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| | ==PV5 nmr solution structure== | | ==PV5 nmr solution structure== |
| - | <StructureSection load='1x7k' size='340' side='right'caption='[[1x7k]], [[NMR_Ensembles_of_Models | 16 NMR models]]' scene=''> | + | <StructureSection load='1x7k' size='340' side='right'caption='[[1x7k]]' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1x7k]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1X7K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1X7K FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1x7k]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1X7K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1X7K FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1rkk|1rkk]]</div></td></tr> | + | </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=1x7k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1x7k OCA], [https://pdbe.org/1x7k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1x7k RCSB], [https://www.ebi.ac.uk/pdbsum/1x7k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1x7k ProSAT]</span></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=1x7k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1x7k OCA], [https://pdbe.org/1x7k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1x7k RCSB], [https://www.ebi.ac.uk/pdbsum/1x7k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1x7k ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/PPM1_LIMPO PPM1_LIMPO]] Significantly inhibits the growth of Gram-negative and Gram-positive bacteria.
| + | [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;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Hancock, R E]] | + | [[Category: Limulus polyphemus]] |
| - | [[Category: Powers, J P]] | + | [[Category: Hancock RE]] |
| - | [[Category: Ramamoorthy, A]] | + | [[Category: Powers JP]] |
| - | [[Category: Tan, A]] | + | [[Category: Ramamoorthy A]] |
| - | [[Category: Antimicrobial peptide]] | + | [[Category: Tan A]] |
| - | [[Category: Antimicrobial protein]]
| + | |
| - | [[Category: Beta hairpin]]
| + | |
| - | [[Category: Disulfide bridge]]
| + | |
| - | [[Category: Polyphemusin variant]]
| + | |
| - | [[Category: Pv5]]
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| Structural highlights
Function
PPM1_LIMPO Significantly inhibits the growth of Gram-negative and Gram-positive bacteria.
Publication Abstract from PubMed
The horseshoe crab cationic antimicrobial peptide polyphemusin I is highly active in vitro but not protective in mouse models of bacterial and LPS challenge, while a synthetic polyphemusin variant, PV5, was previously shown to be protective in vivo. In this study, we investigated the interaction of these peptides with lipid membranes in an effort to propose a mechanism of interaction. The solution structure of PV5 was determined by proton NMR in the absence and presence of dodecylphosphocholine (DPC) micelles. Like polyphemusin I, PV5 is a beta-hairpin but appeared less amphipathic in solution. Upon association with DPC micelles, PV5 underwent side chain rearrangements which resulted in an increased amphipathic conformation. Using fluorescence spectroscopy, both peptides were found to have limited affinity for neutral vesicles composed of phosphatidylcholine (PC). Incorporation of 25 mol % cholesterol or phosphatidylethanolamine into PC vesicles produced little change in the partitioning of either peptide. Incorporation of 25 mol % phosphatidylglycerol (PG) into PC vesicles, a simple prokaryotic model, resulted in a large increase in the affinity for both peptides, but the partition coefficient for PV5 was almost twice that of polyphemusin I. Differential scanning calorimetry studies supported the partitioning data and demonstrated that neither peptide interacted readily with neutral PC vesicles. Both peptides showed affinity for negatively charged membranes incorporating PG. The affinity of PV5 was much greater as the pretransition peak was absent at low peptide to lipid ratios (1:400) and the reduction in enthalpy of the main transition was greater than that produced by polyphemusin I. Both peptides decreased the lamellar to inverted hexagonal phase transition temperature of PE indicating the induction of negative curvature strain. These results, combined with previous findings that polyphemusin I promotes lipid flip-flop but does not induce significant vesicle leakage, ruled out the torroidal pore and carpet mechanisms of antimicrobial action for these polyphemusins.
Solution structure and interaction of the antimicrobial polyphemusins with lipid membranes.,Powers JP, Tan A, Ramamoorthy A, Hancock RE Biochemistry. 2005 Nov 29;44(47):15504-13. PMID:16300399[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Powers JP, Tan A, Ramamoorthy A, Hancock RE. Solution structure and interaction of the antimicrobial polyphemusins with lipid membranes. Biochemistry. 2005 Nov 29;44(47):15504-13. PMID:16300399 doi:10.1021/bi051302m
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