The 118-135 peptide of the human prion protein forms amyloid fibrils and induces liposome fusion.
AuthorsPillot T,Lins L,Goethals M,Vanloo B,Baert J,Vandekerckhove J,Rosseneu M,Brasseur R
JournalJournal of molecular biology
PubMed ID9405147
The prion protein (PrPC) is a glycoprotein of unknown function normally found at the surface of neurons and of glial cells. It is involved in diseases such as bovine spongiform encephalopathy, and Creutzfeldt-Jakob disease in the human, where PrPC is converted into an altered form (termed PrPSc). PrPSc is highly ... More
Fusogenic properties of the C-terminal domain of the Alzheimer beta-amyloid peptide.
AuthorsPillot T,Goethals M,Vanloo B,Talussot C,Brasseur R,Vandekerckhove J,Rosseneu M,Lins L
JournalThe Journal of biological chemistry
PubMed ID8910517
A series of natural peptides and mutants, derived from the Alzheimer beta-amyloid peptide, was synthesized, and the potential of these peptides to induce fusion of unilamellar lipid vesicles was investigated. These peptide domains were identified by computer modeling and correspond to respectively the C-terminal (e.g. residues 29-40 and 29-42) and ... More
The effect of jet-milling on lyophilized liposomes.
AuthorsMobley WC
JournalPharm Res
PubMed ID9487563
ClC-3 is a fundamental molecular component of volume-sensitive outwardly rectifying Cl- channels and volume regulation in HeLa cells and Xenopus laevis oocytes.
AuthorsHermoso M, Satterwhite CM, Andrade YN, Hidalgo J, Wilson SM, Horowitz B, Hume JR
JournalJ Biol Chem
PubMed ID12183454
Volume-sensitive osmolyte and anion channels (VSOACs) are activated upon cell swelling in most vertebrate cells. Native VSOACs are believed to be a major pathway for regulatory volume decrease (RVD) through efflux of chloride and organic osmolytes. ClC-3 has been proposed to encode native VSOACs in Xenopus laevis oocytes and in ... More
Interactions of antigen-sensitized liposomes with immobilized antibody: a homogeneous solid-phase immunoliposome assay.
AuthorsHo RJ, Huang L
JournalJ Immunol
PubMed ID3886794
'Dioleoyl phosphatidylethanolamine (DOPE) does not form stable bilayer liposomes at room temperature and neutral pH. However, stable unilamellar liposomes could be prepared by mixing DOPE with a minimum of 12% of a haptenated lipid, N-(dinitrophenylaminocaproyl)-phosphatidylethanolamine (DNP-cap-PE). When the liposomes bound to rabbit anti-DNP IgG that had been adsorbed on a ... More
Bilayer membrane destabilization induced by dolichylphosphate.
AuthorsSchutzbach JS, Jensen JW
JournalChem Phys Lipids
PubMed ID2611962
'Small vesicles containing the fluorescent probe calcein were used to investigate the effect of dolichyl phosphate (Dol-P) on phospholipid bilayer stability. In the absence of Dol-P, phospholipid vesicles retained the fluorescent probe upon the addition of divalent cations. Small vesicles containing Dol-P, however, exhibited calcein leakage when incubated in the ... More
Coupling of cholesterol and cone-shaped lipids in bilayers augments membrane permeabilization by the cholesterol-specific toxins streptolysin O and Vibrio cholerae cytolysin.
AuthorsZitzer A, Bittman R, Verbicky CA, Erukulla RK, Bhakdi S, Weis S, Valeva A, Palmer M
JournalJ Biol Chem
PubMed ID11279036
'Vibrio cholerae cytolysin (VCC) forms oligomeric pores in lipid bilayers containing cholesterol. Membrane permeabilization is inefficient if the sterol is embedded within bilayers prepared from phosphatidylcholine only but is greatly enhanced if the target membrane also contains ceramide. Although the enhancement of VCC action is stereospecific with respect to cholesterol, ... More
Induction of vesicle-to-micelle transition by bile salts for DOPE vesicles incorporating immunoglobulin G.
AuthorsLee EO, Kim JG, Kim JD
JournalJ Biochem (Tokyo)
PubMed ID1478927
'The vesicle-to-micelle transition of immunoliposomes formed by dioleoylphosphatidyl-ethanolamine (DOPE) and palmitoyl-immunoglobulin G (p-IgG) was investigated in the presence of bile salts and conjugated bile salts. Turbidity and the release of calcein from liposomes were measured as a function of the amount of bile salts added and compared with the solubilizing ... More
Calcitonin-loaded liposomes: stability under acidic conditions and bile salts-induced disruption resulting in calcitonin-phospholipid complex formation.
AuthorsAriën A, Henry-Toulmé N, Dupuy B
JournalBiochim Biophys Acta
PubMed ID8038199
'Calcitonin-loading in liposomes composed of phosphatidylcholine, cholesterol and stearylamine or dipalmitoyl phosphatidylglycerol was studied at low pH values and in the presence of bile salts to check whether liposomal entrapment could be a possible means of protecting the peptide against the aggressive conditions present in the gastrointestinal tract. The association ... More
Characterization of diphtheria toxin-induced lesions in liposomal membranes. An evaluation of the relationship between toxin insertion and "channel" formation.
AuthorsJiang GS, Solow R, Hu VW
JournalJ Biol Chem
PubMed ID2474531
'Diphtheria toxin interaction with membranes has been studied by following the release of a fluorescent dye (calcein) encapsulated within large unilamellar vesicles. Results showed that diphtheria toxin induced temperature- as well as pH-dependent permeability changes in these model membranes. Interestingly, insertion of the "channel-forming" B domain was not sufficient for ... More
Insulin-like growth factor-I increases trabecular bone formation and osteoblastic cell proliferation in unloaded rats.
AuthorsMachwate M, Zerath E, Holy X, Pastoureau P, Marie PJ
JournalEndocrinology
PubMed ID8119139
'We previously found that the inhibition of bone formation and trabecular osteopenia induced by skeletal unloading in rats are associated with reduced proliferation of osteoblastic cells lining the bone surface. In this study, we examined the effects of insulin-like growth factor-I (IGF-I) on trabecular bone formation, bone mineral density, and ... More
Structural analysis of saposin C and B. Complete localization of disulfide bridges.
AuthorsVaccaro AM, Salvioli R, Barca A, Tatti M, Ciaffoni F, Maras B, Siciliano R, Zappacosta F, Amoresano A, Pucci P
JournalJ Biol Chem
PubMed ID7730378
'Saposins A, B, C, and D are a group of homologous glycoproteins derived from a single precursor, prosaposin, and apparently involved in the stimulation of the enzymatic degradation of sphingolipids in lysosomes. All saposins have six cysteine residues at similar positions. In the present study we have investigated the disulfide ... More
Video fluorescence microscopy studies of phospholipid vesicle fusion with a planar phospholipid membrane. Nature of membrane-membrane interactions and detection of release of contents.
AuthorsNiles WD, Cohen FS
JournalJ Gen Physiol
PubMed ID3694175
'Video fluorescence microscopy was used to study adsorption and fusion of unilamellar phospholipid vesicles to solvent-free planar bilayer membranes. Large unilamellar vesicles (2-10 microns diam) were loaded with 200 mM of the membrane-impermeant fluorescent dye calcein. Vesicles were ejected from a pipette brought to within 10 microns of the planar ... More
Chains and fragments of tetanus toxin, and their contribution to toxicity.
AuthorsAhnert-Hilger G, Dauzenroth ME, Habermann E, Henschen A, Krieglstein K, Mauler F, Weller U
JournalJ Physiol (Paris)
PubMed ID2074546
'1. Single-chain toxin is enzymatically converted into two-chain isotoxins which differ from the precursor by their higher pharmacological activity, acidity and hydrophilicity. The interchain disulfide bridge and the disulfide loop within fragment C have been located at the amino acid level. 2. Independent of the enzymes used, the nicking sites ... More
Interactions of serum proteins with small unilamellar liposomes composed of dioleoylphosphatidylethanolamine and oleic acid: high-density lipoprotein, apolipoprotein A1, and amphipathic peptides stabilize liposomes.
AuthorsLiu D, Huang L, Moore MA, Anantharamaiah GM, Segrest JP
JournalBiochemistry
PubMed ID2111162
'Small unilamellar liposomes composed to dioleoylphosphatidylethanolamine (DOPE) and oleic acid (OA) are stabilized by incubation with normal human serum or plasma [Liu, D., & Huang, L. (1989) Biochemistry 28, 7700-7707]. The present report describes a systematic study of interactions of purified serum proteins and lipoproteins with these liposomes. Albumin destabilized ... More
Calcium and hydrogen ion concentrations in the parasitophorous vacuoles of epithelial cells infected with the microsporidian Encephalitozoon hellem.
AuthorsLeitch GJ, Scanlon M, Visvesvara GS, Wallace S
JournalJ Eukaryot Microbiol
PubMed ID7581320
'Microsporidia of the genus Encephalitozoon undergo merogony and sporogony in a parasitophorous vacuole within the host cell. Cultured green monkey kidney cells infected with Encephalitozoon hellem were loaded with the fluorescent dyes fura-2 or BCECF in order to measure intracellular concentrations of calcium and hydrogen ions respectively. Both the parasitophorous ... More
'Sonicated unilamellar liposomes containing phosphatidylethanolamine and palmitoylhomocysteine fuse rapidly when the medium pH is lowered from 7 to 5. Liposome fusion was demonstrated by (i) mixing of the liposomal lipids as shown by resonance energy transfer, (ii) gel filtration, and (iii) electron microscopy. The pH-sensitive fusion of liposomes was observed ... More
Application of calcein-loaded liposomes for the determination of membrane channel size.
AuthorsKatsu T
JournalBiol Pharm Bull
PubMed ID10513625
'We found that calcein-loaded liposomes can be used to evaluate the sizes of channels in membranes by measuring changes in calcein release when the molecular size of the solute added to the outer suspension medium is changed. If the solute added to the outer medium can enter the inner aqueous ... More
Magnetic targeting of thermosensitive magnetoliposomes to mouse livers in an in situ on-line perfusion system.
AuthorsViroonchatapan E, Sato H, Ueno M, Adachi I, Tazawa K, Horikoshi I
JournalLife Sci
PubMed ID8649212
'We recently reported the preparation and in vitro targeting of dextran magnetite (DM)-incorporated thermosensitive liposomes, namely thermosensitive magnetoliposomes (TMs) [Viroonchatapan et al. Pharm. Res. 12 1176-1183 (1995)]. The current study was designed to determine whether these novel liposomes can be targeted to the mouse liver with the aid of an ... More
The dependence of membrane permeability by the antibacterial peptide cecropin B and its analogs, CB-1 and CB-3, on liposomes of different composition.
AuthorsWang W, Smith DK, Moulding K, Chen HM
JournalJ Biol Chem
PubMed ID9765273
'A natural antibacterial peptide, cecropin B (CB), and designed analogs, CB-1 and CB-3, were synthesized. The three peptides have different structural characteristics, with CB having one hydrophobic and one amphipathic alpha-helix, CB-1 having two amphipathic alpha-helices, and CB-3 having two hydrophobic alpha-helices. These differences were used as the rationale for ... More
Cytosolic delivery of membrane-impermeable molecules in dendritic cells using pH-responsive core-shell nanoparticles.
AuthorsHu Y, Litwin T, Nagaraja AR, Kwong B, Katz J, Watson N, Irvine DJ,
JournalNano Lett
PubMed ID17887715
'Polycations that absorb protons in response to the acidification of endosomes can theoretically disrupt these vesicles via the "proton sponge" effect. To exploit this mechanism, we created nanoparticles with a segregated core-shell structure for efficient, noncytotoxic intracellular drug delivery. Cross-linked polymer nanoparticles were synthesized with a pH-responsive core and hydrophilic ... More
Escherichia coli hemolysin permeabilizes small unilamellar vesicles loaded with calcein by a single-hit mechanism.
AuthorsMenestrina G
JournalFEBS Lett
PubMed ID3284764
'Escherichia coli hemolysin produces small unilamellar lipid vesicles permeable to the fluorescent dye calcein by forming pores through their membrane. The process of permeabilization proceeds as a pseudo first-order reaction, indicating that the toxin is active as a monomer; consistently no evidence for cooperativity has been found in a dose-response ... More
Small, but not large, unilamellar liposomes composed of dioleoylphosphatidylethanolamine and oleic acid can be stabilized by human plasma.
AuthorsLiu DX, Huang L
JournalBiochemistry
PubMed ID2611208
'Small unilamellar liposomes, composed of dioleoylphosphatidylethanolamine (DOPE) and oleic acid (OA), prepared by sonication, were incubated in the presence of human plasma at 37 degrees C. The release of entrapped calcein after 8-h incubation was about 15% in plasma, compared with about 70% in phosphate-buffered saline under the same conditions. ... 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
Effects of glucose and its oligomers on the stability of freeze-dried liposomes.
AuthorsSuzuki T, Komatsu H, Miyajima K
JournalBiochim Biophys Acta
PubMed ID8593274
'The effects of glucose and its oligomers (maltodextrins) on the stability of sonicated liposomes during freeze-drying were studied by monitoring the retention of the fluorescent dye, Calcein, entrapped in the liposomal inner aqueous phase and by the use of differential scanning calorimetry (DSC). Glucose showed weak cryoprotective effects on dioleoylphosphatidylcholine ... More
Insertion of glycophorin A, a transmembraneous protein, in lipid bilayers can be mediated by electropermeabilization.
AuthorsRaffy S, Teissie J
JournalEur J Biochem
PubMed ID7607245
'Transmembraneous back-insertion of a solubilized membrane protein, glycophorin A, has been obtained in 1,2 dipalmitoyl-sn-glycero-3-phosphocholine (Pam2GroPCho) cell-size-like liposomes by submitting the lipid/protein mixture to calibrated electric field pulses. Field conditions which are prone to trigger glycophorin insertion are similar to those which mediate lipid layer electropermeabilization. The efflux of calcein, ... More
Characterization of an integral protein of the brush border membrane mediating the transport of divalent metal ions.
AuthorsKnöpfel M, Schulthess G, Funk F, Hauser H
JournalBiophys J
PubMed ID10920019
'The transport of Fe(2+) and other divalent transition metal ions across the intestinal brush border membrane (BBM) was investigated using brush border membrane vesicles (BBMVs) as a model. This transport is an energy-independent, protein-mediated process. The divalent metal ion transporter of the BBM is a spanning protein, very likely a ... More
The effect of medroxyprogesterone acetate on bone metabolism in the oophorectomized, tamoxifen-treated rat.
AuthorsIsserow JA, Rucinski B, Romero DF, Mann GN, Liu CC, Epstein S
JournalEndocrinology
PubMed ID7835304
'Tamoxifen (TAM) is used primarily in the management of breast cancer, and it also has bone-sparing effects similar to estrogen. In breast cancer patients TAM may have a potential role in the prevention and management of osteoporosis. TAM therapy is associated with uterine hyperplasia, and medroxyprogesterone acetate (MPA) added 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
The effects of pH on the interaction of anthrax toxin lethal and edema factors with phospholipid vesicles.
AuthorsKochi SK, Martin I, Schiavo G, Mock M, Cabiaux V
JournalBiochemistry
PubMed ID8117722
'Bacillus anthracis secretes three distinct proteins which interact in binary combinations to produce two toxins. The two effector moieties, edema factor (EF) and lethal factor (LF), interact competitively with the cell receptor-binding moiety, protective antigen (PA), to produce biologically distinct effects. The passage of the toxins through an acidified endosomal ... More
Thermosensitive liposomes: extravasation and release of contents in tumor microvascular networks.
AuthorsGaber MH, Wu NZ, Hong K, Huang SK, Dewhirst MW, Papahadjopoulos D
JournalInt J Radiat Oncol Biol Phys
PubMed ID8985041
'PURPOSE: The purpose of this study was to determine whether hyperthermic exposure would accelerate drug release from thermosensitive sterically stabilized liposomes and enhance their extravasation in tumor tissues. MATERIALS AND METHODS: In vivo fluorescence video microscopy was used to measure the extravasation of liposomes, as well as release of their ... More
Encapsulation of nisin and lysozyme in liposomes enhances efficacy against Listeria monocytogenes.
AuthorsWere LM, Bruce B, Davidson PM, Weiss J
JournalJ Food Prot
PubMed ID15151228
'The efficacy and stability against Listeria monocytogenes of nisin and lysozyme encapsulated in phospholipid liposomes was evaluated. Antimicrobial-containing liposomes were prepared by hydrating dried lipids with buffer containing nisin, nisin plus the fluorescence probe calcein, or calcein and lysozyme. Mixtures were then centrifuged and sonicated, and encapsulated liposomes were collected ... More
A novel linear amphipathic beta-sheet cationic antimicrobial peptide with enhanced selectivity for bacterial lipids.
AuthorsBlazyk J, Wiegand R, Klein J, Hammer J, Epand RM, Epand RF, Maloy WL, Kari UP
JournalJ Biol Chem
PubMed ID11352918
'All known naturally occurring linear cationic peptides adopt an amphipathic alpha-helical conformation upon binding to lipids as an initial step in the induction of cell leakage. We designed an 18-residue peptide, (KIGAKI)3-NH2, that has no amphipathic character as an alpha-helix but can form a highly amphipathic beta-sheet. When bound to ... More
Thermodynamic and phase characterization of phosphatidylethanolamine and ganglioside GD1a mixtures.
AuthorsTsao YS, Freire E, Huang L
JournalBiochim Biophys Acta
PubMed ID3593711
'By employing diphenylhexatriene steady-state fluorescence anisotropy, pyrenedecanoic acid excimer formation, and high sensitivity scanning calorimetry we have demonstrated that the liposomes containing phosphatidylethanolamine (PE) and various mole fractions of ganglioside GD1a had a gel-liquid crystalline phase transition between 15 and 25 degrees C. Calorimetric measurements indicated that these phase transitions ... More
Coupling fiber optics to a permeation liquid membrane for heavy metal sensor development.
AuthorsUeberfeld J, Parthasarathy N, Zbinden H, Gisin N, Buffle J
JournalAnal Chem
PubMed ID11838692
'We present the first sensing system for metal ions based on the combination of separation/preconcentration by a permeation liquid membrane (PLM) and fluorescence detection with an optical fiber. As a model, a system for the detection of Cu(II) ions was developed. The wall of a polypropylene hollow fiber serves as ... More
Measuring the adsorption of Fatty acids to phospholipid vesicles by multiple fluorescence probes.
AuthorsSimard JR, Kamp F, Hamilton JA,
JournalBiophys J
PubMed ID18296488
'Fatty acids (FA) are important nutrients that the body uses to regulate the storage and use of energy resources. The predominant mechanism by which long-chain fatty acids enter cells is still debated widely as it is unclear whether long-chain fatty acids require protein transporters to catalyze their transmembrane movement. We ... More
Lipid requirement of the branched-chain amino acid transport system of Streptococcus cremoris.
AuthorsDriessen AJ, Zheng T, In't Veld G, Op den Kamp JA, Konings WN
JournalBiochemistry
PubMed ID3284574
'The role of the membrane lipid composition on the transport protein of branched-chain amino acids of the homofermentative lactic acid bacterium Streptococcus cremoris has been investigated. The major membrane lipid species identified in S. cremoris were acidic phospholipids (phosphatidylglycerol and cardiolipin), glycolipids, and glycerophosphoglycolipids. Phosphatidylethanolamine (PE) was completely absent. Protonmotive ... More
Histological observations of dental tissues using the confocal laser scanning microscope.
