Linked Life Data

10946013

Source:http://linkedlifedata.com/resource/pubmed/id/10946013

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2000-10-10
pubmed:abstractText
In the present study, 2,2,6,6-tetramethylpiperidinooxy nitroxide (TEMPO) has been applied successfully to discriminate between glucosylceramide in the outer and inner leaflets of closed membrane bilayers. The nitroxyl radicals TEMPO and carboxy-TEMPO, once oxidized to nitrosonium ions, are capable of oxidizing residues that contain primary hydroxyl and amino groups. When applied to radiolabeled glucosylceramide in liposomes, oxidation with TEMPO led to an oxidized product that was easily separated from the original lipid by thin-layer chromatography, and that was identified by mass spectrometric analysis as the corresponding acid glucuronylceramide. To test whether oxidation was confined to the external leaflet, TEMPO was applied to large unilamellar vesicles (LUVs) consisting of egg phosphatidylcholine- egg phosphatidylethanolamine;-cholesterol 55:5:40 (mol/mol). TEMPO oxidized most radiolabeled phosphatidylethanolamine, whereas carboxy-TEMPO oxidized only half. Hydrolysis by phospholipase A(2) confirmed that 50% of the phosphatidylethanolamine was accessible in the external bilayer leaflet, suggesting that TEMPO penetrated the lipid bilayer and carboxy-TEMPO did not. When applied to LUVs containing <1 mol% radiolabeled glucosylceramide or short-chain C(6)-glucosylceramide, carboxy-TEMPO oxidized half the glucosylceramide. However, if surface C(6)-glucosylceramide was first depleted by bovine serum albumin (BSA) (extracting 49 +/- 1%), 94% of the remaining C(6)-glucosylceramide was resistant to oxidation. Carboxy-TEMPO oxidized glucosylceramide on the surface of LUVs without affecting inner leaflet glucosylceramide. At pH 9.5 and at 0 degrees C, the reaction reached completion by 20 min.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antioxidants, http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic N-Oxides, http://linkedlifedata.com/resource/pubmed/chemical/Glucosylceramides, http://linkedlifedata.com/resource/pubmed/chemical/Glucuronic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Glycolipids, http://linkedlifedata.com/resource/pubmed/chemical/Lipid Bilayers, http://linkedlifedata.com/resource/pubmed/chemical/Liposomes, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylcholines, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylethanolamines, http://linkedlifedata.com/resource/pubmed/chemical/Phospholipases A, http://linkedlifedata.com/resource/pubmed/chemical/Serum Albumin, Bovine, http://linkedlifedata.com/resource/pubmed/chemical/TEMPO
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1252-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Assay for the transbilayer distribution of glycolipids. Selective oxidation of glucosylceramide to glucuronylceramide by TEMPO nitroxyl radicals.
pubmed:affiliation
Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, 1100 DE Amsterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't