FLUIDITY OF GLYCEROL SKELETAL REGION IN PHOSPHOLIPID-BILAYERS - A TIME-RESOLVED FLUORESCENCE DEPOLARIZATION STUDY

Authors
Citation
T. Araiso et T. Koyama, FLUIDITY OF GLYCEROL SKELETAL REGION IN PHOSPHOLIPID-BILAYERS - A TIME-RESOLVED FLUORESCENCE DEPOLARIZATION STUDY, Japanese Journal of Physiology, 45(1), 1995, pp. 187-196
Citations number
10
Categorie Soggetti
Physiology
ISSN journal
0021521X
Volume
45
Issue
1
Year of publication
1995
Pages
187 - 196
Database
ISI
SICI code
0021-521X(1995)45:1<187:FOGSRI>2.0.ZU;2-7
Abstract
The fluidity of glycerol skeletal region in phospholipid bilayer was i nvestigated by the time-resolved fluorescence depolarization technique with ero-3-phospho-[N-(4-nitrobenzo-2-oxa-1,3-diazole)] ethanolamine (NBD-PE) as a fluorescent probe. In this probe, the fluorescent moiety , 4-nitrobenz-2-oxa-1,3-diazole (NBD), is attached to a nitrogen atom at the polar head group of phosphatidylethanolamine molecule. When thi s probe is embedded in a lipid bilayer, the NBD moiety locates near th e glycerol skeletal region. The time courses of fluorescence anisotrop y of NBD-PE in dipalmitoylphosphatidylcholine (DPPC) and dimyristoylph osphatidylcholine (DMPC) bilayers were analyzed using a wobbling-in-co ne model, in which the molecular motion is characterized by a half con e angle (theta(c)) and a wobbling diffusion rate (D-w). Values of D-w of NBD moiety in phospholipid bilayers were found to be on the order o f 10(7) s(-1) at the physiological temperatures, which is almost the s ame value as that of the hydrocarbon chain in lipid bilayers. This fac t indicates that the fluidity in the glycerol skeletal region is simil ar to that in the hydrocarbon layer.