Zaire ebolavirus envelope glycoprotein (GP)

The envelope glycoprotein (GP) of Zaire ebolavirus is the sole viral protein expressed on the surface of the virion. It is essential for virus entry into host cells, mediating both attachment to cellular receptors and fusion between viral and host membranes. The GP exists as a trimeric complex composed of two subunits: GP1 and GP2, which are generated by post-translational proteolytic cleavage of a single precursor polypeptide. GP1 functions primarily in receptor binding and contains a glycan cap and mucin-like domain that shield conserved regions from immune recognition. GP2 is responsible for membrane fusion. Upon activation, it undergoes conformational changes exposing its hydrophobic fusion loop, facilitating merger with host membranes. It also downregulates expression of several host cell adhesion molecules (integrins), contributing to vascular leakage seen in Ebola hemorrhagic fever; also modulates immune responses by interacting with TLR4.

Neutralizing antibodies block conformational changes required for membrane fusion.