Poly(aspartic acid)-dependent fusion of liposomes bearing the quaternary ammonium detergent [[[(1,1,3,3-tetramethylbutyl)cresoxy]ethoxy]ethyl] dimethylbenzylammonium hydroxide.
AuthorsBeigel M, Keren-Zur M, Laster Y, Loyter A
JournalBiochemistry
PubMed ID3349055
Addition of the quaternary ammonium detergent [[[(1,1,3,3-tetramethylbutyl)cresoxy]ethoxy]ethyl] dimethylbenzylammonium hydroxide (DEBDA[OH]) and the fluorescent probes N-(7-nitro-2-1,3-benzoxadiazol-4-yl)phosphatidylethanolamine and N-(lissamine rhodamine B sulfonyl)phosphatidylethanolamine (N-NBD-PE and N-Rh-PE, respectively) to liposomes composed of phosphatidylcholine (PC) and cholesterol (chol) resulted in the formation of fluorescently labeled liposomes bearing DEBDA[OH]. Incubation of the anionic polymer poly(aspartic acid) ... More
Use of resonance energy transfer to study the kinetics of amphiphile transfer between vesicles.
AuthorsNichols JW, Pagano RE
JournalBiochemistry
PubMed ID7082641
Topography of the hydrophilic helices of membrane-inserted diphtheria toxin T domain: TH1-TH3 as a hydrophilic tether.
AuthorsWang J, Rosconi MP, London E
JournalBiochemistry
PubMed ID16800637
'After low pH-triggered membrane insertion, the T domain of diphtheria toxin helps translocate the catalytic domain of the toxin across membranes. In this study, the hydrophilic N-terminal helices of the T domain (TH1-TH3) were studied. The conformation triggered by exposure to low pH and changes in topography upon membrane insertion ... More
Immunochemical analysis shows all three domains of diphtheria toxin penetrate across model membranes.
AuthorsTortorella D, Sesardic D, Dawes CS, London E
JournalJ Biol Chem
PubMed ID7499201
'Diphtheria toxin undergoes membrane insertion and translocation across membranes when exposed to low pH. In this study, the translocation of the toxin has been investigated by the binding of antibodies to two preparations of model membrane-inserted toxin. In one preparation, toxin was added externally to model membrane vesicles and then ... More
Liposome-encapsulated antigens are processed in lysosomes, recycled, and presented to T cells.
AuthorsHarding CV, Collins DS, Slot JW, Geuze HJ, Unanue ER
JournalCell
PubMed ID1899049
'Antigen processing requires intracellular antigen catabolism to generate immunogenic peptides that bind to class II MHC molecules (MHC-II) for presentation to T-cells. We now provide direct evidence that these peptides are produced within dense lysosomes, as opposed to earlier endocytic compartments. The protein antigen hen egg lysozyme was targeted to ... More
Phospholipid transfer between phosphatidylcholine-taurocholate mixed micelles.
AuthorsNichols JW
JournalBiochemistry
PubMed ID3415964
'The transfer of fluorescent-labeled N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (N-NBD-PE) between phosphatidylcholine-taurocholate mixed micelles was measured by monitoring the increase in fluorescence as N-NBD-PE, initially contained in mixed micelles at self-quenching concentrations, was diluted into unlabeled mixed micelles. The half-times for transfer of a homologous series of N-NBD-PEs differing in saturated acyl chain length ... More
Membrane fusion by proline-rich Rz1 lipoprotein, the bacteriophage lambda Rz1 gene product.
AuthorsBryl K, Kedzierska S, Laskowska M, Taylor A
JournalEur J Biochem
PubMed ID10651816
'The fusogenic properties of Rz1, the proline-rich lipoprotein that is the bacteriophage lambda Rz1 gene product, were studied. Light scattering was used to monitor Rz1-induced aggregation of artificial neutral (dipalmitoylphosphatidylcholine/cholesterol) and negatively charged (dipalmitoylphosphatidylcholine/cholesterol/dioleoylphosphatidylserin e) liposomes. Fluorescence assays [the resonance energy transfer between N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine and N-(lissamine rhodamine B sulfonyl)dihexadecanol-sn-glycero-3-phosphoethanolamine lipid ... More
Membrane contact, fusion, and hexagonal (HII) transitions in phosphatidylethanolamine liposomes.
AuthorsAllen TM, Hong K, Papahadjopoulos D
JournalBiochemistry
PubMed ID2337577
'The behavior of phosphatidylethanolamine (PE) liposomes has been studied as a function of temperature, pH, ionic strength, lipid concentration, liposome size, and divalent cation concentration by differential scanning calorimetry (DSC), by light scattering, by assays measuring liposomal lipid mixing, contents mixing, and contents leakage, and by a new fluorometric assay ... More
Capacities of pardaxin analogues to induce fusion and leakage of negatively charged phospholipid vesicles are not necessarily correlated.
AuthorsRapaport D, Nir S, Shai Y
JournalBiochemistry
PubMed ID7918487
'Peptide-induced vesicle fusion is frequently accompanied by leakage of vesicle contents. To determine the correlation between these two processes, we studied the interaction of the amphiphilic peptide pardaxin and two of its analogues with large unilamellar vesicles composed of phosphatidylserine. A pardaxin analogue with a positive charge at both its ... More
Lateral organization and domain formation in a two-component lipid membrane system.
'The thermodynamic phase behavior and lateral lipid membrane organization of unilamellar vesicles made from mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2 distearoyl-sn-glycero-3-phosphocholine (DSPC) were investigated by fluorescence resonance energy transfer (FRET) as a function of temperature and composition. This was done by incorporating a headgroup-labeled lipid donor (NBD-DPPE) and acceptor (N-Rh-DPPE) ... More
High density of octaarginine stimulates macropinocytosis leading to efficient intracellular trafficking for gene expression.
AuthorsKhalil IA, Kogure K, Futaki S, Harashima H
JournalJ Biol Chem
PubMed ID16326716
'The mechanism of the arginine-rich peptide-mediated cellular uptake is currently a controversial issue. Several factors, including the type of peptide, the nature of the cargo, and the linker between them, appear to affect uptake. One of the less studied factors, which may affect the uptake mechanism, is the effect of ... More
Measurement of thermodynamic parameters for hydrophobic mismatch 2: intermembrane transfer of a transmembrane helix.
AuthorsYano Y, Ogura M, Matsuzaki K
JournalBiochemistry
PubMed ID16519532
'Hydrophobic matching between proteins and lipids is essential for the thermodynamic stability of integral membrane proteins. However, there is no direct thermodynamic information available about the intermembrane transfer of proteins between membranes with different hydrophobic thicknesses, which is crucial for understanding hydrophobic mismatch. This article reports the complete set of ... More
Fusion of sphingomyelin vesicles induced by proteins from Taiwan cobra (Naja naja atra) venom. Interactions of zwitterionic phospholipids with cardiotoxin analogues.
AuthorsChien KY, Huang WN, Jean JH, Wu WG
JournalJ Biol Chem
PubMed ID1993698
'Egg sphingomyelin vesicles were used to assay aggregation/fusion activities of proteins from Taiwan (Naja naja atra) venom to avoid the problem of phospholipase A2 contamination during protein purification. It led to the identification of a new cardiotoxin (CTX) analogue protein (CTX V) with major aggregation/fusion, but few hemolysis, activities. On ... More
The role of helper lipids in cationic liposome-mediated gene transfer.
