Envelope Glycoprotein 41 (gp41)

Envelope glycoprotein 41 (gp41) is a transmembrane subunit of the HIV-1 envelope glycoprotein complex, which plays a central role in viral entry into host cells. It mediates fusion between viral and cellular membranes—a crucial step for HIV entry. After initial attachment via gp120 to CD4 and coreceptor (CCR5 or CXCR4), conformational changes expose and activate gp41, which inserts its fusion peptide into the target cell membrane. Refolding brings viral and cellular membranes together, facilitating their merger and allowing delivery of viral genetic material into the host cell cytoplasm. Peptides mimicking its heptad repeats can inhibit infection by blocking six-helical bundle formation.

Inhibition of six-helix bundle formation, preventing membrane fusion