Inhibiting HIV-1 entry: Discovery of D-peptide inhibitors that target the gp41 coiled-coil pocket

The HIV-1 gp41 protein promotes viral entry by mediating the fusion of vira l and cellular membranes. A prominent pocket on the surface of a central tr imeric coiled coil within gp41 was previously identified as a potential tar get for drugs that inhibit HIV-1 entry. We designed a peptide, IQN17, which properly presents this pocket. Utilizing IQN17 and mirror-image phage disp lay, we identified cyclic, D-peptide inhibitors of HIV-1 infection that sha re a sequence motif. A1.5 Angstrom cocrystal structure of IQN17 in complex with a D-peptide, and NMR studies, show that conserved residues of these in hibitors make intimate contact with the gp41 pocket. Our studies validate t he pocket per se as a target for drug development. IQN17 and these D-peptid e inhibitors ave likely to be useful for development and identification of a new class of orally bioavailable anti-HIV drugs.