AuthorsHui SW, Langner M, Zhao YL, Ross P, Hurley E, Chan K
JournalBiophys J
PubMed ID8842198
'In the procedure for cationic liposome-mediated transfection, the cationic lipid is usually mixed with a "helper lipid" to increase its transfection potency. The importance of helper lipids, including dioleoylphosphatidylcholine (DOPC) and phosphatidylethanolamine (dioleoyl PE), DO was examined. Freeze-fracture electron microscopy of DNA:cationic complexes containing the pSV-beta-GAL plasmid DNA, the cationic ... More
Kinetics of fluorescent-labeled phosphatidylcholine transfer between nonspecific lipid transfer protein and phospholipid vesicles.
AuthorsNichols JW
JournalBiochemistry
PubMed ID3378037
'Recently, rat liver nonspecific lipid transfer protein (nsLTP) was shown to form a fluorescent complex when allowed to equilibrate with self-quenching vesicles prepared from the fluorescent phospholipid 1-palmitoyl-2-[12-[(7-nitro-2,1,3-benzoxadiazol-4- yl)amino]dodecanoyl]phosphatidylcholine (P-C12-NBD-PC) [Nichols, J. W. (1987) J. Biol. Chem. 262, 14172-14177]. Investigation of the mechanism of complex formation was continued by studying ... More
Protein-induced fusion can be modulated by target membrane lipids through a structural switch at the level of the fusion peptide.
AuthorsPécheur EI, Martin I, Bienvenüe A, Ruysschaert JM, Hoekstra D
JournalJ Biol Chem
PubMed ID10660547
'Regulatory features of protein-induced membrane fusion are largely unclear, particularly at the level of the fusion peptide. Fusion peptides being part of larger protein complexes, such investigations are met with technical limitations. Here, we show that the fusion activity of influenza virus or Golgi membranes is strongly inhibited by minor ... More
Monitoring of phospholipid vesicle fusion by fluorescence energy transfer between membrane-bound dye labels.
AuthorsVanderwerf P, Ullman EF
JournalBiochim Biophys Acta
PubMed ID6766742
'A sensitive method which utilizes fluorescence energy transfer to assay Ca2+ -or Mg2+ -mediated fusion of phospholipid vesicles is reported. More than 85% quenching results when phosphatidylserine vesicles labelled with dansyl phosphatidylethanolamine (donor) are fused with vesicles labelled with rhodamine phosphatidylethanolamine (acceptor) in the presence of 5 mM CaCl2 or ... More
Membrane fusion is induced by a distinct peptide sequence of the sea urchin fertilization protein bindin.
AuthorsUlrich AS, Otter M, Glabe CG, Hoekstra D
JournalJ Biol Chem
PubMed ID9642230
'Fertilization in the sea urchin is mediated by the membrane-associated acrosomal protein bindin, which plays a key role in the adhesion and fusion between sperm and egg. We have investigated the structure/function relationship of an 18-amino acid peptide fragment "B18," which represents the minimal membrane binding motif of the protein ... More
Annexin-mediated membrane fusion of human neutrophil plasma membranes and phospholipid vesicles.
AuthorsOshry L, Meers P, Mealy T, Tauber AI
JournalBiochim Biophys Acta
PubMed ID1830223
'Membrane fusion was studied using human neutrophil plasma membrane preparations and phospholipid vesicles approximately 0.15 microns in diameter and composed of phosphatidylserine and phosphatidylethanolamine in a ratio of 1 to 3. Liposomes were labeled with N-(7-nitrobenzo-2-oxa-1,3-diazol-4-yl (NBD) and lissamine rhodamine B derivatives of phospholipids. Apparent fusion was detected as an ... More
Lipid rafts reconstituted in model membranes.
AuthorsDietrich C, Bagatolli LA, Volovyk ZN, Thompson NL, Levi M, Jacobson K, Gratton E
JournalBiophys J
PubMed ID11222302
'One key tenet of the raft hypothesis is that the formation of glycosphingolipid- and cholesterol-rich lipid domains can be driven solely by characteristic lipid-lipid interactions, suggesting that rafts ought to form in model membranes composed of appropriate lipids. In fact, domains with raft-like properties were found to coexist with fluid ... More
Tunable pH-sensitive liposomes composed of mixtures of cationic and anionic lipids.
AuthorsHafez IM, Ansell S, Cullis PR
JournalBiophys J
PubMed ID10969005
'The pH-dependent fusion properties of large unilamellar vesicles (LUVs) composed of binary mixtures of anionic and cationic lipids have been investigated. It is shown that stable LUVs can be prepared from the ionizable anionic lipid cholesteryl hemisuccinate (CHEMS) and the permanently charged cationic lipid N,N-dioleoyl-N, N-dimethylammonium chloride (DODAC) at neutral ... More
A novel series of amphiphilic imidazolinium compounds for in vitro and in vivo gene delivery.
AuthorsSolodin I, Brown CS, Bruno MS, Chow CY, Jang EH, Debs RJ, Heath TD
JournalBiochemistry
PubMed ID7577942
'We have developed three catioinic amphiphiles based on the structure 1-[2-(acyloxy)ethyl]-2-alkyl(alkenyl)-3-(2-hydroxyethyl)imidazolinium chloride. Although these three compounds differ only in the structure of the hydrophobic acyl chains, they differ greatly in their ability to mediate in vivo and in vitro gene delivery. Moreover, in vitro efficiency is not predictive of in ... More
Saturated anionic phospholipids enhance transdermal transport by electroporation.
AuthorsSen A, Zhao YL, Hui SW
JournalBiophys J
PubMed ID12324424
'Anionic phospholipids, but not cationic or neutral phospholipids, were found to enhance the transdermal transport of molecules by electroporation. When added as liposomes to the milieus of water-soluble molecules to be delivered through the epidermis of porcine skin by electroporation, these phospholipids enhance, by one to two orders of magnitude, ... More
Inhibition of influenza-induced membrane fusion by lysophosphatidylcholine.
AuthorsGünther-Ausborn S, Praetor A, Stegmann T
JournalJ Biol Chem
PubMed ID7493959
'Lysolipids have been reported to inhibit various membrane fusion events, and it was suggested that inhibition was due to their "inverted cone" shape, which hinders the formation of intermediate lipid structures required for fusion (Chernomordik, L. V., Vogel, S. S., Sokoloff, A., Onaran, H. O., Leikina, E. A., and Zimmerberg, ... More
Transport of fluorescent phospholipid analogues from the erythrocyte membrane to the parasite in Plasmodium falciparum-infected cells.
AuthorsHaldar K, de Amorim AF, Cross GA
JournalJ Cell Biol
PubMed ID2661561
'The asexual development of the human malaria parasite Plasmodium falciparum is largely intraerythrocytic. When 1-palmitoyl-2-[6-[(7-nitro-2-1,3-benzoxadiazole-4-yl)amino]caproyl] phosphatidylcholine (NBD-PC) was incorporated into infected and uninfected erythrocyte membranes at 0 degrees C, it remained at the cell surface. At 10 degrees C, the lipid was rapidly internalized in infected erythrocytes at all stages ... More
Exosome release is regulated by a calcium-dependent mechanism in K562 cells.
