HIV-1 envelope glycoprotein gp120 CD4 binding site (CD4bs)

The HIV-1 CD4 binding site is a highly conserved conformational epitope located on the surface of the HIV-1 envelope glycoprotein gp120[1][4][3]. It mediates the initial attachment of HIV-1 to the CD4 receptor found primarily on helper T lymphocytes, facilitating a cascade of structural rearrangements in the viral Env trimer that ultimately allow viral fusion and entry into host cells[1][4][2][9]. The structural integrity and exposure of the CD4 binding site are critical for virus infectivity but also present a major vulnerability, as neutralizing antibodies and entry inhibitors targeting this site can block HIV-1 infection[6][8]. Despite its conservation, the region is subject to immune evasion strategies by the virus, including conformational masking and glycan shielding, making it a challenging but essential focus for HIV-1 vaccine and therapeutic antibody development[3][8].

Other names

CD4bsHIV-1 gp120 CD4 binding siteHIV-1 CD4bsCD4 receptor binding siteHIV-1 Env CD4 binding site

Inhibition of HIV-1 binding to CD4 receptor, preventing viral entry into T cells\nNeutralization of virions by preventing conformational changes in Env required for fusion[5][6][8]\nSteric hindrance or direct competition at the CD4 binding epitope