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
The interaction of an antimicrobial decapeptide with phospholipid vesicles.
AuthorsChoi MJ, Kang SH, Kim S, Chang JS, Kim SS, Cho H, Lee KH
JournalPeptides
PubMed ID15165724
'Previously, by using combinatorial peptide libraries, we have identified activity-optimized decapeptide (KSL, KKVVFKVKFK-NH(2)), which exhibited a broad spectrum of the activity against bacteria and fungi without hemolytic activity. In order to examine lipid requirements and to understand the mode of KSL action, we investigated interactions of the peptide with vesicles ... 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
Free fatty acid enhancement of cation-induced fusion of liposomes: synergism with synexin and other promoters of vesicle aggregation.
AuthorsMeers P, Hong K, Papahadjopoulos D
JournalBiochemistry
PubMed ID2973806
'The effect of free fatty acids on the cation-induced fusion of large unilamellar vesicles (liposomes) was investigated by using fluorescent assays which monitor the mixing of aqueous contents of liposomes. Overall fusion was modeled as a two-step process involving aggregation of vesicles followed by actual fusion. Different experimental conditions were ... More
Polymer-induced membrane fusion: potential mechanism and relation to cell fusion events.
AuthorsLentz BR
JournalChem Phys Lipids
PubMed ID8001186
'Poly(ethylene glycol) (PEG) is used widely to mediate cell-cell fusion in the production of somatic cell hybrids and in the fusion injection of macromolecules into cultured cells from erythrocytes or liposomes. However, little is known about the mechanisms by which PEG induces fusion of cell membranes, making its use much ... More
Pro-apoptotic cleavage products of Bcl-xL form cytochrome c-conducting pores in pure lipid membranes.
AuthorsBasañez G, Zhang J, Chau BN, Maksaev GI, Frolov VA, Brandt TA, Burch J, Hardwick JM, Zimmerberg J
JournalJ Biol Chem
PubMed ID11399768
'During apoptotic cell death, cells usually release apoptogenic proteins such as cytochrome c from the mitochondrial intermembrane space. If Bcl-2 family proteins induce such release by increasing outer mitochondrial membrane permeability, then the pro-apoptotic, but not anti-apoptotic activity of these proteins should correlate with their permeabilization of membranes to cytochrome ... More
Effects of cholesterol on the divalent cation-mediated interactions of vesicles containing amino and choline phospholipids.
AuthorsStamatotos L, Silvius JR
JournalBiochim Biophys Acta
PubMed ID3676317
'We have used assays of lipid probe mixing, contents mixing and contents leakage to monitor the divalent cation-mediated interactions between lipid vesicles containing phosphatidylserine (PS) as a minority component together with mixtures of phosphatidylethanolamine (PE), phosphatidylcholine (PC) or sphingomyelin, and cholesterol in varying proportions. The initial rates of calcium- and ... More
Morphological changes induced by phospholipase C and by sphingomyelinase on large unilamellar vesicles: a cryo-transmission electron microscopy study of liposome fusion.
AuthorsBasáñez G, Ruiz-Argüello MB, Alonso A, Goñi FM, Karlsson G, Edwards K
JournalBiophys J
PubMed ID9168038
'Cryo-transmission electron microscopy has been applied to the study of the changes induced by phospholipase C on large unilamellar vesicles containing phosphatidylcholine, as well as to the action of sphingomyelinase on vesicles containing sphingomyelin. In both cases vesicle aggregation occurs as the earliest detectable phenomenon; later, each system behaves differently. ... More
Interactions of monomeric rabbit neutrophil defensins with bilayers: comparison with dimeric human defensin HNP-2.
AuthorsHristova K, Selsted ME, White SH
JournalBiochemistry
PubMed ID8794771
'Human antimicrobial neutrophil defensin HNP-2 has been shown to form large multimeric pores in pure 1-palmitoyl-2-oleoyl phosphatidylglycerol (POPG) bilayers that lead to all-or-none release of vesicle contents [Wimley et al. (1994) Protein Sci.3, 1362-1373]. Because human neutrophil defensins form natural dimers in solution, the question arises as to the role ... 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
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
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
Effects of hemagglutinin fusion peptide on poly(ethylene glycol)-mediated fusion of phosphatidylcholine vesicles.
AuthorsHaque ME, McCoy AJ, Glenn J, Lee J, Lentz BR
JournalBiochemistry
PubMed ID11714278
'The effects of hemagglutinin (HA) fusion peptide (X-31) on poly(ethylene glycol)- (PEG-) mediated vesicle fusion in three different vesicle systems have been compared: dioleoylphosphatidylcholine (DOPC) small unilamellar vesicles (SUV) and large unilamellar vesicles (LUV) and palmitoyloleoylphosphatidylcholine (POPC) large unilamellar perturbed vesicles (pert. LUV). POPC LUVs were asymmetrically perturbed by hydrolyzing ... 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
Poly(ethylene glycol)-induced lipid mixing but not fusion between synthetic phosphatidylcholine large unilamellar vesicles.
'We have examined the effect of poly(ethylene glycol) (PEG) on stable large unilamellar vesicles formed by a rapid extrusion technique and composed of pure synthetic phosphatidylcholines. The lipid systems studied were the saturated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and the monounsaturated 1,2-dioleoyl-sn-glycerol-3-phosphocholine (DOPC). PEG at all concentrations (3.8-40 wt %) induced lipid mixing ... More
Poly(ethylene glycol)-induced fusion and rupture of dipalmitoylphosphatidylcholine large, unilamellar extruded vesicles.
AuthorsMassenburg D, Lentz BR
JournalBiochemistry
PubMed ID7690251
'High concentrations (> or = 20 wt %) of poly(ethylene glycol) (PEG) induce large, unilamellar, dipalmitoylphosphatidylcholine model membrane vesicles to fuse when the bilayers contain small amounts of amphipathic peturbant molecules. In addition to fusion, similar concentrations of PEG induce these vesicles to leak their contents. In this paper, we ... More
Phospholipase C-promoted membrane fusion. Retroinhibition by the end-product diacylglycerol.