AuthorsSavina A, Furlán M, Vidal M, Colombo MI
JournalJ Biol Chem
PubMed ID12639953
'Multivesicular bodies (MVBs) are endocytic structures that contain small vesicles formed by the budding of an endosomal membrane into the lumen of the compartment. Fusion of MVBs with the plasma membrane results in secretion of the small internal vesicles termed exosomes. K562 cells are a hematopoietic cell line that releases ... More
Nonmonotonic alterations in the fluorescence anisotropy of polar head group labeled fluorophores during the lamellar to hexagonal phase transition of phospholipids.
AuthorsHan X, Gross RW
JournalBiophys J
PubMed ID1420879
'The temperature dependence of the fluorescence anisotropy of polar head group labeled fluorophores (i.e., N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L- alpha-phosphatidylethanolamine or N-(lissamine rhodamine B sulfonyl)dipalmitoyl-L-alpha-phosphatidylethanol- amine) incorporated into multiple phosphatidylethanolamine molecular species was parabolic, possessing minima (dr/dT = 0) that precisely correlated with the respective lamellar (L alpha) to hexagonal (HII) phase transition temperature ... More
Mechanism of protein-induced membrane fusion: fusion of phospholipid vesicles by clathrin associated with its membrane binding and conformational change.
AuthorsMaezawa S, Yoshimura T, Hong K, Düzgünes N, Papahadjopoulos D
JournalBiochemistry
PubMed ID2496757
'The clathrin-induced fusion of liposome membranes, the membrane binding of clathrin, and the conformational states of clathrin were investigated over a wide pH range using large unilamellar and multilamellar vesicles composed of phosphatidylserine (PS), phosphatidylcholine (PC), PS/PC (2:1), PS/PC (1:1), or PS/PC (1:2). The pH profiles of clathrin-induced fusion of ... More
Analysis of simulated and experimental fluorescence recovery after photobleaching. Data for two diffusing components.
AuthorsGordon GW, Chazotte B, Wang XF, Herman B
JournalBiophys J
PubMed ID7756543
'Fluorescence recovery after photobleaching has been a popular technique to quantify the lateral mobility of membrane components. A variety of analysis methods have been used to determine the lateral diffusional mobility, D. However, many of these methods suffer from the drawbacks that they are not able to discern two-component diffusion ... More
Coexisting stripe- and patch-shaped domains in giant unilamellar vesicles.
AuthorsLi L, Cheng JX
JournalBiochemistry
PubMed ID17002282
'We report a new type of gel-liquid phase segregation in giant unilamellar vesicles (GUVs) of mixed lipids. Coexisting patch- and stripe-shaped gel domains in GUV bilayers composed of DOPC/DPPC or DLPC/DPPC are observed by confocal fluorescence microscopy. The lipids in stripe domains are shown to be tilted according to the ... More
Fluorescence lifetime imaging microscopy (flimscopy). Methodology development and application to studies of endosome fusion in single cells.
AuthorsOida T, Sako Y, Kusumi A
JournalBiophys J
PubMed ID8471720
'A new method of fluorescence microscopy for cell imaging has been developed that takes advantage of the spatial variations of fluorescence lifetimes in single cells as a source of image contrast, and thus it is named "fluorescence lifetime imaging microscopy (flimscopy)". Since time-resolved fluorescence measurements are sensitive to molecular dynamics ... More
Mechanism of oligonucleotide release from cationic liposomes.
Authors Zelphati O; Szoka F C Jr;
JournalProc Natl Acad Sci U S A
PubMed ID8876163
'We propose a mechanism for oligonucleotide (ODN) release from cationic lipid complexes in cells that accounts for various observations on cationic lipid-nucleic acid-cell interactions. Fluorescent confocal microscopy of cells treated with rhodamine-labeled cationic liposome/ fluorescein-labeled ODN (F-ODN) complexes show the F-ODN separates from the lipid after internalization and enters the ... More
The location of fluorescence probes with charged groups in model membranes.
AuthorsKachel K, Asuncion-Punzalan E, London E
JournalBiochim Biophys Acta
PubMed ID9814853
'The location of commonly used charged fluorescent membrane probes in membranes was determined in order to: (1) investigate the relationship between the structure of hydrophobic molecules and their depth within membranes; and (2) aid interpretation of experiments in which these fluorescent probes are used to examine membrane structure. Membrane depth ... More
Calcium/phosphate-induced immobilization of fluorescent phosphatidylserine in synthetic bilayer membranes: inhibition of lipid transfer between vesicles.
AuthorsTanaka Y, Schroit AJ
JournalBiochemistry
PubMed ID3707938
'Resonance energy transfer between 4-nitro-2,1,3-benzoxadiazole (NBD) acyl chain labeled phospholipid analogues and (lissamine) rhodamine B labeled phosphatidylethanolamine was used to monitor the rate of NBD-labeled lipid transfer between a variety of small unilamellar donor vesicles and dioleoylphosphatidylcholine (DOPC) acceptor vesicles. In the presence of appropriate concentrations of Ca2+ and phosphate, ... More
Factors governing the assembly of cationic phospholipid-DNA complexes.
AuthorsKennedy MT, Pozharski EV, Rakhmanova VA, MacDonald RC
JournalBiophys J
PubMed ID10692346
'The interaction of DNA with a novel cationic phospholipid transfection reagent, 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EDOPC), was investigated by monitoring thermal effects, particle size, vesicle rupture, and lipid mixing. By isothermal titration calorimetry, the heat of interaction between large unilamellar EDOPC vesicles and plasmid DNA was endothermic at both physiological and low ionic ... More
Mechanisms of action of the bactericidal/permeability-increasing protein BPI on endotoxin and phospholipid monolayers and aggregates.
AuthorsWiese A, Brandenburg K, Lindner B, Schromm AB, Carroll SF, Rietschel ET, Seydel U
JournalBiochemistry
PubMed ID9254629
'We have investigated the mechanisms of interaction of the recombinant N-terminal portion of bactericidal/permeability-increasing protein, rBPI21, with lipopolysaccharide (LPS) isolated from enterobacterial deep rough mutant strains. Experimentally, the ability of rBPI21 to form monolayers at the air/water interface and its action on lipid monolayers were analyzed. We have further studied ... More
Thermosensitive liposomes: extravasation and release of contents in tumor microvascular networks.
AuthorsGaber MH, Wu NZ, Hong K, Huang SK, Dewhirst MW, Papahadjopoulos D
JournalInt J Radiat Oncol Biol Phys
PubMed ID8985041
'PURPOSE: The purpose of this study was to determine whether hyperthermic exposure would accelerate drug release from thermosensitive sterically stabilized liposomes and enhance their extravasation in tumor tissues. MATERIALS AND METHODS: In vivo fluorescence video microscopy was used to measure the extravasation of liposomes, as well as release of their ... More
Trans interactions between galactosylceramide and cerebroside sulfate across apposed bilayers.
AuthorsBoggs JM, Menikh A, Rangaraj G
JournalBiophys J
PubMed ID10653800
'The two glycosphingolipids galactosylceramide (GalC) and its sulfated form, cerebroside sulfate (CBS), are present at high concentrations in the multilayered myelin sheath and are involved in carbohydrate-carbohydrate interactions between the lipid headgroups. In order to study the structure of the complex of these two glycolipids by Fourier transform infrared (FTIR) ... More
Effects of lipid headgroup and packing stress on poly(ethylene glycol)-induced phospholipid vesicle aggregation and fusion.
