Linked Life Data

15461520

Source:http://linkedlifedata.com/resource/pubmed/id/15461520

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2004-10-5
pubmed:abstractText
A study of the interaction of gramicidin A (gA), tert-butyloxycarbonyl-gramicidin (g-BOC), and desformyl gramicidin (g-des) with dioleoyl phosphatidylcholine (DOPC) and DOPC/phosphatidylserine (PS) mixed monolayers on a mercury electrode is reported in this paper. Experiments were carried out in electrolytes KCl (0.1 mol dm(-3)) and Mg(NO3)2 (0.05 mol dm(-3)). The channel-forming properties of the gramicidins were studied by following the reduction of Tl(I) to Tl(Hg). The frequency dependence of the complex impedance of coated electrode surfaces in the presence and absence of the gramicidins was estimated between 65,000 and 0.1 Hz at potentials of -0.4 V versus Ag/AgCl with 3.5 mol dm(-3) KCl. Epifluorescence microscopy was used to qualitatively correlate the interaction of the gramicidin peptides with dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylglycerol (DPPG) at the air-water interface. gA was shown to form Tl+ conducting channels in a DOPC monolayer, while g-BOC and g-des did not. In DOPC-30% PS (DOPC-0.3PS) layers, there is a marked increase in channel activity of all three gramicidin derivatives. None of the peptides facilitate the permeability of the DOPC-0.3PS layer to Cd2+. All three peptides interact with the layer as shown by capacitance-potential curves and impedance spectroscopy indicated by penetration of the peptide into the dielectric, an increase in surface "roughness", and an increased significance of low-frequency relaxations. The order of interaction is gA > g-des > g-BOC. The epifluorescence study of DPPC and DPPG layers at the air-water interface shows a selective action of the different gramicidins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0743-7463
pubmed:author
pubmed:copyrightInfo
Copyright 2004 American Chemical Society
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9291-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Interaction of gramicidin derivatives with phospholipid monolayers.
pubmed:affiliation
Center for Self-Organising Molecular Systems, School of Chemistry, University of Leeds, LS2 9JT, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't