Studies of membrane heterogeneity using fluorescence associative techniques.
AuthorsDavenport L, Knutson JR, Brand L
JournalFaraday Discuss Chem Soc
PubMed ID3582620
Calcium-induced phase separation in phospholipid bilayers. A fluorescence anisotropy study.
AuthorsParasassi T, de Felip E, Lepore F, Conti F
JournalCell Mol Biol
PubMed ID3742537
Interaction between Ca2+ and dipalmitoylphosphatidylcholine membranes. II. Fluorescence anisotropy study.
AuthorsKataoka R, Aruga S, Mitaku S, Kinosita K, Ikegami A
JournalBiophys Chem
PubMed ID3838686
The effect of Ca2+ on the molecular mobility in dipalmitoylphosphatidylcholine membranes was studied by steady-state and time-resolved measurements of fluorescence anisotropy. The fluorescence anisotropy decay of 1,6-diphenyl-1,3,5-hexatriene in the hydrocarbon region indicated that the free volume of molecular rotation became more restricted when the Ca2+ concentration was increased. The decrease ... More
Effects of long-chain cis-unsaturated fatty acids and their alcohol analogs on aggregation of bovine platelets and their relation with membrane fluidity change.
AuthorsKitagawa S, Endo J, Kametani F
JournalBiochim Biophys Acta
PubMed ID4041445
The effects of long-chain cis-unsaturated fatty acids with different alkyl chain lengths and different numbers of double bonds on aggregation of bovine platelets and membrane fluidity were investigated. All the cis-unsaturated fatty acids tested inhibited aggregation and at the same time increased membrane fluidity in accordance with their inhibitory effects. ... More
Lipid dynamics and lipid-protein interactions in rat enterocyte basolateral and microvillus membranes.
AuthorsBrasitus TA, Schachter D
JournalBiochemistry
PubMed ID6249340
Lipid fluidity markedly modulates the binding of serotonin to mouse brain membranes.
AuthorsHeron DS, Shinitzky M, Hershkowitz M, Samuel D
JournalProc Natl Acad Sci U S A
PubMed ID6938985
The binding of [3H]serotonin to mouse brain crude membrane and synaptosomal membrane preparations was investigated as a function of membrane fluidity changes by lipids. The microviscosity (eta) of the synaptic membranes was increased by in vitro incubation with either cholesteryl hemisuccinate or stearic acid, resulting in an up to 5-fold ... More
Cholesterylphosphate incorporation in egg phosphatidylcholine vesicles: gel chromatography, and fluorescence polarization studies.
Increased membrane fluidity precedes fusion of muscle cells.
AuthorsPrives J, Shinitzky M
JournalNature
PubMed ID561316
Evaluation of age-related changes of physicochemical properties and functional activity of rat adipose plasma membranes and their possible relationship.
'Studies were carried out to evaluate structural state of adipose plasma membranes (PM) from mature adult and aged Wistar rats and its possible relation to functional changes in aging. PM lipids were probed by fluorescence of 1,6-diphenyl-1,3,5-hexatriene (DPH) and pyrene. The data on DPH anisotropy, pyrene excimerization and induction resonance ... More
A comparison of the effects of linolenic (18:3 omega 3) and docosahexaenoic (22:6 omega 3) acids on phospholipid bilayers.
AuthorsEhringer W, Belcher D, Wassall SR, Stillwell W
JournalChem Phys Lipids
PubMed ID2142021
'The class of long chain polyunsaturated fatty acids known as omega-3 are believed to be involved in prevention of a number of human afflictions. The mode of action for two of the most common omega-3 fatty acids, linolenic 18:3 delta 9,12,15 and docosahexaenoic 22:6 delta 4,7,10,13,16,19 (DHA), is not known. ... More
Restricted motion of photoexcited bacteriorhodopsin in purple membrane containing ethanol.
AuthorsKikukawa T, Araiso T, Shimozawa T, Mukasa K, Kamo N
JournalBiophys J
PubMed ID9199800
'The molecular motion of retinal within the purple membrane was investigated by flash-induced absorption anisotropies with or without ethanol. In the absence of ethanol, the measured anisotropies at several wavelengths exhibited almost the same slow decay. This slow decay was attributed to only the rotation of purple membrane sheet itself ... More
Molecular organization and dynamics of the outer membrane of Salmonella thyphimurium mutant strains detected by frequency domain fluorometry.
AuthorsBismuto E, Sirangelo I, Adinolfi A, Galdiero F, Tufano MA, Sommese L, Irace G
JournalArch Biochem Biophys
PubMed ID1897974
'The fluorescence decay of 1,6-diphenyl-1,3,5-hexatriene (DPH) in the outer membrane bilayer of two mutant strains of Salmonella thyphimurium, i.e., SH 5014 and SH 6261, at different temperatures was analyzed in terms of continuous Lorentzian lifetime distributions. The results were compared with those obtained for the free fluorophore in an isotropic ... More
Shape and lipid-binding site of the nonspecific lipid-transfer protein (sterol carrier protein 2): a steady-state and time-resolved fluorescence study.
'The nonspecific lipid-transfer protein (nsL-TP) from bovine liver was studied with time-resolved and steady-state fluorescence techniques. From the decay of the intrinsic tryptophanyl fluorescence, it was estimated that the rotational correlation time of nsL-TP is 15 ns. This parameter increased only slightly upon addition of an excess of negatively charged ... More
Deuterium nuclear magnetic resonance spectroscopic study of the fluorescent probe diphenylhexatriene in model membrane systems.
AuthorsKintanar A, Kunwar AC, Oldfield E
JournalBiochemistry
PubMed ID3790538
'We have investigated the deuterium (2H) nuclear magnetic resonance (NMR) spectra of two 2H-labeled fluorescence probes (trans,trans,trans-1,6-diphenylhexa-1,3,5-trienes, DPHs) incorporated into model lipid bilayer membrane systems at various temperatures. The membranes consisted of multilamellar bilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) containing varying concentrations of cholesterol. The conventional one-order parameter approach often used in ... More
Gamma-irradiation of liposomes composed of saturated phospholipids: effect of bilayer composition, size, concentration and absorbed dose on chemical degradation and physical destabilization of liposomes.
AuthorsZuidam NJ, Versluis C, Vernooy EA, Crommelin DJ
JournalBiochim Biophys Acta
PubMed ID8634308
'Liposomes composed of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), or mixtures of these two phospholipids were exposed to gamma-irradiation in an air environment. Disappearance of the mother compounds was monitored by HPLC analysis. Plotting of the logarithmic values of residual DPPC or DPPG concentration versus irradiation dose resulted in straight lines. The ... More
Investigation of the lipid domains and apolipoprotein orientation in reconstituted high density lipoproteins by fluorescence and IR methods.
