Linked Life Data

1703439

Source:http://linkedlifedata.com/resource/pubmed/id/1703439

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1991-3-5
pubmed:abstractText
We have investigated the conformation of gramicidin A reconstituted in different phospholipid environments, small unilamellar vesicles, extensive bilayers, and micelles, by exploiting a recently proposed experimental approach based on high-performance liquid chromatography [Bañó et al. (1988) J. Chromatogr. 458, 105; Bañó et al. (1989) FEBS Lett. 250, 67]. The method allows the separation of conformational species of the peptide, namely, antiparallel double-stranded (APDS) dimers and beta 6.3-helical monomers, and quantitation of their proportions in the lipid environment. Various experimental parameters (e.g., nature of organic solvent, time of incubation in organic solvent, lipid-to-peptide mole ratio, time of sonication, and temperature) commonly involved in sample preparation protocols have been analyzed independently. The results show how the peptide conformation in model membranes is exquisitely dictated by the particular nature of the reconstitution protocol. In addition, we have elucidated the nature of the slow conformational transition of gramicidin toward the channel configuration that takes place upon incubation of the model membranes. This transition has been characterized as a temperature-dependent conversion from APDS dimeric to beta 6.3-helical monomeric forms. Analysis of kinetic data permits an accurate calculation of the rate constant for this process at different temperatures in phospholipid vesicles and micelles. Finally, an explanation is proposed for the laboratory-to-laboratory variation in the observed spectral patterns of inserted gramicidin.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
886-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Conformational transitions of gramicidin A in phospholipid model membranes. A high-performance liquid chromatography assessment.
pubmed:affiliation
Departament de Bioquímica i Biologia Molecular, Universitat de València, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't