1. Opioid Receptor Three-Dimensional Structures from Distance Geometry Calculations with Hydrogen Bonding Constraints 
Irina D. Pogozheva, Andrei L. Lomize, Henry I. Mosberg 
Biophysical Journal 
Volume 75, Issue 2, Pages (August 1998)
DOI: /S (98)
Copyright © 1998 The Biophysical Society Terms and Conditions

2. Figure 1
Sequence alignment of transmembrane helices (TMH I–TMH VII) and extracellular loops (EL-1, EL-2, EL-3) of human δ, μ, and κ receptors. Asterisks above the sequences for each helix indicate the 26-residue transmembrane segments, identified by Baldwin (1993) and used for identification of GPCR residues as the number of helix (Roman numerals):number of residue in the 26-residue fragment (Arabic numerals). For example, Asp128 in the δ-receptor sequence is denoted as III:7. Numbering of the μ receptor is that of the rat receptor for consistency with mutagenesis data.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

3. Figure 2 Structures of nonpeptide opioid ligands.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

4. Figure 3
Superposition of structures of DIANA-calculated δ (bold line), μ (thin line), and κ (dashed line) receptors (stereo view). The r.m.s.d. between 212Cα atoms of transmembrane helices of δ and μ, δ and κ, and μ and κ receptors are 0.74, 0.80, and 0.90Å, respectively.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

5. Figure 4
Cartoon representation of transmembrane helices and extracellular loops of δ-opioid receptors with JOM-13, side view and top view from the extracellular surface. Helical fragments are purple, loop fragments are white, the β-turn is orange, the disulfide bridge between helix III and EL-2 (residues Cys121–Cys198) is yellow, and JOM-13 is green.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

6. Figure 5
Proposed structure of the β-hairpin in EL-2 of the μ opioid receptor with proximal H-bonded polar residues from helices III and VII and from EL-3 and conserved disulfide bond between Cys140(III:0) and Cys217(EL-2). H-bonds are indicated by the dashed line.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

7. Figure 6
H-bond network of the μ opioid receptor (stereo view). Colors of residues depicted: green, Tyr, Trp; red, Asp, Glu; blue, His, Lys; yellow, Ser, Thr, Asn, Gln. The receptor is shown with morphine (purple) in the binding site. H-bonds are indicated by the dashed line.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

8. Figure 7
Comparison of the δ-opioid receptor model transmembrane α-bundle (blue) and the EM-based model of Baldwin et al. (Baldwin, 1997) (red) (stereo view).
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

9. Figure 8
JOM-13 (bold line) inside the binding pocket of the δ-opioid receptor (stereo view). Conserved (thin solid line) and variable (thin dashed line) residues of the binding pocket (within 4.5Å of the ligand) are also shown.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

10. Figure 9
Superposition of δ and μ receptor models with inserted JOM-13 (dark purple) and JH-42 (dark green), respectively (stereo view). Receptor residues that are within 4.5Å of the ligands and are different in δ and μ receptors are shown in light purple and light green, respectively. Lys214(233) is also shown, because it assumes different side-chain conformers in the δ and μ receptors. Numbering in the figure corresponds to the δ receptor.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

11. Figure 10
Two positions (solid and dashed lines) of (−)-morphine in the binding pocket of the μ-opioid receptor (stereo view). The ligand is denoted by the bold line, and receptor residues within 4.5Å of the ligand by the thin line.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

12. Figure 11
The δ-selective agonist BW373U86 (bold line) inside the binding pocket of the δ-opioid receptor (stereo view). Conserved (thin solid line) and variable (thin dashed line) residues of the binding pocket (within 4.5Å of the ligand) are also shown.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

13. Figure 12
Two conformations of cis-(+)-3-methylfentanyl (B, dashed line; C, solid line) in the μ-opioid receptor (stereo view). The ligand is denoted by the bold line, and receptor residues within 4.5Å of the ligand by the thin line.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions

14. Figure 13
The κ-selective alkaloid agonist U69,593 (bold) in the binding pocket of the κ-opioid receptor (stereo view). Conserved (thin solid line) and variable (thin dashed line) residues of the binding pocket within 4.5Å of the ligand are also shown.
Biophysical Journal  , DOI: ( /S (98) )
Copyright © 1998 The Biophysical Society Terms and Conditions