Linked Life Data

6154051

Source:http://linkedlifedata.com/resource/pubmed/id/6154051

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1980-6-25
pubmed:abstractText
Analogues of fatty acids have been synthesized which contain an S-S bridge in the aliphatic chain and at the omega-carbon the photoactivatable p-(3-trifluoromethyldiazirino)phenyl or p-azidophenyl group as a carbene and nitrene precursor, respectively. These acids were used to acylate 1-palmitoyl phosphatidylcholine by the procedure described by Gupta et al. (Gupta, C.M., Radhakrishnan, R., and Khorana, H.G. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 4315-4319). Multilamellar liposomes prepared from various radioactively labeled lipids and 2 to 10 mol% of one of the photosensitive phospholipid analogues were photolyzed and the extent of cross-linking was determined. The carbene-generating probe labeled dipalmitoyl phosphatidylcholine in yields of 15 to 20%, while labeling with the nitrene probe was about 10 times less efficient. In contrast these probes were found to react with the unsaturated fatty acid of 1-palmitoyl-2-oleoyl phosphatidylcholine with almost equal efficiency. The nitrene was 2 to 3 times more efficient than the carbene in cross-linking to gramicidin A. Amino acid analysis and Edman degradation of the labeled peptide indicated that both probes predominantly attacked tryptophan residues. No geometrical correlation was found between the expected penetration of the reactive group of the probe within the bilayer and the labeled sites of the peptide. This result is discussed in terms of chemical selectivities of the photoactivated intermediates. After photocross-linking, the disulfide bridge can be cleaved to generate a free sulfhydryl group which subsequently can be utilized for preparative or analytical purposes. Photolabeled lipids and peptides can be separated easily from the bulk of the unlabeled material. These phospholipid analogues are substrates for the phospholipid exchange protein isolated from calf liver. Transfer from sonicated dispersions of the analogues into an acceptor membrane was demonstrated. Individual monolayers can thus be labeled separately with these reagents.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3319-29
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
Analysis of membranes photolabeled with lipid analogues. Reaction of phospholipids containing a disulfide group and a nitrene or carbene precursor with lipids and with gramicidin A.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.