1gdl: Difference between revisions

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

Haemoglobins have the ability to discriminate between oxygen and other diatomic molecules. To further understanding of this process the X-ray crystal structures of carbonmonoxy and nitrosyl-leghaemoglobin have been determined at 1.8 A resolution. The ligand geometry is discussed in detail and the controversial issue of bent versus linear carbon monoxide binding is addressed. The bond angle of 160 degrees for CO-leghaemoglobin is in conflict with recent spectroscopy results on myoglobin but is consistent with angles obtained for myoglobin X-ray crystal structures. In contrast to the numerous carbon monoxide studies, very little stereochemical information is available for the nitric oxide adduct of haemoglobin. This is provided by the X-ray structure of NO-leghaemoglobin, which conforms to expected geometry with an Fe-NO angle of 147 degrees and a lengthened iron-proximal histidine bond. Thus crystallographic evidence is given for the predicted weakening of this bond on the binding of nitric oxide.

1GDL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Lupinus_luteus Lupinus luteus] with <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=NO:'>NO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GDL OCA].  

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