کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2058328 | 1076220 | 2009 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The bis-histidyl complex in hemoproteins: A detailed conformational analysis of database protein structures and the case of Antarctic fish hemoglobins The bis-histidyl complex in hemoproteins: A detailed conformational analysis of database protein structures and the case of Antarctic fish hemoglobins](/preview/png/2058328.png)
The properties of hemoproteins strictly depend on the type and orientation of axial ligands. Here, the orientations of axially coordinated His in bis-His complexes and the heme geometry in protein data bank have been analyzed. The effect of the bis-histidyl formation on the heme cavity of Antarctic fish hemoglobins has been also evaluated. The results show that protein matrix exerts a major effect on the conformation of axially ligated histidines: the imidazoles in bis-His complexes occupy a preferred relative orientation in globins and in model systems, whereas they adopt a variety of relative orientations in other hemoproteins. The bis-histidyl adducts affect the heme geometry inducing larger distortions from planarity with respect to other ligands. These deviations are larger in bis-His multiheme cytochromes than in globins. In Antarctic fish hemoglobins the bis-histidyl adduct adopts preferentially a distorted coordination and the formation of the bis-His complex induces a slight but significant modification in the shape, area and volume of the heme cavity.
Journal: Marine Genomics - Volume 2, Issue 1, March 2009, Pages 51–56