The Library
Synchrotron radiation linear dichroism spectroscopy of the antibiotic peptide gramicidin in lipid membranes
Tools
Tools
Tools
Hicks, Matthew R., Dafforn, Tim, Damianoglou, Angeliki, Wormell, Paul, Rodger, Alison and Hoffmann, Søren V. (2009) Synchrotron radiation linear dichroism spectroscopy of the antibiotic peptide gramicidin in lipid membranes. Analyst, Vol.134 (No.8). pp. 1623-1628. doi:10.1039/b902523e
Full text not available from this repository, contact author.
Official URL: http://dx.doi.org/10.1039/b902523e
Abstract
We have developed synchrotron radiation linear dichroism (SRLD) to measure the insertion of peptides into lipid bilayers, significantly improving both signal-to-noise and wavelength range over existing methods. Our wavelength cut-off is currently determined by the quality of quartz in the cell, rather than the light source, with signal quality still high at the cut-off. We demonstrate the use of a lipid probe to measure the orientation of the lipid bilayers under flow and describe the way in which this can be used to further interpret SRLD data. The antibiotic peptide gramicidin is shown to exhibit drastically different kinetic and equilibrium behaviour when interacting with lipid membranes with different properties. The charge on the membrane is of interest because of differences in charge between human and bacterial membranes. For this reason we increased the negative charge on the membrane by changing the lipid composition. Increasing negative charge in the gel phase stabilises the liposomes but changes the kinetics of peptide folding. In a gel phase with no negatively charged lipids, gramicidin does not fold well and gives a small signal that indicates a change in orientation of the tryptophan side chains over time. In the fluid phase with no negatively charged lipids, there is initially > 10-fold greater peptide signal relative to the gel phase indicating a highly folded and ordered gramicidin backbone. This is followed by liposome disruption. In the gel phase with negatively charged lipids the liposomes are resistant to disruption by gramicidin and exhibit different folding kinetics depending on membrane composition. In the fluid phase with negatively charged lipids there is little signal from either the peptide or the lipid probe indicating that the liposomes have been disrupted by the gramicidin in the time it takes to make the first measurement.
| Item Type: | Journal Article | ||||
|---|---|---|---|---|---|
| Subjects: | Q Science > QD Chemistry Q Science > QH Natural history > QH301 Biology |
||||
| Divisions: | Faculty of Science > Chemistry | ||||
| Library of Congress Subject Headings (LCSH): | Linear dichroism, Synchrotron radiation, Peptide antibiotics, Lipid membranes, Gramicidins | ||||
| Journal or Publication Title: | Analyst | ||||
| Publisher: | Royal Society of Chemistry | ||||
| ISSN: | 0003-2654 | ||||
| Official Date: | August 2009 | ||||
| Dates: |
|
||||
| Volume: | Vol.134 | ||||
| Number: | No.8 | ||||
| Number of Pages: | 6 | ||||
| Page Range: | pp. 1623-1628 | ||||
| DOI: | 10.1039/b902523e | ||||
| Status: | Peer Reviewed | ||||
| Publication Status: | Published | ||||
| Access rights to Published version: | Restricted or Subscription Access | ||||
| Funder: | Engineering and Physical Sciences Research Council (EPSRC), Statens naturvidenskabelige forskningsråd (Denmark) [Danish Natural Science Research Council] |
Data sourced from Thomson Reuters' Web of Knowledge
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
