Linked Life Data

8509431

Source:http://linkedlifedata.com/resource/pubmed/id/8509431

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1993-7-13
pubmed:abstractText
A tightly membrane-associated form of spectrin (TMA-spectrin) was labeled when human red blood cells were incubated with [3H]palmitic acid. About 90% of spectrin was not fatty acid-acylated and was extracted from membranes by low salt buffers. The 3H-palmitoylated TMA-spectrin, however, resisted low and even high salt extraction and remained associated with inside-out vesicles that were generated in the process of spectrin-actin extraction from membranes. TMA-spectrin was preferentially extracted from KCl-stripped vesicles by 5 M urea at low ionic strength. TMA-spectrin was purified by gel filtration and by ion exchange chromatography in the presence of urea and a non-ionic detergent. Purified TMA-spectrin was 3H-palmitoylated exclusively in the beta subunit to 0.28 mol/mol after a 12-h incubation of red cells. The labeled palmitate may be bound as an ester or thioester, since hydroxylamine (1 M, pH 7.5) released the label completely. Peptide maps of 3H-palmitoylated TMA-spectrin showed three or two labeled peptides from the beta subunit, when generated by V8 protease and trypsin, respectively. Two types of antibodies to spectrin reacted with purified TMA-spectrin, and TMA-spectrin contained the same antigenic peptides as low salt-extractable spectrin. Rabbit anti-ankyrin antibodies did not bind to TMA-spectrin. The substoichiometric incorporation of [3H]palmitic acid into TMA-spectrin could result from the slow turnover of endogenously bound fatty acids. Generation of the tightly membrane-associated and 3H-palmitoylated subpopulation of spectrin cannot be due to entrapment of an unmodified residual fraction of spectrin in right-side-out vesicles. Instead, the data suggest the existence of a subpopulation of spectrin molecules that undergo a covalent fatty acid modification and thereby alter their binding properties. This may offer a new, metabolically dependent mechanism for dynamic interactions between spectrin and the membrane lipid bilayer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12996-3001
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
A tightly membrane-associated subpopulation of spectrin is 3H-palmitoylated.
pubmed:affiliation
Laboratory for Biochemistry, Swiss Federal Institute of Technology, ETH-Zentrum, Zurich.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't