Document Detail

Aggregation and fusion of vesicles composed of N-palmitoyl derivatives of membrane phospholipids.
MedLine Citation:
PMID:  10907786     Owner:  NLM     Status:  MEDLINE    
N-Acylphosphatidylethanolamines and N-acylphosphatidylserines have been isolated from mammalian cells and have been associated with some tissue degenerative changes, although the relationship between their synthesis and the uncontrolled sequence of events that ends in irreversible tissue damage is not completely established. Our results show that monovalent and divalent cations induce aggregation and fusion of liposomes constituted by N-palmitoylphosphatidylethanolamine (NPPE) and N-palmitoylphosphatidylserine (NPPS). The effectiveness of cations to induce the aggregation of NPPE and NPPS liposomes is Ca2+ > Mg2+ >> Na+. NPPS liposomes aggregate at lower concentrations of divalent cations than NPPE liposomes, but with sodium NPPE liposomes aggregate to a higher extent than NPPS liposomes. The reaction order for the aggregation processes depends on the lipid and the cation nature and range from 1.04 to 1.64. Dynamic light scattering shows an irreversible increase of the size of the aggregates in the presence of all cations tested. The irreversibility of the aggregation process and the intermixing of bilayer lipids, as studied by resonance energy transfer assay, suggest that fusion, rather than aggregation, occurs. The existence of a real fusion was demonstrated by the coalescence of the aqueous contents of both NPPS and NPPE liposomes in the presence of either monovalent or divalent cations. The different binding sensitivity of Ca2+ to NPPS and NPPE liposomes, determined by zeta potential measurements, agrees with the results obtained in the aggregation and fusion assays. Our results suggest that the synthesis in vivo of N-acylated phospholipids can introduce important changes in membrane-mediated processes.
M Mora; F Mir; M A de Madariaga; M L Sagristá
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Lipids     Volume:  35     ISSN:  0024-4201     ISO Abbreviation:  Lipids     Publication Date:  2000 May 
Date Detail:
Created Date:  2000-10-30     Completed Date:  2001-01-11     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0060450     Medline TA:  Lipids     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  513-24     Citation Subset:  IM    
Department of Biochemistry and Molecular Biology, Faculty of Chemistry, University of Barcelona, Spain.
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MeSH Terms
Calcium / metabolism
Cell Membrane / chemistry,  metabolism*
Dose-Response Relationship, Drug
Drug Delivery Systems
Lipids / chemistry
Liposomes / chemistry
Magnesium / metabolism
Palmitic Acid / metabolism*
Phosphatidylserines / metabolism
Phospholipids / chemistry*,  metabolism*
Scattering, Radiation
Sodium / metabolism
Sodium Chloride / pharmacology
Succinimides / metabolism
Time Factors
Reg. No./Substance:
0/Lipids; 0/Liposomes; 0/Phosphatidylserines; 0/Phospholipids; 0/Succinimides; 125709-33-3/N-(3-pyridyl)-3-phenylsuccinimide; 3036-82-6/dipalmitoylphosphatidylserine; 57-10-3/Palmitic Acid; 7439-95-4/Magnesium; 7440-23-5/Sodium; 7440-70-2/Calcium; 7647-14-5/Sodium Chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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