Mannosyl/N-acetyl-{beta}-D-glucosaminyl binding properties of the envelope glycoprotein of human immunodeficiency virus type 2

We have recently demonstrated that human immunodeficiency virus type 1 (HIV-1) recombinant envelope glycoprotein precursor gp160 (rgp160) behaves as a mannosyl/N</it>-acetylglucosaminyl (GlcNAc) binding protein. If such a carbohydrate-binding property were of biological relevance it should be shared by other related primate immunodeficiency viruses such as HIV-2. The present study confirms this hypothesis and extends these findings by showing that HIV-2 recombinant gp140 (rgp140) specifically interacts with three affinity matrices substituted by synthetic or natural carbohydrate structures: D-mannosedivinylsulphone-agarose, para-aminophenyl-β-D-GlcNAc-garose and the natural glycoprotein, bovine fetuin, also coupled to agarose. Binding of rgp140 to the matrices was inhibited by α-D-Man<inf>17</inf>-BSA (where BSA is bovine serum albumin), β-D-GlcNAc<inf>47</inf>-BSA and fetuin, and by glycopeptides derived from pronase-treated porcine thyroglobulin. Glycopeptides obtained after endoglycosidase H treatment of thyroglobulin had a limited inhibitory effect, whereas β-D-Gal<inf>17</inf>-BSA and β-D-glucan had no effect. These results indicate that, like HIV-1 envelope glycoprotein, HIV-2 rgp140 interacts with high-mannose and with the mannosyl core of complex-type N-linked glycans, as well as with the N</it>-acetylglucosaminyl core of oligosaccharidic structures.