7pti
From Proteopedia
(New page: 200px<br /><applet load="7pti" size="450" color="white" frame="true" align="right" spinBox="true" caption="7pti, resolution 1.6Å" /> '''STRUCTURAL EFFECTS IN...) |
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| - | [[Image:7pti.gif|left|200px]]<br /><applet load="7pti" size=" | + | [[Image:7pti.gif|left|200px]]<br /><applet load="7pti" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="7pti, resolution 1.6Å" /> | caption="7pti, resolution 1.6Å" /> | ||
'''STRUCTURAL EFFECTS INDUCED BY REMOVAL OF A DISULFIDE BRIDGE. THE X-RAY STRUCTURE OF THE C30A(SLASH)C51A MUTANT OF BASIC PANCREATIC TRYPSIN INHIBITOR AT 1.6 ANGSTROMS'''<br /> | '''STRUCTURAL EFFECTS INDUCED BY REMOVAL OF A DISULFIDE BRIDGE. THE X-RAY STRUCTURE OF THE C30A(SLASH)C51A MUTANT OF BASIC PANCREATIC TRYPSIN INHIBITOR AT 1.6 ANGSTROMS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The X-ray structure of a variant of basic pancreatic trypsin inhibitor | + | The X-ray structure of a variant of basic pancreatic trypsin inhibitor (BPTI) has been analyzed to determine the structural accommodation resulting from removal of a disulfide cross-link in a protein. The disulfide removed, Cys30-Cys51, has been implicated in both the folding pathway of the protein and its overall thermal stability. In the variant studied, C30A/C51A, the disulfide cysteines were replaced by less bulky alanines. The atomic displacements observed for C30A/C51A indicate a set of concerted shifts of two segments of chains, which together significantly diminish a packing defect at the site of the removed cysteine sulfur atoms. The observed structural changes are distributed asymmetrically around the sites of mutation, indicating that the adjacent beta-sheet is more resistant to the perturbation than the alpha-helix on the opposite side of the disulfide bond. The thermal parameters of groups involved in the structural accommodation are not significantly altered. A comparison of the X-ray structures reported for native BPTI determined in three different crystal forms indicates that the magnitude of its conformational variability exceeds that of the structural changes caused by the disulfide removal. This emphasizes the necessity of using isomorphous crystal systems to determine the relatively small effects due to mutation. |
==About this Structure== | ==About this Structure== | ||
| - | 7PTI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with PO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 7PTI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7PTI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Eigenbrot, C.]] | [[Category: Eigenbrot, C.]] | ||
| - | [[Category: Kossiakoff, A | + | [[Category: Kossiakoff, A A.]] |
[[Category: Randal, M.]] | [[Category: Randal, M.]] | ||
[[Category: PO4]] | [[Category: PO4]] | ||
[[Category: proteinase inhibitor (trypsin)]] | [[Category: proteinase inhibitor (trypsin)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:17:34 2008'' |
Revision as of 17:17, 21 February 2008
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STRUCTURAL EFFECTS INDUCED BY REMOVAL OF A DISULFIDE BRIDGE. THE X-RAY STRUCTURE OF THE C30A(SLASH)C51A MUTANT OF BASIC PANCREATIC TRYPSIN INHIBITOR AT 1.6 ANGSTROMS
Overview
The X-ray structure of a variant of basic pancreatic trypsin inhibitor (BPTI) has been analyzed to determine the structural accommodation resulting from removal of a disulfide cross-link in a protein. The disulfide removed, Cys30-Cys51, has been implicated in both the folding pathway of the protein and its overall thermal stability. In the variant studied, C30A/C51A, the disulfide cysteines were replaced by less bulky alanines. The atomic displacements observed for C30A/C51A indicate a set of concerted shifts of two segments of chains, which together significantly diminish a packing defect at the site of the removed cysteine sulfur atoms. The observed structural changes are distributed asymmetrically around the sites of mutation, indicating that the adjacent beta-sheet is more resistant to the perturbation than the alpha-helix on the opposite side of the disulfide bond. The thermal parameters of groups involved in the structural accommodation are not significantly altered. A comparison of the X-ray structures reported for native BPTI determined in three different crystal forms indicates that the magnitude of its conformational variability exceeds that of the structural changes caused by the disulfide removal. This emphasizes the necessity of using isomorphous crystal systems to determine the relatively small effects due to mutation.
About this Structure
7PTI is a Single protein structure of sequence from Bos taurus with as ligand. Full crystallographic information is available from OCA.
Reference
Structural effects induced by removal of a disulfide-bridge: the X-ray structure of the C30A/C51A mutant of basic pancreatic trypsin inhibitor at 1.6 A., Eigenbrot C, Randal M, Kossiakoff AA, Protein Eng. 1990 Jul;3(7):591-8. PMID:1699222
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