Vp2

Vp2, short for viral protein 2, is a structural component of the viral capsid in many picornaviruses. It is commonly one of the four major capsid proteins, designated VP1–VP4, that assemble into the icosahedral virion.

Genomic origin and maturation: VP2 is encoded in the P1 region of the viral genome and is produced as part of a polyprotein that is cleaved by viral proteases, yielding the mature capsid proteins. The exact processing can vary among genera, but VP2 is a consistent element of the external capsid in many members of the family.

Structure and function: In the assembled virion, VP2 resides on the outer surface in association with VP1 and VP3, contributing to capsid stability and integrity and participating in the receptor-binding interface. Loops and exposed regions of VP2 can contain antigenic determinants and neutralizing epitopes in some viruses, making it a focus of immunological studies.

Genetic variation and applications: VP2 sequences display considerable variation across serotypes and strains, and are used in phylogenetic analyses and, for certain viruses, serotype identification. Recombinant VP2 constructs and peptides are used in basic research, diagnostic contexts, and in vaccine development frameworks.

Notes: While common to many picornaviruses, some genera differ in the processing of capsid precursors, and the exact maturation steps may vary. VP2 is typically studied alongside VP1, VP3, and VP4 to understand capsid structure and virus–host interactions.