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| - | [[Image:1djf.jpg|left|200px]]<br /><applet load="1djf" size="450" color="white" frame="true" align="right" spinBox="true" | |
| - | caption="1djf" /> | |
| - | '''NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIPATHIC HELICAL BASIC PEPTIDE'''<br /> | |
| | | | |
| - | ==Overview== | + | ==NMR STRUCTURE OF A MODEL HYDROPHILIC AMPHIPATHIC HELICAL BASIC PEPTIDE== |
| - | 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. | + | <StructureSection load='1djf' size='340' side='right'caption='[[1djf]]' scene=''> |
| | + | == Structural highlights == |
| | + | <table><tr><td colspan='2'>[[1djf]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DJF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1DJF FirstGlance]. <br> |
| | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1djf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1djf OCA], [https://pdbe.org/1djf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1djf RCSB], [https://www.ebi.ac.uk/pdbsum/1djf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1djf ProSAT]</span></td></tr> |
| | + | </table> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | 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==
| + | 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<ref>PMID:10913242</ref> |
| - | 1DJF is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1DJF OCA].
| + | |
| | | | |
| - | ==Reference==
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | 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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10913242 10913242]
| + | </div> |
| - | [[Category: Protein complex]] | + | <div class="pdbe-citations 1djf" style="background-color:#fffaf0;"></div> |
| - | [[Category: Bockmann, A.]] | + | == References == |
| - | [[Category: Geourjon, C.]] | + | <references/> |
| - | [[Category: McLeish, M.J.]] | + | __TOC__ |
| - | [[Category: Montserret, R.]] | + | </StructureSection> |
| - | [[Category: Penin, F.]] | + | [[Category: Large Structures]] |
| - | [[Category: hydrophilic amphipathic basic helix peptide model]]
| + | [[Category: Bockmann A]] |
| - | | + | [[Category: Geourjon C]] |
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 03:12:07 2007''
| + | [[Category: McLeish MJ]] |
| | + | [[Category: Montserret R]] |
| | + | [[Category: Penin F]] |
| Structural highlights
Publication Abstract from PubMed
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.
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[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Montserret R, McLeish MJ, Bockmann A, Geourjon C, Penin F. Involvement of electrostatic interactions in the mechanism of peptide folding induced by sodium dodecyl sulfate binding. Biochemistry. 2000 Jul 25;39(29):8362-73. PMID:10913242
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