AuthorsKabasawa M, Ejiri S, Hanada K, Ozawa H
JournalBiotech Histochem
PubMed ID7578590
'To investigate the time course of mineralization in undecalcified dental tissues, calcein- and tetracycline-labeled rat maxillary molar sections were stained with Villanueva bone stain en bloc, embedded in methyl-methacrylate (MMA), ground to 50 microns thickness, and observed by confocal laser scanning microscopy (CLSM). This method allowed observation of dental structures ... More
Quantitative study of electroporation-mediated molecular uptake and cell viability.
'Electroporation''s use for laboratory transfection and clinical chemotherapy is limited by an incomplete understanding of the effects of electroporation parameters on molecular uptake and cell viability. To address this need, uptake of calcein and viability of DU 145 prostate cancer cells were quantified using flow cytometry for more than 200 ... More
The intracellular iron sensor calcein is catalytically oxidatively degraded by iron(II) in a hydrogen peroxide-dependent reaction.
AuthorsHasinoff BB
JournalJ Inorg Biochem
PubMed ID12763660
'The fluorescent metal chelating dye calcein is used to obtain an estimate of cellular iron levels and to measure the kinetics of the entry of chelators and chelating drugs into cells. Under reducing conditions in the presence of ascorbic acid, such as that would be present in the cell, the ... More
Liposomes with prolonged circulation times: factors affecting uptake by reticuloendothelial and other tissues.
AuthorsAllen TM, Hansen C, Rutledge J
JournalBiochim Biophys Acta
PubMed ID2719971
'Many of the applications of liposomes drug-delivery systems have been limited by their short circulation half-lives as a result of rapid uptake into the reticuloendothelial (mononuclear phagocyte) system. We have recently described liposomes formulations with long circulation half-lives in mice (Allen, T.M. and Chonn, A. (1987) FEBS Lett. 223, 42-46). ... More
Interaction of sesame oil with soybean phosphatidylcholine and their formation of small dispersed particles.
AuthorsAsai Y, Watanabe S
JournalJ Microencapsul
PubMed ID10575623
'Stable aqueous dispersions of sesame oil (SO) were obtained by co-sonication with soybean phosphatidylcholine (PC) in the SO mole fraction range of 0.1-0.8. In order to clarify the dispersal mechanism, the dispersed particles were characterized and the interaction of SO with PC was investigated using several physicochemical techniques. Dynamic light ... More
Changes in the mode of calcium and phosphate transport during rat incisal enamel formation.
AuthorsKawamoto T, Shimizu M
JournalCalcif Tissue Int
PubMed ID2364328
'The distribution of 45Ca, 32PO4, 22Na, and calcein in the freeze-dried sections of rat lower incisor was examined. Also, the ratio of 45Ca to 32PO4 transported into the enamel at various developmental stages was studied after the simultaneous injection of 45Ca and 32PO4. The distribution of calcein fluorescence indicated the ... 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
A new paramagnetic analogue of cholesterol as a tool for studying molecular interactions of genuine cholesterol.
AuthorsMaurin L, Morin P, Bienvenue A
JournalBiochim Biophys Acta
PubMed ID3036225
'The synthesis of a new paramagnetic (nitroxide) analogue of cholesterol is described. This compound (called CNO) contains a doxyl group in the lateral chain at position 25. Our results show that CNO retains three molecular interactions which characterize authentic cholesterol: It assumes an orientation perpendicular to the phospholipid bilayer with ... More
Simultaneous measurement of liposome extravasation and content release in tumors.
AuthorsWu NZ, Braun RD, Gaber MH, Lin GM, Ong ET, Shan S, Papahadjopoulos D, Dewhirst MW
JournalMicrocirculation
PubMed ID9110286
'OBJECTIVE: The success of liposome-based drug delivery systems for tumor targeting relies on maximum extravasation of liposomes into tumor interstitium, as well as optimal release of contents from the liposomes once within the tumor Liposome extravasation and content release are two separate processes that can be individually or jointly manipulated ... More
Electric depolarization of photosensitized cells: lipid vs. protein alterations.
AuthorsEhrenberg B, Gross E, Nitzan Y, Malik Z
JournalBiochim Biophys Acta
PubMed ID8373800
'We have monitored several photosensitized reactions in proteins, liposomes and cells under similar conditions. We found that the depolarization of K(+)-diffusion potential of liposomes or the leakage of an entrapped molecule, calcein, progress at a much slower rate than the photosensitized damage to proteins and the photosensitized killing of bacterial ... More
The fusogenic effect of synthetic polycations on negatively charged lipid bilayers.
AuthorsOku N, Yamaguchi N, Yamaguchi N, Shibamoto S, Ito F, Nango M
JournalJ Biochem (Tokyo)
PubMed ID3818570
'The effect of synthetic polycations, polyallylamine, and polyethylenimine, on liposomes containing phosphatidylserine was investigated along with that of polylysine and divalent cations. The addition of polycations caused aggregation of sonicated vesicles composed of phosphatidylserine and phosphatidylcholine (molar ratio 1:4) as determined by measuring the turbidity changes. Liposomal turbidity increased 10 ... More
Fluorescence measurements of the labile iron pool of sickle erythrocytes.
AuthorsDarbari D, Loyevsky M, Gordeuk V, Kark JA, Castro O, Rana S, Apprey V, Kurantsin-Mills J
JournalBlood
PubMed ID12623854
'Sickle erythrocytes have increased ferritin and increased molecular iron on the inner membrane leaflet, and we postulated that cytosolic labile iron is also elevated. We used the fluorescent metallosensor, calcein, and a permeant Fe2+ chelator to estimate labile cytoslic Fe2+, and calcein plus an Fe3+ chelator to estimate total cytosolic ... More
Folate-mediated tumor cell targeting of liposome-entrapped doxorubicin in vitro.
AuthorsLee RJ, Low PS
JournalBiochim Biophys Acta
PubMed ID7865538
'Receptors for the vitamin folic acid are frequently overexpressed on epithelial cancer cells. To examine whether this overexpression might be exploited to specifically deliver liposome-encapsulated drug molecules in vitro, folate-targeted liposomes were prepared by incorporating 0.1 mol% of a folate-polyethyleneglycol-distearoylphatidylethanolamine (folate-PEG-DSPE) construct into the lipid bilayer, and were loaded with ... More
Cholate-induced disruption of calcitonin-loaded liposomes: formation of trypsin-resistant lipid-calcitonin-cholate complexes.
