Biomaterial Database

Effects of probucol on phase transition and fluidity of phosphatidylcholine membranes: a spin label study. 1994

W K Subczynski, and J Wojas, and V Pezeshk, and A Pezeshk

Department of Biophysics, Jagiellonian University, Krakow, Poland.

Spin labeling methods were applied to study the structure and dynamics of phosphatidylcholine membranes as a function of temperature and the mole fraction of probucol. Multilamellar liposomes made of dimyristoylphosphatidyclcholine, dipalmitoylphosphatidylcholine both saturated, and egg yolk phosphatidylcholine, an unsaturated membrane, were used. In fluid phase membranes probucol was found to increase the order and decrease the motional freedom of alkyl chains of lipids as shown with stearic acid spin labels. The effect of probucol on order and motional freedom is more pronounced in the membrane center (16-doxylstearic acid spin label position) than in the near polar headgroup region (5-doxylstearic acid spin label position). The presence of unsaturation in alkyl chains significantly decreased the ordering effect of probucol. The main phase transition temperature of saturated bilayers was lowered by 2 degrees C in the presence of 3 mol% of probucol and significantly broadened at higher concentrations as measured with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) partitioning. Also, pretransition was no longer observed in the presence of probucol. In gel phase membranes, the effect of probucol was complex. Close to the main phase transition the motion of alkyl chains was increased, showing a regulatory effect of probucol on membrane fluidity. It is proposed that probucol is located in the membrane center as opposed to vitamin E, which locates its phenolic -OH group at the membrane surface; therefore, it inhibits lipid peroxidation in this region which is less accessible to vitamin E.

UI	MeSH Term	Description	Entries
D008051	Lipid Bilayers	Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.	Bilayers, Lipid,Bilayer, Lipid,Lipid Bilayer
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D008560	Membrane Fluidity	The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.	Bilayer Fluidity,Bilayer Fluidities,Fluidities, Bilayer,Fluidities, Membrane,Fluidity, Bilayer,Fluidity, Membrane,Membrane Fluidities
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D011341	Probucol	A drug used to lower LDL and HDL cholesterol yet has little effect on serum-triglyceride or VLDL cholesterol. (From Martindale, The Extra Pharmacopoeia, 30th ed, p993).	Biphenabid,DH-581,Lorelco,Lurselle,Panavir,Superlipid,DH 581,DH581
D003497	Cyclic N-Oxides	Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.	Heterocyclic N-Oxides,Cyclic N Oxides,Heterocyclic N Oxides,N Oxides, Cyclic,N-Oxides, Cyclic,N-Oxides, Heterocyclic,Oxides, Cyclic N
D004134	Dimyristoylphosphatidylcholine	A synthetic phospholipid used in liposomes and lipid bilayers for the study of biological membranes.	Dimyristoyllecithin,1,2-Dimyristoyl-glycero-3-phosphorylcholine,1,2-Ditetradecanoyl-glycero-3-phosphocholine,1,2-Ditetradecyl-glycero-3-phosphocholine,DMCP,DMPC,1,2 Dimyristoyl glycero 3 phosphorylcholine,1,2 Ditetradecanoyl glycero 3 phosphocholine,1,2 Ditetradecyl glycero 3 phosphocholine
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D013113	Spin Labels	Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)	Spin Label,Label, Spin,Labels, Spin
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures