Envelope glycoprotein gp120 (HIV-1 IIIB) (gp120)

Envelope glycoprotein gp120 is a heavily glycosylated, surface-exposed protein on the HIV-1 viral envelope that forms a trimeric complex with the transmembrane glycoprotein gp41, collectively termed Env. gp120 is essential for viral entry, mediating binding to the CD4 receptor on host T-cells, followed by interaction with a chemokine coreceptor (usually CCR5 or CXCR4), triggering conformational changes that enable the fusion of viral and cellular membranes. The protein is the primary target for broadly neutralizing antibodies and is central to immune evasion due to its glycan shield and sequence variability. gp120 is derived from proteolytic cleavage of gp160 and remains associated with gp41 via non-covalent bonds. The subtype "HIV-1 IIIB" refers to a well-characterized laboratory strain frequently used in structural and drug development studies.

Other names

HIV-1 gp120HIV envelope glycoproteinSU (surface unit)HIV-1 Env (with gp41)

Inhibition of CD4-gp120 binding; Prevention of conformational changes essential for membrane fusion; Neutralization of virus by steric hindrance or glycan locking