title: Small molecules that bind the inner core of gp41 and inhibit HIV envelope-mediated fusion.
abstract: HIV-1 enters cells by membrane fusion, mediated by the trimeric viral envelope glycoprotein gp160, which is processed by a single proteolytic cleavage into stably associated gp120 and gp41. The gp120/gp41 trimer can be triggered to undergo an irreversible conformational change. Using a protein-based assay designed to mimic the gp41 conformational change, we screened for small molecules that prevent the formation of postfusion gp41. Several compounds were identified. One set of structurally related molecules inhibited formation of a postfusion-like assembly with an IC50 of approximately 5 microM. The compounds also inhibited envelope-mediated membrane fusion in both cell-cell fusion and viral infectivity assays. Thus, our screen identifies effective fusion inhibitors. Tested against a panel of envelope proteins from primary HIV-1 isolates, the compounds inhibited fusion across a broad range of clades, including both M and T tropic strains. They bind in a highly conserved, hydrophobic pocket on the inner core of the gp41 trimer, a region previously identified as a potential inhibitor site.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Frey
authors.forename: Sophia
authors.initials: S
authors.lastname: Rits-Volloch
authors.forename: X-Q
authors.initials: XQ
authors.lastname: Zhang
authors.forename: Robert T
authors.initials: RT
authors.lastname: Schooley
authors.forename: Bing
authors.initials: B
authors.lastname: Chen
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
mesh_terms: D000595:Amino Acid Sequence; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015658:HIV Infections / Q000517:prevention & control; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D008561:Membrane Fusion / Q000502:physiology*; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053586:Virus Internalization
chemical_list: D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D010455:Peptides; D011993:Recombinant Fusion Proteins