Envelope glycoprotein (EBOV GP) (EBOV GP)

The Ebola virus Zaire strain glycoprotein (GP) is the sole protein expressed on the surface of the Ebola virus virion and is essential for viral entry into host cells (UniProt P87666). It is synthesized as a precursor (GP0) that is cleaved by host furin into two subunits, GP1 and GP2, which remain disulfide-linked in a trimeric spike configuration. GP1 mediates initial attachment to host cell surface receptors and subsequent binding to the endosomal receptor Niemann-Pick C1 (NPC1), while GP2 facilitates the fusion of the viral envelope with the host endosomal membrane (Carette et al., 2011). Because of its critical role in the viral life cycle and its exposure on the virion surface, GP is the primary target for neutralizing antibodies and vaccine development. Therapeutic interventions, such as the monoclonal antibody cocktail Inmazeb (atoltivimab, maftivimab, and odesivimab) and the single monoclonal antibody Ebanga (ansuvimab-zykl), specifically target various epitopes on GP to prevent viral entry and promote clearance (FDA, 2020). Beyond its role in entry, GP also contributes to immune evasion through several mechanisms. The protein is heavily glycosylated, creating a "glycan shield" that masks conserved epitopes from antibody recognition (Cook and Lee, 2013). Furthermore, the expression of a secreted, soluble form of the glycoprotein (sGP) may act as a decoy, subverting the host's humoral immune response by absorbing neutralizing antibodies (Watanabe et al., 2000). Understanding these structural and functional complexities is vital for the design of next-generation therapeutics and vaccines aimed at providing broad protection against multiple ebolavirus species.

Other names

GPGP1,2GP1GP2sGPssGPSpike proteinEbola virus Zaire strain glycoprotein

Monoclonal antibodies target the Ebola virus glycoprotein (GP) to neutralize the virus. They work by binding to specific epitopes on the GP1 or GP2 subunits, which prevents the virus from attaching to host cells or binding to the essential endosomal receptor Niemann-Pick C1 (NPC1) (Carette et al., 2011). Additionally, some antibodies block the conformational changes in GP2 required for the fusion of the viral envelope with the host cell membrane, thereby halting the viral entry process (Corti et al., 2016). Some antibodies may also trigger Fc-mediated effector functions like antibody-dependent cellular cytotoxicity (ADCC) to clear infected cells.