Preservation of HIV-1 Gag Helical Bundle Symmetry by Bevirimat Is Central to Maturation Inhibition

The HIV-1 envelope glycoprotein transmembrane subunit, gp41, mediates the fusion of viral and target cell membranes. The 2 helical regions in the ectodomain of gp41, the N-helix and the C-helix, form a helical bundle complex that has been suggested as a fusion-active conformation. Previously, an enzyme-linked immunosorbent assay (ELISA) method had been established to measure the interaction of 2 helical regions of gp41. In this study, the ELISA method was modified to apply high-throughput screening (HTS) of an organic compound library. A few compounds had been identified to prevent the interaction between 2 helical regions of gp41, and they were further shown to inhibit the gp41-mediated viral infection. In addition, they specifically quenched the fluorescence of tryptophan in the N-helix region, indicating that these compounds bound to the N-helix rather than the C-helix of gp41. These results suggested that this assay method targeting gp41 could be used for HTS of HIV fusion inhibitors. ( Journal of Biomolecular Screening 2005:13-19)

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Cryo-EM Structures of HIV-1 trimer bound to CD4-mimetics M48U1 and BNM-III-170 adopt a CD4-bound open conformation

10.1101/2020.08.21.261974 ◽

2020 ◽

Author(s):

Claudia A. Jette ◽

Christopher O. Barnes ◽

Sharon M. Kirk ◽

Bruno Melillo ◽

Amos B. Smith ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Membrane Fusion ◽

Conformational Changes ◽

Structural Changes ◽

Target Cells ◽

Helical Bundle ◽

Open Conformation ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Human Immunodeficiency Virus 1

AbstractHuman Immunodeficiency Virus-1 (HIV-1), the causative agent of AIDS, impacts millions of people. Entry into target cells is mediated by the HIV-1 envelope (Env) glycoprotein interacting with host receptor CD4, which triggers conformational changes allowing binding to a coreceptor and subsequent membrane fusion. Small molecule or peptide CD4-mimetic drugs mimic CD4’s Phe43 interaction with Env by inserting into the conserved Phe43 pocket on Env subunit gp120. Here, we present single-particle cryo-EM structures of CD4-mimetics BNM-III-170 and M48U1 bound to a BG505 native-like Env trimer plus the CD4-induced antibody 17b at 3.7Å and 3.9Å resolution, respectively. CD4-mimetic-bound BG505 exhibits canonical CD4-induced conformational changes including trimer opening, formation of the 4-stranded gp120 bridging sheet, displacement of the V1V2 loop, and formation of a compact and elongated gp41 HR1C helical bundle. We conclude that CD4-induced structural changes on both gp120 and gp41 Env subunits are induced by binding to the gp120 Phe43 pocket.

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Cryo-EM structures of HIV-1 trimer bound to CD4-mimetics BNM-III-170 and M48U1 adopt a CD4-bound open conformation

Nature Communications ◽

10.1038/s41467-021-21816-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Claudia A. Jette ◽

Christopher O. Barnes ◽

Sharon M. Kirk ◽

Bruno Melillo ◽

Amos B. Smith ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Membrane Fusion ◽

Conformational Changes ◽

Structural Changes ◽

Target Cells ◽

Helical Bundle ◽

Open Conformation ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Human Immunodeficiency Virus 1

AbstractHuman immunodeficiency virus-1 (HIV-1), the causative agent of AIDS, impacts millions of people. Entry into target cells is mediated by the HIV-1 envelope (Env) glycoprotein interacting with host receptor CD4, which triggers conformational changes allowing binding to a coreceptor and subsequent membrane fusion. Small molecule or peptide CD4-mimetic drugs mimic CD4’s Phe43 interaction with Env by inserting into the conserved Phe43 pocket on Env subunit gp120. Here, we present single-particle cryo-EM structures of CD4-mimetics BNM-III-170 and M48U1 bound to a BG505 native-like Env trimer plus the CD4-induced antibody 17b at 3.7 Å and 3.9 Å resolution, respectively. CD4-mimetic-bound BG505 exhibits canonical CD4-induced conformational changes including trimer opening, formation of the 4-stranded gp120 bridging sheet, displacement of the V1V2 loop, and formation of a compact and elongated gp41 HR1C helical bundle. We conclude that CD4-induced structural changes on both gp120 and gp41 Env subunits are induced by binding to the gp120 Phe43 pocket.

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Ultrastructural observations of human monocytes infected with HIV-1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084843 ◽

1991 ◽

Vol 49 ◽

pp. 108-109

Author(s):

James K. Koehler ◽

Steven G. Reed ◽

Joao S. Silva

Keyword(s):

Gradient Centrifugation ◽

Virus Production ◽

Human Monocyte ◽

Red Cross ◽

Human Monocytes ◽

Blood Monocytes ◽

Hiv Replication ◽

Electron Microscopic ◽

Ultrastructural Studies ◽

Hiv 1

As part of a larger study involving the co-infection of human monocyte cultures with HIV and protozoan parasites, electron microscopic observations were made on the course of HIV replication and infection in these cells. Although several ultrastructural studies of the cytopathology associated with HIV infection have appeared, few studies have shown the details of virus production in “normal,” human monocytes/macrophages, one of the natural targets of the virus, and suspected of being a locus of quiescent virus during its long latent period. In this report, we detail some of the interactions of developing virons with the membranes and organelles of the monocyte host.Peripheral blood monocytes were prepared from buffy coats (Portland Red Cross) by Percoll gradient centrifugation, followed by adherence to cover slips. 90-95% pure monocytes were cultured in RPMI with 5% non-activated human AB serum for four days and infected with 100 TCID50/ml of HIV-1 for four hours, washed and incubated in fresh medium for 14 days.

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