Mu Opioid Receptor

Mu Opioid Receptor and Gi Protein Complex
(based on 6dde.pdb)
This model shows the receptor affiliated with the G protein complex. The receptor is in purple, the endorphin-like analog is in green, and the parts of the G protein complext in the following colors; alpha subunit - red, beta subunit -orange; gamma subunit yellow. The blue structure is a fragment that helps to crystallize the entire structure.
Here the polar(magenta) and hydrophobic(light yellow) regions of the receptor show the approximate likely position of the hydrophobic cell membrane. The G protein complex is intracellular while the receptor spans the membrane.
Focusing just on the receptor and the endorphin-like agonist. Top is extracellular.
Receptor rotated 90 degrees to show the extracellular binding pocket.
Here the receptor is shown in backbone style with the main sidechains responsible for binding the opiate in purple. It is this bonding that causes the conformational change in the receptor and initiates the G protein signaling.
Here's a cutaway showing the endogenous-like molecule, DAMGO, binding to the mu opioid receptor
Here the endorphin-like molecule, DAMGO(green), is isolated and enlarged.
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Mu Opioid Receptor with Morphine-like Agonist (based on 5C1m.pdb)
The structure of the activated mu opiod receptor(light blue)with the morphinan agonist Bu72 (red) attached to the nanobody (light green) aiding crystallization of the complex. The orange structures are also ancillaries used in the crystallization process.
Only the mu opioid receptor (in cpk colors) and the morphinan agonist Bu72 (blue) are shown
Here the polar(magenta) and nonpolar(light yellow)parts of the receptor are shown in relation to the morphinan agonist Bu72(blue)
The mu opiod receptor(light blue)is shown in backbone style with the important residues cyan relative to the morphinan agonist Bu72(blue)
Mu opioid receptor is portrayed in backbone with the key binding residues shown in two different colors. The polar ligand binding residues are colored in cpk.The yellow colors show the hydrophobic ligand binding residues. The two yellow green residues, both hydrophobic are two residues do not block the agonist from initiating a receptor response.
Here's another closeup showing the receptor binding to the morphine-like agonist.
The morphinan agonist Bu72 is isolated and enlarged here.
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Mu Opioid Receptor bound to a Morphinan Antagonist (based on 4dkl.pdb)
Mu opioid receptor (light blue) with morphinan antagonist, BF0, in purple.
Mu opiod receptor(light blue) is rotated to show the binding pocket with bound BF0(purple)
Mu Opiod receptor highlighting the polar (magenta) and hydrophobic (light yellow) regions.
Mu opioid receptor is portrayed in backbone with the key binding residues shown in light cyan. Notice the backbone really shows how the receptor has a different conformation in this inactive state.
Mu opioid receptor is portrayed in backbone with the key binding residues shown in two different colors. The polar ligand binding residues are colored in cpk.The yellow colors show the hydrophobic ligand binding residues. The two yellow green residues, both hydrophobic are two residues which presumably block the antagonist from initiating a receptor response.
A cutaway emphazing the bonding of the antagonist to the mu opioid receptor
The BF0 antagonist isolated and enlarged.
A rotated surface modeling of the mu opioid receptor with the antagonist enlarged to show the binding cavity. Keep in mind the cavity/ligand is extracellular and that much of the receptor is embedded in the cell membrane.
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