1rkk
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| - | [[Image:1rkk.gif|left|200px]] | ||
| - | + | ==POLYPHEMUSIN I NMR SOLUTION STRUCTURE== | |
| - | + | <StructureSection load='1rkk' size='340' side='right'caption='[[1rkk]]' scene=''> | |
| - | | | + | == Structural highlights == |
| - | | | + | <table><tr><td colspan='2'>[[1rkk]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RKK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RKK 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='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></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=1rkk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rkk OCA], [https://pdbe.org/1rkk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1rkk RCSB], [https://www.ebi.ac.uk/pdbsum/1rkk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1rkk ProSAT]</span></td></tr> | |
| - | + | </table> | |
| - | + | == Function == | |
| - | + | [https://www.uniprot.org/uniprot/PPM1_LIMPO PPM1_LIMPO] Significantly inhibits the growth of Gram-negative and Gram-positive bacteria. | |
| - | + | <div style="background-color:#fffaf0;"> | |
| - | + | == Publication Abstract from PubMed == | |
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The solution structure of polyphemusin I was determined using (1)H-NMR spectroscopy. Polyphemusin I was found to be an amphipathic, beta-hairpin connected by a type I' beta-turn. The 17 low-energy structures aligned very well over the beta-sheet region while both termini were poorly defined due in part to a hinge-like region centred in the molecule about arginine residues 6 and 16. Conversely, a linear analogue, PM1-S, with all cysteines simultaneously replaced with serine was found to be dynamic in nature, and a lack of medium and long-range NOEs indicated that this molecule displayed no favoured conformation. Circular dichroism (CD) spectroscopy confirmed that in solution, 50% trifluoroethanol (TFE) and in the presence of liposomes, PM1-S remained unstructured. The antimicrobial activity of PM1-S was found to be 4- to 16-fold less than that of polyphemusin I and corresponded with a 4-fold reduction in bacterial membrane depolarization. Both peptides were able to associate with lipid bilayers in a similar fashion; however, PM1-S was completely unable to translocate model membranes while polyphemusin I retained this activity. It was concluded that the disulfide-constrained, beta-sheet structure of polyphemusin I is required for maximum antimicrobial activity. Disruption of this structure results in reduced antimicrobial activity and completely abolishes membrane translocation indicating that the linear PM1-S acts through a different antimicrobial mechanism. | The solution structure of polyphemusin I was determined using (1)H-NMR spectroscopy. Polyphemusin I was found to be an amphipathic, beta-hairpin connected by a type I' beta-turn. The 17 low-energy structures aligned very well over the beta-sheet region while both termini were poorly defined due in part to a hinge-like region centred in the molecule about arginine residues 6 and 16. Conversely, a linear analogue, PM1-S, with all cysteines simultaneously replaced with serine was found to be dynamic in nature, and a lack of medium and long-range NOEs indicated that this molecule displayed no favoured conformation. Circular dichroism (CD) spectroscopy confirmed that in solution, 50% trifluoroethanol (TFE) and in the presence of liposomes, PM1-S remained unstructured. The antimicrobial activity of PM1-S was found to be 4- to 16-fold less than that of polyphemusin I and corresponded with a 4-fold reduction in bacterial membrane depolarization. Both peptides were able to associate with lipid bilayers in a similar fashion; however, PM1-S was completely unable to translocate model membranes while polyphemusin I retained this activity. It was concluded that the disulfide-constrained, beta-sheet structure of polyphemusin I is required for maximum antimicrobial activity. Disruption of this structure results in reduced antimicrobial activity and completely abolishes membrane translocation indicating that the linear PM1-S acts through a different antimicrobial mechanism. | ||
| - | + | Structure-activity relationships for the beta-hairpin cationic antimicrobial peptide polyphemusin I.,Powers JP, Rozek A, Hancock RE Biochim Biophys Acta. 2004 May 6;1698(2):239-50. PMID:15134657<ref>PMID:15134657</ref> | |
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| - | Structure-activity relationships for the beta-hairpin cationic antimicrobial peptide polyphemusin I., Powers JP, Rozek A, Hancock RE | + | |
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| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| + | </div> | ||
| + | <div class="pdbe-citations 1rkk" style="background-color:#fffaf0;"></div> | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
| + | [[Category: Large Structures]] | ||
| + | [[Category: Synthetic construct]] | ||
| + | [[Category: Hancock REW]] | ||
| + | [[Category: Powers JPS]] | ||
| + | [[Category: Rozek A]] | ||
Current revision
POLYPHEMUSIN I NMR SOLUTION STRUCTURE
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