Myoglobin: Difference between revisions
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{{STRUCTURE_1a6m| PDB=1a6m | SIZE=400| SCENE='Myoglobin/Myoglobin/2 right'|CAPTION=Sperm whale myoglobin complex with O2 and sulfate, [[1a6m]] }} | {{STRUCTURE_1a6m| PDB=1a6m | SIZE=400| SCENE='Myoglobin/Myoglobin/2 right'|CAPTION=Sperm whale myoglobin complex with O2 and sulfate, [[1a6m]] }} | ||
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View2 is a closeup of the heme from the same direction as View1. Turn on the "HemeLigand" button to display, in cyan, the sidechain of His 93, the proximal His, liganding the heme's Fe(II) ion (white bond). The Fe(II) is also liganded in a square-planar array by the heme's four pyrrole N atoms and hence has a total of 5 pyramidally arranged ligands. In oxyMb, the reversibly bound O2 molecule ligands the Fe from the opposite side of the heme as does the proximal His so that the Fe(II) becomes octahedrally coordinated. The Fe atom is not oxidized by its O2 ligand; it remains in the Fe(II) oxidation state. | View2 is a closeup of the heme from the same direction as View1. Turn on the "HemeLigand" button to display, in cyan, the sidechain of His 93, the proximal His, liganding the heme's Fe(II) ion (white bond). The Fe(II) is also liganded in a square-planar array by the heme's four pyrrole N atoms and hence has a total of 5 pyramidally arranged ligands. In oxyMb, the reversibly bound O2 molecule ligands the Fe from the opposite side of the heme as does the proximal His so that the Fe(II) becomes octahedrally coordinated. The Fe atom is not oxidized by its O2 ligand; it remains in the Fe(II) oxidation state. | ||
Rotate the image about the vertical axis until you see heme edge-on. Is the Heme planar? Note that the Fe atom is displaced towards the proximal His by 0.55 Å from the best plane though the porphyrin ring atoms. In oxyMb, the Fe is only 0.22 Å out of the heme plane and still on the side of the proximal His (for details see [[Oxymyoglobin]]). See also [[Molecular Playground/Myoglobin]]. | Rotate the image about the vertical axis until you see heme edge-on. Is the Heme planar? Note that the Fe atom is displaced towards the proximal His by 0.55 Å from the best plane though the porphyrin ring atoms. In oxyMb, the Fe is only 0.22 Å out of the heme plane and still on the side of the proximal His (for details see [[Oxymyoglobin]]). See also [[Molecular Playground/Myoglobin]]. | ||
Exercise in large part by John H. Connor (present address: Department of Microbiology, Boston University School of Medicine, 850 Harrison Ave, Boston, MA, 02118, USA) | Exercise in large part by John H. Connor (present address: Department of Microbiology, Boston University School of Medicine, 850 Harrison Ave, Boston, MA, 02118, USA) | ||
== 3D Structures of Myoglobin == | == 3D Structures of Myoglobin == | ||