AuthorsWald JH, Coormaghtigh E, De Meutter J, Ruysschaert JM, Jonas A
JournalJ Biol Chem
PubMed ID2123199
'The reconstituted high density lipoproteins (rHDL) that were described in the preceding paper (Hefele Wald, J., Krul, E. S., and Jonas, A. (1990) J. Biol. Chem. 265, 20037-20043) are used in this study to analyze the organization, conformation, and dynamics of the lipid phase, as well as the relative orientation ... More
A model for the effect of lipid oxidation on diphenylhexatriene fluorescence in phospholipid vesicles.
AuthorsBarrow DA, Lentz BR
JournalBiochim Biophys Acta
PubMed ID7260083
'We have determined by means of a standard spectrophotometric assay that lipid oxidation occurred at a significant rate in large, multilamellar vesicles containing egg phosphatidylcholine under normal experimental conditions. We have also observed that the fluorescence intensity of the vesicle-associated probe, 1,6-diphenyl-1,3,5-hexatriene, decreased with time in vesicles containing such oxidizing ... More
Cardiolipin regulates the activity of the reconstituted mitochondrial calcium uniporter by modifying the structure of the liposome bilayer.
AuthorsZazueta C, Ramírez J, García N, Baeza I
JournalJ Membr Biol
PubMed ID12533778
'Reconstitution of mitochondrial calcium transport activity requires the incorporation of membrane proteins into a lipidic ambient. Calcium uptake has been measured previously using Cytochrome oxidase vesicles. The enrichment of these vesicles with cardiolipin, an acidic phospholipid that is found only in the inner mitochondrial membrane of eukaryotic cells, strongly inhibits ... More
Rotational relaxation times of 1,6-diphenyl-1,3,5-hexatriene in phospholipids isolated from LM cell membranes. Effects of phospholipid polar head-group and fatty acid composition.
AuthorsGilmore R, Cohn N, Glaser M
JournalBiochemistry
PubMed ID427095
'Phospholipids were isolated from mitochondrial, microsomal, and plasma membranes of LM cells and fractionated into individual phospholipid classes on silicic acid columns. The fatty acid composition and the rotational relaxation time of 1,6-diphenyl-1,3,5-hexatriene (DPH) were determined for each phospholipid class. Sphingomyelin was the only phospholipid isolated from LM cell membranes ... More
Particle-mediated membrane uptake of chemical carcinogens studied by fluorescence spectroscopy.
AuthorsLakowicz JR, McNamara M, Steenson L
JournalScience
PubMed ID202026
'The fluorescence emissions of chrysene, N-ethylcarbazole, and 1,6-diphenylhexatriene undergo large spectral shifts or changes in quantum yield, or both, upon their uptake from particulates by phospholipid vesicles. This membrane uptake of carcinogen and carcinogen-like molecules by model membranes does not result in any disruption of the lipid bilayers. The fluorescence ... More
Glucocorticoid-induced alterations of renal sulfate transport.
AuthorsSagawa K, Darling IM, Murer H, Morris ME
JournalJ Pharmacol Exp Ther
PubMed ID10900245
'Glucocorticoid administration decreases renal sodium/phosphate cotransport in the proximal tubule due to a down-regulation of the sodium/phosphate cotransporter but has no effect on the sodium-dependent transport of glucose or proline. The objectives of the present investigation were to determine the effects of the glucocorticoid methylprednisolone (MPL) on 1) inorganic sulfate ... More
Inhibition of ADP-induced aggregation of bovine platelets by saturated fatty acids and its relation with the change of membrane surface charge.
AuthorsKitagawa S, Nishitama H, Kametani F
JournalBiochim Biophys Acta
PubMed ID6466668
'The inhibitory effects of saturated fatty acids with 4 to 18 carbon atoms on ADP-induced aggregation of bovine platelets were investigated. The inhibitory effects of the acids increased with increase of their alkyl chain length up to C14. On the other hand, from C16 the inhibitory effects tended to decrease ... More
Temperature dependence of 1,6-diphenyl-1,3,5-hexatriene fluorescence in phophoslipid artificial membranes.
AuthorsAndrich MP, Vanderkooi JM
JournalBiochemistry
PubMed ID1252446
'The fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene in phospholipid vesicles is a function of the physical state of the lipid. Below the phase transition, the polarization approaches the theoretical maximum for total immobilization while above the phase transition the fluorescence becomes nearly completely depolarized. The discontinuity in the temperature dependence of polarization ... More
Estrogen modulates ileal basolateral membrane lipid dynamics and Na+-K+-ATPase activity.
AuthorsSchwarz SM, Bostwick HE, Medow MS
JournalAm J Physiol
PubMed ID2834962
'The effects of ethinyl estradiol, a synthetic estrogen with cholestatic properties and a propensity to alter hepatocyte and ileal brush-border membrane fluidity, on lipid structure and Na+-K+-ATPase activity of rabbit small intestinal basolateral membranes were determined. Utilizing the fluorophores 1,6-diphenyl-1,3,5-hexatriene and DL-12-(9-anthroyl)stearic acid, increases in fluorescence anisotropy, the reciprocal of ... More
Gross structural changes in isolated liver cell plasma membranes upon binding of insulin.
AuthorsLuly P, Shinitzky M
JournalBiochemistry
PubMed ID420790
'The addition of 10(-9) M insulin to a suspension of rat liver plasma membranes increases the overall lipid microviscosity, eta, by about 10--20%. The effect is confined to physiological concentrations of the hormone and is highly specific. The specificity was demonstrated in experiments where insulin analogues were added to liver ... More
Postnatal development of mixed-function oxidation as measured in microsomes from the small intestine and liver of rabbits.
AuthorsTredger JM, Chhabra RS, Fouts JR
JournalDrug Metab Dispos
PubMed ID3396
'The postnatal development of aminopyrine N-demethylase, aniline 4-hydroxylase, benzpyrene hydroxylase, biphenyl 4-hydroxylase, 7-ethoxycoumarin 0-deethylase activities, NADPH-cytochrome c reductase, and cytochrome P-450 was compared in microsomes from the liver and small intestine of New Zealand white rabbits. Apart from hepatic aniline hydroxylase activity, all of the xenobiotic-metabolizing enzyme activities examined had ... More
Cholesterol-dependent modification of microsomal dynamics and UDPglucuronyltransferase kinetics.
AuthorsCastuma CE, Brenner RR
JournalBiochemistry
PubMed ID3094577
'The effect of both in vitro incorporation and removal of cholesterol in guinea pig liver microsomes on the lipid composition, dynamic properties of the membrane, and kinetic constants of UDPglucuronyltransferase was studied. No significant changes either in the fatty acid composition or in the distribution of phospholipid classes were observed ... More
Dexamethasone influences the lipid fluidity, lipid composition and glycosphingolipid glycosyltransferase activities of rat proximal-small-intestinal Golgi membranes.
AuthorsDudeja PK, Dahiya R, Brown MD, Brasitus TA
JournalBiochem J
PubMed ID3140778
'Experiments were performed to examine the effects of subcutaneous administration of the synthetic glucocorticoid dexamethasone (100 micrograms/day per 100 g body wt.) on the lipid fluidity, lipid composition and glycosphingolipid glycosyltransferase activities of rat proximal-small-intestinal Golgi membranes. After 4 days of treatment, Golgi membranes and liposomes prepared from treated rats ... More
Effect of n-alkanols on lipid bilayer hydration.
AuthorsHo C, Stubbs CD
JournalBiochemistry
PubMed ID9271493
'The effect of a homologous series of aliphatic n-alkanols on the presence of water within the head group and acyl chain region of lipid bilayers was investigated using time-resolved fluorescence spectroscopy according to a previously published approach [Ho, C., Slater, S. J., & Stubbs, C. D. (1995) Biochemistry 34, 6188-6195]. ... More
Fluorescence depolarization of cis- and trans-parinaric acids in artificial and red cell membranes resolved by a double hindered rotational model.
AuthorsCalafut TM, Dix JA, Verkman AS
JournalBiochemistry
PubMed ID2765524
'Although steady-state anisotropy measurements of phase-sensitive probes provide a qualitative description of the phase behavior of biomembranes, there is little information about the physical state of lipid domains. We have developed a ground-state double hindered rotator model (DHR) for fluorescence anisotropy decay, in which probes possess separate rotational correlation times ... More
Membrane structural domains. Resolution limits using diphenylhexatriene fluorescence decay.
AuthorsBarrow DA, Lentz BR
JournalBiophys J
PubMed ID4052559
'Measurement of multiple fluorescence decay times of 1,6-diphenyl-1,3,5-hexatriene (DPH) in membranes can in principle be used to investigate structural domains of lipid bilayers. To assess the feasibility of this approach using phase and modulation techniques, we reduced experimental errors specifically associated with performing these measurements on membrane suspensions (probe self-quenching, ... More
Synergistic activation of the human red cell calcium ATPase by magnesium and vanadate.
AuthorsRomero PJ
JournalBiochim Biophys Acta
PubMed ID8499454
'The Ca(2+)-ATPase activity of human red cells was studied on calmodulin-free membrane fragments after previous incubation with Mg2+ and vanadate. In the presence of EGTA (5 mM), the activity was slightly affected by either ion alone. However, when added together, both Ca2+ affinity and Vmax were increased up to levels ... More
Orientational distribution of 1,6-diphenyl-1,3,5-hexatriene in phospholipid vesicles as determined by global analysis of frequency domain fluorimetry data.
AuthorsWang S, Beechem JM, Gratton E, Glaser M
JournalBiochemistry
PubMed ID2036426
'Polarized differential phase and modulation ratios were obtained for 1,6-diphenyl-1,3,5-hexatriene (DPH) in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles by using multifrequency phase fluorometry. Data were analyzed in terms of both empirical sums-of-exponentials modeling and directly in terms of the orientational distribution functions. The orientational analysis model was used ... More
Fluidity changes and chemical composition of lipoproteins in type IIa hyperlipoproteinemia.
AuthorsDachet C, Motta C, Neufcour D, Jacotot B
JournalBiochim Biophys Acta
PubMed ID2397246
'The chemical composition and the physical properties of lipoproteins (VLDL, LDL and HDL) were studied in two groups of patients: 14 healthy normolipidemic subjects and 15 type IIa familial hypercholesterolemic patients. The steady-state fluorescence anisotropy rs was estimated in lipoproteins by the fluorescence depolarization of two fluorescent probes: the DPH ... More
Dynamic motions of 1,6-diphenyl-1,3,5-hexatriene in interdigitated C(18):C(10)phosphatidylcholine bilayers.
AuthorsKao YL, Chong PL, Huang CH
JournalBiophys J
PubMed ID2248998
'This study investigates the dynamic behavior of 1,6-diphenyl-1,3,5-hexatriene (DPH) in C(18):C(10)phosphatidylcholine [C(18):C(10)PC] bilayers. C(18):C(10)PC is an asymmetric mixed-chain phosphatidylcholine known to form mixed-interdigitated structures below the transition temperature and form partially interdigitated bilayers above the transition temperature. The rotation of DPH in C(18):C(10)PC has been described in terms of the ... More
Thermodynamic characterization of interactions between ornithine transcarbamylase leader peptide and phospholipid bilayer membranes.
AuthorsMyers M, Mayorga OL, Emtage J, Freire E
JournalBiochemistry
PubMed ID3663592
'The interactions of the targeting sequence of the mitochondrial enzyme ornithine transcarbamylase with phospholipid bilayers of different molecular compositions have been studied by high-sensitivity heating and cooling differential scanning calorimetry, high-sensitivity isothermal titration calorimetry, fluorescence spectroscopy, and electron microscopy. These studies indicate that the leader peptide interacts strongly with dipalmitoylphosphatidylcholine ... More
Fluorescence energy transfer from diphenylhexatriene to bacteriorhodopsin in lipid vesicles.
AuthorsRehorek M, Dencher NA, Heyn MP
JournalBiophys J
PubMed ID6882861
'Fluorescence energy transfer between the donor diphenylhexatriene (DPH) and the acceptor retinal and fluorescence depolarization of DPH are used to test current theories for fluorescence energy transfer in two-dimensional systems and to obtain information on the effect of the intrinsic membrane protein, bacteriorhodopsin, on the order and dynamics of the ... More
Fluorescence polarization study on the increase of membrane fluidity of human erythrocyte ghosts induced by synthetic water-soluble polymers.
AuthorsOhno H, Shimidzu N, Tsuchida E, Sasakawa S, Honda K
JournalBiochim Biophys Acta
PubMed ID7317393
'The effect of water-soluble polymers on the membrane fluidity of human erythrocyte ghosts was investigated and was compared with that of concanavalin A by means of the fluorescence polarization technique. 8-Anilino-1-naphthalene sulfonic acid sodium salt and 1,6-diphenyl-1,3,5-hexatriene were used as probe molecules. The membrane fluidity was increased by the addition ... More
Effect of charged residue substitutions on the membrane-interactive properties of signal sequences of the Escherichia coli LamB protein.
