Ebola virus glycoprotein (GP) glycan cap (EBOV GP glycan cap)

The Ebola virus glycoprotein (GP) is the sole protein expressed on the surface of the Ebola virus virion and is essential for viral attachment, fusion, and entry into host cells (Misasi et al., 2016). It is a trimeric class I fusion protein composed of GP1 and GP2 subunits, where GP1 mediates cell surface attachment and GP2 facilitates membrane fusion (Bornholdt et al., 2016). A critical structural feature of the GP1 subunit is the glycan cap, a heavily glycosylated region that physically shields the conserved receptor-binding site (RBS) from the host immune system (Zhao et al., 2016). This glycan shield prevents the virus from being neutralized by antibodies and also prevents premature binding to the endosomal receptor Niemann-Pick C1 (NPC1) until the virus has reached the appropriate intracellular compartment (Misasi et al., 2016). Within the host endosome, the glycan cap must be proteolytically cleaved by cathepsins B and L to expose the RBS, allowing for viral-host membrane fusion (Bornholdt et al., 2016). Therapeutic monoclonal antibodies, such as Maftivimab (a component of the Inmazeb cocktail), specifically target epitopes within the glycan cap to neutralize the virus by blocking its initial attachment or by hindering the necessary proteolytic processing (FDA, 2020).

Other names

GP1 glycan capEbola virus surface glycoprotein glycan capEBOV GP1 subunit glycan capGlycan cap epitope

Neutralization of viral entry by blocking attachment to host cell surfaces or interfering with the proteolytic processing of the glycoprotein within the endosome (Misasi et al., 2016; FDA, 2020).