1n0a
From Proteopedia
(New page: 200px<br /><applet load="1n0a" size="450" color="white" frame="true" align="right" spinBox="true" caption="1n0a" /> '''Turn stability in beta-hairpin peptides: 3:5...) |
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'''Turn stability in beta-hairpin peptides: 3:5 type I G1 bulge turns'''<br /> | '''Turn stability in beta-hairpin peptides: 3:5 type I G1 bulge turns'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The turn-forming ability of a series of three-residue sequences was | + | The turn-forming ability of a series of three-residue sequences was investigated by substituting them into a well-characterized beta-hairpin peptide. The starting scaffold, bhpW, is a disulfide-cyclized 10-residue peptide that folds into a stable beta-hairpin with two antiparallel strands connected by a two-residue reverse turn. Substitution of the central two residues with the three-residue test sequences leads to less stable hairpins, as judged by thiol-disulfide equilibrium measurements. However, analysis of NMR parameters indicated that each molecule retains a significant folded population, and that the type of turn adopted by the three-residue sequence is the same in all cases. The solution structure of a selected peptide with a PDG turn contained an antiparallel beta-hairpin with a 3:5 type I + G1 bulge turn. Analysis of the energetic contributions of individual turn residues in the series of peptides indicates that substitution effects have significant context dependence, limiting the predictive power of individual amino acid propensities for turn formation. The most stable and least stable sequences were also substituted into a more stable disulfide-cyclized scaffold and a linear beta-hairpin scaffold. The relative stabilities remained the same, suggesting that experimental measurements in the bhpW context are a useful way to evaluate turn stability for use in protein design projects. Moreover, these scaffolds are capable of displaying a diverse set of turns, which can be exploited for the mimicry of protein loops or for generating libraries of reverse turns. |
==About this Structure== | ==About this Structure== | ||
| - | 1N0A is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with ACE and NH2 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1N0A is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=ACE:'>ACE</scene> and <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N0A OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Blandl, T.]] | [[Category: Blandl, T.]] | ||
| - | [[Category: Cochran, A | + | [[Category: Cochran, A G.]] |
| - | [[Category: Skelton, N | + | [[Category: Skelton, N J.]] |
[[Category: ACE]] | [[Category: ACE]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
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[[Category: beta-turn]] | [[Category: beta-turn]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:00:54 2008'' |
Revision as of 12:01, 21 February 2008
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Turn stability in beta-hairpin peptides: 3:5 type I G1 bulge turns
Overview
The turn-forming ability of a series of three-residue sequences was investigated by substituting them into a well-characterized beta-hairpin peptide. The starting scaffold, bhpW, is a disulfide-cyclized 10-residue peptide that folds into a stable beta-hairpin with two antiparallel strands connected by a two-residue reverse turn. Substitution of the central two residues with the three-residue test sequences leads to less stable hairpins, as judged by thiol-disulfide equilibrium measurements. However, analysis of NMR parameters indicated that each molecule retains a significant folded population, and that the type of turn adopted by the three-residue sequence is the same in all cases. The solution structure of a selected peptide with a PDG turn contained an antiparallel beta-hairpin with a 3:5 type I + G1 bulge turn. Analysis of the energetic contributions of individual turn residues in the series of peptides indicates that substitution effects have significant context dependence, limiting the predictive power of individual amino acid propensities for turn formation. The most stable and least stable sequences were also substituted into a more stable disulfide-cyclized scaffold and a linear beta-hairpin scaffold. The relative stabilities remained the same, suggesting that experimental measurements in the bhpW context are a useful way to evaluate turn stability for use in protein design projects. Moreover, these scaffolds are capable of displaying a diverse set of turns, which can be exploited for the mimicry of protein loops or for generating libraries of reverse turns.
About this Structure
1N0A is a Protein complex structure of sequences from [1] with and as ligands. Full crystallographic information is available from OCA.
Reference
Turn stability in beta-hairpin peptides: Investigation of peptides containing 3:5 type I G1 bulge turns., Blandl T, Cochran AG, Skelton NJ, Protein Sci. 2003 Feb;12(2):237-47. PMID:12538887
Page seeded by OCA on Thu Feb 21 14:00:54 2008
Categories: Protein complex | Blandl, T. | Cochran, A G. | Skelton, N J. | ACE | NH2 | Beta hairpin | Beta-bulge | Beta-turn