AuthorsJones JD, Gierasch LM
JournalBiophys J
PubMed ID7819486
'Although the central role of the signal sequence in protein export is well established, the molecular details underlying signal sequence in vivo function remain unclear. As part of our continuing effort to relate signal sequence phenotypes to specific biophysical properties, we have carried out an extensive characterization of the secondary ... More
Fluorescence probes in metastatic B16 melanoma membranes.
AuthorsSchroeder F
JournalBiochim Biophys Acta
PubMed ID6477911
'Fluorescence probe molecules, trans-parinaric acid and 1,6-diphenylhexatriene, were utilized to characterize the structure of plasma membranes, microsomes and mitochondria from B16 melanoma cells. High metastastic B16-F10 and low metastatic B16-F1 melanoma cell lines had markedly different membrane structures. The fluorescence polarization, fluorescence lifetime and limiting anisotropy of trans-parinaric acid were ... More
Effects of lindane on membrane fluidity: intramolecular excimerization of a pyrene derivative and polarization of diphenylhexatriene.
AuthorsAntunes-Madeira MC, Almeida LM, Madeira VM
JournalBiochim Biophys Acta
PubMed ID1689182
'Fluorescence polarization studies of 1,6-diphenyl-1,3,5-hexatriene (DPH) have been compared with the excimer/monomer fluorescence intensity ratio (I''/I) of 1,3-di(2-pyrenyl)propane, (2Py(3)2Py). This ratio permits evaluation of changes in fluidity of the outer regions of the bilayer, where 2Py(3)2Py preferentially distributes. On the other hand, fluorescence polarization of DPH reports the structural order ... More
Specific reactivity of lipid vesicles conjugated with oriented anti-lactose antibody fragments.
AuthorsSinha D, Karush F
JournalBiochim Biophys Acta
PubMed ID6173068
'The method previously described (Sinha, D. and Karush, F. (1979) Biochem. Biophys. Res. Commun. 90, 554--560) for the oriented attachment of immunoglobulins to lipid vesicles has been used to confer specific reactivity on liposomes by their conjugation with anti-lactose Fab'' fragments derived from rabbit IgG antibody. It is estimated that ... More
Fluorescence depolarization studies and phase transition in human apoprotein . phospholipid complexes.
AuthorsRosseneu M, Vercaemst R, Caster H, Lievens MJ, van Tornout P, Herbert PN
JournalEur J Biochem
PubMed ID456381
'The microviscosity of unilamellar vesicles of dimyristoyl-3-sn-phosphatidylcholine and that of phosphatidylcholine . apoprotein complexes was followed by fluorescence depolarization after labeling with 1,6-diphenyl-1,3,5-hexatriene. The transition temperature from gel-crystalline to liquid-crystalline phase in 24 degrees C for the dimyristoyl-phosphatidylcholine vesicles and is shifted to around 30 degrees C in the complexes ... More
The lipid fluidity of rat colonic brush-border membrane vesicles modulates Na+-H+ exchange and osmotic water permeability.
AuthorsBrasitus TA, Dudeja PK, Worman HJ, Foster ES
JournalBiochim Biophys Acta
PubMed ID3002472
'Brush-border membrane vesicles were prepared from rat colonic epithelial cells. Steady-state fluorescence polarization techniques, using the fluorophores 1,6-diphenyl-1,3,5-hexatriene and DL-12-(9-anthroyl)stearic acid (12-AS), revealed that benzyl alcohol (25-75 mM) but not methyl alcohol (50-125 mM) significantly increased the fluidity of these vesicles. Benzyl alcohol (50 and 75 mM) but not methyl ... More
Location of diphenylhexatriene (DPH) and its derivatives within membranes: comparison of different fluorescence quenching analyses of membrane depth.
AuthorsKaiser RD, London E
JournalBiochemistry
PubMed ID9609714
'The average membrane location of a series of diphenylhexatriene (DPH)-derived membrane probes was analyzed by measuring the quenching of DPH fluorescence with a series of nitroxide-labeled lipids in which the depth of the nitroxide group is varied. All DPH derivatives were located deeply within the bilayer. Some derivatives were anchored ... More
Fluorescence studies on the lipoprotein complex of the fatty acid synthetase from the insect Ceratitis capitata.
AuthorsGavilanes JG, Lizarbe MA, Municio AM, Oñaderra M
JournalBiochemistry
PubMed ID6895316
'The fatty acid synthetase complex from the insect Ceratitis capitata forms a stable lipoprotein complex. The intrinsic fluorescence of the complex was studied by observing the emission spectra with different excitation wavelengths, both in the native complex and after temperature with sodium cholate and sodium dodecyl sulfate. The excitation spectrum ... More
Modification of ceftibuten transport by the addition of non-ionic surfactants.
AuthorsKoga K, Ohyashiki T, Murakami M, Kawashima S
JournalEur J Pharm Biopharm
PubMed ID10613923
'The effects of non-ionic surfactants on the carrier-mediated transport of ceftibuten by rat intestinal brush-border membrane vesicles (BBMVs) were investigated. Ceftibuten uptake by BBMVs was measured by a rapid filtration technique. The concentration of surfactants for the uptake experiments was determined by a decrease in the turbidity of BBMV suspension ... More
Nanosecond time-resolved emission anisotropy of the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene in human amniotic fluid.
AuthorsCavalieri RL, Kowalczyk AA, Davenport L, Chin C, Brand L
JournalBiochim Biophys Acta
PubMed ID6696927
'The fluorescence emission anisotropy of 1,6-diphenyl-1,3,5-hexatriene in human amniotic fluid has been studied using nanosecond time-resolved emission techniques. These studies demonstrate that the previously reported decrease in the steady state emission anisotropy, [r], with gestational age is due to a change in the rate of rotational motion of the probe. ... More
Inborn errors of steroid biosynthesis: detection by a new mass-spectrometric method.
AuthorsShackleton CH
JournalClin Chem
PubMed ID6600419
'A new mass-spectrometric technique relies on ionization during bombardment of the analyte (dissolved in a liquid matrix, usually glycerol) by an atom beam (e.g., Ar0, Xe0). This technique, termed "fast atom bombardment," is particularly useful in the characterization of polar charged molecules. A neutral beam is not essential, and a ... More
Effects of insulin on the lipid structure of liver plasma membrane measured with fluorescence and ESR spectroscopic methods.