AuthorsAriën A, Toulmé-Henry N, Dupuy B
JournalPharm Res
PubMed ID8570523
'PURPOSE. The work was performed to obtain a better understanding why the oral administration of calcitonin (CT)-loaded liposomes to rats results in a hypocalcemia, while liposomes are normally disrupted in the gastro-intestinal tract and cannot protect the hormone from enzymatic digestion. METHODS. In vitro comparisons between the stability of calcein ... More
Changes of cancellous bone mass in rat mandibular condyle following ovariectomy.
AuthorsTanaka M, Ejiri S, Nakajima M, Kohno S, Ozawa H
JournalBone
PubMed ID10495138
'Changes in cancellous bone of the rat mandibular condyle following estrogen deficiency were histomorphometrically examined with 120-day-old female Fischer rats. Sixty-four animals were either ovariectomized bilaterally (ovx) or subjected to sham surgery (sham), and eight from each group were killed at 7, 14, 30, and 60 days after surgery. Seven ... 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
beta-Galactosidase-induced destabilization of liposome composed of phosphatidylethanolamine and ganglioside GM1.
AuthorsPinnaduwage P, Huang L
JournalBiochim Biophys Acta
PubMed ID3128327
'A novel type of liposome bilayer destabilization catalyzed by the enzyme, beta-galactosidase, is described. Unsaturated phosphatidylethanolamine (PE), an HII-phase-forming lipid, does not form stable liposomes at physiological temperature and pH. However, stable unilamellar liposomes can be prepared by mixing PE with a minimum of 5 mol% ganglioside GM1, a micellar-phase-forming ... More
Stability against temperature and external agents of vesicles composed of archael bolaform lipids and egg PC.
AuthorsFan Q, Relini A, Cassinadri D, Gambacorta A, Gliozzi A
JournalBiochim Biophys Acta
PubMed ID7495852
'The bolaform lipid PLE extracted from the thermophilic archaeon Sulfolobus solfataricus and its mixtures with egg phosphatidyl-choline (egg PC) have been used to prepare sonicated vesicles. The leakage of entrapped calcein was continuously monitored by fluorescence dequenching. The half times of leakage have been used to compare vesicle stability under ... More
Dilation of the influenza hemagglutinin fusion pore revealed by the kinetics of individual cell-cell fusion events.
AuthorsBlumenthal R, Sarkar DP, Durell S, Howard DE, Morris SJ
JournalJ Cell Biol
PubMed ID8858163
'We have monitored kinetics of fusion between cell pairs consisting of a single influenza hemaglutinin (HA)-expressing cell and a single erythrocyte (RBC) that had been labeled with both a fluorescent lipid (Dil) in the membrane and a fluorescent solute (calcein) in the aqueous space. Initial fusion pore opening between the ... More
Bacteria-selective synergism between the antimicrobial peptides alpha-helical magainin 2 and cyclic beta-sheet tachyplesin I: toward cocktail therapy.
AuthorsKobayashi S, Hirakura Y, Matsuzaki K
JournalBiochemistry
PubMed ID11724544
'Magainin 2 and tachyplesin I (T-SS) are membrane-permeabilizing antimicrobial peptides discovered from frog skin and horseshoe crab hemolymph, respectively. They are classified into different secondary structural classes, i.e., alpha-helix and cyclic beta-sheet, respectively. We found that F5W-magainin 2 (MG2) and T-SS exhibited marked synergistic effects against Gram-negative and Gram-positive bacteria ... More
The interaction of lipodepsipeptide toxins from Pseudomonas syringae pv. syringae with biological and model membranes: a comparison of syringotoxin, syringomycin, and two syringopeptins.
AuthorsDalla Serra M, Fagiuoli G, Nordera P, Bernhart I, Della Volpe C, Di Giorgio D, Ballio A, Menestrina G
JournalMol Plant Microbe Interact
PubMed ID10226372
'Pseudomonas syringae pv. syringae produces two groups of cyclic lipodepsipeptides (LDPs): the nona-peptides syringomycins, syringostatins, and syringotoxin (ST), and the more complex syringopeptins composed of either 22 or 25 amino acid residues (SP22 and SP25). Both classes of peptides significantly contribute to bacterial pathogenesis and their primary target of action ... More
Phosphatidylserine vesicle lysis by Sendai virus at low pH is not due to virus-vesicle fusion.
AuthorsMacDonald RI
JournalArch Biochem Biophys
PubMed ID2843103
'As a model of the fusion of Sendai virus with red cells, the interaction of the virus with phosphatidylserine (PS) vesicles at pH 5 was quantitated by the release of a trapped marker from target vesicles and by mixing of lipids of the virus and the vesicles. Release of the ... More
Modulation of Na+,K+-ATPase activity is of importance for RVD.
AuthorsAndersson RM, Aizman O, Aperia A, Brismar H
JournalActa Physiol Scand
PubMed ID15030374
'AIM: This study was performed to examine the role of Na+,K+-ATPase activity for the adaptive response to cell swelling induced by hypoosmoticity, i.e. the regulatory volume decrease (RVD). METHODS: The studies were performed on COS-7 cells transfected with rat Na+,K+-ATPase. To study changes in cell volume, cells were loaded with ... More
Progression of subcellular changes during chemical hypoxia to cultured rat hepatocytes: a laser scanning confocal microscopic study.
'The aim of this study was to evaluate changes in the subcellular organelles of cultured hepatocytes by laser scanning confocal microscopy during chemical hypoxia with cyanide and iodoacetate, inhibitors of mitochondrial respiration and glycolysis, respectively. Parameter-specific fluorophores used were calcein for cell topography and membrane permeability, rhodamine-dextran for lysosomes, rhodamine ... More
Interactions of liposomes with human erythrocyte ghosts.
AuthorsGreidziak M, Ehrke R, Baust G, Torchilin VP, Lasch J
JournalBiomed Biochim Acta
PubMed ID2403338
'Interactions between human erythrocyte ghosts and small unilamellar vesicles consisting of various lipids and containing high intravesicular concentrations of calcein were studied. The entrapped marker leaked out under the influence of erythrocyte ghost in dependence on ghost and vesicle concentration, phospholipid composition as well as cholesterol content of the liposomes. ... More
Staphylococcal alpha-toxin increases the permeability of lipid vesicles by cholesterol- and pH-dependent assembly of oligomeric channels.
AuthorsForti S, Menestrina G
JournalEur J Biochem
PubMed ID2471641
'alpha-Toxin, a lethal hemolytic toxin secreted by Staphylococcus aureus, forms ionic channels of large size in lipid membranes. To investigate the mechanism of channel assembly we have studied the kinetics of pore formation on small unilamellar vesicles. We have used two assays of vesicle permeabilization: one is the release of ... More
Formation and structure of stably dispersed particles composed of retinal with dipalmitoylphosphatidylcholine: coexistence of emulsion particles with bilayer vesicles.
AuthorsAsai Y, Watanabe S
JournalEur J Pharm Biopharm
PubMed ID10477332
'In order to develop an intravenous formulation of all-trans-retinal (vitamin A aldehyde, VAA) for the treatment of night blindness, VAA and dipalmitoylphosphatidylcholine (DPPC) were sonicated and the dispersions in the VAA mole fraction range of 0.1-0.7 were stable at room temperature for 3 days. In order to clarify the dispersal ... More
Lysenin, a novel sphingomyelin-specific binding protein.
AuthorsYamaji A, Sekizawa Y, Emoto K, Sakuraba H, Inoue K, Kobayashi H, Umeda M
JournalJ Biol Chem
PubMed ID9478988
'Lysenin, a novel 41-kDa protein purified from coelomic fluid of the earthworm Eisenia foetida, induced erythrocyte lysis. Preincubation of lysenin with vesicles containing sphingomyelin inhibited lysenin-induced hemolysis completely, whereas vesicles containing phospholipids other than sphingomyelin showed no inhibitory activity, suggesting that lysenin bound specifically to sphingomyelin on erythrocyte membranes. The ... More
Interaction of ubiquinone-10 with dipalmitoylphosphatidylcholine and their formation of small dispersed particles.
AuthorsAsai Y, Watanabe S
JournalDrug Dev Ind Pharm
PubMed ID10677814
'Stable aqueous dispersions of ubiquinone-10 (UQ) were obtained by cosonication with dipalmitoylphosphatidylcholine (DPPC) in the UQ mole fraction range 0.1-0.7. To clarify the dispersal mechanism, the dispersed particles were characterized, and the interaction between UQ and DPPC was investigated using several physicochemical techniques. Dynamic light scattering (DLS) measurements showed that ... More
Metals in neurobiology: probing their chemistry and biology with molecular imaging.
AuthorsQue EL, Domaille DW, Chang CJ,
JournalChem Rev
PubMed ID18426241
'In this review, we will provide a brief overview of the field of transition metals in neurobiology, focusing on the contributions of d-block metals zinc, iron, and copper to neurophysiology, aging, and neuropathology, as well as progress in the development of molecular probes for visualizing zinc, iron, and copper ion ... More
Relationship between antibacterial activity of (+)-catechin derivatives and their interaction with a model membrane.
AuthorsKajiya K, Hojo H, Suzuki M, Nanjo F, Kumazawa S, Nakayama T
JournalJ Agric Food Chem
PubMed ID15030204
'(+)-Catechin derivatives with different alkyl chain lengths were synthesized from (+)-catechin and various straight chain alkylaldehydes in the presence of methyl mercaptan, and their antibacterial activities against Gram-positive bacteria were evaluated. The antibacterial activity increased markedly with elongation of the alkyl chain lengths of the derivatives and reached a maximum ... More
The shuttling of dolichol between VLDL and HDL: involvement of a protein factor from lipoprotein-deficient human serum.
AuthorsVan Dessel G, Lagrou A, Hilderson HJ, Dierick W
JournalBiochim Biophys Acta
PubMed ID8431493
'The occurrence of a dolichol transfer factor in LPDS has been demonstrated using three different transfer assays. Applying a three step purification procedure, the transfer factor could be enriched 4000-5000-fold with a recovery of 1-2%. SDS-gel electrophoresis revealed a molecular weight of 64 kDa. Kinetics as well as the influence ... More
Serum-induced leakage of liposome contents.
AuthorsAllen TM, Cleland LG
JournalBiochim Biophys Acta
PubMed ID7370258
'Efflux of contents from small unilamellar vesicles of various compositions, conaining a highly quenched fluorescent compound (calcein, 175 mM) was determined as a function of temperature in the presence and absence of human serum. Efflux of calcein from the liposomes was monitored as an increase in fluorescence as calcein became ... More
Repetitive, selective angiography of individual vessels of the retina.
AuthorsKhoobehi B, Niesman MR, Peyman GA, Oncel M
JournalRetina
PubMed ID2772425
'Recent experiments have shown the feasibility of using laser or microwave energy for the externally controlled release of both dyes and drugs from temperature-sensitive liposomes (lipid vesicles). In the present study, calcein, a fluorescent dye, was used to improve the in vivo capabilities of this controlled release system. In vitro ... More
Hydrophilic fluorescein derivatives: useful reagents for liposome immunolytic assays.
AuthorsFiechtner M, Wong M, Bieniarz C, Shipchandler MT
JournalAnal Biochem
PubMed ID2817337
'Hydrophilic derivatives of fluorescein containing hydroxyalkyl substituents were synthesized and encapsulated within liposomes. The fluorophores showed significantly more retention with time than did fluorescein, carboxyfluorescein, or calcein. Unlike calcein, the fluorophores are minimally susceptible to fluorescence quenching by Co2+. The utility of these compounds as immunodiagnostic reagents was demonstrated by ... More
Design and applications of methods for fluorescence detection of iron in biological systems.
AuthorsEspósito BP, Breuer W, Cabantchik ZI
JournalBiochem Soc Trans
PubMed ID12196179
'Fluorescence metalosensors provide a means to detect iron in biological systems that is versatile, economical, sensitive and of a high-throughput nature. They rely on relatively high-affinity iron-binding carriers conjugated to highly fluorescent probes that undergo quenching after metal complexation. Metal specificity is determined by probes containing either an iron-binding moiety ... More
Gangliosides reduce leakage of aqueous-space markers from liposomes in the presence of human plasma.
AuthorsAllen TM, Ryan JL, Papahadjopoulos D
JournalBiochim Biophys Acta
PubMed ID4027247
'We have studied the role of glycolipids in reducing leakage of aqueous-space markers from liposomes, composed primarily of egg phosphatidylcholine, in the presence of human plasma. Liposomes were either small unilamellar (SUV) or large unilamellar (LUV). Leakage of liposome contents as affected by the incorporation into the liposomal bilayer of ... More
Precise microinjection into skin using hollow microneedles.
AuthorsWang PM, Cornwell M, Hill J, Prausnitz MR
JournalJ Invest Dermatol
PubMed ID16484988
'Hollow needles of micron dimensions have previously been fabricated and envisioned for use with transdermal patches or infusion pumps to achieve painless delivery of drugs to the skin for local and systemic effects without the need for hypodermic needles. However, little work has been carried out to identify methods to ... More
Bilayer stabilization of phosphatidylethanolamine by N-biotinylphosphatidylethanolamine.
AuthorsWright SE, Huang L
JournalBiochim Biophys Acta
PubMed ID1730017
'We have examined the ability of biotinylated phosphatidylethanolamine and similar lipids to stabilize the bilayer phase of polymorphic dioleoylphosphatidylethanolamine (DOPE). Sonicated lipid mixtures were characterized in terms of their aggregation state, size and ability to encapsulate and retain the fluorescent dye, calcein. Titration of DOPE with N-biotinyl-PE indicated that stable ... More
Transfected connexin45 alters gap junction permeability in cells expressing endogenous connexin43.
'Many cells express multiple connexins, the gap junction proteins that interconnect the cytosol of adjacent cells. Connexin43 (Cx43) channels allow intercellular transfer of Lucifer Yellow (LY, MW = 443 D), while connexin45 (Cx45) channels do not. We transfected full-length or truncated chicken Cx45 into a rat osteosarcoma cell line ROS-17/2.8, ... More
Fusion of phospholipid vesicles produced by the anti-tumour protein alpha-sarcin.
AuthorsGasset M, Oñaderra M, Thomas PG, Gavilanes JG
JournalBiochem J
PubMed ID2306215
'The anti-tumour protein alpha-sarcin causes fusion of bilayers of phospholipid vesicles at neutral pH. This is demonstrated by measuring the decrease in the efficiency of the fluorescence energy transfer between N-(7-nitro-2-1,3-benzoxadiazol-4-yl)-dimyristoylphosphatidylethano lamine (NDB-PE) (donor) and N-(lissamine rhodamine B sulphonyl)-diacylphosphatidylethanolamine (Rh-PE) (acceptor) incorporated in dimyristoylphosphatidylcholine (DMPG) vesicles. The effect of alpha-sarcin ... More
Immobilization of phospholipid vesicles and protein-lipid vesicles containing red cell membrane proteins on octyl derivatives of large-pore gels.
AuthorsYang Q, Wallstén M, Lundahl P
JournalBiochim Biophys Acta
PubMed ID3342235
'For improved immobilization of phospholipid vesicles and protein-lipid vesicles (cf. Sandberg, M., Lundahl, P., Greijer, E. and Belew, M. (1987) Biochim. Biophys. Acta 924, 185-192) and for chromatographic experiments with vesicles containing membrane protein, we have prepared octyl sulfide derivatives of the large-pore gels Sephacryl S-1000 and Sepharose 2B with ... More
Early induction of alterations in cancellous and cortical bone histology after orchiectomy in mature rats.
AuthorsGunness M, Orwoll E
JournalJ Bone Miner Res
PubMed ID8592951
'Androgen deficiency is associated with low bone mass in humans and animals, but the remodeling alterations that lead to bone loss are unclear. Our objective was to define early responses in both cancellous and cortical bone to orchiectomy (ORX) using histomorphometry in sexually mature (4-month-old) rats. A total of 62 ... More
Palmitoylated peptides from the cysteine-rich domain of SNAP-23 cause membrane fusion depending on peptide length, position of cysteines, and extent of palmitoylation.
AuthorsPallavi B, Nagaraj R
JournalJ Biol Chem
PubMed ID12551899
'Synaptosome-associated proteins SNAP-23/25, members of a family of proteins essential for exocytosis, have a highly conserved central cysteine-rich domain that plays an important role in membrane targeting. More than one cysteine in this domain is modified by palmitic acid through a thioester linkage. In an effort to address the biological ... More
Simulation of bone resorption-repair coupling in vitro.
AuthorsJones SJ, Gray C, Boyde A
JournalAnat Embryol (Berl)
PubMed ID7840421
'In the normal adult human skeleton, new bone formation by osteoblasts restores the contours of bone surfaces following osteoclastic bone resorption, but the evidence for resorption-repair coupling remains circumstantial. To investigate whether sites of prior resorption, more than the surrounding unresorbed surface, attract osteoblasts or stimulate them to proliferate or ... 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
Ethanol-enhanced permeation of phosphatidylcholine/ phosphatidylethanolamine mixed liposomal membranes due to ethanol-induced lateral phase separation.
AuthorsKomatsu H, Okada S
JournalBiochim Biophys Acta
PubMed ID8765097
'Effects of ethanol on permeability of large unilamellar vesicles (ca. 160 nm in diameter), composed of dipalmitoyl phosphatidylcholine/dilauroyl phosphatidylethanolamine (DLPE) mixture, were studied by monitoring leakage of the fluorescent dye, calcein, entrapped in the inner aqueous phase of the vesicles. In the presence of 2.1 M ethanol, permeabilities of membranes ... More
Fusion of synaptic vesicle membranes with planar bilayer membranes.
AuthorsPerin MS, MacDonald RC
JournalBiophys J
PubMed ID2720083
'The interaction of synaptic vesicles with horizontal bilayer lipid membranes (BLMs) was investigated as a model system for neurotransmitter release. High concentrations (200 mM) of the fluorescent dye, calcein, were trapped within synaptic vesicles by freezing and thawing. In the presence of divalent ions (usually 15 mM CaCl2), these frozen ... More
P2X7 receptor activates multiple selective dye-permeation pathways in RAW 264.7 and human embryonic kidney 293 cells.
AuthorsCankurtaran-Sayar S, Sayar K, Ugur M,
JournalMol Pharmacol
PubMed ID19749088
'P2X7 receptor has gained an increasing importance as a drug target. One important response to P2X7 receptor stimulation is the uptake of large molecular weight tracers into cells. However, mechanism for this response is not understood clearly, but it is generally believed that a nonselective large pore protein forms this ... More
Transport properties of the multidrug resistance-associated protein (MRP) in human tumour cells.
AuthorsHolló Z, Homolya L, Hegedüs T, Sarkadi B
JournalFEBS Lett
PubMed ID8612802
'In this paper we demonstrate that the expression of the multidrug resistance-associated protein (MRP) in a variety of intact human tumour cells results in the ATP-dependent, mutually exclusive extrusion of both the acetoxymethyl ester and the free anion forms of the fluorescent dye calcein, as well as that of a ... More
Interactions of an antimicrobial peptide, tachyplesin I, with lipid membranes.
