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
Membrane vesicles containing the Sendai virus binding glycoprotein, but not the viral fusion protein, fuse with phosphatidylserine liposomes at low pH.
AuthorsChejanovsky N, Zakai N, Amselem S, Barenholz Y, Loyter A
JournalBiochemistry
PubMed ID3021204
Membrane vesicles containing the Sendai virus hemagglutinin/neuraminidase (HN) glycoprotein were able to induce carboxyfluorescein (CF) release from loaded phosphatidylserine (PS) but not loaded phosphatidylcholine (PC) liposomes. Similarly, fluorescence dequenching was observed only when HN vesicles, bearing self-quenched N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (N-NBD-PE), were incubated with PS but not PC liposomes. Thus, fusion between ... More
Order in supported phospholipid monolayers detected by the dichroism of fluorescence excited with polarized evanescent illumination.
AuthorsThompson NL, McConnell HM, Burhardt TP
JournalBiophys J
PubMed ID6518254
A technique is described and demonstrated for measuring the orientation distribution of fluorescent molecules in a two-dimensional system. A laser beam is totally internally reflected at the interface between a glass slide and an aqueous solution, which creates a thin layer of evanescent illumination that excites fluorescent molecules near the ... More
Lateral mobility of phospholipids in the external and internal leaflets of normal and hereditary spherocytic human erythrocytes.
AuthorsRimon G, Meyerstein N, Henis YI
JournalBiochim Biophys Acta
PubMed ID6466671
The lateral diffusion coefficients (D) and the mobile fractions of the fluorescent phospholipid N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine (NBD-PE) and of membrane proteins labelled with fluorescein isothiocyanate, were measured by fluorescence photobleaching recovery on erythrocytes from healthy persons and from a hereditary spherocytosis patient. Measurements of lipid probe mobility were performed on ghosts labelled ... More
Reconstituted syntaxin1a/SNAP25 interacts with negatively charged lipids as measured by lateral diffusion in planar supported bilayers.
AuthorsWagner ML, Tamm LK
JournalBiophys J
PubMed ID11423412
According to the soluble N-ethylmaleimide-sensitive factor (NSF)-attachment protein (SNAP) receptor hypothesis (SNARE hypothesis), interactions between target SNAREs and vesicle SNAREs (t- and v-SNAREs) are required for membrane fusion in intracellular vesicle transport and exocytosis. The precise role of the SNAREs in tethering, docking, and fusion is still disputed. Biophysical measurements ... More
Topography of diphtheria toxin A chain inserted into lipid vesicles.
AuthorsHayashibara M, London E
JournalBiochemistry
PubMed ID15697244
'The membrane-inserting T domain of diphtheria toxin aids the low-pH-triggered translocation of the catalytic A chain of the toxin across endosomal membranes. To evaluate the role of the isolated A chain in translocation, the topography of isolated A chain inserted into model membrane vesicles was investigated using a mixture either ... More
Mechanistic studies of lantibiotic-induced permeabilization of phospholipid vesicles.
AuthorsDriessen AJ, van den Hooven HW, Kuiper W, van de Kamp M, Sahl HG, Konings RN, Konings WN
JournalBiochemistry
PubMed ID7849020
'Nisin is a cationic polycyclic bacteriocin secreted by some lactic acid bacteria. Nisin has previously been shown to permeabilize liposomes. The interaction of nisin was analyzed with liposomes prepared of the zwitterionic phosphatidylcholine (PC) and the anionic phosphatidylglycerol (PG). Nisin induces the release of 6-carboxyfluorescein and other small anionic fluorescent ... 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
Lateral distribution and diffusion of the C3b receptor of complement, HLA antigens, and lipid probes in peripheral blood leukocytes.