AuthorsHyslop PA, York DA, Sauerheber RD
JournalBiochim Biophys Acta
PubMed ID6089886
'Insulin increased the lipid order of rat and mouse liver plasma membrane domains sampled by the hydrophobic fluorescent probe 1,6-diphenyl-1,3,5-hexatriene in a concentration-dependent saturable manner. The ordering is half maximal at 5.1 X 10(-11) M and fully saturated at 1.7 X 10(-10) M insulin. Membranes prepared from obese hyperglycemic (ob/ob) ... More
Gangliosides enhance the membrane actions of ethanol and pentobarbital.
'The physical properties of vesicles containing phosphatidylcholine (PC) and gangliosides were evaluated by the fluorescent probes 1,6-diphenyl-1,3,5-hexatriene, trans- parinarate (probes of the lower acyl regions), and 1-(4- trimethylammoniumphenyl )-6-phenyl-1,3,5-hexatriene (a probe of the glycerol backbone and upper acyl regions). Exposure of PC vesicles to ethanol produced a decrease in polarization ... More
Family study of platelet membrane fluidity in Alzheimer's disease.
AuthorsZubenko GS, Wusylko M, Cohen BM, Boller F, Teply I
JournalScience
PubMed ID3659926
'The fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene in labeled platelet membranes, an index of membrane fluidity, identifies a prominent subgroup of patients with Alzheimer''s disease who manifest distinct clinical features. In a family study, the prevalence of this platelet membrane abnormality was 3.2 to 11.5 times higher in asymptomatic, first-degree relatives of ... More
Light-scattering effects in the measurement of membrane microviscosity with diphenylhexatriene.
AuthorsLentz BR, Moore BM, Barrow DA
JournalBiophys J
PubMed ID262401
'Data from several membrane systems are presented to confirm an empirical means of correcting diphenylhexatriene fluorescence for depolarization caused by sample turbidity. The depolarization proportionally constants obtained are not equal, but are shown to vary with (a) the physical state of the membrane, (b) the cholesterol content of the membrane, ... More
Angle resolved fluorescence depolarisation of 1,6-diphenyl-1,3,5 hexatriene (DPH) in unsaturated digalactosyl diacylglycerol (DGDG) lipid bilayers.
Authorsvan de Ven M, van Ginkel G, Levine YK
JournalBiochem Biophys Res Commun
PubMed ID6477586
'The orientational ordering and dynamics of DPH molecules embedded in macroscopically ordered bilayers of the unsaturated galactolipid digalactosyl diacylglycerol (DGDG) were studied by angle-resolved fluorescence depolarisation at room temperature. The depolarisation ratios exhibited a weaker angular dependence than those observed for DPH incorporated in multi-bilayers of saturated lecithins above their ... More
Basolateral membrane lipid dynamics alter Na-K ATPase activity in rabbit small intestine.
AuthorsMadsen KL, Meddings JB, Fedorak RN
JournalCan J Physiol Pharmacol
PubMed ID1338373
'The role of basolateral membrane fluidity in regulating Na-K ATPase activity along the crypt-villus axis in rabbit distal small intestine was assessed. Basolateral membranes were prepared from isolated villus and crypt enterocytes at 24- to 28-fold enhancement. Villus basolateral membranes were significantly (p < 0.001) more fluid than crypt basolateral ... More
Fluorescence studies of the aged erythrocyte membranes.
AuthorsTozzi-Ciancarelli MG, D'Alfonso A, Tozzi E, Troiani-Sevi E, De Matteis G
JournalCell Mol Biol
PubMed ID2731189
'The most important purpose of this research is to characterize by means of fluorescence polarization the structural and functional changes which occur in the membrane of the human erythrocytes during aging process. Our results provide evidence of a significant increase of membrane fluidity in the deep lipid core and in ... More
Effects of lindane on fluidity and lipid composition in rat renal cortex membranes.
'The influence of lindane upon dynamic properties of plasma membranes from rat renal cortex has been investigated using a fluorescence polarization technique. Preincubation with lindane increased membrane fluidity in a manner that is dose-dependent. This increase was higher in brush border membranes than in basolateral membranes. However, a significant decrease ... More
Detergent-induced conformational changes of Humicola lanuginosa lipase studied by fluorescence spectroscopy.
AuthorsJutila A, Zhu K, Patkar SA, Vind J, Svendsen A, Kinnunen PK
JournalBiophys J
PubMed ID10692347
'Detergent (pentaoxyethylene octyl ether, C(8)E(5))-induced conformational changes of Humicola lanuginosa lipase (HLL) were investigated by stationary and time-resolved fluorescence intensity and anisotropy measurements. Activation of HLL is characterized by opening of a surface loop (the "lid") residing directly over the enzyme active site. The interaction of HLL with C(8)E(5) increases ... More
Dynamic microstructure of plasma and mitochondrial membranes from bullfrog myocardium--a nanosecond time-resolved fluorometric study.
AuthorsKoyama T, Zhu MY, Araiso T, Kinjo M, Kitagawa H, Sugimura M
JournalJpn J Physiol
PubMed ID2141883
'The viscosity of the phospholipid bilayer and the wobbling angle of the phospholipid molecules of mitochondrial membranes and plasma membranes from bullfrog myocardium were measured with a nanosecond time-resolved fluorometer using pulsed excitation of a hydrophobic fluorescent probe, 1,6-diphenyl-1,3,5-hexatriene (DPH). The mean +/- S.D. in the viscosity of the mitochondrial ... More
A direct method for the correction of pressure-induced scrambling of polarized fluorescence intensities.
AuthorsTargowski P, Davenport L
JournalAnal Biochem
PubMed ID10527523
'A simple and direct method for the simultaneous correction of steady-state polarized fluorescence intensities, depolarized (or scrambled) by the effects of applied hydrostatic pressure, is described. In the method discussed here, it is not necessary to first determine the scrambling factors from a separate experiment with a dye immobilized in ... More
Modulation by small hydrophobic molecules of valinomycin-mediated potassium transport across phospholipid vesicle membranes.
AuthorsClement NR, Gould MJ
JournalBiochemistry
PubMed ID6261799
'The effects of small hydrophobic molecules on valinomycin-mediated K+ transport in small unilamellar soybean phospholipid vesicles have been studied by using a vesicle-entrapped pH-sensitive hydrophilic fluorescence probe to monitor counterion-limited, passive H+ diffusion into vesicles after an abrupt decrease in external pH [Clement, N. R., & Gould, J. M. (1981) ... More
Formulation and evaluation of itraconazole via liquid crystal for topical delivery system.
