%0 Journal Article %A Malvoisin, Etienne %A Wild, Fabian %T Analysis of the human immunodeficiency virus type 1 envelope protein interaction with the CD4 host cell receptor %D 1994 %J Journal of General Virology, %V 75 %N 4 %P 839-847 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-75-4-839 %I Microbiology Society, %X A secreted form of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (gp160s), expressed in HeLa cells from a vaccinia virus recombinant was analysed by velocity-gradient centrifugation and chemical cross-linking. We showed that gp160s existed predominantly as a dimer, but higher forms corresponding to trimers and tetramers were also found. Soluble CD4 (sCD4) and native CD4 expressed by recombinant vaccinia viruses were analysed by sucrose- gradient sedimentation alone or after complexing with gp160s. The sCD4 sedimented in sucrose gradients as a monomer, whereas after solubilization the native CD4 was in a dimeric state. Both forms of CD4 were able to form complexes when incubated with gp160s. In the case of the sCD4, the M r corresponded to a (sCD4)2- (gp160s)2 complex, whereas with CD4 the complexes were of a greater order of magnitude. HIV gpl20 was secreted into the medium in a monomeric state. With sCD4 it gave a one-to-one complex, whereas with the native CD4 high M r complexes were formed. The importance of the oligomeric state of the virus- and cell-receptor proteins are discussed regarding their avidities. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-75-4-839