Norwalk virus major capsid protein VP1 (VP1)

The major capsid protein VP1 of Norovirus GI.1 (Norwalk virus) is the primary structural component of the viral shell, self-assembling into an icosahedral capsid composed of 180 VP1 monomers organized as 90 dimers [1, 5, 8]. The protein is structurally divided into a conserved shell (S) domain and a protruding (P) domain; the P2 subdomain of the latter is highly variable and is responsible for binding to host histo-blood group antigens (HBGAs), which serve as critical attachment factors for infection [3, 5, 7, 11]. As the most surface-exposed part of the virus, VP1 contains the major neutralizing epitopes and is the predominant target for norovirus vaccine development [9, 10]. Current therapeutic and prophylactic strategies include virus-like particle (VLP) vaccines, such as HIL-214, and oral adenovirus-vectored vaccines like VXA-GI.1-NN, as well as small-molecule carbohydrate mimetics designed to block the VP1-HBGA interaction [9, 11, 12, 18]. Despite its promise as a target, the rapid antigenic evolution and diversity of noroviruses present significant hurdles for achieving durable, broad-spectrum immunity [9, 13].

Other names

Norovirus GI.1 VP1Major capsid proteinCapsid protein VP1Coat proteinCPp59Protein 30kp30

Neutralization of viral particles, induction of mucosal (IgA) and systemic (IgG) immune responses, and competitive inhibition of histo-blood group antigen (HBGA) binding to prevent viral attachment to host cells.