As part of our continuing efforts to study the molecular events involved in HIV recognition of mucosal membrane cells, we are studying the interactions of the HIV-associated glycoprotein gp120, with the cellular receptor GalCer. In this work, we report investigations of multivalent interactions of Au glyconanoparticles containing galactosyl and glucosyl headgroups with recombinant gp120. These particles were prepared from disulfides containing C-glycosides linked to triethylene glycol via an amide bond using a modification of the Brust method.1 Results from transmission electron microscopy, atomic force microscopy, and UV-vis absorption spectroscopy data are consistent with an average particle diameter of 2 nm. Elemental analyses indicate that the average composition of the particles is 1.6:1 Au:carbohydrate. A biotin-NeutrAvidin adhesion assay was used to evaluate the relative ability of carbohydrate disulfides and Au glyconanopraticles to displace rgp120 from plate-bound GalCer. The data indicate that divalent disulfides were less than 12% as active as biotinylated GalCer, a water-soluble surrogate of GalCer. However, when these same carbohydrates were presented in a polyvalent display on gold, they were greater than 300 times more active than the disulfides and at least 20 times more active than biotinylated GalCer. These results collectively demonstrate, the potential utility of polyvalent ligand arrays on nanoplatforms.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry