Characteristics of HIV-1 gp120 glycoprotein binding to glycolipids

We examined the binding of the gp120 envelope glycoprotein (gp120) of the human immunodeficiency virus (HIV-1) to sulfatide (GalS), galactocerebroside (GalC), and GM1-ganglioside (GM1). The gp120 glycoprotein bound to GalS but not to GalC or GM1 by enzyme-linked immunosorbent assay (ELISA) and by an immunospot assay on nitrocellulose paper. However, it bound to all three glycolipids by an immunospot assay on thin layer chromatography (TLC) plates. In studies to determine whether GalS could be a receptor for gp120 on the surface of cells, gp120 bound to GalS incorporated into the plasma membrane of lymphoid cells as determined by cytofluorometric analysis and immunofluorescence microscopy. These studies indicate that GalS may function as a receptor for gp120 and HIV-1.