AuthorsYang Q, Guo Y, Li L, Hui SW
JournalBiophys J
PubMed ID9199792
'The effect of lipid headgroup and curvature-related acyl packing stress on PEG-induced phospholipid vesicle aggregation and fusion were studied by measuring vesicle and aggregate sizes using the quasi-elastic light scattering and fluorescence energy transfer techniques. The effect of the lipid headgroup was monitored by varying the relative phosphatidylcholine (PC) and ... More
Direct visualization of saposin remodelling of lipid bilayers.
AuthorsAlattia JR, Shaw JE, Yip CM, Privé GG
JournalJ Mol Biol
PubMed ID16949605
'Saposins A, B, C and D are soluble, non-enzymatic proteins that interact with lysosomal membranes to activate the breakdown and transfer of glycosphingolipids. The mechanisms of hydrolase activation and lipid transfer by saposins remain unknown. We have used in situ atomic force microscopy (AFM) with simultaneous confocal fluorescence microscopy to ... More
The pre-transmembrane region of the human immunodeficiency virus type-1 glycoprotein: a novel fusogenic sequence.
AuthorsSuárez T, Nir S, Goñi FM, Saéz-Cirión A, Nieva JL
JournalFEBS Lett
PubMed ID10899326
'We have investigated membrane interactions and perturbations induced by NH(2)-DKWASLWNWFNITNWLWYIK-COOH (HIV(c)), representing the membrane interface-partitioning region that precedes the transmembrane anchor of the human immunodeficiency virus type-1 gp41 fusion protein. The HIV(c) peptide bound with high affinity to electrically neutral vesicles composed of dioleoylphosphatidylcholine, dioleoylphosphatidylethanolamine and cholesterol (molar ratio, 1:1:1), ... More
Biophysical characterization of triacyl monosaccharide lipid a partial structures in relation to bioactivity.
AuthorsBrandenburg K, Matsuura M, Heine H, Müller M, Kiso M, Ishida H, Koch MH, Seydel U
JournalBiophys J
PubMed ID12080123
'Synthetic triacyl glucosamine monosaccharide lipid A part structures corresponding to the non-reducing moiety of enterobacterial lipid A with an acyloxyacyl chain linked to position 3 of the glucosamine and an unbranched chain linked to position 2 (group 1) and vice versa (group 2) were analyzed biophysically: Fourier-transform infrared spectroscopy was ... More
Generation of pH-sensitive liposomes: use of large unilamellar vesicles containing N-succinyldioleoylphosphatidylethanolamine.
AuthorsNayar R, Schroit AJ
JournalBiochemistry
PubMed ID4084501
'By use of a carboxylated derivative of phosphatidylethanolamine, N-succinyldioleoylphosphatidylethanolamine (COPE), pH-sensitive liposomes have been designed that have a wide range of leakage properties. The leakage rate of the vesicle contents, as determined by the release kinetics of the water-soluble fluorophore 8-aminonaphthalene-1,3,6-trisulfonic acid complexed with the quencher p-xylenebis(pyridinium) dibromide [Ellens, H., ... More
The movement of fluorescent endocytic tracers in Plasmodium falciparum infected erythrocytes.
AuthorsHaldar K, Uyetake L
JournalMol Biochem Parasitol
PubMed ID1371847
'The fluorescent lipophilic probe 1,1''-dihexadecyl-3-3''-3-3''- tetramethylindocarbocyanine (diIC16) inserted in the red cell surface, functioned as a non-exchangeable lipid marker which was not metabolised or toxic in plasmodial cultures. Invasion by Plasmodium falciparum resulted in the internalisation of the lipid, suggesting the uptake of red cell membrane components during parasite entry. ... More
A protein containing a serine-rich domain with vesicle fusing properties mediates cell cycle-dependent cytosolic pH regulation.
AuthorsBrazill DT, Caprette DR, Myler HA, Hatton RD, Ammann RR, Lindsey DF, Brock DA, Gomer RH
JournalJ Biol Chem
PubMed ID10747962
'Initial differentiation in Dictyostelium involves both asymmetric cell division and a cell cycle-dependent mechanism. We previously identified a gene, rtoA, which when disrupted randomizes the cell cycle-dependent mechanism without affecting either the underlying cell cycle or asymmetric differentiation. We find that in wild-type cells, RtoA levels vary during the cell ... More
Use of spin-labeled and fluorescent lipids to study the activity of the phospholipid transfer protein from maize seedlings.
AuthorsGeldwerth D, de Kermel A, Zachowski A, Guerbette F, Kader JC, Henry JP, Devaux PF
JournalBiochim Biophys Acta
PubMed ID1851443
'The transfer of spin-labeled and fluorescent lipids between sonicated vesicles and different host membranes has been measured in the presence or absence of a phospholipid transfer protein purified from maize seedlings. It was found that the protein has little specificity towards the phospholipid head group and allows the transfer of ... More
Stability and fusion of lipid vesicles containing headgroup-modified analogues of phosphatidylethanolamine.
AuthorsBrown PM, Silvius JR
JournalBiochim Biophys Acta
PubMed ID2930786
'We have used lipid mixing, contents mixing and contents-leakage assays to characterize the divalent cation-mediated interactions of vesicles composed of various headgroup-modified analogues of phosphatidylethanolamine, PE (N- and C-2-alkylated derivatives, and analogues with increased separations of the phosphoryl and amino groups) together with a low mole percentage of phosphatidylserine (PS). ... More
Calcium-independent stimulation of membrane fusion and SNAREpin formation by synaptotagmin I.
'Neurotransmitter release requires the direct coupling of the calcium sensor with the machinery for membrane fusion. SNARE proteins comprise the minimal fusion machinery, and synaptotagmin I, a synaptic vesicle protein, is the primary candidate for the main neuronal calcium sensor. To test the effect of synaptotagmin I on membrane fusion, ... More
Fusion of influenza virus with cardiolipin liposomes at low pH: mass action analysis of kinetics and extent.
AuthorsNir S, Stegmann T, Wilschut J
JournalBiochemistry
PubMed ID3954989
'The kinetics and extent of low pH induced fusion between influenza virus and large unilamellar cardiolipin liposomes were investigated with an assay for lipid mixing based on fluorescence resonance energy transfer. The results were analyzed in terms of a mass action kinetic model, which views the overall fusion reaction as ... More
Leaky vesicle fusion induced by phosphatidylinositol-specific phospholipase C: observation of mixing of vesicular inner monolayers.
AuthorsVillar AV, Alonso A, Goñi FM
JournalBiochemistry
PubMed ID11087348
'Large unilamellar vesicles containing phosphatidylinositol (PI), neutral phospholipids, and cholesterol are induced to fuse by the catalytic activity of phosphatidylinositol-specific phospholipase C (PI-PLC). PI cleavage by PI-PLC is followed by vesicle aggregation, intervesicular lipid mixing, and mixing of vesicular aqueous contents. An average of 2-3 vesicles merge into a large ... More
Physical and biological properties of cationic triesters of phosphatidylcholine
AuthorsMacDonald RC, Ashley GW, Shida MM, Rakhmanova VA, Tarahovsky YS, Pantazatos DP, Kennedy MT, Pozharski EV, Baker KA, Jones RD, Rosenzweig HS, Choi KL, Qiu R, McIntosh TJ
JournalBiophys J
PubMed ID10545361
'The properties of a new class of phospholipids, alkyl phosphocholine triesters, are described. These compounds were prepared from phosphatidylcholines through substitution of the phosphate oxygen by reaction with alkyl trifluoromethylsulfonates. Their unusual behavior is ascribed to their net positive charge and absence of intermolecular hydrogen bonding. The O-ethyl, unsaturated derivatives ... More
Asymmetric fusion between phospholipid vesicles and vesicles formed from synthetic di(n-alkyl)phosphates.
