1rkk
From Proteopedia
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|PDB= 1rkk |SIZE=350|CAPTION= <scene name='initialview01'>1rkk</scene> | |PDB= 1rkk |SIZE=350|CAPTION= <scene name='initialview01'>1rkk</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=NH2:AMINO GROUP'>NH2</scene> | + | |LIGAND= <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<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.ebi.ac.uk/pdbsum/1rkk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1rkk RCSB]</span> | ||
}} | }} | ||
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[[Category: Powers, J P.S.]] | [[Category: Powers, J P.S.]] | ||
[[Category: Rozek, A.]] | [[Category: Rozek, A.]] | ||
| - | [[Category: NH2]] | ||
[[Category: anti-microbial peptide]] | [[Category: anti-microbial peptide]] | ||
[[Category: beta hairpin]] | [[Category: beta hairpin]] | ||
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[[Category: polyphemusin]] | [[Category: polyphemusin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:29:27 2008'' |
Revision as of 20:29, 30 March 2008
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| Ligands: | |||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
POLYPHEMUSIN I NMR SOLUTION STRUCTURE
Overview
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.
About this Structure
1RKK is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
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
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