AuthorsPetty HR, Smith LM, Fearon DT, McConnell HM
JournalProc Natl Acad Sci U S A
PubMed ID6935669
'Fluorescence microscopy and fluorescence redistribution after pattern photobleaching have been used to measure the distribution and motion of a number of fluorescent molecules bound to the plasma membranes of human leukocytes. The fluorescent molecules include fluorescein-labeled F(ab'')2 and Fab'' fragments of an anti-C3b receptor antibody, fluorescein-labeled IgG and Fab fragments ... More
pH- and ionic strength-dependent fusion of phospholipid vesicles induced by pardaxin analogues or by mixtures of charge-reversed peptides.
AuthorsRapaport D, Hague GR, Pouny Y, Shai Y
JournalBiochemistry
PubMed ID8461295
'The fusogenic properties of the neurotoxin paradaxin and eight of its analogues with small unilamellar vesicles (SUV), composed of egg phosphatidylcholine and phosphatidylserine (PC/PS), were investigated. Fusion was demonstrated by a lipid-mixing assay and by an increase in vesicle size as revealed by electron microscopy. The lipid-mixing assay was performed ... 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
Interaction of nisin with planar lipid bilayers monitored by fluorescence recovery after photobleaching.
AuthorsGiffard CJ, Ladha S, Mackie AR, Clark DC, Sanders D
JournalJ Membr Biol
PubMed ID8661516
'Nisin, a prominent member of the lantibiotic family of antimicrobial agents, has wide application as a food preservative despite poor understanding of its mode of action. Fluorescence recovery after photobleaching has been used with planar lipid bilayers as a model membrane system to examine how nisin might interact with the ... 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
Fluorescence microscopy of phospholipid monolayer phase transitions.
AuthorsWeis RM
JournalChem Phys Lipids
PubMed ID2054906
'Over many years, a detailed picture of the phase transitions in phospholipid monolayers at the air-water interface has been constructed from extensive studies of the force-area, viscoelastic and surface potential properties of phospholipid monolayers, yet the microscopic nature of the transitions has remained obscure. Recent investigations have focused specifically on ... 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
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
Tethered polymer-supported planar lipid bilayers for reconstitution of integral membrane proteins: silane-polyethyleneglycol-lipid as a cushion and covalent linker.
AuthorsWagner ML, Tamm LK
JournalBiophys J
PubMed ID10969002
'There is increasing interest in supported membranes as models of biological membranes and as a physiological matrix for studying the structure and function of membrane proteins and receptors. A common problem of protein-lipid bilayers that are directly supported on a hydrophilic substrate is nonphysiological interactions of integral membrane proteins with ... 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
Assembly of complement components C5b-8 and C5b-9 on lipid bilayer membranes: visualization by freeze-etch electron microscopy.
AuthorsMcCloskey MA, Dankert JR, Esser AF
JournalBiochemistry
PubMed ID2713330
'We have visualized by freeze-etch electron microscopy the macromolecular complexes of complement, C5b-8 and C5b-9, respectively, assembled on synthetic phospholipid bilayers. These complexes were formed sequentially by using purified human complement components C5b-6 followed by C7, C8, and C9. Complexes of C5b-8 were observed on the external surface (ES) of ... More
Influence of receptor lateral mobility on adhesion strengthening between membranes containing LFA-3 and CD2.
AuthorsChan PY, Lawrence MB, Dustin ML, Ferguson LM, Golan DE, Springer TA
JournalJ Cell Biol
PubMed ID1717480
'We have used an in vitro model system of glass-supported planar membranes to study the effects of lateral mobility of membrane-bound receptors on cell adhesion. Egg phosphatidylcholine (PC) bilayers were reconstituted with two anchorage isoforms of the adhesion molecule lymphocyte function-associated antigen 3 (LFA-3). The diffusion coefficient of glycosyl phosphatidylinositol ... More
Transient alterations in the lateral mobility of erythrocyte membrane components during Sendai virus-mediated fusion.
AuthorsAroeti B, Gutman O, Henis YI
JournalJ Biol Chem
PubMed ID1320013
'Destabilization of the target membrane structure by fusion-promoting viral glycoproteins is assumed to be an essential part of the fusion mechanism. To explore this possibility, we employed fluorescence photobleaching recovery to investigate changes in the lateral mobility of native membrane constituents in human red blood cells (RBCs) during the course ... 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 adipocyte fatty acid-binding protein binds to membranes by electrostatic interactions.