AuthorsMatsuzaki K, Fukui M, Fujii N, Miyajima K
JournalBiochim Biophys Acta
PubMed ID1751532
'Tachyplesin I, isolated from the acid extracts of hemocytes of Tachypleus tridentatus, is a cyclic broad-spectrum antimicrobial peptide forming a rigid, antiparallel beta-sheet because of two intramolecular S-S linkages. The strong binding of the peptide to lipopolysaccharides cannot explain the susceptibilities of gram positive bacteria and fungi to the peptide. ... More
Imaging of fluorescent molecule and small ion transport through human stratum corneum during high voltage pulsing: localized transport regions are involved.
'During the application of high-voltage pulses across the skin, transport of two negatively charged fluorescent molecules through the stratum corneum is highly localized. The apparent size of these localized transport regions (LTR''s) is initially 10 microns in diameter for both calcein and sulforhodamine. Appearance of LTR''s occurred at or above ... More
Extemporaneous preparation of large unilamellar liposomes.
AuthorsPhilippot JR, Mutaftschiev S, Liautard JP
JournalBiochim Biophys Acta
PubMed ID4063364
'Direct contact between lipids solubilized by octyl glucoside and Amberlite XAD-2 beads yielded large liposomes (240 nm diameter) with no residual detergent molecules, in less than 10 min. This extemporaneous preparation of liposomes was prepared with a detergent/bead ratio no higher than 0.12 (mumol/mg) and a phosphatidylcholine/phosphatidylserine/cholesterol molar ratio of ... More
Sendai virus-mediated lysis of liposomes requires cholesterol.
AuthorsKundrot CE, Spangler EA, Kendall DA, MacDonald RC, MacDonald RI
JournalProc Natl Acad Sci U S A
PubMed ID6300860
'Vesicles were constituted with glycophorin, the Sendai virus receptor of human erythrocytes, and loaded with calcein, a polar derivative of fluorescein, at self-quenching concentrations. On exposure to Sendai virus and mild hypo-osmotic stress, vesicles of the appropriate composition released a significant portion of their internal contents, as indicated by an ... More
Increase of permeability of synaptosomes and liposomes by the heavy chain of tetanus toxin.
AuthorsHögy B, Dauzenroth ME, Hudel M, Weller U, Habermann E
JournalToxicon
PubMed ID1595080
'In search of a role for the heavy chain of tetanus toxin in poisoning, its actions on natural and artificial membranes have been assessed. The heavy chain increases the permeability of synaptosomes to lactate dehydrogenase and potassium ions, and promotes the outward shift of the lipophilic cation tetraphenylphosphonium which is ... More
Transient and long-lasting openings of the mitochondrial permeability transition pore can be monitored directly in intact cells by changes in mitochondrial calcein fluorescence.
AuthorsPetronilli V, Miotto G, Canton M, Brini M, Colonna R, Bernardi P, Di Lisa F
JournalBiophys J
PubMed ID9929477
'The occurrence and the mode of opening of the mitochondrial permeability transition pore (MTP) were investigated directly in intact cells by monitoring the fluorescence of mitochondrial entrapped calcein. When MH1C1 cells and hepatocytes were loaded with calcein AM, calcein was also present within mitochondria, because (i) its mitochondrial signal was ... More
Regulators of G-protein signaling (RGS) 4, insertion into model membranes and inhibition of activity by phosphatidic acid.
AuthorsOuyang YS, Tu Y, Barker SA, Yang F
JournalJ Biol Chem
PubMed ID12538649
'Regulators of G-protein signaling (RGS) proteins are critical for attenuating G protein-coupled signaling pathways. The membrane association of RGS4 has been reported to be crucial for its regulatory activity in reconstituted vesicles and physiological roles in vivo. In this study, we report that RGS4 initially binds onto the surface of ... More
Development and characterization of a recombinant Madin-Darby canine kidney cell line that expresses rat multidrug resistance-associated protein 1 (rMRP1).
AuthorsYang Z, Horn M, Wang J, Shen DD, Ho RJ
JournalAAPS PharmSci
PubMed ID15198509
'Multidrug resistance-associated protein 1 (MRP1) is one of the major proteins shown to mediate efflux transport of a broad range of antitumor drugs, glucuronide conjugates, and glutathione, in addition to endogenous substrates. Significant differences in substrate selectivity were reported for murine and human MRP1. As preclinical drug disposition and pharmacokinetics ... More
The deleterious effects of long-term cyclosporine A, cyclosporine G, and FK506 on bone mineral metabolism in vivo.
AuthorsCvetkovic M, Mann GN, Romero DF, Liang XG, Ma Y, Jee WS, Epstein S
JournalTransplantation
PubMed ID7513912
'Administration of cyclosporine A to male and female rats accelerates bone remodeling and causes bone loss, among other side-effects. The newer immunosuppressant drugs, FK506 and CsG, have been synthesized to counteract the toxic effects of CsA, yet maintain clinical efficacy. We investigated the in vivo effects of long-term administration of ... More
Do different fluorochrome labels give equivalent histomorphometric information?
AuthorsSun TC, Mori S, Roper J, Brown C, Hooser T, Burr DB
JournalBone
PubMed ID1476823
'Substances that bind calcium are given to determine where and how fast bone is forming. Several vital dyes are used (tetracycline, calcein, alizarin, xylenol), but it is not known whether the histomorphometric results they provide are equivalent. This work tests whether different fluorochrome labels give the same results when they ... More
Effect of lipid peroxidation inhibition on retinal ganglion cell death.
AuthorsLevin LA, Clark JA, Johns LK
JournalInvest Ophthalmol Vis Sci
PubMed ID8977490
'PURPOSE: To determine whether the lipid peroxidation inhibitor tirilazad mesylate can block the death of retinal ganglion cells induced by the inhibition of oxidative phosphorylation and glycolysis. METHODS: Rat retinal ganglion cells were labeled retrogradely with the fluorescent tracer DiI, and mixed cultures were prepared. Cell death was induced with ... More
Mode of action of an antiviral peptide from HIV-1. Inhibition at a post-lipid mixing stage.
AuthorsKliger Y, Gallo SA, Peisajovich SG, Munoz-Barroso I, Avkin S, Blumenthal R, Shai Y
JournalJ Biol Chem
PubMed ID11027678
'DP178, a synthetic peptide corresponding to a segment of the transmembrane envelope glycoprotein (gp41) of human immunodeficiency virus, type 1 (HIV-1), is a potent inhibitor of viral infection and virus-mediated cell-cell fusion. Nevertheless, DP178 does not contain gp41 coiled-coil cavity binding residues postulated to be essential for inhibiting HIV-1 entry. ... More