1dn3
From Proteopedia
(New page: 200px<br /> <applet load="1dn3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1dn3" /> '''NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIP...) |
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'''NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIPATHIC HELICAL BASIC PEPTIDE'''<br /> | '''NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIPATHIC HELICAL BASIC PEPTIDE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1DN3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1DN3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DN3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: hydrophilic amphipathic basic helix model]] | [[Category: hydrophilic amphipathic basic helix model]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 15:40:20 2008'' |
Revision as of 13:40, 15 February 2008
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NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIPATHIC HELICAL BASIC PEPTIDE
Overview
Sodium dodecyl sulfate (SDS) has consistently been shown to induce, secondary structure, particularly alpha-helices, in polypeptides, and is, commonly used to model membrane and other hydrophobic environments., However, the precise mechanism by which SDS induces these conformational, changes remains unclear. To examine the role of electrostatic interactions, in this mechanism, we have designed two hydrophilic, charged amphipathic, alpha-helical peptides, one basic (QAPAYKKAAKKLAES) and the other acidic, (QAPAYEEAAEELAKS), and their structures were studied by CD and NMR. The, design of the peptides is based on the sequence of the segment of residues, 56-70 of human platelet factor 4 [PF4(56-70), QAPLYKKIIKKLLES]. Both, peptides were unstructured in water, and in the presence of neutral, zwitterionic, or cationic detergents. However, in SDS at neutral pH, the, basic peptide folded into an alpha-helix. By contrast, the pH needed to be, lowered to 1.8 before alpha-helix formation was observed for the acidic, peptide. Strong, attractive electrostatic interactions, between the, anionic groups of SDS and the cationic groups of the lysines, appeared to, be necessary to initiate the folding of the basic peptide. NMR analysis, showed that the basic peptide was fully embedded in SDS-peptide micelles, and that its three-dimensional alpha-helical structure could be, superimposed on that of the native structure of PF4(56-70). These results, enabled us to propose a working model of the basic peptide-SDS complex, and a mechanism for SDS-induced alpha-helical folding. This study, demonstrates that, while the folding of peptides is mostly driven by, hydrophobic effects, electrostatic interactions play a significant role in, the formation and the stabilization of SDS-induced structure.
About this Structure
1DN3 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Involvement of electrostatic interactions in the mechanism of peptide folding induced by sodium dodecyl sulfate binding., Montserret R, McLeish MJ, Bockmann A, Geourjon C, Penin F, Biochemistry. 2000 Jul 25;39(29):8362-73. PMID:10913242
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