HIV type 1 envelope glycoprotein gp41 (gp41)

HIV type 1 envelope glycoprotein gp41 is a transmembrane subunit of the viral envelope glycoprotein complex, forming a trimer with gp120 on the HIV virion surface[1][4]. Gp41 is synthesized as part of a gp160 precursor (encoded by the env gene), which is cleaved into gp120 and gp41 by host proteases; these subunits then associate non-covalently[1]. Gp41 is essential for HIV infection, catalyzing the fusion of viral and host cell membranes following receptor (CD4) and co-receptor (CCR5 or CXCR4) engagement by the gp120 subunit[1][2]. Upon activation, gp41 undergoes dramatic conformational changes, refolding into a six-helix bundle that drives membrane fusion and viral entry[1][2][4]. Its ectodomain includes several functional regions: the fusion peptide, heptad repeats (NHR and CHR), a central loop, and the membrane proximal external region (MPER), many of which are targets of potent neutralizing antibodies[1][2]. Gp41 is less glycosylated and more conserved than gp120, making it an attractive target for vaccine and antiviral drug development[1][6]. Therapeutic agents such as enfuvirtide target gp41-mediated fusion, and broadly neutralizing antibodies may also recognize epitopes in gp41 (especially in the MPER region)[2][4]. Presence of antibodies against gp41 is used for HIV diagnostic testing in clinical practice[1].

Other names

Glycoprotein 41HIV-1 gp41Envelope protein gp41HIV Env gp41

Inhibition of membrane fusion by binding to gp41 and preventing formation of the six-helix bundle, thus blocking viral entry; Antibody-mediated neutralization by stabilization of specific gp41 conformations, especially targeting the MPER (membrane proximal external region)