1uhg
From Proteopedia
(New page: 200px<br /><applet load="1uhg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1uhg, resolution 1.90Å" /> '''Crystal Structure of...) |
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| - | [[Image:1uhg.gif|left|200px]]<br /><applet load="1uhg" size=" | + | [[Image:1uhg.gif|left|200px]]<br /><applet load="1uhg" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1uhg, resolution 1.90Å" /> | caption="1uhg, resolution 1.90Å" /> | ||
'''Crystal Structure of S-Ovalbumin At 1.9 Angstrom Resolution'''<br /> | '''Crystal Structure of S-Ovalbumin At 1.9 Angstrom Resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Ovalbumin, a non-inhibitory member of serine proteinase inhibitors | + | Ovalbumin, a non-inhibitory member of serine proteinase inhibitors (serpin), is transformed into a heat-stabilized form, S-ovalbumin, under elevated pH conditions. The structural mechanism for the S-ovalbumin formation has long been a puzzling question in food science and serpin structural biology. On the basis of the commonly observed serpin thermostabilization by insertion of the reactive center loop into the proximal beta-sheet, the most widely accepted hypothetical model has included partial loop insertion. Here we demonstrate, for the first time, the crystal structure of S-ovalbumin at 1.9-A resolution. This structure unequivocally excludes the partial loop insertion mechanism; the overall structure, including the reactive center loop structure, is almost the same as that of native ovalbumin, except for the significant motion of the preceding loop of strand 1A away from strand 2A. The most striking finding is that Ser-164, Ser-236, and Ser-320 take the d-amino acid residue configuration. These chemical inversions can be directly related to the irreversible and stepwise nature of the transformation from native ovalbumin to S-ovalbumin. As conformational changes of the side chains, significant alternations are found in the values of the chi 1 of Phe-99 and the chi 3 of Met-241. The former conformational change leads to the decreased solvent accessibility of the hydrophobic core around Phe-99, which includes Phe-180 and Phe-378, the highly conserved residues in serpin. This may give a thermodynamic advantage to the structural stability of S-ovalbumin. |
==About this Structure== | ==About this Structure== | ||
| - | 1UHG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with NAG and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1UHG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=NAG:'>NAG</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UHG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: serpin]] | [[Category: serpin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:24:32 2008'' |
Revision as of 13:24, 21 February 2008
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Crystal Structure of S-Ovalbumin At 1.9 Angstrom Resolution
Overview
Ovalbumin, a non-inhibitory member of serine proteinase inhibitors (serpin), is transformed into a heat-stabilized form, S-ovalbumin, under elevated pH conditions. The structural mechanism for the S-ovalbumin formation has long been a puzzling question in food science and serpin structural biology. On the basis of the commonly observed serpin thermostabilization by insertion of the reactive center loop into the proximal beta-sheet, the most widely accepted hypothetical model has included partial loop insertion. Here we demonstrate, for the first time, the crystal structure of S-ovalbumin at 1.9-A resolution. This structure unequivocally excludes the partial loop insertion mechanism; the overall structure, including the reactive center loop structure, is almost the same as that of native ovalbumin, except for the significant motion of the preceding loop of strand 1A away from strand 2A. The most striking finding is that Ser-164, Ser-236, and Ser-320 take the d-amino acid residue configuration. These chemical inversions can be directly related to the irreversible and stepwise nature of the transformation from native ovalbumin to S-ovalbumin. As conformational changes of the side chains, significant alternations are found in the values of the chi 1 of Phe-99 and the chi 3 of Met-241. The former conformational change leads to the decreased solvent accessibility of the hydrophobic core around Phe-99, which includes Phe-180 and Phe-378, the highly conserved residues in serpin. This may give a thermodynamic advantage to the structural stability of S-ovalbumin.
About this Structure
1UHG is a Single protein structure of sequence from Gallus gallus with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of S-ovalbumin as a non-loop-inserted thermostabilized serpin form., Yamasaki M, Takahashi N, Hirose M, J Biol Chem. 2003 Sep 12;278(37):35524-30. Epub 2003 Jul 1. PMID:12840013
Page seeded by OCA on Thu Feb 21 15:24:32 2008
Categories: Gallus gallus | Single protein | Hirose, M. | Takahashi, N. | Yamasaki, M. | NAG | SO4 | Allergen | Egg white protein | Serpin
