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1rkk
From Proteopedia
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| - | [[ | + | ==POLYPHEMUSIN I NMR SOLUTION STRUCTURE== |
| + | <StructureSection load='1rkk' size='340' side='right' caption='[[1rkk]], [[NMR_Ensembles_of_Models | 17 NMR models]]' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[1rkk]] is a 1 chain structure. 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 [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1RKK FirstGlance]. <br> | ||
| + | </td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1rkk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rkk OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1rkk RCSB], [http://www.ebi.ac.uk/pdbsum/1rkk PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | 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> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | == References == | |
| - | + | <references/> | |
| - | == | + | __TOC__ |
| - | + | </StructureSection> | |
[[Category: Hancock, R E.W.]] | [[Category: Hancock, R E.W.]] | ||
[[Category: Powers, J P.S.]] | [[Category: Powers, J P.S.]] | ||
Revision as of 08:28, 8 October 2014
POLYPHEMUSIN I NMR SOLUTION STRUCTURE
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