AuthorsSmith ER, Storch J
JournalJ Biol Chem
PubMed ID10585398
'The adipocyte fatty acid-binding protein (AFABP) is believed to transfer unesterified fatty acids (FA) to phospholipid membranes via a collisional mechanism that involves ionic interactions between lysine residues on the protein surface and phospholipid headgroups. This hypothesis is derived largely from kinetic analysis of FA transfer from AFABP to membranes. ... 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
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
In vitro fusion of rabbit liver Golgi membranes with liposomes.
AuthorsKagiwada S, Murata M, Hishida R, Tagaya M, Yamashina S, Ohnishi S
JournalJ Biol Chem
PubMed ID8419344
'Fusion of Golgi membranes isolated from rabbit liver with liposomes was studied by lipid mixing of fluorescent lipid analogues and internal content mixing and by electron microscopic observation of transfer of horseradish peroxidase from liposomes into Golgi membranes. A monoclonal antibody was used to confirm fusion of Golgi membranes but ... 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
Effect of nonpolar substitutions of the conserved Phe11 in the fusion peptide of HIV-1 gp41 on its function, structure, and organization in membranes.
AuthorsPritsker M, Rucker J, Hoffman TL, Doms RW, Shai Y
JournalBiochemistry
PubMed ID10471286
'The fusion domain of the HIV-1 envelope glycoprotein (gp120-gp41) is a conserved hydrophobic region located at the N-terminus of the transmembrane subunit (gp41). A prominent feature of this domain is a conserved five-residue "FLGFL" sequence at positions 8-12. Mutation of the highly conserved Phe(11) to Val (F11V), presumed not to ... More
Groups with polar characteristics can locate at both shallow and deep locations in membranes: the behavior of dansyl and related probes.
AuthorsAsuncion-Punzalan E, Kachel K, London E
JournalBiochemistry
PubMed ID9521780
'To understand the relationship between the chemical structure of polar molecules and their membrane location, the behavior of dansyl (dimethylaminonaphthalenesulfonyl) and related polar fluorescent probes was examined. The depth of these probes in lipid bilayers was determined by parallax analysis of fluorescence quenching [Chattopadhyay and London (1987) Biochemistry 26, 39-45; ... 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
pH-dependent fusion of reconstituted vesicular stomatitis virus envelopes with Vero cells. Measurement by dequenching of fluorescence.
AuthorsPaternostre MT, Lowy RJ, Blumenthal R
JournalFEBS Lett
PubMed ID2537231
'Reconstituted vesicular stomatitis virus (VSV) envelopes were formed by solubilization of the viral envelope with Triton X-100 followed by removal of detergent by direct addition of SM2 biobeads. We provide direct demonstration of fusion of reconstituted VSV with cells using fluorescent lipid and aqueous probes incorporated into the VSV virosomes ... 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
On the use of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine in the study of lipid polymorphism.
AuthorsStubbs CD, Williams BW, Boni LT, Hoek JB, Taraschi TF, Rubin E
JournalBiochim Biophys Acta
PubMed ID2819099
'The change in the fluorescence properties of dioleoyl-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanola mine (N-NBD-PE) as an indicator of the (liquid-crystalline) bilayer-to-non-bilayer hexagonalII (HII) phase transition has been investigated. Lipid bilayer systems which are known to undergo the bilayer-to-HII phase transition on addition of Ca2+ were compared with systems which can undergo aggregation and fusion ... More
Fatty acid transfer in taurodeoxycholate mixed micelles.
AuthorsNarayanan VS, Storch J
JournalBiochemistry
PubMed ID8652524
'Dietary triacylglycerol is acted upon by lipolytic enzymes in the stomach and the proximal small intestine, releasing fatty acids and monoacylglycerol as the ultimate products. These digestive products are solubilized by bile released from the gall bladder, resulting in the formation of two product phases-vesicles and micelles-depending upon the concentration ... More
Membrane-protein structural mapping of chloroplast coupling factor in asolectin vesicles.
