poliovirus serotype 1, composed of 60 copies each of four viral proteins (VP1, VP2, VP3, VP4) arranged with icosahedral symmetry[2][4][5]. The **capsid encapsulates the viral RNA genome and presents conformational and linear epitopes** that are major targets for host neutralizing antibodies and vaccine design[1][3]. Distinct antigenic sites are located primarily on the surface-exposed loops of VP1, VP2, and VP3, notably the BC, DE, and GH loops of VP1, which are crucial for antibody and cell receptor (CD155) interactions[1][2][4]. Upon binding to its receptor, the capsid undergoes conformational changes necessary for viral entry into host cells[2][4][5]. Monitoring antibody responses to capsid antigens is central to assessing immunity against poliovirus, and capsid stability or mutational changes influence the effectiveness of vaccines and the emergence of escape mutants[1][4].

Other names

Poliovirus type 1 capsidPoliovirus serotype 1 capsid antigenPV1 capsid antigenPoliovirus serotype 1 neutralizing determinant

Antibodies neutralize virus by binding antigenic sites on the capsid, preventing receptor-mediated cell entry[1][3][4] - Some small molecules bind conserved hydrophobic pockets in the capsid, stabilizing the virion and blocking uncoating[4][5]