Article Figures & Data
Figures
- Fig. 1.
Chemical structures of lemborexant, almorexant, and suvorexant.
- Fig. 2.
Predicted binding locations of lemborexant in the orthosteric sites of hOX1R and hOX2R. The OXR residues found to be important for association with lemborexant are shown. (A) and (C) Three-dimensional structures. Lemborexant carbon atoms are shown as orange; differing residues in the orthosteric site between both receptors, as well as the carbon atoms of directly interacting and water-bridged protein residues are shown as pink (A: hOX1R) and turquoise (C: hOX2R), and other carbon atoms are shown as gray. Nitrogen atoms are colored blue, oxygen atoms red, and fluorine atoms green. Two-dimensional interaction diagrams of lemborexant with hOX1R (B) and hOX2R (D). Hydrophobic residues are shown as green, and hydrophilic residues are shown as light blue.
Tables
- TABLE 1
IC50 and Ki values of lemborexant, almorexant, and suvorexant when competing against OXA on human, rat, and mouse OX1R and OX2R in RBA and a cell-based FDSS
Data represent the mean ± S.E.M.
RBA FDSS Ca2+ Imaging Assay EC50 Ki Lemborexant Almorexant Suvorexant OXA Lemborexant Almorexant Suvorexant IC50 in 10−9 mol/l 10−9 mol/l hOX1R 6.1 ± 1.4 8.6 ± 6.5 8.8 ± 2.5 1.32 ± 0.22 4.8 ± 1.4 7.0 ± 1.2 1.4 ± 0.2 hOX2R 2.6 ± 0.4 4.6 ± 1.6 12.0 ± 2.8 0.89 ± 0.14 0.61 ± 0.10 2.6 ± 0.3 2.2 ± 0.3 rOX1R N.D. N.D. N.D. 0.39 ± 0.11 7.7 ± 1.8 8.6 ± 2.3 1.8 ± 0.3 rOX2R N.D. N.D. N.D. 0.50 ± 0.20 0.66 ± 0.13 3.6 ± 1.0 2.5 ± 0.5 mOX1R N.D. N.D. N.D. 0.92 ± 0.11 8.3 ± 2.5 10.2 ± 2.2 1.6 ± 0.3 mOX2R N.D. N.D. N.D. 1.04 ± 0.10 0.64 ± 0.15 2.9 ± 0.6 2.2 ± 0.4 mOX1R, mouse OX1R; N.D., not determined; rOX1R, rat OX1R; rOX2R, rat OX2R.
- TABLE 2
Ki values and Schild slope values of lemborexant when competing against three orexin peptide agonists on human and mouse OX1R and OX2R in a cell-based functional reporter assay
Data represent the mean ± S.E.M.
hOX1R mOX1R hOX2R mOX2R Ki (10−9 mol/l) OXA 14.1 ± 3.1 16.3 ± 4.0 0.39 ± 0.08 0.37 ± 0.07 OXB N.D. N.D. 0.58 ± 0.13 0.28 ± 0.08 [Ala11,D-Leu15]-OXB N.D. N.D. 0.42 ± 0.05 0.49 ± 0.05 Schild Slope OXA 1.08 ± 0.05 0.95 ± 0.05 1.00 ± 0.02 1.00 ± 0.03 OXB N.D. N.D. 0.93 ± 0.02 0.99 ± 0.03 [Ala11,D-Leu15]-OXB N.D. N.D. 1.01 ± 0.01 1.03 ± 0.02 mOX1R, mouse OX1R; N.D., not determined.
- TABLE 3
Binding and dissociation kinetic parameters of radiolabeled tracers ([125I]OXA and [3H]EMPA) and nonlabeled test compounds (lemborexant, almorexant, and suvorexant) on human OXRs
Data represent the mean ± S.E.M.
hOX1R hOX2R [125I]OXA Lemborexant [3H]EMPA Lemborexant Almorexant Suvorexant kona (l · nmol−1 · min−1) 0.0378 ± 0.0106 0.0262 ± 0.0028 0.0363 ± 0.0008 0.0496 ± 0.0010 0.0350 ± 0.0014 0.0052 ± 0.0002 koffa (min−1) 0.0423 ± 0.0016 0.2444 ± 0.0229 0.0578 ± 0.0014 0.0626 ± 0.0014 0.0022 ± 0.0003 0.0164 ± 0.0011 Dissociation half-life (min) 16.4 ± 1.0 2.8 ± 0.4 12.0 ± 0.5 11.1 ± 0.4 309 ± 55 42.2 ± 3.1 koff, dissociation rate constant.
↵a Harmonic mean.
- TABLE 4
Computational simulation results: Binding free energy and its components by prime MM-GBSA calculation
All energy values are in kcal/mol and median score from trajectory of MD simulation.
Receptor ΔGbind ΔGCoul ΔGH-bond ΔGCov ΔGvdW ΔGLipo ΔGPacking ΔGSolv GB hOX1R −55.100 −11.715 −0.626 0.215 −43.335 −19.237 −3.002 23.774 hOX2R −58.173 −12.254 −0.577 0.372 −44.357 −21.723 −2.892 22.676 ΔGbind, lemborexant receptor binding free energies; ΔGCoul, the Coulomb binding free energy; ΔGCov, the covalent binding free energy; ΔGH-bond, the hydrogen bonding free energy; ΔGLipo, the lipophilic binding free energy; ΔGPacking, the π-π packing free energy; ΔGSolv GB, the generalized Born solvation binding free energy; ΔGvdW, the van der Waals binding free energy.
Data Supplement
- Supplemental Data -
Supplemental table and figures.
- PDB file 1
- PDB file 2
- Supplemental Data -
