Separation and characterization of late endosomal membrane domains.
AuthorsKobayashi T, Beuchat MH, Chevallier J, Makino A, Mayran N, Escola JM, Lebrand C, Cosson P, Kobayashi T, Gruenberg J
JournalJ Biol Chem
PubMed ID12065580
'Very little is known about the biophysical properties and the lipid or protein composition of membrane domains presumably present in endocytic and biosynthetic organelles. Here we analyzed the membrane composition of late endosomes by suborganellar fractionation in the absence of detergent. We found that the internal membranes of this multivesicular ... More
Multidrug transporter activity in lymphocytes.
AuthorsElliott JI, Raguz S, Higgins CF,
JournalBr J Pharmacol
PubMed ID15492020
'Multidrug transporters play a dual role in haematopoietic cells, mediating the efflux of xenobiotics and regulating cell migration. For several reasons including the lack of specific antibodies, reports of multidrug transporter distribution on lymphocytes conflict. Murine B cells have been reported to completely lack transporter activity. Through analysis of parental ... More
gamma-cyclodextrins greatly enhance translocation of hydrophobic fluorescent phospholipids from vesicles to cells in culture. Importance of molecular hydrophobicity in phospholipid trafficking studies.
AuthorsTanhuanpää K, Somerharju P
JournalJ Biol Chem
PubMed ID10585403
'Short-chain, fluorescent derivatives are commonly used to investigate intracellular phospholipid trafficking. However, their use can yield misleading results because they, unlike the native species, can rapidly distribute between organelles due to their low hydrophobicity. On the other hand, hydrophobic derivatives are very difficult to introduce to cells and thus have ... More
'The spectroscopic properties of a new series of fatty acid analogs in which a dipyrrometheneboron difluoride fluorophore forms a segment of the acyl methylene chain are presented and their characteristics as fluorescent membrane probes are examined. When incorporated as a low mole fraction component in model phospholipid membranes, the probes ... More
Intracellular surfactant removal from phagocytized minerals: development of a fluorescent method using a BODIPY-labeled phospholipid.
AuthorsDas AR, Cilento EV, Keane MJ, Wallace WE
JournalInhal Toxicol
PubMed ID10880156
'Lung surfactant serves as a protective coating when adsorbed on particle surfaces, so its removal or rate of removal in vivo may affect expression of mineral cytotoxicity. Removal of phospholipid surfactant components from the surface of mineral particles ingested by alveolar macrophages (AM) was measured using fluorescence microscopy. Dipalmitoylphosphatidylcholine with ... More
Optical anisotropy in lipid bilayer membranes: coupled plasmon-waveguide resonance measurements of molecular orientation, polarizability, and shape.
AuthorsSalamon Z, Tollin G
JournalBiophys J
PubMed ID11222316
'The birefringence and linear dichroism of anisotropic thin films such as proteolipid membranes are related to molecular properties such as polarizability, shape, and orientation. Coupled plasmon-waveguide resonance (CPWR) spectroscopy is shown in the present work to provide a convenient means of evaluating these parameters in a single lipid bilayer. This ... More
Characterization of a regulated form of phospholipase D in the yeast Saccharomyces cerevisiae.
AuthorsElla KM, Dolan JW, Meier KE
JournalBiochem J
PubMed ID7741711
'Phospholipase D (PLD), which is present in bacterial, plant and animal cells, can serve as an important element of signal-transduction pathways. This study examined the potential role of this enzyme in the regulation of Saccharomyces cerevisiae. An assay in vitro using a fluorescent 1-acyl-2-alkyl glycerophosphocholine as substrate was used to ... More
Fluorometric Analysis of Individual Cationic Lipid-DNA Complexes.
AuthorsPozharski E,
JournalMethods Mol Biol
PubMed ID20013410
Lipoplex preparations are heterogeneous mixtures of lipoplex particles of different structures. As these structures determine the efficiency of the delivery of genetic material, it is important to characterize the distribution of particles of different types in lipoplex preparations with good statistics. We describe the application of flow fluorometry which allows ... More
Characterization of the resonance energy transfer couple coumarin-BODIPY and its possible applications in protein-lipid research.
AuthorsKeller RC, Silvius JR, De Kruijff B
JournalBiochem Biophys Res Commun
PubMed ID7864836
In our search for suitable resonance energy transfer (RET) couples for studying protein-lipid interactions, the promising couple coumarin-BODIPY was found and characterized. We characterized the RET from the donor coumarin to two different dipyrrometheneboron difluoride (BODIPY)-labeled phospholipid analogs both experimentally and theoretically. Calculations using the spectral overlap revealed a Förster ... More
Islet amyloid polypeptide-induced membrane leakage involves uptake of lipids by forming amyloid fibers.
AuthorsSparr E, Engel MF, Sakharov DV, Sprong M, Jacobs J, de Kruijff B, Höppener JW, Killian JA
JournalFEBS Lett
PubMed ID15527771
Fibril formation of islet amyloid polypeptide (IAPP) is associated with cell death of the insulin-producing pancreatic beta-cells in patients with Type 2 Diabetes Mellitus. A likely cause for the cytotoxicity of human IAPP is that it destroys the barrier properties of the cell membrane. Here, we show by fluorescence confocal ... More
Lipoplex formulation of superior efficacy exhibits high surface activity and fusogenicity, and readily releases DNA.
