Identification of novel TMEM16A blockers through integrated virtual screening, molecular dynamics, and experimental studies

Figures

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  Fig. 1. (A) Mechanism of TMEM16A channel gating, pore-blocker inhibition, and (B) the overview of this study is shown as schematic.

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  Fig. 2. (A) The 2-dimensional scatter plot displays the binding affinity (ΔG) of the 89,200 Chemdiv database compounds toward both forms of TMEM16A, 5OYB (X-axis) and 7ZK3 (Y-axis), from the molecular docking study. The green dash line represents the ΔG of the pore-blocker, 1PBC, against 7ZK3. The top 20 screened compounds are shown as red dots. (B) The binding poses of the top 20 screened compounds (stick) are illustrated and compared to 1PBC (sphere). The ion channel comprised α3, α4, α5, and α6 helices, shown in the cartoon structure (orange).

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  Fig. 3. (A) TMEM16A inhibitory activity of the top 20 compounds and Ani9 at 5 µM. (B) The effect of compounds on the TMEM16A channels measured as % Inhibition of Isc (µA/cm2)), and the IC50 values of N066-0059, N066-0060, and N066-0067 as potential compounds from this study.

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  Fig. 4. (A–D) Electrophysiological data of N066-0059 at concentrations of 0.1, 0.5, 1, and 5 µM.

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  Fig. 5. (A) The percentage of distribution for the atomic contacts between the ligand and the TMEM16A channel over 500 ns-trajectories is plotted as the density function. (B) The number of hydrogen bonds between the ligand and TMEM16A is shown as time-series plot over 500-ns across three independent simulation runs.

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  Fig. 6. (A) Per-residue decomposition free energy and energy components of TMEM16A residues contributing to the binding of N066-059 and 1PBC from three independent replicates. (B) Representative structures extracted from MD trajectories illustrating the key amino acids in a 3D structural perspective. Amino acids with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:\text{Δ}{\text{G}}_{\text{bind}}^{\text{residue}}$$\end{document} lower than − 1.0 kcal/mol are shown with the color of each residue indicating their respective \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:\text{Δ}{\text{G}}_{\text{bind}}^{\text{residue}}$$\end{document} values, according to the color spectrum provided.