Ebola Virus GP2

GP2 is the transmembrane fusion subunit of Ebola virus glycoprotein, a class I fusion machine that merges the viral envelope with the late-endosomal membrane. Its ectodomain contains the internal fusion loop, two heptad-repeat regions HR1 and HR2 that refold into a six-helix bundle to pull the membranes together, the membrane-proximal external region, the transmembrane domain, and a cytoplasmic tail. Fusion is triggered only after endosomal cathepsins process the associated GP1 subunit and GP1 binds the intracellular receptor NPC1, restricting productive entry to the endolysosomal compartment. GP2 is far more conserved than GP1 and hosts epitopes of broadly protective antibodies such as ansuvimab, as well as targets of fusion-inhibitory peptides, making recombinant GP2 valuable for pan-ebolavirus antibody screening and entry-inhibition studies.