AuthorsKoynova R, Tarahovsky YS, Wang L, MacDonald RC,
JournalBiochim Biophys Acta
PubMed ID17156744
Lipoplexes containing a mixture of cationic phospholipids dioleoylethylphosphatidylcholine (EDOPC) and dilauroylethylphosphatidylcholine (EDLPC) are known to be far more efficient agents in transfection of cultured primary endothelial cells than are lipoplexes containing either lipid alone. The large magnitude of the synergy permits comparison of the physical and physico-chemical properties of lipoplexes ... More
Glycosphingolipid synthesis requires FAPP2 transfer of glucosylceramide.
AuthorsD'Angelo G, Polishchuk E, Di Tullio G, Santoro M, Di Campli A, Godi A, West G, Bielawski J, Chuang CC, van der Spoel AC, Platt FM, Hannun YA, Polishchuk R, Mattjus P, De Matteis MA,
JournalNature
PubMed ID17687330
The molecular machinery responsible for the generation of transport carriers moving from the Golgi complex to the plasma membrane relies on a tight interplay between proteins and lipids. Among the lipid-binding proteins of this machinery, we previously identified the four-phosphate adaptor protein FAPP2, the pleckstrin homology domain of which binds ... More
Functional tests for the characterization of surfactant protein B (SP-B) and a fluorescent SP-B analog.
AuthorsDiemel RV, Bader D, Walch M, Hotter B, van Golde LM, Amann A, Haagsman HP, Putz G
JournalArch Biochem Biophys
PubMed ID11368015
Surfactant protein B (SP-B) enhances lipid insertion into the alveolar air/liquid interface upon inhalation. The aim of this study was (i) to apply a palette of tests for a detailed biochemical and biophysical characterization of SP-B and (ii) to use these tests to compare native SP-B with a fluorescent (Bodipy) ... More
Analysis of the structure and composition of individual lipoplex particles by flow fluorometry.
AuthorsPozharski EV, Macdonald RC
JournalAnal Biochem
PubMed ID15907868
A flow fluorometric approach to study cationic lipoid-DNA complexes is presented. The approach uses standard flow cytometry equipment and common fluorescent dyes (BODIPY and ethidium homodimer-2) to detect both lipoid and DNA content in individual particles. In addition, a procedure that allows determination of whether or not liposomes remain intact ... More
Diffusion analysis within single nanometric apertures reveals the ultrafine cell membrane organization.
We describe the development of a new methodology to probe the plasma membrane organization of living cells at the nanometric scale. Single nanometric apertures in a metallic film limit the observed membrane area below the optical diffraction barrier. The new approach performs fluorescence correlation spectroscopy with increasing aperture sizes and ... More
A lipid-specific toxin reveals heterogeneity of sphingomyelin-containing membranes.
AuthorsIshitsuka R, Yamaji-Hasegawa A, Makino A, Hirabayashi Y, Kobayashi T
JournalBiophys J
PubMed ID14695271
Little is known about the heterogenous organization of lipids in biological membranes. Sphingomyelin (SM) is a major plasma membrane lipid that forms lipid domains together with cholesterol and glycolipids. Using SM-specific toxin, lysenin, we showed that in cultured epithelial cells the accessibility of the toxin to SM is different between ... More
Scanning force microscopy at the air-water interface of an air bubble coated with pulmonary surfactant.
AuthorsKnebel D, Sieber M, Reichelt R, Galla HJ, Amrein M
JournalBiophys J
PubMed ID11751334
To study the structure-function relationship of pulmonary surfactant under conditions close to nature, molecular films of a model system consisting of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, and surfactant-associated protein C were prepared at the air-water interface of air bubbles about the size of human alveoli (diameter of 100 microm). The high mechanical stability ... More
Fluorescence light microscopy of pulmonary surfactant at the air-water interface of an air bubble of adjustable size.
AuthorsKnebel D, Sieber M, Reichelt R, Galla HJ, Amrein M
JournalBiophys J
PubMed ID12080141
The structural dynamics of pulmonary surfactant was studied by epifluorescence light microscopy at the air-water interface of a bubble as a model close to nature for an alveolus. Small unilamellar vesicles of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, a small amount of a fluorescent dipalmitoylphosphatidylcholine-analog, and surfactant-associated protein C were injected into the buffer ... More
Separation of phospholipids in microfluidic chip device: application to high-throughput screening assays for lipid-modifying enzymes.
AuthorsLin S, Fischl AS, Bi X, Parce W
JournalAnal Biochem
PubMed ID12633607
Phospholipid molecules such as ceramide and phosphoinositides play crucial roles in signal transduction pathways. Lipid-modifying enzymes including sphingomyelinase and phosphoinositide kinases regulate the generation and degradation of these lipid-signaling molecules and are important therapeutic targets in drug discovery. We now report a sensitive and convenient method to separate these lipids ... More
Uptake and cellular localization of exogenous lipids by Giardia lamblia, a primitive eukaryote.
AuthorsStevens TL, Gibson GR, Adam R, Maier J, Allison-Ennis M, Das S
JournalExp Parasitol
PubMed ID9207743
Giardia lamblia trophozoites are unable to carry out de novo lipid synthesis. It is therefore likely that lipids are acquired from the small intestine of the host, in which the trophozoites are exposed to free and conjugated fatty acids, various sterols, phospholipids, bile acids, and bile-lipid mixed micelles. Here we ... More
Dynamic behavior of rod photoreceptor disks.
AuthorsChen C, Jiang Y, Koutalos Y
JournalBiophys J
PubMed ID12202366
Eukaryotic cells use membrane organelles, like the endoplasmic reticulum or the Golgi, to carry out different functions. Vertebrate rod photoreceptors use hundreds of membrane sacs (the disks) for the detection of light. We have used fluorescent tracers and single cell imaging to study the properties of rod photoreceptor disks. Labeling ... More
Release of phospholipids from erythrocyte membranes by taurocholate is determined by their transbilayer orientation and hydrophobic backbone.
AuthorsWüstner D, Pomorski T, Herrmann A, Müller P
JournalBiochemistry
PubMed ID9836604
Bile salts mediate a specific release of phosphatidylcholine (PC) from the canalicular membrane into the bile fluid. We utilized human red blood cells (RBC) as a model system to study the release of endogenous phospholipids as well as phospholipid analogues from plasma membranes in the presence of the bile salt ... More
Dual role for phosphoinositides in regulation of yeast and mammalian phospholipase D enzymes.
AuthorsSciorra VA, Rudge SA, Wang J, McLaughlin S, Engebrecht J, Morris AJ
JournalJ Cell Biol
PubMed ID12486109
Phospholipase D (PLD) generates lipid signals that coordinate membrane trafficking with cellular signaling. PLD activity in vitro and in vivo is dependent on phosphoinositides with a vicinal 4,5-phosphate pair. Yeast and mammalian PLDs contain an NH2-terminal pleckstrin homology (PH) domain that has been speculated to specify both subcellular localization and ... More
Purification and analysis of a phospholipase A2-like lytic factor of Trichomonas vaginalis.
AuthorsLubick KJ, Burgess DE
JournalInfect Immun
PubMed ID14977929
Trichomonas vaginalis produces soluble factors that have been reported to have the ability to damage target cells in vitro, and it has been hypothesized that these factors may play a role in the pathogenesis of human trichomoniasis. A lytic factor (LF) was purified from T. vaginalis, and the molecular characteristics ... More
Confocal microscopic analysis of morphogenetic movements.
AuthorsCooper MS, D'Amico LA, Henry CA
JournalMethods Cell Biol
PubMed ID9891361
Confocal microscopy is an excellent means of imaging cellular dynamics within living zebrafish embryos because it provides a means of optically sectioning tissues that have been labeled with specific fluorescent probe molecules. In order to study genetically encoded patterns of cell behavior that are involved in the formation of germ ... More
Neuronal SNAREs do not trigger fusion between synthetic membranes but do promote PEG-mediated membrane fusion.
At low surface concentrations that permit formation of impermeable membranes, neuronal soluble N-ethyl maleimide sensitive factor attachment protein receptor (SNARE) proteins form a stable, parallel, trans complex when vesicles are brought into contact by a low concentration of poly(ethylene glycol) (PEG). Surprisingly, formation of a stable SNARE complex does not ... More
Uptake and compartmentalization of fluorescent lipid analogs in larval Schistosoma mansoni.
AuthorsFurlong ST, Thibault KS, Morbelli LM, Quinn JJ, Rogers RA
JournalJ Lipid Res
PubMed ID7706934
Recent studies have suggested that host lipids are both a requirement for the human parasite Schistosoma mansoni and may play a role in evasion of host immunity. To study lipid utilization by this organism we have followed the uptake of fluorescent fatty acid and phospholipid analogs in two parasite stages, ... More
Mode of insertion of the signal sequence of a bacterial precursor protein into phospholipid bilayers as revealed by cysteine-based site-directed spectroscopy.
AuthorsKeller RC, ten Berge D, Nouwen N, Snel MM, Tommassen J, Marsh D, de Kruijff B
JournalBiochemistry
PubMed ID8608147
The interactions between a bacterial precursor protein and phospholipids in bilayer-based model membrane systems is addressed in this study. The precursor-lipid interactions were assessed from the side of the lipid phase by fluorescence and electron spin resonance spectroscopy, using the precursor of the Escherichia coli outer membrane protein PhoE. The ... More
The role of NSP6 in the biogenesis of the SARS-CoV-2 replication organelle.
Authors
JournalNature
PubMed ID35551511
Metabolic effects of RUBCN/Rubicon deficiency in kidney proximal tubular epithelial cells.
Authors
JournalAutophagy
PubMed ID31944172
A bipotential organoid model of respiratory epithelium recapitulates high infectivity of SARS-CoV-2 Omicron variant.