2npv
From Proteopedia
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'''Structure and dynamics of surfactin studied by NMR in micellar media''' | '''Structure and dynamics of surfactin studied by NMR in micellar media''' | ||
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| + | ==Overview== | ||
| + | The NMR structure of the cyclic lipopeptide surfactin from Bacillus subtilis was determined in sodium dodecyl sulfate (SDS) micellar solution. The two negatively charged side chains of surfactin form a polar head opposite to most hydrophobic side chains, accounting for its amphiphilic nature and its strong surfactant properties. Disorder was observed around the fatty acid chain, and 15N relaxation studies were performed to investigate whether it originates from a dynamic phenomenon. A very large exchange contribution to transverse relaxation rate R(2) was effectively observed in this region, indicating slow conformational exchange. Temperature variation and Carr-Purcell-Meiboom-Gill (CPMG) delay variation relaxation studies provided an estimation of the apparent activation energy around 35-43 kJ x mol(-1) and an exchange rate of about 200 ms(-1) for this conformational exchange. 15N relaxation parameters were also recorded in dodecylphosphocholine (DPC) micelles and DMSO. Similar chemical exchange around the fatty acid was found in DPC but not in DMSO, which demonstrates that this phenomenon only occurs in micellar media. Consequently, it may either reflect the disorder observed in our structures determined in SDS or originate from an interaction of the lipopeptide with the detergent, which would be qualitatively similar with an anionic (SDS) or a zwitterionic (DPC) detergent. These structural and dynamics results on surfactin are the first NMR characterization of a lipopeptide incorporated in micelles. Moreover, they provide a model of surfactin determined in a more biomimetic environment than an organic solvent, which could be useful for understanding the molecular mechanism of its biological activity. | ||
==About this Structure== | ==About this Structure== | ||
| - | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NPV OCA]. | + | 2NPV is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NPV OCA]. |
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| + | ==Reference== | ||
| + | Structure and dynamics of surfactin studied by NMR in micellar media., Tsan P, Volpon L, Besson F, Lancelin JM, J Am Chem Soc. 2007 Feb 21;129(7):1968-77. Epub 2007 Jan 26. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17256853 17256853] | ||
| + | [[Category: Bacillus subtilis]] | ||
| + | [[Category: Single protein]] | ||
[[Category: Lancelin, J M.]] | [[Category: Lancelin, J M.]] | ||
[[Category: Tsan, P.]] | [[Category: Tsan, P.]] | ||
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[[Category: Cyclic lipopeptide]] | [[Category: Cyclic lipopeptide]] | ||
[[Category: Sds micelle]] | [[Category: Sds micelle]] | ||
| + | [[Category: Surface active protein]] | ||
[[Category: Surfactin]] | [[Category: Surfactin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jun 18 12:16:13 2008'' |
Revision as of 09:16, 18 June 2008
Structure and dynamics of surfactin studied by NMR in micellar media
Overview
The NMR structure of the cyclic lipopeptide surfactin from Bacillus subtilis was determined in sodium dodecyl sulfate (SDS) micellar solution. The two negatively charged side chains of surfactin form a polar head opposite to most hydrophobic side chains, accounting for its amphiphilic nature and its strong surfactant properties. Disorder was observed around the fatty acid chain, and 15N relaxation studies were performed to investigate whether it originates from a dynamic phenomenon. A very large exchange contribution to transverse relaxation rate R(2) was effectively observed in this region, indicating slow conformational exchange. Temperature variation and Carr-Purcell-Meiboom-Gill (CPMG) delay variation relaxation studies provided an estimation of the apparent activation energy around 35-43 kJ x mol(-1) and an exchange rate of about 200 ms(-1) for this conformational exchange. 15N relaxation parameters were also recorded in dodecylphosphocholine (DPC) micelles and DMSO. Similar chemical exchange around the fatty acid was found in DPC but not in DMSO, which demonstrates that this phenomenon only occurs in micellar media. Consequently, it may either reflect the disorder observed in our structures determined in SDS or originate from an interaction of the lipopeptide with the detergent, which would be qualitatively similar with an anionic (SDS) or a zwitterionic (DPC) detergent. These structural and dynamics results on surfactin are the first NMR characterization of a lipopeptide incorporated in micelles. Moreover, they provide a model of surfactin determined in a more biomimetic environment than an organic solvent, which could be useful for understanding the molecular mechanism of its biological activity.
About this Structure
2NPV is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structure and dynamics of surfactin studied by NMR in micellar media., Tsan P, Volpon L, Besson F, Lancelin JM, J Am Chem Soc. 2007 Feb 21;129(7):1968-77. Epub 2007 Jan 26. PMID:17256853 Page seeded by OCA on Wed Jun 18 12:16:13 2008