AuthorsMitra B, Hammes GG
JournalBiochemistry
PubMed ID2148689
'The spatial relationship of specific sites on chloroplast coupling factor, reconstituted in asolectin vesicles, to the bilayer surface has been studied with fluorescence methods. Fluorescence resonance energy transfer measurements have been used to map the distances of closest approach of the N,N''-dicyclohexylcarbodiimide-binding site and the disulfide on the gamma-polypeptide to ... 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
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
Membrane fusion mediated by the influenza virus hemagglutinin requires the concerted action of at least three hemagglutinin trimers.
AuthorsDanieli T, Pelletier SL, Henis YI, White JM
JournalJ Cell Biol
PubMed ID8636231
'In this study we tested the hypothesis that fusion mediated by the influenza virus hemagglutinin (HA) is a cooperative event. To so this we characterized 3T3 cell lines that express HA at nine different defined surface densities. HA densities ranged from 1.0 to 12.6 x 10(3) HA trimers/microns2 as determined ... 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
The membrane-permeabilizing effect of avenacin A-1 involves the reorganization of bilayer cholesterol.
AuthorsArmah CN, Mackie AR, Roy C, Price K, Osbourn AE, Bowyer P, Ladha S
JournalBiophys J
PubMed ID9876141
'Avenacin A-1 is a member of a group of naturally occurring compounds called saponins. It is found in oat plants, where it protects against fungal pathogens. A combined electrical and optical chamber was used to determine the interaction of avenacin A-1 with Montal-Mueller planar lipid bilayers. This system allowed simultaneous ... More
Effect of average phospholipid curvature on supported bilayer formation on glass by vesicle fusion.
AuthorsHamai C, Yang T, Kataoka S, Cremer PS, Musser SM
JournalBiophys J
PubMed ID16299084
'The adsorption of large unilamellar vesicles composed of various combinations of phosphatidylcholine, phosphatidylethanolamine (PE), monomethyl PE, and dimethyl PE (PE-Me2) onto a glass surface was studied using fluorescence microscopy. The average lipid geometry within the vesicles, described mathematically by the average intrinsic curvature, C(0,ave), was methodically altered by changing the ... 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
Isolation of bright aggregate fluctuations in a multipopulation image correlation spectroscopy system using intensity subtraction.
AuthorsRocheleau JV, Wiseman PW, Petersen NO
JournalBiophys J
PubMed ID12770905
'Image correlation spectroscopy allows sensitive measurement of the spatial distribution and aggregation state of fluorescent membrane macro molecules. When studying a single population system (i.e., aggregates of similar brightness), an accurate measure can be made of the aggregate number per observation area, but this measurement becomes much more complex in ... 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
Interaction of cholera toxin with ganglioside GM1 receptors in supported lipid monolayers.
AuthorsReed RA, Mattai J, Shipley GG
JournalBiochemistry
PubMed ID3567148
'Lipid monolayers formed at the air-water interface containing the ganglioside GM1 in egg yolk phosphatidylcholine have been transferred according to the Langmuir-Blodgett technique to glass cover slips coated with octadecyl- or hexadecyltrichlorosilane and carbon-coated electron microscope grids. Monolayer transfer has been demonstrated with fluorescence microscopy, by the transfer of a ... More
Zn(2+) ions selectively induce antimicrobial salivary peptide histatin-5 to fuse negatively charged vesicles. Identification and characterization of a zinc-binding motif present in the functional domain.
AuthorsMelino S, Rufini S, Sette M, Morero R, Grottesi A, Paci M, Petruzzelli R
JournalBiochemistry
PubMed ID10423240
'The salivary antimicrobial peptide histatin-5 is able to aggregate and fuse negatively charged small unilamellar vesicles, and this fusogenic activity is selectively induced by the presence of zinc ions. Circular dichroism spectroscopy shows that histatin-5, in the presence of negatively charged vesicles and zinc ions, undergoes a conformational change leading ... 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
Membrane interaction and conformational properties of the putative fusion peptide of PH-30, a protein active in sperm-egg fusion.
AuthorsMuga A, Neugebauer W, Hirama T, Surewicz WK
JournalBiochemistry
PubMed ID8161498
'A peptide representing the putative fusion domain of PH-30, a sperm surface protein involved in sperm-egg fusion, was synthesized, and its interaction with model lipid membranes was characterized by biophysical methods. While the peptide binds to the vesicles composed of both neutral and acidic lipids, the apparent affinity is significantly ... 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
Lateral mobility of reconstituted Sendai virus envelope glycoproteins on human erythrocytes: correlation with cell-cell fusion.
AuthorsHenis YI, Gutman O
JournalBiochemistry
PubMed ID3032238
'We have recently employed fluorescence photobleaching recovery (FPR) to demonstrate that the envelope glycoproteins of Sendai virions become laterally mobile on the surface of human erythrocytes following fusion [Henis, Y. I., Gutman, O., & Loyter, A. (1985) Exp. Cell Res. 160, 514-526]. In order to investigate whether this lateral mobilization ... More
Translational diffusion in phospholipid monolayers measured by fluorescence microphotolysis.
AuthorsPeters R, Beck K
JournalProc Natl Acad Sci U S A
PubMed ID6580635
'A method is described that eliminates surface flow in monolayers at the air-water interface and makes possible diffusion measurements by fluorescence microphotolysis ("photobleaching"). In contrast to previous studies that did not account for surface flow, lipid probe diffusion has been found to be similar in densely packed monolayers and in ... 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
Evidence for a Trypanosoma brucei lipoprotein scavenger receptor.
AuthorsGreen HP, Del Pilar Molina Portela M, St Jean EN, Lugli EB, Raper J
JournalJ Biol Chem
PubMed ID12401813
'African trypanosomes are lipid auxotrophs that live in the bloodstream of their human and animal hosts. Trypanosomes require lipoproteins in addition to other serum components in order to multiply under axenic culture conditions. Delipidation of the lipoproteins abrogates their capacity to support trypanosome growth. Both major classes of serum lipoproteins, ... 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
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
Lipid interactions with human antiphospholipid antibody, beta 2-glycoprotein 1, and normal human IgG using the fluorescent probes NBD-PE and DPH.
AuthorsTang D, Borchman D, Harris N, Pierangeli S
JournalBiochim Biophys Acta
PubMed ID9651477
'Recurrent venous thrombosis, arterial thrombosis and pregnancy losses are clinical manifestation associated with antiphospholipid antibody (aPL) that recognizes negatively charged phospholipid antigens. Enzyme-linked immunosorbent assays (ELISA) are generally used to determine the presence and specificity of aPL. In this paper, a fluorescence spectroscopy method has been applied, through monitoring the ... 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
Characterization of phospholipid transfer between mixed phospholipid-bile salt micelles.
AuthorsFullington DA, Shoemaker DG, Nichols JW
JournalBiochemistry
PubMed ID2340281
'Concentration-dependent self-quenching of the fluorescent phospholipid N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (N-NBD-PE) was used to measure the rate of N-NBD-PE transfer between phosphatidylcholine-bile salt mixed micelles. In a previous study using the same technique, the rate of N-NBD-PE transfer between phosphatidylcholine-taurocholate mixed micelles was found to be several orders of magnitude faster than its ... More
Consequences of hydrophobic mismatch between lipids and melibiose permease on melibiose transport.
AuthorsDumas F, Tocanne JF, Leblanc G, Lebrun MC
JournalBiochemistry
PubMed ID10769142
'The structural and functional consequences of a mismatch between the hydrophobic thickness d(P) of a transmembrane protein and that d(L) of the supporting lipid bilayer were investigated using melibiose permease (MelB) from Escherichia coli reconstituted in a set of bis saturated and monounsaturated phosphatidylcholine species differing in acyl-chain length. Influence ... More
Fatty acid transfer from liver and intestinal fatty acid-binding proteins to membranes occurs by different mechanisms.
AuthorsHsu KT, Storch J
JournalJ Biol Chem
PubMed ID8662836
'Intestinal absorptive cells contain high levels of expression of two homologous fatty acid-binding proteins (FABP), liver FABP (L-FABP), and intestinal FABP (I-FABP). Both bind long chain fatty acids with relatively high affinity. The functional distinction, if any, between these two proteins remains unknown. It is often hypothesized that FABP are ... 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
Two lipid-packing sensor motifs contribute to the sensitivity of ArfGAP1 to membrane curvature.
AuthorsMesmin B, Drin G, Levi S, Rawet M, Cassel D, Bigay J, Antonny B
JournalBiochemistry
PubMed ID17253781
'ArfGAP1 (Arf GTPase activating protein 1) controls the cycling of the COPI coat on Golgi membranes by catalyzing GTP hydrolysis in the small G protein Arf1. ArfGAP1 contains a central motif named ALPS (ArfGAP1 lipid-packing sensor) that adsorbs preferentially onto highly curved membranes. This motif allows coupling of the rate ... More
Use of resonance energy transfer to monitor membrane fusion.
AuthorsStruck DK, Hoekstra D, Pagano RE
JournalBiochemistry
PubMed ID7284312
'An assay for vesicle--vesicle fusion involving resonance energy transfer between N-(7-nitro-2,1,3-benzoxadiazol-4-yl), the energy donor, and rhodamine, the energy acceptor, has been developed. The two fluorophores are coupled to the free amino group of phosphatidylethanolamine to provide analogues which can be incorporated into a lipid vesicle bilayer. When both fluorescent lipids ... 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
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
Dispersion state of phospholipids and fluorescence production with peroxidation in organic solvents: investigated by time-resolved fluorescence technique.
AuthorsWang JY, Suzuki K, Fujisawa T, Ueki T, Kouyama T
JournalBiochim Biophys Acta
PubMed ID7794961
'Fluorescent substances were found to be produced efficiently when phospholipids containing phosphatidylethanolamine (PE) and linoleic chains were autoxidized in non-polar solvents. By using these fluorescent substances as intrinsic probes, the dispersion state of phospholipids was investigated in various organic solvents. Fluorescence anisotropy decay measurements indicated that the aggregation size of ... More
Fatty acid flip-flop in phospholipid bilayers is extremely fast.
AuthorsKamp F, Zakim D, Zhang F, Noy N, Hamilton JA
JournalBiochemistry
PubMed ID7547929
'The rate of movement of fatty acids (FA) across phospholipid bilayers is an important consideration for their mechanism of transport across cell membranes but has not yet been measured. When FA move undirectionally across phospholipid bilayers, the rapid movement of un-ionized FA compared to ionized FA results in transport of ... More
Translational diffusion and fluid domain connectivity in a two-component, two-phase phospholipid bilayer.
AuthorsVaz WL, Melo EC, Thompson TE
JournalBiophys J
PubMed ID2605301
'The two-dimensional connectivity is examined for mixed bilayers of dimyristoyl phosphatidylcholine (DMPC) and distearoyl phosphatidylcholine (DSPC) as a function of composition and temperature at constant pressure using the fluorescence recovery after photobleaching (FRAP) method. These phospholipid mixtures exhibit peritectic behavior with a large region in which both gel and liquid ... More
Transfer of long-chain fluorescent fatty acids between small and large unilamellar vesicles.
AuthorsKleinfeld AM, Storch J
JournalBiochemistry
PubMed ID8448164
'Transfer of 12-(9-anthroyloxy)stearic acid (12AS) was measured between small unilamellar vesicles (SUV) and between large unilamellar vesicles (LUV), over a temperature range of 5-50 degrees C. The results of this study clearly establish the biexponential nature of the time dependence of the transfer in a variety of vesicle types and ... More
Raft composition at physiological temperature and pH in the absence of detergents.