AuthorsFonteijn TA, Engberts JB, Hoekstra D
JournalBiochemistry
PubMed ID2036399
'We have investigated the fusion behavior of a mixed vesicle system consisting of vesicles prepared from the simple synthetic surfactants di(n-dodecyl)phosphate (DDP) or di(n-tetradecyl)phosphate (DTP) and vesicles prepared from the phospholipids phosphatidylserine (PS) or dioleoylphosphatidylcholine (DOPC). Fusion between the vesicles, induced by Ca2+, was determined by a resonance energy transfer ... More
Formation of asymmetric phospholipid membranes via spontaneous transfer of fluorescent lipid analogues between vesicle populations.
AuthorsPagano RE, Martin OC, Schroit AJ, Struck DK
JournalBiochemistry
PubMed ID7295659
'A method is presented for generating artificial lipid vesicles bearing an asymmetric distribution of either of the fluorescent lipid analogues 1-acyl-2-[6-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]caproyl]phosphatidylcholine or 1-acyl-2-[12[(7-nitro-2,1,3-benzoxadiazol-4-yl]amino]dodecanoyl]-phosphatidylcholine, in which the fluorescent lipid is located predominantly in either the outer or inner leaflet of the vesicle bilayer. The procedure is based on the observation that ... More
Cellular retention of liposome-delivered anionic compounds modulated by a probenecid-sensitive anion transporter.
AuthorsOh YK, Straubinger RM
JournalPharm Res
PubMed ID9327449
'PURPOSE: Drug carriers such as liposomes may enhance the intracellular delivery of therapeutic agents for infectious or neoplastic diseases. However, the mechanisms affecting cellular retention of liposome contents are understood poorly. We tested the hypothesis that retention of anionic compounds may be modulated by a nonspecific probenecid-sensitive anion transport mechanism, ... More
Characteristics of self-quenching of the fluorescence of lipid-conjugated rhodamine in membranes.
AuthorsMacDonald RI
JournalJ Biol Chem
PubMed ID2380172
'Self- or concentration quenching of octadecylrhodamine B (C18-Rh) fluorescence increases linearly in egg phosphatidylcholine (PC) vesicles but exponentially in vesicles composed of egg PC:cholesterol, 1:1, as the probe concentration is raised to 10 mol%. Cholesterol-dependent enhancement of self-quenching also occurs when N-(lissamine-rhodamine-B-sulfonyl)dioleoylphosphatidylethanolamine is substituted for C18-Rh and resembles that in ... More
Preferential distribution of the fluorescent phospholipid probes NBD-phosphatidylcholine and rhodamine-phosphatidylethanolamine in the exofacial leaflet of acetylcholine receptor-rich membranes from Torpedo marmorata.
AuthorsGutiérrez-Merino C, Bonini de Romanelli IC, Pietrasanta LI, Barrantes FJ
JournalBiochemistry
PubMed ID7718591
'The distribution of the two fluorescent phospholipid analogs across acetylcholine receptor (AChR)-rich membranes from Torpedo marmorata has been studied by a combination of nonradiative fluorescence resonance energy transfer using fluorescent lipid probes and quenching of their fluorescence with Co2+ and 2,4,6-trinitrobenzenesulfonic acid. The fluorescent lipid analogs were supplied to the ... More
A non-exchangeable fluorescent phospholipid analog as a membrane traffic marker of the endocytic pathway.
AuthorsWillem J, ter Beest M, Scherphof G, Hoekstra D
JournalEur J Cell Biol
PubMed ID2076704
'The fluorescent phospholipid analog N-(lissamine rhodamine B sulfonyl)phosphatidylethanolamine (N-Rh-PE) was inserted into the plasma membrane of Baby hamster kidney cells at low temperature (2 degrees C). The mobility characteristics of the analog--as revealed by fluorescence photobleaching recovery--were very similar to those of membrane-inserted 1-acyl-2[6-[N-(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]caproyl] phosphatidylcholine (C6-NBD-PC). Upon warming to ... More
Detection of lipid domains in docasahexaenoic acid-rich bilayers by acyl chain-specific FRET probes.
AuthorsStillwell W, Jenski LJ, Zerouga M, Dumaual AC
JournalChem Phys Lipids
PubMed ID10669305
'A major problem in defining biological membrane structure is deducing the nature and even existence of lipid microdomains. Lipid microdomains have been defined operationally as heterogeneities in the behavior of fluorescent membrane probes, particularly the fluorescence resonance energy transfer (FRET) probes 7-nitrobenz-2-oxa-1,3-diazol-4-yl-diacyl-sn-glycero-3-phosphoethan olamine (N-NBD-PE) and (N-lissamine rhodamine B sulfonyl)-diacyl-snglycero-3-phosphoethanolamine (N-Rh-PE). ... More
Intracellular translocation and metabolism of a fluorescent phosphatidic acid analogue in cultured fibroblasts.
AuthorsPagano RE, Longmuir KJ, Martin OC
JournalJ Biol Chem
PubMed ID6822547
'We have investigated the metabolism and intracellular translocation of a fluorescent derivative of phosphatidic acid, 1-acyl-2-[(N-4-nitrobenzo-2-oxa-1,3-diazole)aminocaproyl] phosphatidic acid (C6-NBD-PA), and its metabolites, in Chinese hamster fibroblasts. This derivative is rapidly transferred from phospholipid vesicles to cells at 2 degrees C, and results in fluorescent labeling of the mitochondria, endoplasmic reticulum, ... More
Influenza hemagglutinin-mediated membrane fusion: influence of receptor binding on the lag phase preceding fusion.
AuthorsStegmann T, Bartoldus I, Zumbrunn J
JournalBiochemistry
PubMed ID7849043
'Fusion of influenza virus with liposomes is triggered by low pH, resulting in a conformational change in the fusion protein (HA) and the insertion of fusion peptides from HA into the liposomal membrane. Fusion does not take place immediately after insertion but is preceded by a lag phase, the duration ... More
Synthesis and properties of radioiodinated phospholipid analogues that spontaneously undergo vesicle-vesicle and vesicle-cell transfer.
AuthorsSchroit AJ, Madsen JW
JournalBiochemistry
PubMed ID6615789
'An efficient method for the synthesis and purification of a variety of iodinated phospholipid analogues is described. 1-Acyl-2-[[[3-(3-[125I]iodo-4-hydroxyphenyl)- propionyl]amino]caproyl]phosphatidylcholine (125I-PC) was prepared by alkylation of 1-acyl-2-(aminocaproyl)phosphatidylcholine with monoiodinated Bolton-Hunter reagent. 125I-Labeled phosphatidic acid, phosphatidylethanolamine, and phosphatidylserine were produced from 125I-PC by phospholipase D catalyzed base exchange in the presence of ... More
Hydrophobic lipid additives affect membrane stability and phase behavior of N-monomethyldioleoylphosphatidylethanolamine.
