Norovirus VP1 capsid protein (genotype GII.3) (VP1)

The Norovirus VP1 capsid protein (genotype GII.3) is the primary structural component of the GII.3 norovirus, which is a leading cause of acute gastroenteritis worldwide, especially in pediatric populations. This protein self-assembles into a T=3 icosahedral capsid consisting of 180 monomeric units that protect the viral genome and mediate host cell recognition. Structurally, VP1 is organized into a conserved shell (S) domain and a protruding (P) domain, the latter of which is further divided into P1 and P2 subdomains. The P2 subdomain is the most surface-exposed region and contains the binding sites for host histo-blood group antigens (HBGAs), which serve as essential attachment factors for infection. Because it contains the major neutralizing epitopes, VP1 is the primary target for vaccine strategies, including the development of virus-like particles (VLPs) and mRNA-based vaccines. Therapeutic research also focuses on small-molecule inhibitors and carbohydrate mimics that target the HBGA-binding pocket to prevent viral entry. However, the high rate of genetic evolution and antigenic variation within the GII.3 genotype poses a significant challenge for the development of long-lasting and broadly effective medical countermeasures.

Other names

Major capsid protein VP1ORF2 proteinCapsid protein VP1GII.3 VP1Norovirus GII.3 capsid protein

Vaccines utilizing VP1 or virus-like particles (VLPs) aim to induce neutralizing antibodies (blockade antibodies) that prevent the virus from binding to host histo-blood group antigens (HBGAs). Small-molecule inhibitors and carbohydrate mimics target the HBGA-binding pocket on the P2 subdomain to competitively inhibit viral attachment and subsequent entry into host cells.