AuthorsNesseem DI
JournalJ Pharm Biomed Anal
PubMed ID11489384
'Liquid crystal systems are used to tailor drug delivery from topical delivery system. Ternary polyoxyethylene [21] stearyl ether/ oil and water form liquid crystalline system cream, which has a potential as dosage form for 1% itraconazole as topical dermal drug delivery. Evaluation of the suggested formula was performed for the ... More
[Determination of metabolizing activities of xenobiotic tissue in rat embryo fibroblasts]
AuthorsTurchi G, Citti L, Lippi A, Gervasi PG
JournalBoll Soc Ital Biol Sper
PubMed ID7138688
'Rat embryo fibroblast suspensions were prepared from 19-day-old wistar rat fetuses by trypsin digestion of the minced fetal tissue. Drug-metabolizing capability of isolated viable rat embryo cells on 7-ethoxycoumarin and 1,3-cyclohexadiene has been investigated. The biotransformation of 7-ethoxycoumarin represents a suitable experimental tool to measure the level and significance of ... More
Effect of bacterial endotoxin on the transmembrane electrical potential and plasma membrane fluidity of human monocytes.
AuthorsLarsen NE, Enelow RI, Simons ER, Sullivan R
JournalBiochim Biophys Acta
PubMed ID3986196
'In order to gain insight into the physical interaction between bacterial endotoxins and the surface of human monocytes, we investigated the effects of Salmonella typhi endotoxin and lipid A on two functional properties of the plasma membrane of these cells: (1) the transmembrane electrical potential and (2) the fluidity of ... More
Changes in brain striatum dopamine and acetylcholine receptors induced by chronic CDP-choline treatment of aging mice.
AuthorsGiménez R, Raïch J, Aguilar J
JournalBr J Pharmacol
PubMed ID1839138
'1. Spiroperidol binding (dopamine D2 receptors) and quinuclidinyl benzilate binding (muscarinic receptors) in striata of 19-month old mice was analyzed for animals that had received chronic administration of cytidine 5''-diphosphocholine (CDP-choline) incorporated into the chow consumed (100 or 500 mg kg-1 added per day) for the 7 months before they ... More
Membrane lipid dynamics in human promyelocytic leukemia cells sensitive and resistant to 12-O-tetradecanoylphorbol-13-acetate induction of differentiation.
AuthorsFisher PB, Schachter D, Abbott RE, Callaham MF, Huberman E
JournalCancer Res
PubMed ID6594192
'A series of fluorescent probes was used to analyze membrane lipid dynamics in promyelocytic leukemic cells sensitive (HL-60) or resistant (R-55) to phorbol diester induction of cell differentiation. When examined with the probe 1,6-diphenyl-1,3,5-hexatriene, which can penetrate the plasma membrane and intercalate in the lipids of both leaflets of the ... More
Interaction of trans-parinaric acid with phosphatidylcholine bilayers: comparison with the effect of other fluorophores.
AuthorsBen Yashar V, Menashe M, Biltonen RL, Johnson ML, Barenholz Y
JournalBiochim Biophys Acta
PubMed ID3663661
'The effect of the fluorophore trans-parinaric acid on the structure of lipid bilayer was studied and compared with the effect of other ''perturbants''. These include commonly used fluorophores (diphenylhexatriene, heptadecylhydroxycoumarin, cis-parinaric acid and two fatty acids, palmitic and oleic acids). Differential scanning calorimetry (DSC) and proton nuclear magnetic resonance techniques ... More
The influence of cholesteryl ester transfer protein on the composition, size, and structure of spherical, reconstituted high density lipoproteins.
AuthorsRye KA, Hime NJ, Barter PJ
JournalJ Biol Chem
PubMed ID7814372
'The effect of cholesteryl ester transfer protein (CETP) on the size, composition, and structure of spherical, reconstituted HDL (rHDL) which contain apolipoprotein (apo) A-I as their sole apolipoprotein has been studied. Spherical rHDL were incubated with CETP and Intralipid for up to 24 h. During this time CETP promoted transfers ... More
Lymphocyte membrane lipid composition and mitogen responsiveness in chickens: role of membrane "fluidity".
AuthorsTraill KN, Ratheiser K, Pfeilschifter R, Wick G
JournalEur J Immunol
PubMed ID3948907
'After establishing optimal conditions for measuring the membrane lipid packing density ("fluidity") of chicken peripheral blood lymphocytes, the fluidity was modulated in vitro by incubation in cholesterol or phospholipid ("active lipid", AL)-enriched serum-free tissue culture medium. The effect of these lipids on mitogen responsiveness was then investigated, the aim being ... More
[The effect of biologically active compounds on lysosome fusion with phagosomes and the F-actin content in mouse peritoneal macrophages and on the status of the lysosomal membranes in mouse hepatocytes]
'Effects of biologically active compounds bilirubin (BR, 0.1 and 0.2 mM), chelerythrine (CR, 0.1 and 0.5 mM) and farmorubicin (FR, 0.6 and 6.0 mM) on the phagosome-lysosome fusion (P-LF) were studied using fluorescent dye acridine orange for lysosomal labelling and yeast cells as a target. To investigate mechanisms of these ... More
Ethinylestradiol administration selectively alters liver sinusoidal membrane lipid fluidity and protein composition.
AuthorsRosario J, Sutherland E, Zaccaro L, Simon FR
JournalBiochemistry
PubMed ID3415965
'Administration of high-dose ethinylestradiol to rats decreases bile flow, Na,K-ATPase specific activity, and liver plasma membrane fluidity. By use of highly purified sinusoidal and bile canalicular membrane fractions, the effect of ethinylestradiol administration on the protein and lipid composition and fluidity of plasma membrane fractions was examined. In sinusoidal fractions, ... More
A photophysical model for diphenylhexatriene fluorescence decay in solvents and in phospholipid vesicles.
AuthorsParasassi T, De Stasio G, Rusch RM, Gratton E
JournalBiophys J
PubMed ID2009361
'The fluorescence decay of 1,6-diphenyl-1,3,5-hexatriene (DPH) in pure solvents and in phospholipid vesicles has been measured using frequency domain fluorometry. Data analysis uses a model with two energetically close excited states. The model explains the high quantum yield and the double exponential decay of DPH observed in some pure solvents ... More
Fluorescence study on the interaction of a multiple antigenic peptide from hepatitis A virus with lipid vesicles.
