1coh: Difference between revisions

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[[Image:1coh.gif|left|200px]]<br />

[[Image:1coh.gif|left|200px]]<br /><applet load="1coh" size="350" color="white" frame="true" align="right" spinBox="true"

<applet load="1coh" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

caption="1coh, resolution 2.9Å" />

'''STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS'''<br />

==Overview==

We report the X-ray crystal structure of two analogues of human, haemoglobin in the deoxy quaternary (T) state with ligand bound, exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II), beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and, alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by, difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is, analysed. In both the native deoxy and liganded T molecules, the mean, plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the, oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically, restrict haem tilting in the T state. We propose that strain energy, develops at the contact between the haem and these residues in the, liganded T-state haemoglobin, and that the strain is, in part, responsible, for the low affinity of the T-state alpha haem.

We report the X-ray crystal structure of two analogues of human haemoglobin in the deoxy quaternary (T) state with ligand bound exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II) beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is analysed. In both the native deoxy and liganded T molecules, the mean plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically restrict haem tilting in the T state. We propose that strain energy develops at the contact between the haem and these residues in the liganded T-state haemoglobin, and that the strain is, in part, responsible for the low affinity of the T-state alpha haem.

==Disease==

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==About this Structure==

1COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with HEM, CMO and COH as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1COH OCA].

1COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=CMO:'>CMO</scene> and <scene name='pdbligand=COH:'>COH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1COH OCA].

==Reference==

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[[Category: oxygen transport]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Mon Nov~~ 12 16:24:~~14 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:08:04 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1coh.gif|left|200px]]<br />
+[[Image:1coh.gif|left|200px]]<br /><applet load="1coh" size="350" color="white" frame="true" align="right" spinBox="true"
-<applet load="1coh" size="450" color="white" frame="true" align="right" spinBox="true"
 caption="1coh, resolution 2.9&Aring;" />
 '''STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS'''<br />
 ==Overview==
-We report the X-ray crystal structure of two analogues of human, haemoglobin in the deoxy quaternary (T) state with ligand bound, exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II), beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and, alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by, difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is, analysed. In both the native deoxy and liganded T molecules, the mean, plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the, oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically, restrict haem tilting in the T state. We propose that strain energy, develops at the contact between the haem and these residues in the, liganded T-state haemoglobin, and that the strain is, in part, responsible, for the low affinity of the T-state alpha haem.
+We report the X-ray crystal structure of two analogues of human haemoglobin in the deoxy quaternary (T) state with ligand bound exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II) beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is analysed. In both the native deoxy and liganded T molecules, the mean plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically restrict haem tilting in the T state. We propose that strain energy develops at the contact between the haem and these residues in the liganded T-state haemoglobin, and that the strain is, in part, responsible for the low affinity of the T-state alpha haem.
 ==Disease==
@@ Line 11: / Line 10: @@
 ==About this Structure==
-COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with HEM, CMO and COH as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1COH OCA].
+COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=CMO:'>CMO</scene> and <scene name='pdbligand=COH:'>COH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1COH OCA].
 ==Reference==
@@ Line 23: / Line 22: @@
 [[Category: oxygen transport]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 16:24:14 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:08:04 2008''