Surfactin activity depends on the membrane dipole potential
The effect of dipole modifying agents phloretin and RH 421 on the membrane conductance induced by surfactin, a lipopeptide antibiotic from Bacillus subtilis, was studied. Surfactin added on both sides of a bilayer formed from diphytanoylphosphocholine in 1 M KCl (pH 6.5) leads to the formation of vo...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1991. - 26(2010), 19 vom: 05. Okt., Seite 15092-7 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2010
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Chlorides Lipid Bilayers Lipopeptides Peptides, Cyclic surfactin peptide 24730-31-2 Potassium RWP5GA015D |
| Zusammenfassung: | The effect of dipole modifying agents phloretin and RH 421 on the membrane conductance induced by surfactin, a lipopeptide antibiotic from Bacillus subtilis, was studied. Surfactin added on both sides of a bilayer formed from diphytanoylphosphocholine in 1 M KCl (pH 6.5) leads to the formation of voltage-independent channels of different conductance levels. The conductance of different states of SA channels varies from tens of picosiemens for small pores up to tens of nanosiemens for large ones. Small channels demonstrate pronounced cationic selectivity, whereas large ones practically lose their K(+)/Cl(-) selectivity, most probably because of their large effective radii. The addition of phloretin to the bilayer bathing solution, the agent known to decrease the membrane dipole potential, results in a decrease in the surfactin-induced membrane conductance. At the same time, increasing the membrane dipole potential because of the introduction of RH 421 leads to a rise in the steady-state conductance. Increasing dipole potential is accompanied by increases in both the number of open channels and their conductance. The observed changes in the channel-forming activity of surfactin might be caused by varying the partition coefficient of lipopeptide between the lipid and aqueous phases |
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| Beschreibung: | Date Completed 03.01.2011 Date Revised 21.11.2013 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la102691y |