Authorsvan Gorkom LC, Nie SQ, Epand RM
JournalBiochemistry
PubMed ID1731922
'The rate of formation of high-curvature intermediates or disordered cubic phases in N-methyldioleoylphosphatidylethanolamine (N-methyl-DOPE) dispersions with or without additives was studied by 31P NMR spectroscopy. In N-methyl-DOPE dispersions, both the L alpha liquid-crystalline phase and the hexagonal HII phase convert into phases of high curvature giving rise to isotropic 31P ... More
Fluorescence method for measuring the kinetics of fusion between biological membranes.
AuthorsHoekstra D, de Boer T, Klappe K, Wilschut J
JournalBiochemistry
PubMed ID6098295
'An assay is presented that allows continuous and sensitive monitoring of membrane fusion in both artificial and biological membrane systems. The method relies upon the relief of fluorescence self-quenching of octadecyl Rhodamine B chloride. When the probe is incorporated into a lipid bilayer at concentrations up to 9 mol% with ... More
The charge of endotoxin molecules influences their conformation and IL-6-inducing capacity.
AuthorsSchromm AB, Brandenburg K, Loppnow H, Zähringer U, Rietschel ET, Carroll SF, Koch MH, Kusumoto S, Seydel U
JournalJ Immunol
PubMed ID9820522
'The activation of cells by endotoxin (LPS) is one of the early host responses to infections with Gram-negative bacteria. The lipid A part of LPS molecules is known to represent the endotoxic principle; however, the specific requirements for the expression of biologic activity are still not fully understood. We previously ... More
Poly(ethylene glycol)--lipid conjugates regulate the calcium-induced fusion of liposomes composed of phosphatidylethanolamine and phosphatidylserine.
AuthorsHolland JW, Hui C, Cullis PR, Madden TD
JournalBiochemistry
PubMed ID8611565
'The effect of poly(ethylene glycol)--lipid (PEG--lipid) conjugates on liposomal fusion was investigated. Incorporation of PEG--lipids into large unilamellar vesicles (LUVs) composed of equimolar phosphatidylethanolamine (PE) and phosphatidylserine (PS) inhibited calcium-induced fusion. The degree of inhibition increased with increasing molar ratio of the PEG conjugate and with increasing size of the ... More
Direct high affinity modulation of connexin channel activity by cyclic nucleotides.
AuthorsBevans CG, Harris AL
JournalJ Biol Chem
PubMed ID9920924
'Connexin channels mediate molecular communication between cells. However, positive identification of biological ligands that directly and noncovalently modulate their activity has been elusive. This study demonstrates a high affinity inhibition of connexin channels by the purine cyclic monophosphates cAMP and cGMP. Purified homomeric connexin-32 and heteromeric connexin-32/connexin-26 channels were inhibited ... More
Binding of fluorescent-labeled phosphatidylcholine to rat liver nonspecific lipid transfer protein.
AuthorsNichols JW
JournalJ Biol Chem
PubMed ID3654657
'The fluorescent-labeled phospholipid, 1-palmitoyl-2-[12-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]dodecan oyl] phosphatidylcholine (P-C12-NBD-PC), is highly self-quenched when contained as a high mole percent in phospholipid vesicles. The addition of nonspecific lipid transfer protein (nsLTP), which is identical to sterol carrier protein2, to P-C12-NBD-PC self-quenching vesicles results in a large increase in the fluorescence yield. Evidence is ... More
Liposome targeting to human immunodeficiency virus type 1-infected cells via recombinant soluble CD4 and CD4 immunoadhesin (CD4-IgG).
AuthorsFlasher D, Konopka K, Chamow SM, Dazin P, Ashkenazi A, Pretzer E, Düzgünes N
JournalBiochim Biophys Acta
PubMed ID8075135
'HIV-infected cells producing virions express the viral envelope glycoprotein gp120/gp41 on their surface. We examined whether liposomes coupled to recombinant soluble CD4 (sCD4, the ectodomain of CD4 which binds gp120 with high affinity) could specifically bind to HIV-infected cells. sCD4 was chemically coupled by 2 different methods to liposomes containing ... More
Thermodynamics and kinetics of phospholipid monomer-vesicle interaction.
AuthorsNichols JW
JournalBiochemistry
PubMed ID4084528
'Resonance energy transfer between acyl chain labeled (7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylcholine (NBD-PC) and head group labeled (lissamine rhodamine B sulfonyl)phosphatidylethanolamine (N-Rh-PE) was used to monitor the rate of NBD-PC transfer between two populations of dioleoylphosphatidylcholine (DOPC) vesicles. Equilibration of NBD-PC between DOPC vesicles occurs by the diffusion of soluble monomers through the water ... More
Lipid mixing during membrane aggregation and fusion: why fusion assays disagree.
AuthorsDüzgünes N, Allen TM, Fedor J, Papahadjopoulos D
JournalBiochemistry
PubMed ID3442666
'The kinetics of lipid mixing during membrane aggregation and fusion was monitored by two assays employing resonance energy transfer between N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (NBD-PE) and N-(lissamine Rhodamine B sulfonyl)phosphatidylethanolamine (Rh-PE). For the "probe mixing" assay, NBD-PE and Rh-PE were incorporated into separate populations of phospholipid vesicles. For the "probe dilution" assay, both ... More
Fusion of human neutrophil phagosomes with lysosomes in vitro: involvement of tyrosine kinases of the Src family and inhibition by mycobacteria.
AuthorsPeyron P, Maridonneau-Parini I, Stegmann T
JournalJ Biol Chem
PubMed ID11463789
'The intracellular killing of microorganisms in phagocytes involves the fusion of lysosomes containing bactericidal factors with phagosomes, and several intracellular pathogens are able to inhibit this fusion event. In this study, we report the reconstitution of phagosome-lysosome fusion in vitro, using an assay based on resonance energy transfer between fluorescent ... More
Transbilayer movement of a fluorescent phosphatidylethanolamine analogue across the plasma membranes of cultured mammalian cells.
AuthorsSleight RG, Pagano RE
JournalJ Biol Chem
PubMed ID3968058
'The internalization of a fluorescent analogue of phosphatidylethanolamine following its insertion into the plasma membrane of cultured Chinese hamster fibroblasts was examined. When liposomes composed of 50 mol % 1-acyl-2-(N-4-nitrobenzo-2-oxa-1,3-diazole)-aminocaproyl phosphatidylethanolamine (C6-NBD-PE) and dioleoylphosphatidylcholine were incubated with monolayer cell cultures at 2 degrees C, a spontaneous transfer of the fluorescent ... More
The interaction of Sendai virus with negatively charged liposomes: virus-induced lysis of carboxyfluorescein-loaded small unilamellar vesicles.
AuthorsAmselem S, Loyter A, Lichtenberg D, Barenholz Y
JournalBiochim Biophys Acta
PubMed ID2996597
'The interaction of Sendai virus with small, unilamellar vesicles, lacking virus receptors and loaded with self-quenched 6-carboxyfluorescein, was studied. Sendai virions induced release of carboxyfluorescein from vesicles composed of negative charged phospholipids, despite the fact that they did not contain virus receptors. Preliminary experiments indicate that the carboxyfluorescein release is ... More
Fluorescence resonance energy transfer study of shape changes in membrane-bound bovine prothrombin and meizothrombin.