AuthorsOrtiz A, Cajal Y, Haro I, Reig F, Alsina MA
JournalBiopolymers
PubMed ID10775061
'The interaction of the multiple antigenic peptide MAP4VP3 with lipid membranes has been studied by spectroscopic techniques. MAP4VP3 is a multimeric peptide that corresponds to four units of the sequence 110-121 of the capsid protein VP3 of hepatitis A virus. In order to evaluate the electrostatic and hydrophobic components on ... More
Effects of DDE on the fluidity of model and native membranes: implications for the mechanisms of toxicity.
AuthorsAntunes-Madeira Mdo C, Madeira VM
JournalBiochim Biophys Acta
PubMed ID8318533
'2,2-Bis(p-chlorophenyl)-1,1-dichloroethylene (DDE) interaction with model and native membranes was studied by means of fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), probing the bilayer core, and by intramolecular excimerization of 1,3-di(1-pyrenyl) propane (Py(3)Py), probing the outer regions of the bilayer. In the gel phase of DMPC bilayers, DDE induces concentration-dependent fluidizing effects into ... More
The active metabolite hydroxytamoxifen of the anticancer drug tamoxifen induces structural changes in membranes.
AuthorsCustódio JB, Almeida LM, Madeira VM
JournalBiochim Biophys Acta
PubMed ID8274502
'The effects of hydroxytamoxifen (OHTAM) on lipid organization of pure phospholipid liposomes, native sarcoplasmic reticulum (SR) membranes and liposomes of SR lipids were evaluated by intramolecular excimer formation of 1,3-di(1-pyrenyl)propane (Py(3)Py) and by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative 3-[p-(6-phenyl)-1,3,5-hexatrienyl]phenylpropionic acid (DPH-PA). OHTAM promotes alterations in the thermotropic ... More
Cellular membrane composition defines A beta-lipid interactions.
AuthorsWaschuk SA, Elton EA, Darabie AA, Fraser PE, McLaurin JA
JournalJ Biol Chem
PubMed ID11438533
'Alzheimer''s disease pathology has demonstrated amyloid plaque formation associated with plasma membranes and the presence of intracellular amyloid-beta (A beta) accumulation in specific vesicular compartments. This suggests that lipid composition in different compartments may play a role in A beta aggregation. To test this hypothesis, we have isolated cellular membranes ... More
Lipid peroxidation of the brush-border membrane: membrane physical properties and glucose transport.
AuthorsJourd'Heuil D, Vaananen P, Meddings JB
JournalAm J Physiol
PubMed ID8333526
'During inflammatory conditions, peroxidation of biological membranes often takes place. Deleterious physiological consequences, in terms of membrane function, could theoretically be mediated by either direct oxidative attack upon integral membrane proteins or by indirectly altering the lipid environment surrounding these proteins. To address this issue, in vitro peroxidation of guinea ... More
Thermodynamic and phase characterization of phosphatidylethanolamine and ganglioside GD1a mixtures.
AuthorsTsao YS, Freire E, Huang L
JournalBiochim Biophys Acta
PubMed ID3593711
'By employing diphenylhexatriene steady-state fluorescence anisotropy, pyrenedecanoic acid excimer formation, and high sensitivity scanning calorimetry we have demonstrated that the liposomes containing phosphatidylethanolamine (PE) and various mole fractions of ganglioside GD1a had a gel-liquid crystalline phase transition between 15 and 25 degrees C. Calorimetric measurements indicated that these phase transitions ... More
High-performance liquid chromatographic analysis of phospholipids from different sources with combined fluorescence and ultraviolet detection.
AuthorsBernhard W, Linck M, Creutzburg H, Postle AD, Arning A, Martin-Carrera I, Sewing KF
JournalAnal Biochem
PubMed ID7978242
'An isocratic high-performance liquid chromatographic (HPLC) system was developed for the separation of major phospholipid classes, i.e., phosphatidylcholine, sphingomyelin, lysophosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine. Phospholipids were detected with ultraviolet absorption at 205 nm and subsequent fluorescence detection. Fluorescence of the phospholipids (excitation, 340 nm; emission, 460 nm) was achieved ... More
Sphingomyelinase induces lipid microdomain formation in a fluid phosphatidylcholine/sphingomyelin membrane.
AuthorsHolopainen JM, Subramanian M, Kinnunen PK
JournalBiochemistry
PubMed ID9860872
'The behaviors of two chemically well-defined sphingolipids, N-palmitoyl-sphingomyelin (C16:0-SM) and the corresponding ceramide (C16:0-Cer), in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) matrix were compared. Minor attenuation of lateral diffusion upon increasing the mole fraction of C16:0-SM (XSM, up to 0.25) was indicated by the slight decrement in the excimer/monomer intensity ratio (Ie/Im) for ... More
Effect of lipid composition changes on carbocyanine dye fluorescent response.
AuthorsDeleers M, Servais JP, de Laveleye F, Wulfert E
JournalBiochem Biophys Res Commun
PubMed ID6541041
'Egg yolk phosphatidyl choline liposomes containing variable amounts of phosphatidyl ethanolamine, phosphatidyl inositol or phosphatidyl serine demonstrated important variations in the fluorescence of 3.3'' dipropylthiodicarbocyanine. When the membrane contained no cholesterol, fluorescence was not correlated with membrane fluidity as measured by diphenyl hexatriene polarization. Increasing cholesterol concentration in valinomycin containing ... More
Diacylglycerol-rich domain formation in giant stearoyl-oleoyl phosphatidylcholine vesicles driven by phospholipase C activity.
AuthorsRiske KA, Döbereiner HG
JournalBiophys J
PubMed ID14507699
'We have studied the effect of phospholipase C from Bacillus cereus and Clostridium perfringens (alpha-toxin) on giant stearoyl-oleoyl phosphatidylcholine (SOPC) vesicles. Enzyme activity leads to a binary mixture of SOPC and the diacylglycerol SOG, which phase separates into a SOPC-rich bilayer phase and a SOG-rich isotropic bulk-like domain embedded within ... More
Lipid composition determines the effects of arbutin on the stability of membranes.
AuthorsHincha DK, Oliver AE, Crowe JH
JournalBiophys J
PubMed ID10512822
'Arbutin (hydroquinone-beta-D-glucopyranoside) is an abundant solute in the leaves of many freezing- or desiccation-tolerant plants. Its physiological role in plants, however, is not known. Here we show that arbutin protects isolated spinach (Spinacia oleracea L.) thylakoid membranes from freeze-thaw damage. During freezing of liposomes, the presence of only 20 mM ... More
Steady-state fluorescence studies on lipase-vesicle interactions.
