Article (Scientific journals)
Properties of mixed monolayers of lecithin and spin probe. II Analysis of the molecular organization
Chatelain, P.; Brasseur, Robert; Ruysschaert, J. M. et al.
1979In Journal of Colloid and Interface Science, 72 (2), p. 294-303
Peer Reviewed verified by ORBi
 

Files


Full Text
2-cv.pdf
Publisher postprint (1.32 MB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Abstract :
[en] This paper seeks to investigate the molecular organization of fatty acid spin label (4-palmitamido-2,2,6,6-tetramethylpiperidine-1-oxyl) and dipalmitoylphosphatidylcholine molecules in monolayer vesicles. The molar ratio of the spin probe was varied from 1 to 22% and the corresponding electron spin resonance spectra were measured at 25 and 48°C. These spectra were analysed in terms of the dipole-dipole and exchange interactions occuring between the radicals. From a computer simulation, a quantitative analysis of these interactions could be made. Comparison of these data with theoretical models indicate that above the lipid phase transition, i.e., at 48°C, the membrane is homogeneous and the label molecules diffuse randomly in the lecithin bulk phase (D = 3.8 X 10-8 cm2/sec). At 25°C, the membrane model can be viewed as a mosaic structure composed of spin probe clusters (7.9 X 1011 clusters/cm2). The size of the clusters as well as the minimal mean distance between two cluster edges could be calculated as a function of the spin label molar ratio. These results are used to interpret the observations made in the first paper of this series [Chatelain et ak., J. Colloid Interface Sci. 72, 287 (1979)] concerning the surface viscosity of the mixed monolayer and the kinetics of the enzymatic activity of phospholipase A2. It can be concluded that above a critical spin label concentration (10-15%) the properties of the entire lecithin phase are influenced by the presence of the spin probe clusters.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Chatelain, P.
Brasseur, Robert ;  Université de Liège - ULiège > Chimie et bio-industries > Centre de Bio. Fond. - Section de Biophysique moléc. numér.
Ruysschaert, J. M.
Delmelle, M.
Language :
English
Title :
Properties of mixed monolayers of lecithin and spin probe. II Analysis of the molecular organization
Publication date :
November 1979
Journal title :
Journal of Colloid and Interface Science
ISSN :
0021-9797
eISSN :
1095-7103
Publisher :
Academic Press, Orlando, United States - Florida
Volume :
72
Issue :
2
Pages :
294-303
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 20 January 2012

Statistics


Number of views
36 (0 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
6
Scopus citations®
without self-citations
1
OpenCitations
 
6

Bibliography


Similar publications



Contact ORBi