Human immunodeficiency virus 1 envelope glycoprotein complex (HIV-1 Env)

The HIV-1 envelope glycoprotein complex (Env) is a trimeric assembly of heterodimers, each composed of an exterior subunit (gp120) and a transmembrane subunit (gp41), initially produced as a single precursor polypeptide (gp160) that is cleaved by host-cell proteases[1][2][3][6]. Env mediates viral attachment and entry by binding the host cell receptor CD4 and a chemokine co-receptor (either CCR5 or CXCR4), which triggers conformational changes necessary for fusion of the viral and host membranes[1][3][6][9]. Env is the sole virus-specific surface antigen accessible to neutralizing antibodies and thus is a principal target for vaccines and entry inhibitors; it has evolved a high degree of sequence variability and dense glycosylation ("glycan shield") to evade immune recognition[3][6][7][9]. Structural studies have revealed the oligomeric, metastable nature of the functional Env spike, its complex rearrangements upon ligand binding, and the challenge of eliciting broadly neutralizing antibodies against conserved functional domains[6][7][9].

Other names

HIV-1 EnvHIV-1 envelope glycoproteingp160gp120-gp41 complexHIV-1 surface glycoproteinHIV-1 transmembrane glycoproteinHIV-1 glycoprotein 120 (gp120)HIV-1 glycoprotein 41 (gp41)

Prevention of viral entry/fusion by interfering with Env–receptor interactions (CD4 or chemokine receptor blockade); Inhibition of conformational changes required for membrane fusion (gp41 inhibition); Neutralization by antibody-mediated blockade of functional Env epitopes