Linked Life Data

19708263

Source:http://linkedlifedata.com/resource/pubmed/id/19708263

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-8-26
pubmed:abstractText
Alamethicin, a hydrophobic peptide that is considered a paradigm for membrane channel formation, was uniformly labeled with 15N, reconstituted into oriented phosphatidylcholine bilayers at concentrations of 1 or 5 mol %, and investigated by solid-state NMR spectroscopy as a function of temperature. Whereas the peptide adopts a transmembrane alignment in POPC bilayers at all temperatures investigated, it switches from a transmembrane to an in-plane orientation in DPPC membranes when passing the phase transition temperature. This behavior can be explained by an increase in membrane hydrophobic thickness and the resulting hydrophobic mismatch condition. Having established the membrane topology of alamethicin at temperatures above and below the phase transition, ESEEM EPR was used to investigate the water accessibility of alamethicin synthetic analogues carrying the electron spin label TOAC residue at one of positions 1, 8, or 16. Whereas in the transmembrane alignment the labels at positions 8 and 16 are screened from the water phase, this is only the case for the latter position when adopting an orientation parallel to the surface. By comparing the EPR and solid-state NMR data of membrane-associated alamethicin it becomes obvious that the TOAC spin labels and the cryo-temperatures required for EPR spectroscopy have less of an effect on the alamethicin-POPC interactions when compared to DPPC. Finally, at P/L ratios of 1/100, spectral line broadening due to spin-spin interactions and thereby peptide oligomerization within the membrane were detected for transmembrane alamethicin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3034-42
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Alamethicin topology in phospholipid membranes by oriented solid-state NMR and EPR spectroscopies: a comparison.
pubmed:affiliation
Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090 Novosibirsk, Russian Federation.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't