1rkk
From Proteopedia
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| - | [[Image:1rkk.gif|left|200px]] | + | [[Image:1rkk.gif|left|200px]] |
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| - | '''POLYPHEMUSIN I NMR SOLUTION STRUCTURE''' | + | {{Structure |
| + | |PDB= 1rkk |SIZE=350|CAPTION= <scene name='initialview01'>1rkk</scene> | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=NH2:AMINO GROUP'>NH2</scene> | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''POLYPHEMUSIN I NMR SOLUTION STRUCTURE''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1RKK is a [ | + | 1RKK is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RKK OCA]. |
==Reference== | ==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:[http:// | + | 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:[http://www.ncbi.nlm.nih.gov/pubmed/15134657 15134657] |
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Hancock, R E.W.]] | [[Category: Hancock, R E.W.]] | ||
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[[Category: polyphemusin]] | [[Category: polyphemusin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 13:52:52 2008'' |
Revision as of 11:52, 20 March 2008
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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
Page seeded by OCA on Thu Mar 20 13:52:52 2008
