Norovirus capsid protein VP1, GII.4 (VP1 (GII.4))

Norovirus capsid protein VP1, GII.4, is the principal structural protein forming the icosahedral capsid of GII.4 human norovirus, which is responsible for the majority of global norovirus outbreaks. The VP1 protein assembles into a T = 3 symmetric lattice, creating a shell and protruding domains that display remarkable conformational flexibility. This adaptability is stabilized by a hinge region and metal ion coordination at the dimeric interface, influencing capsid stability, antigenicity, and access to neutralizing antibodies. The structure and antigenic landscape of GII.4 VP1 are critical for ongoing vaccine development, as shifts in conformation can expose or occlude key neutralization sites, thereby modulating immune protection and posing challenges for broad vaccine coverage. The protein itself is not a classic 'receptor,' but it is targeted by immune interventions (antibodies, vaccines). There are currently no small-molecule drugs targeting VP1, but it remains an essential target for immunotherapies and vaccine candidates.

Other names

GII.4 VP1Major capsid protein VP1 (GII.4)Norovirus GII.4 virus-like particle (VLP) capsidHuman norovirus capsid protein (GII.4)

Neutralizing antibody binding inhibits virus attachment and infection (structural antigenic sites exposed/occluded depending on capsid conformation). Vaccine-induced immune response generates protective antibodies.