Porcine circovirus type 2 capsid protein (PCV2 Cap)

Porcine circovirus type 2 capsid protein is encoded by the ORF2 gene, consists of 233 amino acids, and forms the only structural shell of the virus[8]. It is the primary immunogenic component of PCV2, responsible for viral particle assembly, host receptor binding, and induction of host immune responses[1][3][6]. The Cap protein is essential for virion formation and is the major target for protective immunity and vaccine development in swine. Mutations in key regions of the Cap protein can modulate infectivity, host range, and antigenic properties, making it a central focus for epidemiological studies and PCV2 control strategies[4][10][7]. It is used in all commercially available vaccines for PCV2-associated diseases[8]. The ORF2 capsid protein is not a receptor, enzyme, transporter, or transcription factor; rather, it is a structural viral protein and immunogenic marker. Its functional specificity and antigenicity are the basis for most interventions against Porcine circovirus type 2 infections[3][4][8]. No small-molecule drugs are known to target Cap directly; intervention is via vaccination or antibody response. There are multiple PCV2 genotypes with variant Cap sequences, which have clinical relevance for vaccine effectiveness[1][5][10].

Other names

Cap proteinCPPCV2 CapPCV2 capsid protein

Inducing protective immune response via antibody formation Blockade of viral attachment and entry by neutralizing antibodies Prevention of PCV2 infection and dissemination