Norovirus GI.1 capsid protein VP1 (VP1)

Norovirus GI.1 capsid protein VP1 is the primary structural component of the Norwalk virus (GI.1 genotype) capsid, playing a central role in viral architecture and pathogenesis. It self-assembles into a T=3 icosahedral shell consisting of 180 subunits that protect the viral RNA genome and facilitate infection through host-cell attachment. Structurally, VP1 is divided into a conserved shell (S) domain that forms the viral scaffold and a highly variable protruding (P) domain; the latter contains the binding sites for host histo-blood group antigens (HBGAs) required for viral entry. Because it is the main target for neutralizing antibodies, VP1 is the primary antigen used in the development of recombinant vaccines, including virus-like particles (VLPs), adenoviral vectors, and mRNA-based platforms. Therapeutically, VP1 is also a target for experimental entry inhibitors designed to block its interaction with cellular receptors, thereby preventing the initial steps of infection. However, the high genetic diversity of noroviruses and the emergence of new variants present significant challenges for achieving broad and durable protection across multiple genogroups.

Other names

Major capsid protein VP1Norwalk virus VP1Coat proteinp59CPORF2 protein

As a vaccine antigen, it primes the immune system to produce neutralizing antibodies (IgG and IgA) and memory B cells that recognize the viral capsid. As an antiviral target, it is the site for attachment inhibitors designed to block binding to host histo-blood group antigens (HBGAs).