title: Monitoring binding of HIV-1 capsid assembly inhibitors using (19)F ligand-and (15)N protein-based NMR and X-ray crystallography: early hit validation of a benzodiazepine series.
abstract: The emergence of resistance to existing classes of antiretroviral drugs underlines the need to find novel human immunodeficiency virus (HIV)-1 targets for drug discovery. The viral capsid protein (CA) represents one such potential target. Recently, a series of benzodiazepine inhibitors was identified via high-throughput screening using an in vitro capsid assembly assay (CAA). Here, we demonstrate how a combination of NMR and X-ray co-crystallography allowed for the rapid characterization of the early hits from this inhibitor series. Ligand-based (19)F NMR was used to confirm inhibitor binding specificity and reversibility as well as to identify the N-terminal domain of the capsid (CA(NTD)) as its molecular target. Protein-based NMR ((1)H and (15)N chemical shift perturbation analysis) identified key residues within the CA(NTD) involved in inhibitor binding, while X-ray co-crystallography confirmed the inhibitor binding site and its binding mode. Based on these results, two conformationally restricted cyclic inhibitors were designed to further validate the possible binding modes. These studies were crucial to early hit confirmation and subsequent lead optimization.
authors: Dept. of Chemistry and Biological Sciences, Research & Development, Boehringer Ingelheim (Canada) Ltd, 2100 Cunard Street, Laval, Québec, H7S 2G5, Canada. nathalie.goudreau@boehringer-ingelheim.com
authors: Nathalie
authors: N
authors: Goudreau
authors: René
authors: R
authors: Coulombe
authors: Anne-Marie
authors: AM
authors: Faucher
authors: Chantal
authors: C
authors: Grand-Maître
authors: Jean-Eric
authors: JE
authors: Lacoste
authors: Christopher T
authors: CT
authors: Lemke
authors: Eric
authors: E
authors: Malenfant
authors: Yves
authors: Y
authors: Bousquet
authors: Lee
authors: L
authors: Fader
authors: Bruno
authors: B
authors: Simoneau
authors: Jean-François
authors: JF
authors: Mercier
authors: Steve
authors: S
authors: Titolo
authors: Stephen W
authors: SW
authors: Mason
mesh_terms: D001569:Benzodiazepines / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism*; D018360:Crystallography, X-Ray; D005461:Fluorine / Q000737:chemistry; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D009587:Nitrogen Isotopes / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D036022:Capsid Proteins; D008024:Ligands; D009587:Nitrogen Isotopes; D001569:Benzodiazepines; D005461:Fluorine