AuthorsMosmuller EW, Pap EH, Visser AJ, Engbersen JF
JournalBiochim Biophys Acta
PubMed ID8305458
'The interaction of lipase from Candida cylindracea (CCL) with positively charged polymerizable surfactant vesicles was studied by the use of steady-state fluorescence techniques. The phase transition of vesicles composed of nonpolymerized and polymerized N-allylbis[2-(hexadecanoyloxy)ethyl]methylammonium bromide (ABHEMA Br) was determined in the absence of lipase, by measuring the change in fluorescence ... More
Fluorescence polarization order parameters and phase transitions in lipids and lipoproteins.
AuthorsBerlin E, Sainz E
JournalBiochim Biophys Acta
PubMed ID6733129
'Fluorescence polarization measurements with 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to monitor phase changes in sonicated dispersions of triacylglycerols, cholesteryl esters and phospholipids. Lipid transitions to a fluid state were detected in a novel way by noting the temperature, t0.08, at which rs, the steady state anisotropy, was equal to 0.08. According ... More
Lipid requirement of the branched-chain amino acid transport system of Streptococcus cremoris.
AuthorsDriessen AJ, Zheng T, In't Veld G, Op den Kamp JA, Konings WN
JournalBiochemistry
PubMed ID3284574
'The role of the membrane lipid composition on the transport protein of branched-chain amino acids of the homofermentative lactic acid bacterium Streptococcus cremoris has been investigated. The major membrane lipid species identified in S. cremoris were acidic phospholipids (phosphatidylglycerol and cardiolipin), glycolipids, and glycerophosphoglycolipids. Phosphatidylethanolamine (PE) was completely absent. Protonmotive ... More
Flow cytometry, a very useful technique for the characterization of intestinal membrane vesicles.
AuthorsGorvel JP, Mishal Z
JournalBiol Cell
PubMed ID2950957
'The plasma membrane of enterocytes comprises two structurally and functionally distinct domains. These are the apical brush border, containing digestive hydrolases and glycocalyx, and the basolateral domain, characterized by other specific markers. Using a fast and easy subcellular fractionation, we purified four membrane vesicle fractions from rabbit small intestinal mucosa: ... More
Temperature-induced transitions of porcine intestinal brush border membranes.
AuthorsOhyashiki T, Takeuchi M, Kodera M, Mohri T
JournalBiochim Biophys Acta
PubMed ID7093271
'Thermotropic transitions of the membrane components in porcine intestinal brush border membranes were studied by means of fluorimetry using a fluorogenic thiol reagent, N-[7-dimethylamino-4-methylcoumarinyl]maleimide (DACM), and a lipophilic fluorescent probe, 1,6-diphenyl-1,3,5-hexatriene (DPH). 1. The reactivity of the sulfhydryl groups of the membrane proteins with DACM was dependent on temperature, with ... More
Gramicidin conformational studies with mixed-chain unsaturated phospholipid bilayer systems.
AuthorsCox KJ, Ho C, Lombardi JV, Stubbs CD
JournalBiochemistry
PubMed ID1370909
'The transition of gramicidin from a nonchannel to a channel form was investigated using mixed-chain phosphatidylcholine lipid bilayers. Gramicidin and phospholipids were codispersed, after removal of the solvents chloroform/methanol or trifluoroethanol which resulted in nonchannel and channel conformations, respectively, as confirmed using circular dichroism (CD). The fluorescence emission maxima of ... More
Lipid composition and fluidity of rat enterocyte basolateral membranes. Regional differences.
AuthorsBrasitus TA, Schachter D
JournalBiochim Biophys Acta
PubMed ID6329292
'The lipid composition and fluidity of basolateral membranes prepared from the mucosa of the proximal, middle and distal thirds of the rat small intestine were determined. Fluidity, as assessed by the fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene and a series of anthroyloxy fatty acid derivatives, is decreased in the distal third as ... More
Fluorometry of turbid and absorbant samples and the membrane fluidity of intact erythrocytes.
AuthorsEisinger J, Flores J
JournalBiophys J
PubMed ID4016211
'In employing intrinsic or extrinsic fluorophores in the study of whole cells, or other strongly absorbant and/or scattering samples, the measured fluorescence intensity and polarization is seriously affected by absorption and scattering within the sample cuvet. These artifacts are analyzed and simple protocols are provided for overcoming them. An expression ... More
Interaction of biologically active molecules with phospholipid membranes. I. Fluorescence depolarization studies on the effect of polymeric biocide bearing biguanide groups in the main chain.
AuthorsIkeda T, Tazuke S, Watanabe M
JournalBiochim Biophys Acta
PubMed ID6639946
'Interaction of poly(hexamethylene biguanide hydrochloride) (PHMB), which is a polymeric biocide bearing biguanide groups in its main chain, with phospholipid bilayers was studied by the fluorescence depolarization method. A strong interaction of PHMB with negatively charged bilayers composed of phosphatidylglycerol(PG) alone or of PG and phosphatidylcholine (PC) was observed, whereas ... More
Control of electric field induced cell membrane permeabilization by membrane order.
AuthorsRols MP, Dahhou F, Mishra KP, Teissié J
JournalBiochemistry
PubMed ID2337576
'Cells can be made temporarily permeable if pulsed by high-intensity short-duration electric fields. The molecular mechanisms underlying this electropermeabilization are still unknown. The kinetic events may be described by four successive steps: induction, expansion, stabilization, and resealing. On one hand, cell electropermeabilization is detected only under more stringent conditions when ... More
Cholesterol biosynthesis and modulation of membrane cholesterol and lipid dynamics in rat intestinal microvillus membranes.
AuthorsBrasitus TA, Schachter D
JournalBiochemistry
PubMed ID7093243
'Experiments were performed to test the hypothesis that cholesterol biosynthesis in the rat ileal enterocyte, the major absorptive cell lining the distal epithelium of the small intestine, can modulate the cholesterol content and the motional freedom of the plasma membrane lipids. Decreased sterol biosynthesis in vivo was elicited by feeding ... More
Flow cytometry is a new method for the characterization of intestinal plasma membrane.
AuthorsGorvel JP, Mawas C, Maroux S, Mishal Z
JournalBiochem J
PubMed ID6477477
'The highly differentiated plasma membrane of rabbit enterocytes constitutes an interesting model for membrane studies. Flow cytometry allows combined measurements of the size of membrane vesicles by light-scatter and fluorescence polarization at a single-particle level. The degree of fluorescence polarization of 1,6-diphenylhexa-1,3,5-triene was determined at 4, 18 and 37 degrees ... More