AuthorsChen Q, Lentz BR
JournalBiochemistry
PubMed ID9109682
'Prothrombin activation to thrombin is a key control reaction in blood coagulation. During the process, prothrombin is sequentially cleaved at two peptide bonds (Arg323-Ile and Arg274-Thr) by factor X(a) to generate meizothrombin and then thrombin. Phosphatidylserine (PS)-containing membranes from platelets are believed to facilitate this two-step process. Using fluorescence energy ... More
Fusion peptides derived from the HIV type 1 glycoprotein 41 associate within phospholipid membranes and inhibit cell-cell Fusion. Structure-function study.
AuthorsKliger Y, Aharoni A, Rapaport D, Jones P, Blumenthal R, Shai Y
JournalJ Biol Chem
PubMed ID9153194
'The fusion domain of human immunodeficiency virus (HIV-1) envelope glycoprotein (gp120-gp41) is a conserved hydrophobic region located at the N terminus of the transmembrane glycoprotein (gp41). A V2E mutant has been shown to dominantly interfere with wild-type envelope-mediated syncytium formation and virus infectivity. To understand this phenomenon, a 33-residue peptide ... More
Phospholipase C beta2 association with phospholipid interfaces assessed by fluorescence resonance energy transfer. G protein betagamma subunit-mediated translocation is not required for enzyme activation.
AuthorsRomoser V, Ball R, Smrcka AV
JournalJ Biol Chem
PubMed ID8810260
'Phospholipase C beta2 (PLC beta2) is activated by G protein betagamma subunits and calcium. The enzyme is soluble and its substrate, phosphatidylinositol 4,5-bisphosphate (PIP2), is present in phospholipid membranes. A potential mechanism for regulation of this enzyme is through influencing the equilibrium association of the enzyme with membrane surfaces. In ... More
Large liposome agglutination technique for the serological detection of syphilis.
AuthorsKung VT, Vollmer YP, Martin FJ
JournalJ Immunol Methods
PubMed ID3722824
'In response to tissue invasion by Treponema pallidum, an antibody complex, called reagin, appears in the serum of the syphilitic patients. Reagin has the ability to combine with cardiolipin, therefore, cardiolipin has traditionally been used as the antigen in different test configurations for the serological detection of syphilis: the VDRL ... More
Myelin basic protein component C1 in increasing concentrations can elicit fusion, aggregation, and fragmentation of myelin-like membranes.
AuthorsMac Millan SV, Ishiyama N, White GF, Palaniyar N, Hallett FR, Harauz G
JournalEur J Cell Biol
PubMed ID10887963
'Myelin basic protein (MBP) is considered to have a primary role in the formation and maintenance of the myelin sheath. Many studies using artificial vesicle systems of simple lipid composition, and generally small size, have shown that MBP can elicit vesicle fusion, aggregation, or even fragmentation under different conditions. Here, ... More
Ca2+-independent, protein-mediated fusion of chromaffin granule ghosts with liposomes.
AuthorsBental M, Lelkes PI, Scholma J, Hoekstra D, Wilschut J
JournalBiochim Biophys Acta
PubMed ID6331508
'We have investigated the interaction between isolated membrane vesicles from chromaffin granules and large unilamellar phospholipid vesicles (liposomes). Mixing of membrane lipids has been monitored continuously, utilizing the fluorescence resonance energy transfer assay described by Struck et al. ((1982) Biochemistry 20, 4093-4099). To demonstrate coalescence of the internal vesicle volumes ... More
Plasmenylethanolamine facilitates rapid membrane fusion: a stopped-flow kinetic investigation correlating the propensity of a major plasma membrane constituent to adopt an HII phase with its ability to promote membrane fusion.
AuthorsGlaser PE, Gross RW
JournalBiochemistry
PubMed ID8180209
'A critical step in membrane fusion involves the formation of a lipid intermediate which shares a conformational similarity with an inverted hexagonal phase (HII). Since plasmenylethanolamines possess a marked propensity for hexagonal phase formation and represent a major lipid constituent of several membrane systems which undergo rapid membrane fusion (e.g., ... More
Ca2+-induced fusion of phosphatidylserine vesicles: mass action kinetic analysis of membrane lipid mixing and aqueous contents mixing.
AuthorsWilschut J, Scholma J, Bental M, Hoekstra D, Nir S
JournalBiochim Biophys Acta
PubMed ID4063361
'We have investigated the initial kinetics of Ca2+-induced aggregation and fusion of phosphatidylserine large unilamellar vesicles at 3, 5 and 10 mM Ca2+ and 15, 25 and 35 degrees C, utilizing the Tb/dipicolinate (Tb/DPA) assay for mixing of aqueous vesicle contents and a resonance energy transfer (RET) assay for mixing ... More
Composition of octyl glucoside-phosphatidylcholine mixed micelles.
AuthorsEidelman O, Blumenthal R, Walter A
JournalBiochemistry
PubMed ID3401451
'The composition of mixed micelles of egg phosphatidylcholine (PC) and octyl glucoside was studied by a novel technique based on measuring resonance energy-transfer efficiency between two fluorescent lipid probes present in trace amounts. Equations were derived for calculating the stoichiometry of the composition of mixed micelles from the energy-transfer measurements. ... More
Liposome fusion induced by a M(r) 18,000 protein localized to the acrosomal region of acrosome-reacted abalone spermatozoa.
AuthorsSwanson WJ, Vacquier VD
JournalBiochemistry
PubMed ID7578018
'A M(r) 18,000 protein is secreted by abalone spermatozoa during the acrosome reaction. Immunofluorescence of acrosome-reacted sperm localizes the protein as a coating on the spent acrosomal granule hull and on the surface of the acrosomal process. The membrane of the acrosomal process fuses with the egg plasma membrane at ... More
Interactions of cationic lipid vesicles with negatively charged phospholipid vesicles and biological membranes.
AuthorsStamatatos L, Leventis R, Zuckermann MJ, Silvius JR
JournalBiochemistry
PubMed ID3415963
'Lipid vesicles with a positive surface charge have been prepared by using mixtures of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) together with low mole fractions of a cationic lipid analogue, 1,2-bis(oleoyloxy)-3-(trimethylammonio)propane (DOTAP). We have used measurements of vesicle aggregation, lipid mixing, contents mixing, and contents leakage to examine the interactions between ... More
Spatial organization of bacteriorhodopsin in model membranes. Light-induced mobility changes.
AuthorsKahya N, Wiersma DA, Poolman B, Hoekstra D
JournalJ Biol Chem
PubMed ID12167614
'Bacteriorhodopsin is a proton-transporting membrane protein in Halophilic archaea, and it is considered a prototype of membrane transporters and a model for G-protein-coupled receptors. Oligomerization of the protein has been reported, but it is unknown whether this feature is correlated with, for instance, light activation. Here, we have addressed this ... More
The purified and functionally reconstituted multidrug transporter LmrA of Lactococcus lactis mediates the transbilayer movement of specific fluorescent phospholipids.
AuthorsMargolles A, Putman M, van Veen HW, Konings WN
JournalBiochemistry
PubMed ID10587454
'Lactococcus lactis possesses an ATP-binding cassette transporter, LmrA, which is a homolog of the mammalian multidrug resistance (MDR) P-glycoprotein, and is able to transport a broad range of structurally unrelated amphiphilic drugs. A histidine tag was introduced at the N-terminus of LmrA to facilitate purification by nickel affinity chromatography. The ... More
Intervesicular exchange of lipids with weak acid and weak base characteristics: influence of transmembrane pH gradients.
