In Situ Electrochemical and PM-IRRAS Studies of Colicin E1 Ion Channels in the Floating Bilayer Lipid Membrane
Colicin E1 is a channel-forming bacteriocin produced by certain Escherichia coli cells in an effort to reduce competition from other bacterial strains. The colicin E1 channel domain was incorporated into a 1,2-diphytanoyl- sn-glycero-3-phosphocholine floating bilayer situated on a 1-thio-?-d-glucose...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 35(2019), 25 vom: 25. Juni, Seite 8452-8459 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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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 Colicins Ion Channels Lipid Bilayers |
| Zusammenfassung: | Colicin E1 is a channel-forming bacteriocin produced by certain Escherichia coli cells in an effort to reduce competition from other bacterial strains. The colicin E1 channel domain was incorporated into a 1,2-diphytanoyl- sn-glycero-3-phosphocholine floating bilayer situated on a 1-thio-?-d-glucose-modified gold (111) surface. The electrochemical properties of the colicin E1 channel in the floating bilayer were measured by electrochemical impedance spectroscopy; the configuration and orientation of colicin E1 in the bilayer were determined by polarization-modulation-infrared-reflection absorption spectroscopy. The EIS and IR results indicate that colicin E1 adopts a closed-channel state at the positive transmembrane potential, leading to high membrane resistance and a large tilt angle of ?-helices. When the transmembrane potential becomes negative, colicin E1 begins to insert into the lipid bilayer, corresponding to low membrane resistance and a low tilt angle of ?-helices. The insertion of colicin E1 into the lipid bilayer is driven by the negative transmembrane potential, and the ion-channel open and closed states are potential reversible. The data in this report provide new insights into the voltage-gated mechanism of colicin E1 ion channels in phospholipid bilayers and illustrate that the floating bilayer lipid membrane at the metal electrode surface is a robust platform to study membrane-active proteins and peptides in a quasi-natural environment |
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| Beschreibung: | Date Completed 17.08.2020 Date Revised 17.08.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.9b01251 |