Human immunodeficiency virus type 1 envelope glycoprotein (subtype C) (HIV-1 Env (subtype C))

The HIV-1 envelope (Env) glycoprotein is a trimeric complex composed of three gp120 surface subunits and three gp41 transmembrane subunits, derived from the gp160 precursor (NIH, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4775441/). It is the sole viral protein on the surface of the HIV-1 virion and is essential for viral entry into host cells (Wikipedia, https://en.wikipedia.org/wiki/HIV). Subtype C is the most prevalent HIV-1 clade globally, particularly in Southern Africa and India, and its Env protein exhibits unique characteristics such as a high frequency of CCR5 coreceptor usage and specific glycan patterns (NIH, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3814512/). The entry process involves gp120 binding to the host CD4 receptor, followed by a conformational change that allows binding to a coreceptor (CCR5 or CXCR4) and subsequent gp41-mediated membrane fusion (NIH, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4775441/). Because of its critical role in infection and its exposure to the immune system, Env is the primary target for neutralizing antibodies and various classes of entry inhibitors, including attachment inhibitors like fostemsavir and fusion inhibitors like enfuvirtide (NIH, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4451110/). However, the protein's extreme sequence diversity and dense glycan shield present significant challenges for vaccine development and long-term drug efficacy (NIH, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC40702326/).

Other names

gp160gp120/gp41 complexHIV-1 subtype C envelope proteinEnv proteingp120gp41HIV-1 Env glycoprotein – subtype C–derived sequences

Attachment inhibition (blocking gp120-CD4 interaction), fusion inhibition (blocking gp41-mediated membrane fusion), and viral neutralization (binding of antibodies to conserved epitopes to prevent entry).