AuthorsAyuyan AG, Cohen FS,
JournalBiophys J
PubMed ID17993486
'Biological rafts were identified and isolated at 37 degrees C and neutral pH. The strategy for isolating rafts utilized membrane tension to generate large domains. For lipid compositions that led only to microscropically unresolvable rafts in lipid bilayers, membrane tension led to the appearance of large, observable rafts. The large ... More
Polar angle as a determinant of amphipathic alpha-helix-lipid interactions: a model peptide study.
AuthorsUematsu N, Matsuzaki K
JournalBiophys J
PubMed ID11023911
'Various physicochemical properties play important roles in the membrane activities of amphipathic antimicrobial peptides. To examine the effects of the polar angle, two model peptides, thetap100 and thetap180, with polar angles of 100 degrees and 180 degrees, respectively, were designed, and their interactions with membranes were investigated in detail. These ... 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
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
Lateral diffusion in inhomogeneous membranes. Model membranes containing cholesterol.
AuthorsOwicki JC, McConnell HM
JournalBiophys J
PubMed ID6894875
'The problem of lateral diffusion in inhomogeneous membranes is illustrated by a theoretical calculation of the lateral diffusion of a fluorescent lipid probe in binary mixtures of phosphatidylcholine and cholesterol under conditions of temperature and composition such that this lipid mixture consists of alternating parallel domains of fluid and solid ... 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
Brownian ratchets: molecular separations in lipid bilayers supported on patterned arrays.
Authorsvan Oudenaarden A, Boxer SG
JournalScience
PubMed ID10446046
'Brownian ratchets use a time-varying asymmetric potential that can be applied to separate diffusing particles or molecules. A new type of Brownian ratchet, a geometrical Brownian ratchet, has been realized. Charged, fluorescently labeled phospholipids in a two-dimensional fluid bilayer were driven in one direction by an electric field through a ... More
Modification of the N-terminus of membrane fusion-active peptides blocks the fusion activity.
AuthorsMurata M, Kagiwada S, Hishida R, Ishiguro R, Ohnishi S, Takahashi S
JournalBiochem Biophys Res Commun
PubMed ID1898385
'The amphiphilic anionic peptides E5 and E5L can mimic the fusogenic activity of influenza hemagglutinin(HA). These peptides induced fusion of egg yolk phosphatidylcholine small or large unilamellar vesicles only at acidic pH in a similar manner to viral HA. Acetylation or acetimidylation of the N-terminus of the peptides drastically reduced ... More
Fluorescent high-content imaging allows the discrimination and quantitation of E-LDL-induced lipid droplets and Ox-LDL-generated phospholipidosis in human macrophages.
AuthorsGrandl M, Schmitz G,
JournalCytometry A
PubMed ID20014301
'Macrophage foam cells formed during uptake of atherogenic lipoproteins are a hallmark of atherosclerotic lesion development. In this study, human macrophages were incubated with two prototypic atherogenic LDL modifications enzymatically degraded LDL (E-LDL) and oxidized LDL (Ox-LDL) prepared from the same donor LDL. To detect differences in macrophage lipid storage, ... More
Temperature-dependent aggregation of pH-sensitive phosphatidyl ethanolamine-oleic acid-cholesterol liposomes as measured by fluorescent spectroscopy.
AuthorsTorchilin VP, Omelyanenko VG, Lukyanov AN
JournalAnal Biochem
PubMed ID1489082
'pH-sensitive liposomes made of phosphatidyl ethanolamine-oleic acid-cholesterol (4:2:4 molar ratio) at neutral pH values aggregate at approximately 40 degrees C. The aggregation is accompanied by liposome destabilization and by the release of intraliposomal fluorescent marker (calcein). Both aggregation and calcein leakage start at the temperature corresponding to the lipid phase ... 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