AuthorsNieva JL, Goñi FM, Alonso A
JournalBiochemistry
PubMed ID8424934
'The catalytic activity of phospholipase C induces fusion of pure lipid vesicles. When large unilamellar liposomes composed of phosphatidylcholine/phosphatidylethanolamine/cholesterol (2:1:1 mole ratio) are treated with phospholipase C, in the presence of 10 mM Ca2+, two enzyme effects can be distinguished: a fast one (half-time on the order of seconds) consisting ... 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
Proton-induced fusion of oleic acid-phosphatidylethanolamine liposomes.
AuthorsDüzgünes N, Straubinger RM, Baldwin PA, Friend DS, Papahadjopoulos D
JournalBiochemistry
PubMed ID4027231
'Liposomes composed of oleic acid and phosphatidylethanolamine (3:7 mole ratio) aggregate, become destabilized, and fuse below pH 6.5 in 150 mM NaCl. Fusion is monitored by (i) the intermixing of internal aqueous contents of liposomes, utilizing the quenching of aminonaphthalene-3,6,8-trisulfonic acid (ANTS) by N,N''-p-xylylenebis(pyridinium bromide) (DPX) encapsulated in two separate ... More
Reciprocal effects of apolipoprotein and lytic peptide analogs on membranes. Cross-sectional molecular shapes of amphipathic alpha helixes control membrane stability.
'Apolipoprotein (class A) amphipathic helixes are postulated to act as detergents by virtue of their cross-section being wedge-shaped. Using computer analysis of naturally occurring class A and lytic (class L) amphipathic helixes, we designed two archetypical model peptides. Analogs of these two peptides, incorporating substitutions or modifications of interfacial or ... 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
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
Reversible adsorption and nonreversible insertion of Escherichia coli alpha-hemolysin into lipid bilayers.
AuthorsBakás L, Ostolaza H, Vaz WL, Goñi FM
JournalBiophys J
PubMed ID8889162
'Alpha-Hemolysin is an extracellular protein toxin (107 kDa) produced by some pathogenic strains of Escherichia coli. Although stable in aqueous medium, it can bind to lipid bilayers and produce membrane disruption in model and cell membranes. Previous studies had shown that toxin binding to the bilayer did not always lead ... More
Mechanism of the cell-penetrating peptide transportan 10 permeation of lipid bilayers.
AuthorsYandek LE, Pokorny A, Florén A, Knoelke K, Langel U, Almeida PF
JournalBiophys J
PubMed ID17218466
'The mechanism of the interaction between the cell-penetrating peptide transportan 10 (tp10) and phospholipid membranes was investigated. Tp10 induces graded release of the contents of phospholipid vesicles. The kinetics of peptide association with vesicles and peptide-induced dye efflux from the vesicle lumen were examined experimentally by stopped-flow fluorescence. The experimental ... More
The calcium-binding C-terminal domain of Escherichia coli alpha-hemolysin is a major determinant in the surface-active properties of the protein.
AuthorsSánchez-Magraner L, Viguera AR, García-Pacios M, Garcillán MP, Arrondo JL, de la Cruz F, Goñi FM, Ostolaza H
JournalJ Biol Chem
PubMed ID17324923
'alpha-Hemolysin (HlyA) from Escherichia coli is a protein toxin (1024 amino acids) that targets eukaryotic cell membranes, causing loss of the permeability barrier. HlyA consists of two main regions, an N-terminal domain rich in amphipathic helices, and a C-terminal Ca(2+)-binding domain containing a Gly- and Asp-rich nonapeptide repeated in tandem ... More
Colicin Ia inserts into negatively charged membranes at low pH with a tertiary but little secondary structural change.
AuthorsMel SF, Stroud RM
JournalBiochemistry
PubMed ID8448167
'Colicin Ia, a member of the channel-forming family of colicins, inserts into model membranes in a pH- and lipid-dependent fashion. This insertion occurs with single-hit kinetics, requires negatively charged lipids in the target membrane, and increases in rate as the pH is reduced below 5.2. The low-pH requirement does not ... More
Glycophorin as a receptor for Escherichia coli alpha-hemolysin in erythrocytes.
AuthorsCortajarena AL, Goñi FM, Ostolaza H
JournalJ Biol Chem
PubMed ID11134007
'Escherichia coli alpha-hemolysin (HlyA) can lyse both red blood cells (RBC) and liposomes. However, the cells are lysed at HlyA concentrations 1-2 orders of magnitude lower than liposomes (large unilamellar vesicles). Treatment of RBC with trypsin, but not with chymotrypsin, reduces the sensitivity of RBC toward HlyA to the level ... More
Inhibition of Sendai virus fusion with phospholipid vesicles and human erythrocyte membranes by hydrophobic peptides.
AuthorsKelsey DR, Flanagan TD, Young JE, Yeagle PL
JournalVirology
PubMed ID1850923
'Hydrophobic di- and tripeptides which are capable of inhibiting enveloped virus infection of cells are also capable of inhibiting at least three different types of membrane fusion events. Large unilamellar vesicles (LUV) of N-methyl dioleoylphosphatidylethanolamine (N-methyl DOPE), containing encapsulated 1-aminonaphthalene-3,6,8-trisulfonic acid (ANTS) and/or p-xylene bis(pyridinium bromide) (DPX), were formed by ... 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
Eserine and other tertiary amine interactions with Torpedo acetylcholine receptor postsynaptic membrane vesicles.
AuthorsKawai H, Carlson BJ, Okita DK, Raftery MA
JournalBiochemistry
PubMed ID9890891
'Interaction of the tertiary amines, arecolone, eserine (physostigmine), (+)-epibatidine, and (+/-)-epibatidine, with Torpedo nicotinic acetylcholine receptor-enriched membrane vesicles was investigated to characterize their action on the receptor, using stopped-flow thallium (I)-flux spectrofluorimetry. Arecolone, (+)-epibatidine, and (+/-)-epibatidine were agonists with activation constants of 390, 19, and 39 microM, respectively. Eserine was ... More
Direct measurement of ferrous ion transport across membranes using a sensitive fluorometric assay.
AuthorsShingles R, North M, McCarty RE
JournalAnal Biochem
PubMed ID11520038
'The fluorophore, Phen Green SK (PGSK), was assessed for its suitability to be used in an assay for ferrous ion transport into membrane vesicles. The long wavelengths of excitation and emission (506 and 520 nm, respectively) enable PGSK fluorescence to be detected in membranes, such as the chloroplast inner envelope, ... More
Liposome fusion catalytically induced by phospholipase C.
AuthorsNieva JL, Goñi FM, Alonso A
JournalBiochemistry
PubMed ID2819074
'Large unilamellar vesicles composed of phosphatidylcholine/phosphatidylethanolamine/cholesterol (50:25:25 mole ratio) were treated with phospholipase C. The early stages of phospholipid cleavage are accompanied by mixing of bilayer lipids (monitored by dequenching of octadecylrhodamine fluorescence) and leakage-free mixing of vesicle contents [measured by using 8-aminonaphthalene-1,3,6-trisulfonic acid (ANTS) and p-xylylenebis(pyridinium bromide) (DPX)]. These ... 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
Functional reconstitution in lipid vesicles of influenza virus M2 protein expressed by baculovirus: evidence for proton transfer activity.
AuthorsSchroeder C, Ford CM, Wharton SA, Hay AJ
JournalJ Gen Virol
PubMed ID7527837
'The influenza virus M2 protein was expressed from a recombinant baculovirus in Spodoptera frugiperda Sf9 cells, purified and reconstituted into artificial membrane vesicles. The specific inhibitor amantadine overcame the toxic activity of the protein and boosted the rate of M2 synthesis by a factor of 10, allowing yields of about ... 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
The concentration-dependent membrane activity of cecropin A.
'Cecropin A is a naturally occurring, linear, cationic, 37-residue antimicrobial peptide. The precise mechanism by which it kills bacteria is not known, but its site of action is believed to be the cell membrane. To investigate the nature of its membrane activity, we examined the ability of cecropin A to ... More
"De novo" design of peptides with specific lipid-binding properties.
AuthorsLins L, Charloteaux B, Heinen C, Thomas A, Brasseur R
JournalBiophys J
PubMed ID16275638
'In this study, we describe an in silico method to design peptides that can be made of non-natural amino acids and elicit specific membrane-interacting properties. The originality of the method holds in the capacities developed to design peptides from any non-natural amino acids as easily as from natural ones, and ... More
Synexin enhances the aggregation rate but not the fusion rate of liposomes.
AuthorsMeers P, Bentz J, Alford D, Nir S, Papahadjopoulos D, Hong K
JournalBiochemistry
PubMed ID2971392
'The effect of synexin on the calcium-induced fusion of large unilamellar liposomes was studied by using two assays for the mixing of aqueous contents. The results were analyzed in terms of the mass action kinetic model, which describes the overall fusion reaction as a two-step sequence consisting of a second-order ... More
Mode of membrane interaction and fusogenic properties of a de novo transmembrane model peptide depend on the length of the hydrophobic core.
AuthorsLorin A, Charloteaux B, Fridmann-Sirkis Y, Thomas A, Shai Y, Brasseur R
JournalJ Biol Chem
PubMed ID17459883
'Model peptides composed of alanine and leucine residues are often used to mimic single helical transmembrane domains. Many studies have been carried out to determine how they interact with membranes. However, few studies have investigated their lipid-destabilizing effect. We designed three peptides designated KALRs containing a hydrophobic stretch of 14, ... More
Interaction of earthworm hemolysin with lipid membranes requires sphingolipids.
AuthorsLange S, Nüssler F, Kauschke E, Lutsch G, Cooper EL, Herrmann A
JournalJ Biol Chem
PubMed ID9252415
'Lytic activity in the coelomic fluid of earthworm (Eisenia fetida fetida) has been ascribed to eiseniapore, a hemolytic protein of 38 kDa. Since receptors for eiseniapore on target cell membranes are not known, we used lipid vesicles of various composition to determine whether specific lipids may serve as receptors. Lytic ... More
Viroporin-mediated membrane permeabilization. Pore formation by nonstructural poliovirus 2B protein.
AuthorsAgirre A, Barco A, Carrasco L, Nieva JL
JournalJ Biol Chem
PubMed ID12183456
'Enterovirus nonstructural 2B protein is involved in cell membrane permeabilization during late viral infection. Here we analyze the pore forming activity of poliovirus 2B and several of its variants. Solubilization of 2B protein was achieved by generating a fusion protein comprised of poliovirus 2B attached to a maltose-binding protein (MBP) ... More
Evolution of lipidic structures during model membrane fusion and the relation of this process to cell membrane fusion.
AuthorsLee J, Lentz BR
JournalBiochemistry
PubMed ID9174340
'The sequence of events involved in poly(ethylene glycol)-mediated fusion of small unilamellar vesicles (SUVs) has been studied. Fusion events were monitored using light scattering for vesicle aggregation, the fluorescence lifetime of membrane probe lipids (DPHpPC and NBD-PS) for membrane mixing, the aqueous fluorescent marker (Tb3+/DPA and H+/HPTS) for contents mixing; ... More
Fluorescence assays to monitor membrane fusion: potential application in biliary lipid secretion and vesicle interactions.
AuthorsHoekstra D
JournalHepatology
PubMed ID2210660
'Membrane fusion constitutes an essential, intermediate step in numerous cell biological processes, occurring for example during endocytosis, membrane recycling and exocytosis. Also less desirable events such as the infection of cells by animal viruses are mediated by membrane fusion during which the viral envelope merges with a cellular membrane, causing ... More
Functional signal peptide reduces bilayer thickness of phosphatidylcholine liposomes.
AuthorsTahara Y, Murata M, Ohnishi S, Fujiyoshi Y, Kikuchi M, Yamamoto Y
JournalBiochemistry
PubMed ID1390661
'To investigate the interaction between a signal peptide and the lipid bilayer, two kinds of peptides, L8-M5 (L8 = MRL8PLAALG, M5 = KVFER) and L14-M5 (L14 = MRL14PLAALG), were examined in membranes composed of dioleoylphosphatidylcholine (DOPC). Peptides L8 and L14 are artificially designed signal sequences, and M5 is the N-terminal ... More
Effect of cholesterol and charge on pore formation in bilayer vesicles by a pH-sensitive peptide.
AuthorsNicol F, Nir S, Szoka FC
JournalBiophys J
PubMed ID8968598
'The effect of cholesterol on the bilayer partitioning of the peptide GALA (WEAALAEALAEALAEHLAEALAEALEALAA) and its assembly into a pore in large unilamellar vesicles composed of neutral and negatively charged phospholipids has been determined. GALA undergoes a conformational change from a random coil to an amphipathic alpha-helix when the pH is ... More
Photoinduced destabilization of liposomes.
AuthorsLamparski H, Liman U, Barry JA, Frankel DA, Ramaswami V, Brown MF, O'Brien DF
JournalBiochemistry
PubMed ID1731924
'The stability of two-component liposomes composed of the polymerizable 1,2-bis-[10-(2'',4''-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphati dylcholine (SorbPC) and either a phosphatidylethanolamine (PE) or a phosphatidylcholine (PC) were examined via fluorescence leakage assays. Ultraviolet light exposure of SorbPC-containing liposomes forms poly-SorbPC, which phase separates from the remaining monomeric lipids. If the nonpolymerizable lipids are PE''s, then ... More
Membrane insertion of Escherichia coli alpha-hemolysin is independent from membrane lysis.
AuthorsSánchez-Magraner L, Cortajarena AL, Goñi FM, Ostolaza H
JournalJ Biol Chem
PubMed ID16377616
'Escherichia coli alpha-hemolysin (HlyA) is a protein exotoxin that binds and lyses eukaryotic cell and model membranes in the presence of calcium. Previous studies have been able to distinguish between reversible toxin binding to the membrane and irreversible insertion into the lipid matrix. Membrane lysis occurs as the combined effect ... More
Delivery of macromolecules into cytosol using liposomes containing hemolysin from Listeria monocytogenes.
AuthorsLee KD, Oh YK, Portnoy DA, Swanson JA
JournalJ Biol Chem
PubMed ID8631734
'The cytosolic space of cells is an important but relatively inaccessible target for the delivery of therapeutic macromolecules. Here we describe the efficient delivery of macromolecules into the cytosolic space of macrophages from liposomes that contain listeriolysin O (LLO), the hemolytic protein of Listeria monocytogenes that normally mediates bacterial passage ... More
Fusion between retinal rod outer segment membranes and model membranes: a role for photoreceptor peripherin/rds.
AuthorsBoesze-Battaglia K, Lamba OP, Napoli AA, Sinha S, Guo Y
JournalBiochemistry
PubMed ID9649331
'Peripherin/rds plays an essential role in the maintenance of photoreceptor rod cell disk membrane structure. The purification of this protein to homogeneity [Boesze-Battaglia, K., et al. (1997) Biochemistry 36, 6835-6846] has allowed us to characterize the functional role of peripherin/rds in the maintenance of rod outer segment (ROS) membrane fusion ... More
Interactions of the low molecular weight group of surfactant-associated proteins (SP 5-18) with pulmonary surfactant lipids.
AuthorsShiffer K, Hawgood S, Düzgünes N, Goerke J
JournalBiochemistry
PubMed ID3401444
'The interaction of the low molecular weight group of surfactant-associated proteins, SP 5-18, with the major phospholipids of pulmonary surfactant was studied by fluorescence measurements of liposomal permeability and fusion, morphological studies, and surface activity measurements. The ability of SP 5-18 to increase the permeability of large unilamellar lipid vesicles ... More
Abscisic acid enhances aggregation and fusion of phospholipid vesicles.
AuthorsStillwell W, Brengle B, Wassall SR
JournalBiochem Biophys Res Commun
PubMed ID2972286
The plant hormone abscisic acid (ABA) is shown to enhance the aggregation and fusion of small unilamellar lipid vesicles composed of 80 mol% dimyristoylphosphatidylcholine (DMPC) and 20 mol% dimyristoylphosphatidylcholine (DMPE). Aggregation and fusion did not occur with single component (100 mol%) DMPC vesicles. Fusion was followed by two fundamentally different ... More
A simple fluorescent method to determine complement-mediated liposome immune lysis.
AuthorsSmolarsky M, Teitelbaum D, Sela M, Gitler C
JournalJ Immunol Methods
PubMed ID323363
A simple inexpective method is described to study the kinetics of complement-mediated immune lysis of liposomes containing sheep red blood cell lipid antigens. It is based on the fact that trapping the fluorescent molecule 1-aminonaphthalene-3,6,8-trisulfonate and the dynamic quencher, alpha, alpha'-dipyridinium p-xylene dibromide within the liposome inner volume results in ... More
Sizing membrane pores in lipid vesicles by leakage of co-encapsulated markers: pore formation by melittin.
AuthorsLadokhin AS, Selsted ME, White SH
JournalBiophys J
PubMed ID9083680
Many toxins and antimicrobial peptides permeabilize membrane vesicles by forming multimeric pores. Determination of the size of such pores is an important first step for understanding their structure and the mechanism of their self-assembly. We report a simple method for sizing pores in vesicles based on the differential release of ... More
Ferrous ion transport across chloroplast inner envelope membranes.
AuthorsShingles R, North M, McCarty RE
JournalPlant Physiol
PubMed ID11891257
The initial rate of Fe(2+) movement across the inner envelope membrane of pea (Pisum sativum) chloroplasts was directly measured by stopped-flow spectrofluorometry using membrane vesicles loaded with the Fe(2+)-sensitive fluorophore, Phen Green SK. The rate of Fe(2+) transport was rapid, coming to equilibrium within 3s. The maximal rate and concentration ... More
Pardaxin induces aggregation but not fusion of phosphatidylserine vesicles.
AuthorsLelkes PI, Lazarovici P
JournalFEBS Lett
PubMed ID2450781
The effects on membranes of pardaxin, an amphipathic polypeptide, purified from the gland secretion of the Red Sea Moses sole flatfish Pardachirus marmoratus are dose-dependent and range from formation of voltage-gated, cation-selective pores to lysis. We have now investigated the interactions of pardaxin with small unilamellar liposomes. Light scattering showed ... More
Design, synthesis, and characterization of a cationic peptide that binds to nucleic acids and permeabilizes bilayers.
AuthorsWyman TB, Nicol F, Zelphati O, Scaria PV, Plank C, Szoka FC
JournalBiochemistry
PubMed ID9062132
We have designed a cationic amphipathic peptide, KALA (WEAKLAKALAKALAKHLAKALAKALKACEA), that binds to DNA, destabilizes membranes, and mediates DNA transfection. KALA undergoes a pH-dependent random coil to amphipathic alpha-helical conformational change as the pH is increased from 5.0 to 7.5. One face displays hydrophobic leucine residues, and the opposite face displays ... More
Inhibition of membrane fusion by lysophosphatidylcholine.
AuthorsYeagle PL, Smith FT, Young JE, Flanagan TD
JournalBiochemistry
PubMed ID8110784
The ability of lysophosphatidylcholine to inhibit membrane fusion at subsolubilizing concentrations (between 1 and 9 mol % with respect to the membrane lipids) was examined. Fusion between N-methyldioleoylphosphatidylethanolamine (DOPE) large unilamellar vesicles (LUV) and fusion between Sendai virus and N-methyl-DOPE LUV were measured. A contents mixing fusion assay was used ... More
The membrane-active regions of the hepatitis C virus E1 and E2 envelope glycoproteins.
AuthorsPérez-Berna AJ, Moreno MR, Guillén J, Bernabeu A, Villalaín J
JournalBiochemistry
PubMed ID16533059
We have identified the membrane-active regions of the full sequences of the HCV E1 and E2 envelope glycoproteins by performing an exhaustive study of membrane leakage, hemifusion, and fusion induced by 18-mer peptide libraries on model membranes having different phospholipid compositions. The data and their comparison have led us to ... More
Structure and interaction with membrane model systems of a peptide derived from the major epitope region of HIV protein gp41: implications on viral fusion mechanism.
The HIV-1 gp41 envelope protein mediates entry of the virus into the target cell by promoting membrane fusion. With a view toward possible new insights into viral fusion mechanisms, we have investigated by infrared, fluorescence, and nuclear magnetic resonance spectroscopies and calorimetry a fragment of 19 amino acids corresponding to ... More
Time-resolved and equilibrium measurements of the effects of poly(ethylene glycol) on small unilamellar phospholipid vesicles.
AuthorsViguera AR, Mencía M, Goñi FM
JournalBiochemistry
PubMed ID8466910
The effects of poly(ethylene glycol) (PEG) on sonicated unilamellar vesicles made of phosphatidylcholine have been examined. Stopped-flow and equilibrium data are presented for vesicle aggregation, vesicle leakage, lipid mixing, and aqueous contents mixing. Vesicle aggregation is detected as a monoexponential increase in light scattering, for PEG concentrations between 5 and ... More
Bax-type apoptotic proteins porate pure lipid bilayers through a mechanism sensitive to intrinsic monolayer curvature.
During apoptosis, Bax-type proteins permeabilize the outer mitochondrial membrane to release intermembrane apoptogenic factors into the cytosol via a poorly understood mechanism. We have proposed that Bax and DeltaN76Bcl-x(L) (the Bax-like cleavage fragment of Bcl-x(L)) function by forming pores that are at least partially composed of lipids (lipidic pore formation). ... More
Novel lipid transfer property of two mitochondrial proteins that bridge the inner and outer membranes.
AuthorsEpand RF, Schlattner U, Wallimann T, Lacombe ML, Epand RM
JournalBiophys J
PubMed ID17028143
This study provides evidence of a novel function for mitochondrial creatine kinase (MtCK) and nucleoside diphosphate kinase (NDPK-D). Both are basic peripheral membrane proteins with symmetrical homo-oligomeric structure, which in the case of MtCK was already shown to allow crossbridging of lipid bilayers. Here, different lipid dilution assays clearly demonstrate ... More
Solid-state nuclear magnetic resonance evidence for an extended beta strand conformation of the membrane-bound HIV-1 fusion peptide.
AuthorsYang J, Gabrys CM, Weliky DP
JournalBiochemistry
PubMed ID11434782
Solid-state nuclear magnetic resonance (NMR) spectroscopy was applied to the membrane-bound form of a synthetic peptide representing the 23-residue N-terminal fusion peptide domain of the HIV-1 gp41 envelope glycoprotein. 1D solid-state NMR line width measurements of singly 13C carbonyl labeled peptides showed that a significant population of the membrane-bound peptide ... More
Influence of phospholipid asymmetry on fusion between large unilamellar vesicles.
AuthorsEastman SJ, Hope MJ, Wong KF, Cullis PR
JournalBiochemistry
PubMed ID1567871
The ability of lipid asymmetry to regulate Ca(2+)-stimulated fusion between large unilamellar vesicles has been investigated. It is shown that for 100-nm-diameter LUVs composed of dioleoylphosphatidylcholine, dioleoylphosphatidylethanolamine, phosphatidylinositol, and dioleoylphosphatidic acid (DOPC/DOPE/PI/DOPA; 25:60:5:10) rapid and essentially complete fusion is observed by fluorescent resonance energy transfer techniques when Ca2+ (8 mM) ... More
Electrophysiological study with oxonol VI of passive NO3- transport by isolated plant root plasma membrane.
AuthorsPouliquin P, Grouzis J, Gibrat R
JournalBiophys J
PubMed ID9876148
In contrast to animal cells, plant cells contain approximately 5-50 mM nitrate in cytosol and vacuole. The lack of specific spectroscopic probes, or suitable isotopes, impedes in vitro studies of NO3- transport. Reconstitution of root cell plasma membrane (PM) proteins in mixed soybean lipid:egg phosphatidylcholine allowed for the generation of ... More
Modulation of membrane fusion by asymmetric transbilayer distributions of amino lipids.
AuthorsBailey AL, Cullis PR
JournalBiochemistry
PubMed ID7918482
The fusion of model lipid bilayers containing synthetic amino lipids and the regulation of this fusion by inducing transbilayer asymmetry of these amino lipids via imposed pH gradients are demonstrated. Liposomes of 100 nm diameter consisting of 5 mol% 1,2-dioleoyl-3-(N,N-dimethylamino)propane (AL1) in a mixture of egg phosphatidylcholine (EPC), dioleoylphosphatidylethanolamine (DOPE), ... More
Reconstitution of holin activity with a synthetic peptide containing the 1-32 sequence region of EJh, the EJ-1 phage holin.
AuthorsHaro A, Vélez M, Goormaghtigh E, Lago S, Vázquez J, Andreu D, Gasset M
JournalJ Biol Chem
PubMed ID12464609
Pneumococcal EJ-1 phage holin (EJh) is a hydrophobic polypeptide of 85 amino acid residues displaying lethal inner membrane disruption activity. To get an insight into holin structure and function, several peptides representing the different topological regions predicted by sequence analysis have been synthesized. Peptides were structurally characterized in both aqueous ... More
pH-induced destabilization of phosphatidylethanolamine-containing liposomes: role of bilayer contact.
AuthorsEllens H, Bentz J, Szoka FC
JournalBiochemistry
PubMed ID6722105
The mechanism of pH-induced destabilization of liposomes composed of phosphatidylethanolamine and a charged cholesteryl ester was studied by following the release of encapsulated aqueous contents. The kinetics of release were measured continuously by using the water-soluble fluorophore 8-aminonaphthalene-1,3,6-trisulfonic acid in combination with the water-soluble quencher p- xylylenebis (pyridinium) bromide. With ... More
The membrane-perturbing properties of palmitoyl-coenzyme A and palmitoylcarnitine. A comparative study.
AuthorsRequero MA, Goñi FM, Alonso A
JournalBiochemistry
PubMed ID7654694
Fatty acyl-coenzyme A's are temporarily converted into fatty acylcarnitines while transferred across the inner mitochondrial membrane, in their catabolic pathway. In search of an explanation for the need of this coenzyme exchange, the present work describes comparatively the abilities of both kinds of fatty acyl derivatives (represented by palmitoyl-coenzyme A ... More
Differential interaction of equinatoxin II with model membranes in response to lipid composition.
AuthorsCaaveiro JM, Echabe I, Gutiérrez-Aguirre I, Nieva JL, Arrondo JL, González-Mañas JM
JournalBiophys J
PubMed ID11222295
Equinatoxin II is a 179-amino-acid pore-forming protein isolated from the venom of the sea anemone Actinia equina. Large unilamellar vesicles and lipid monolayers of different lipid compositions have been used to study its interaction with membranes. The critical pressure for insertion is the same in monolayers made of phosphatidylcholine or ... More
A mechanism for tamoxifen-mediated inhibition of acidification.
AuthorsChen Y, Schindler M, Simon SM
JournalJ Biol Chem
PubMed ID10373441
Tamoxifen has been reported to inhibit acidification of cytoplasmic organelles in mammalian cells. Here, the mechanism of this inhibition is investigated using in vitro assays on isolated organelles and liposomes. Tamoxifen inhibited ATP-dependent acidification in organelles from a variety of sources, including isolated microsomes from mammalian cells, vacuoles from Saccharomyces ... More
Bactericidal and tumoricidal activities of synthetic peptides derived from granulysin.
AuthorsWang Z, Choice E, Kaspar A, Hanson D, Okada S, Lyu SC, Krensky AM, Clayberger C
JournalJ Immunol
PubMed ID10903754
Granulysin, a 9-kDa protein localized to human CTL and NK cell granules, is cytolytic against tumor cells and microbes. Molecular modeling predicts that granulysin is composed of five alpha-helices separated by short loop regions. In this report, synthetic peptides corresponding to the linear granulysin sequence were characterized for lytic activity. ... More
Detection and quantification of asymmetric lipid vesicle fusion using deuterium NMR.
AuthorsFranzin CM, Macdonald PM
JournalBiochemistry
PubMed ID9054541
It is demonstrated that deuterium nuclear magnetic resonance (2H NMR) spectroscopy can be used to detect and to quantify fusion between anionic giant unilamellar vesicles (GUVs) and cationic small unilamellar vesicles (SUVs). The sensitivity to fusion relies on the conformational response of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) to changes in membrane surface electrostatic ... More
Mechanism of pH-triggered collapse of phosphatidylethanolamine liposomes stabilized by an ortho ester polyethyleneglycol lipid.
AuthorsGuo X, MacKay JA, Szoka FC
JournalBiophys J
PubMed ID12609880
The mechanism of pH-triggered destabilization of liposomes composed of a polyethyleneglycol-orthoester-distearoylglycerol lipid (POD) and phosphatidyl ethanolamine (PE) has been studied using an ANTS/DPX leakage and a lipid-mixing assay. We developed a kinetic model that relates POD hydrolysis to liposome collapse. This minimum-surface-shielding model describes the kinetics of the pH-triggered release ... More
Phospholipase C-induced aggregation and fusion of cholesterol-lecithin small unilamellar vesicles.
AuthorsLuk AS, Kaler EW, Lee SP
JournalBiochemistry
PubMed ID8334126
We have investigated the effects of the Ca(2+)-requiring enzyme phospholipase C on the stability of sonicated vesicles made with different molar ratios of cholesterol to lecithin. Vesicle aggregation is detected by following turbidity with time. Upon the addition of phospholipase C and after a short lag period, the turbidity of ... More
Purine but not pyrimidine nucleotides support rotation of F(1)-ATPase.
AuthorsNoji H, Bald D, Yasuda R, Itoh H, Yoshida M, Kinosita K
JournalJ Biol Chem
PubMed ID11279248
The binding change model for the F(1)-ATPase predicts that its rotation is intimately correlated with the changes in the affinities of the three catalytic sites for nucleotides. If so, subtle differences in the nucleotide structure may have pronounced effects on rotation. Here we show by single-molecule imaging that purine nucleotides ... More
Visible light-induced destabilization of endocytosed liposomes.
AuthorsMiller CR, Clapp PJ, O'Brien DF
JournalFEBS Lett
PubMed ID10664455
The potential biomedical utility of the photoinduced destabilization of liposomes depends in part on the use of green to near infrared light with its inherent therapeutic advantages. The polymerization of bilayers can be sensitized to green light by associating selected amphiphilic cyanine dyes, i.e. the cationic 1,1'-dioctadecyl-3,3,3', 3'-tetramethylindocarbocyanine (DiI), or ... More
Interaction of erythrocyte protein 4.1 with phospholipids. A monolayer and liposome study.
AuthorsShiffer KA, Goerke J, Düzgünes N, Fedor J, Shohet SB
JournalBiochim Biophys Acta
PubMed ID3337803
We have studied the interaction of purified human erythrocyte protein 4.1 with phospholipid membranes by monitoring both the increase in surface pressure of monolayers at the air/water interface and the change in permeability in liposomes to fluorescent molecules, in the presence of protein 4.1. Protein 4.1 penetrated into monolayers of ... More
Structural requirements for the inhibition of membrane fusion by carbobenzoxy-D-Phe-Phe-Gly.
The peptide ZfFG is known to inhibit non-bilayer phase formation as well as vesicle-vesicle and viral fusion. In order to ascertain some of the properties or structural features of this peptide which were important for the inhibition of membrane fusion, the blocking group was transferred from the amino to the ... More
Dual inhibitory effect of gangliosides on phospholipase C-promoted fusion of lipidic vesicles.
AuthorsBasáñez G, Fidelio GD, Goñi FM, Maggio B, Alonso A
JournalBiochemistry
PubMed ID8652529
The effect of a variety of gangliosides has been tested on the phospholipase C-induced fusion of large unilamellar vesicles. Bilayer composition was phosphatidylcholine:phosphatidylethanolamine: cholesterol (2:1:1 mole ratio) plus the appropriate amounts of glycosphingolipids. Enzyme phosphohydrolase activity, vesicle aggregation, mixing of bilayer lipids and mixing of liposomal aqueous contents were separately ... More
Different effects of enzyme-generated ceramides and diacylglycerols in phospholipid membrane fusion and leakage.
AuthorsRuiz-Argüello MB, Basáñez G, Goñi FM, Alonso A
JournalJ Biol Chem
PubMed ID8900135
When large unilamellar vesicles consisting of sphingomyelin:phosphatidylethanolamine:cholesterol (2:1:1 molar ratio) are treated with sphingomyelinase, production of ceramides in the bilayer is accompanied by leakage of vesicle aqueous contents and by vesicle aggregation in the absence of lipid mixing or vesicle fusion. This is in contrast to the situation of phosphatidylcholine:phosphatidylethanolamine:cholesterol ... More
The role of the ganglioside GD1a as a receptor for Sendai virus.
AuthorsEpand RM, Nir S, Parolin M, Flanagan TD
JournalBiochemistry
PubMed ID7827024
The ganglioside GD1a, which serves as a receptor for Sendai virus, also affects lipid polymorphism as determined by 31P nuclear magnetic resonance. The ganglioside promotes the formation of isotropic structures in monomethyldioleoylphosphatidylethanolamine. GD1a also raises the bilayer to hexagonal phase transition temperature of this lipid. The effects of GD1a on ... More
Development of an aqueous-space mixing assay for fusion of granules and plasma membranes from human neutrophils.
AuthorsBlackwood RA, Smolen JE, Hessler RJ, Harsh DM, Transue A
JournalBiochem J
PubMed ID8670059
Several models have been developed to study neutrophil degranulation. At the most basic level, phospholipid vesicles have been used to investigate the lipid interactions occurring during membrane fusion. The two major forms of assays used to measure phospholipid vesicle fusion are based either on the dilution of tagged phospholipids within ... More
Immunotargeting of liposomes to activated vascular endothelial cells: a strategy for site-selective delivery in the cardiovascular system.
AuthorsSpragg DD, Alford DR, Greferath R, Larsen CE, Lee KD, Gurtner GC, Cybulsky MI, Tosi PF, Nicolau C, Gimbrone MA
JournalProc Natl Acad Sci U S A
PubMed ID9238057
Endothelial-selective delivery of therapeutic agents, such as drugs or genes, would provide a useful tool for modifying vascular function in various disease states. A potential molecular target for such delivery is E-selectin, an endothelial-specific cell surface molecule expressed at sites of activation in vivo and inducible in cultured human umbilical ... More
Interaction of viscotoxins A3 and B with membrane model systems: implications to their mechanism of action.
AuthorsGiudici M, Pascual R, de la Canal L, Pfüller K, Pfüller U, Villalaín J
JournalBiophys J
PubMed ID12885644
Viscotoxins are small proteins that are thought to interact with biomembranes, displaying different toxic activities against a varied number of cell types, being viscotoxin A(3) (VtA(3)) the most cytotoxic whereas viscotoxin B (VtB) is the less potent. By using infrared and fluorescence spectroscopies, we have studied the interaction of VtA(3) ... More
Release of lipid vesicle contents by an antibacterial cecropin A-melittin hybrid peptide.
AuthorsMancheño JM, Oñaderra M, Martínez del Pozo A, Díaz-Achirica P, Andreu D, Rivas L, Gavilanes JG
JournalBiochemistry
PubMed ID8703963
A synthetic cecropin A(1-8)-melittin(1-18) hybrid peptide, with antimalarial and antibacterial properties, promotes leakage of aqueous contents of phospholipid vesicles, as determined by measuring the induced release of vesicle-entrapped fluorescence probes. The release of vesicle contents corresponds to an all-or-none mechanism. High molecular weight entrapped solutes (fluorescence-labeled dextrans, 20 and 4 ... More
Quantitative studies on the melittin-induced leakage mechanism of lipid vesicles.
AuthorsRex S, Schwarz G
JournalBiochemistry
PubMed ID9485380
We have investigated, both experimentally and theoretically, the efflux of carboxyfluorescein (a self-quenching fluorescent dye) from vesicles of different sizes and lipid species (POPC, DOPC) after having added the bee venom peptide melittin. This comprises quantitative analyses regarding the extent of lipid-associated peptide, the mode as well as the temporal ... More
Diffusion-limited interaction between unfolded polypeptides and the Escherichia coli chaperone SecB.
AuthorsFekkes P, den Blaauwen T, Driessen AJ
JournalBiochemistry
PubMed ID7543278
SecB is a chaperone dedicated to protein translocation in Escherichia coli. SecB binds to a subset of precursor proteins, and targets them in a translocation-competent state to the SecA subunit of the translocase. The nature and kinetics of the interaction of SecB with polypeptides were studied by spectroscopic techniques using ... More
Retinal and retinol promote membrane fusion.
AuthorsBoesze-Battaglia K, Fliesler SJ, Li J, Young JE, Yeagle PL
JournalBiochim Biophys Acta
PubMed ID1420260
Disk membranes from the bovine retinal rod outer segments (ROS) were found to fuse with vesicles made of lipids extracted from unbleached ROS disk membranes, using a lipid mixing assay for membrane fusion (relief of self-quenching of R18, octadecylrhodamine B chloride). If the retinal chromophore of rhodopsin was reductively linked ... More
Osmotically induced membrane tension modulates membrane permeabilization by class L amphipathic helical peptides: nucleation model of defect formation.
AuthorsPolozov IV, Anantharamaiah GM, Segrest JP, Epand RM
JournalBiophys J
PubMed ID11463637
The mechanism of action of lytic peptides on membranes is widely studied and is important in view of potential medical applications. Previously (I. V. Polozov, A. I. Polozova, E. M. Tytler, G. M. Anantharamaiah, J. P. Segrest, G. A. Woolley, and R. M., Biochemistry, 36:9237--9245) we analyzed the mechanism of ... More
Mechanism of leakage of phospholipid vesicle contents induced by the peptide GALA.
AuthorsParente RA, Nir S, Szoka FC
JournalBiochemistry
PubMed ID2271552
The synthetic, amphipathic peptide GALA undergoes a pH-dependent conformational change and induces leakage of contents from large unilamellar phosphatidylcholine vesicles when in a helical conformation. The kinetics of this process have been investigated over a wide range of pH and lipid and peptide concentrations. Leakage from lipid vesicles is rapidly ... More
Role of lateral phase separation in the modulation of phospholipase A2 activity.
AuthorsBurack WR, Yuan Q, Biltonen RL
JournalBiochemistry
PubMed ID8422369
Phospholipase A2-catalyzed hydrolysis of phosphatidylcholine large unilamellar vesicles is characterized by a period of slow hydrolysis followed by a rapid increase in the rate of hydrolysis. The temporal relationship between the burst of PLA2 activity and the lateral distribution of substrate and product lipids was examined by simultaneously recording product ... More
Photoactivated enhancement of liposome fusion.
AuthorsBennett DE, O'Brien DF
JournalBiochemistry
PubMed ID7893722
The photopolymerization of two-component large unilamellar liposomes (LUV) composed of 3:1 dioleoylphosphatidylethanolamine (DOPE) and either 1,2-bis[10-(2'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphatidylc holine (bis-SorbPC) or 1-palmitoyl-2-[10-(2'-hexadienoyloxy)decanoyl]-sn- glycero-3-phosphatidylcholine (mono-SorbPC) facilitated liposome fusion. Fusion was characterized by fluorescent assays for lipid mixing, aqueous contents mixing, and aqueous contents leakage. The rate and extent of the liposome fusion was ... More
Vesicle membrane fusion induced by the concerted activities of sphingomyelinase and phospholipase C.
AuthorsRuiz-Argüello MB, Goñi FM, Alonso A
JournalJ Biol Chem
PubMed ID9722520
When vesicles composed of an equimolar mixture of sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, and cholesterol are treated with phospholipase C, phospholipid hydrolysis occurs without major changes in vesicle architecture. In the same way, addition of sphingomyelinase leads only to sphingomyelin cleavage. However, when both enzymes are added together, their joint hydrolytic activities ... More
Biophysical studies and intracellular destabilization of pH-sensitive liposomes.
AuthorsVan Bambeke F, Kerkhofs A, Schanck A, Remacle C, Sonveaux E, Tulkens PM, Mingeot-Leclercq MP
JournalLipids
PubMed ID10757553
We examined changes in membrane properties upon acidification of dioleoylphosphatidylethanolamine/cholesterylhemisuccinate liposomes and evaluated their potential to deliver entrapped tracers in cultured macrophages. Membrane permeability was determined by the release of entrapped calcein or hydroxypyrene-1,3,6-trisulfonic acid (HPTS)-p-xylene-bis-pyridinium bromide (DPX); membrane fusion, by measuring the change in size of the liposomes and ... More
pH-dependent bilayer destabilization and fusion of phospholipidic large unilamellar vesicles induced by diphtheria toxin and its fragments A and B.
AuthorsDefrise-Quertain F, Cabiaux V, Vandenbranden M, Wattiez R, Falmagne P, Ruysschaert JM
JournalBiochemistry
PubMed ID2742843
The passage by the low endosomal pH is believed to be an essential step of the diphtheria toxin (DT) intoxication process in vivo. Several studies have suggested that this low pH triggers the insertion of DT into the membrane. We demonstrate here that its insertion into large unilamellar vesicles (LUV) ... More
Kinetic analysis of endocytosis and intracellular fate of liposomes in single macrophages.
AuthorsYoshimura T, Shono M, Imai K, Hong K
JournalJ Biochem (Tokyo)
PubMed ID7775396
Endocytosis and the intracellular fate of liposomes in single mouse peritoneal macrophages were examined kinetically by fluorescence microphotometry. Liposomes labeled with N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine or containing 8-amino-naphthalene-1,3,6-trisulfonate were promptly incorporated into macrophages on incubation at 37 degrees C, but fluorescence increase caused by hydrolysis of 4-methylumbelliferyl-beta-D-glucoside encapsulated in the liposomes was observed ... More
Molecular organization and stability of hydrated dispersions of headgroup-modified phosphatidylethanolamine analogues.
AuthorsLeventis R, Fuller N, Rand RP, Yeagle PL, Sen A, Zuckermann MJ, Silvius JR
JournalBiochemistry
PubMed ID1854731
Measurements of the thermotropic behavior of various headgroup-modified analogues of 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE) and of the ion-triggered destabilization of unilamellar vesicles containing these species have been correlated with X-ray diffraction measurements of the organization of hydrated dispersions of these analogues in the absence and presence of dodecane. The hexagonal II lattice ... More
H+- and Ca2+-induced fusion and destabilization of liposomes.
AuthorsEllens H, Bentz J, Szoka FC
JournalBiochemistry
PubMed ID4027232
A new liposome fusion assay has been developed that monitors the mixing of aqueous contents at neutral and low pH. With this assay we have investigated the ability of H+ to induce membrane destabilization and fusion. The assay involves the fluorophore 1-aminonaphthalene-3,6,8-trisulfonic acid (ANTS) and its quencher N,N'-p-xylylenebis(pyridinium bromide) (DPX). ... More