AuthorsEastman SJ, Wilschut J, Cullis PR, Hope MJ
JournalBiochim Biophys Acta
PubMed ID2730899
'Transmembrane pH gradients have previously been shown to induce an asymmetric transmembrane distribution of simple lipids that exhibit weak acid or basic characteristics (Hope, M.J. and Cullis, P.R. (1987) J. Biol. Chem. 262, 4360-4366). In the present study we have examined the influence of proton gradients on the inter-vesicular exchange ... More
Early endosomal SNAREs form a structurally conserved SNARE complex and fuse liposomes with multiple topologies.
AuthorsZwilling D, Cypionka A, Pohl WH, Fasshauer D, Walla PJ, Wahl MC, Jahn R
JournalEMBO J
PubMed ID17159904
'SNARE proteins mediate membrane fusion in eukaryotic cells. They contain conserved SNARE motifs that are usually located adjacent to a C-terminal transmembrane domain. SNARE motifs spontaneously assemble into four helix bundles, with each helix belonging to a different subfamily. Liposomes containing SNAREs spontaneously fuse with each other, but it is ... More
Interaction of CAP18-derived peptides with membranes made from endotoxins or phospholipids.
AuthorsGutsmann T, Hagge SO, Larrick JW, Seydel U, Wiese A
JournalBiophys J
PubMed ID11371466
'Antimicrobial peptides with alpha-helical structures and positive net charges are in the focus of interest with regard to the development of new antibiotic agents, in particular against Gram-negative bacteria. Interaction between seven polycationic alpha-helical CAP18-derived peptides and different types of artificial membranes composed of phosphatidylcholine or lipopolysaccharide of the Gram-negative ... More
pH-dependent fusion of phosphatidylcholine small vesicles. Induction by a synthetic amphipathic peptide.
AuthorsParente RA, Nir S, Szoka FC
JournalJ Biol Chem
PubMed ID2450874
'A synthetic, amphipathic 30-amino acid peptide with the major repeat unit Glu-Ala-Leu-Ala (GALA) was designed to mimic the behavior of the fusogenic sequences of viral fusion proteins. GALA is a water-soluble peptide with an aperiodic conformation at neutral pH and becomes an amphipathic alpha-helix as the pH is lowered to ... More
Calcium-dependent association of calmodulin with the C-terminal domain of the tetraspanin protein peripherin/rds.
AuthorsEdrington TC, Yeagle PL, Gretzula CL, Boesze-Battaglia K
JournalBiochemistry
PubMed ID17323925
'Peripherin/rds (p/rds), an integral membrane protein from the transmembrane 4 (TMF4) superfamily, possesses a multi-functional C-terminal domain that plays crucial roles in rod outer segment (ROS) disk renewal and structure. Here, we report that the calcium binding protein calmodulin (CaM) binds to the C-terminal domain of p/rds. Fluorescence spectroscopy reveals ... More
Dolichyl phosphate induces non-bilayer structures, vesicle fusion and transbilayer movement of lipids: a model membrane study.
Authorsvan Duijn G, Valtersson C, Chojnacki T, Verkleij AJ, Dallner G, de Kruijff B
JournalBiochim Biophys Acta
PubMed ID3756157
'The effect of dolichol and dolichyl phosphate on fusion between large unilamellar vesicles comprised of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) was studied using a fluorescence resonance energy transfer assay. The influence of dolichyl phosphate on the transbilayer movement of DOPC in multilamellar vesicles (MLV) and large unilamellar vesicles (LUV) composed ... More
The polar region consecutive to the HIV fusion peptide participates in membrane fusion.
AuthorsPeisajovich SG, Epand RF, Pritsker M, Shai Y, Epand RM
JournalBiochemistry
PubMed ID10677233
'The fusion peptide of HIV-1 gp41 is formed by the 16 N-terminal residues of the protein. This 16-amino acid peptide, in common with several other viral fusion peptides, caused a reduction in the bilayer to hexagonal phase transition temperature of dipalmitoleoylphosphatidylethanolamine (T(H)), suggesting its ability to promote negative curvature in ... More
Fusion of phospholipid vesicles produced by the anti-tumour protein alpha-sarcin.
AuthorsGasset M, Oñaderra M, Thomas PG, Gavilanes JG
JournalBiochem J
PubMed ID2306215
'The anti-tumour protein alpha-sarcin causes fusion of bilayers of phospholipid vesicles at neutral pH. This is demonstrated by measuring the decrease in the efficiency of the fluorescence energy transfer between N-(7-nitro-2-1,3-benzoxadiazol-4-yl)-dimyristoylphosphatidylethano lamine (NDB-PE) (donor) and N-(lissamine rhodamine B sulphonyl)-diacylphosphatidylethanolamine (Rh-PE) (acceptor) incorporated in dimyristoylphosphatidylcholine (DMPG) vesicles. The effect of alpha-sarcin ... More
Palmitoylated peptides from the cysteine-rich domain of SNAP-23 cause membrane fusion depending on peptide length, position of cysteines, and extent of palmitoylation.
AuthorsPallavi B, Nagaraj R
JournalJ Biol Chem
PubMed ID12551899
'Synaptosome-associated proteins SNAP-23/25, members of a family of proteins essential for exocytosis, have a highly conserved central cysteine-rich domain that plays an important role in membrane targeting. More than one cysteine in this domain is modified by palmitic acid through a thioester linkage. In an effort to address the biological ... More
Calcium-dependent annexin V binding to phospholipids: stoichiometry, specificity, and the role of negative charge.
AuthorsMeers P, Mealy T
JournalBiochemistry
PubMed ID8218240
'Annexin V is a Ca(2+)-dependent, phospholipid-binding protein that may have one or more membrane-related functions. The binding of annexin V to phospholipids in a detergent micelle matrix was studied to attempt to determine directly the stoichiometry of specific phospholipid-binding sites and the importance of negative charge. When annexin V binds ... More
Ca(2+)-induced fusion of phospholipid vesicles containing free fatty acids: modulation by transmembrane pH gradients.
'The influence of a transmembrane pH gradient on the Ca(2+)-induced fusion of phospholipid vesicles, containing free fatty acids, has been investigated. Large unilamellar vesicles composed of an equimolar mixture of cardiolipin, dioleoylphosphatidylcholine, and cholesterol, containing 20 mol % oleic acid, were employed. Fusion was measured using a kinetic assay for ... More
Comparison of two liposome fusion assays monitoring the intermixing of aqueous contents and of membrane components.
AuthorsRosenberg J, Düzgünes N, Kayalar C
JournalBiochim Biophys Acta
PubMed ID6626546
'Divalent cation-induced fusion of large unilamellar vesicles (approx. 0.1 micron diameter) made of phosphatidylserine (PS) or phosphatidylglycerol (PG) has been studied. Intermixing of aqueous contents during fusion was followed by the Tb/dipicolinic acid fluorescence assay, and intermixing of membrane components by resonance energy transfer between fluorescent lipid probes. Both assays ... More
Fluorescence lifetime imaging by asynchronous pump-probe microscopy.
AuthorsDong CY, So PT, French T, Gratton E
JournalBiophys J
PubMed ID8599631
'We report the development of a scanning lifetime fluorescence microscope using the asynchronous, pump-probe (stimulated emission) approach. There are two significant advantages of this technique. First, the cross-correlation signal produced by overlapping the pump and probe lasers results in i) an axial sectioning effect similar to that in confocal and ... More