949 results match your criteria Biochimica et biophysica acta. Biomembranes[Journal]


Spicule movement on RBCs during echinocyte formation and possible segregation in the RBC membrane.

Biochim Biophys Acta Biomembr 2020 May 30:183338. Epub 2020 May 30.

Institute for Transfusion Medicine and Immunology, Flowcore Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. Electronic address:

We use phase contrast microscopy of red blood cells to observe the transition between the initial discocyte shape and a spiculated echinocyte form. During the early stages of this change, spicules can move across the surface of the cell; individual spicules can also split apart into pairs. One possible explanation of this behaviour is that the membrane forms large scale domains in association with the spicules. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183338DOI Listing

Magnetically-orientable Tween-based model membranes for NMR studies of proteins.

Biochim Biophys Acta Biomembr 2020 May 28:183379. Epub 2020 May 28.

Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Montréal, QC, H3C 3P8, Canada. Electronic address:

We present a new membrane mimetic system using a membrane softening detergent commonly known as Tween 80 (TW80), to form oriented systems for solid-state NMR applications. TW80 is a fatty acid ester (oleate) of sorbitan polyethoxylate and a mild non-ionic surfactant. Phosphatidylcholine (PC)/TW80 model membrane systems were characterized by solid-state NMR and FTIR spectroscopy. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183379DOI Listing

The insecticide fipronil affects the physical properties of model membranes: A combined experimental and molecular dynamics simulations study in Langmuir monolayers.

Biochim Biophys Acta Biomembr 2020 May 25;1862(10):183378. Epub 2020 May 25.

Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Córdoba, Argentina. Electronic address:

Fipronil is a widely used commercial insecticide whose action mechanism consists in blocking the influx of chloride ions through the γ-aminobutyric acid type A receptor (GABA-R), an integral membrane protein. The present study investigates the interaction of fipronil with phospholipid Langmuir monolayers, in order to characterize the effects that its partition could exert on the physical properties of these model membranes. A combined experimental and molecular dynamics (MD) simulations approach was performed. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183378DOI Listing

Phase separation behavior of binary mixture of photopolymerizable diacetylene and unsaturated phospholipids in liposomes.

Biochim Biophys Acta Biomembr 2020 May 25;1862(9):183377. Epub 2020 May 25.

Center for Membrane and Film Technology, Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan. Electronic address:

Photopolymerizable lipids, such as diacetylene lipids have attracted much attention for their ability to stabilize lipid bilayer structure. In this study, we investigated the phase separation behavior of a lipid bilayer containing 1,2‑bis(10,12‑tricosadiynoyl)‑sn‑glycero‑3‑phosphocholine (DiynePC). The phase separation behavior of liposomes composed of DiynePC and the non-polymerizable lipid, 1,2‑dioleoyl‑sn‑glycero‑3‑phosphocholine (DOPC) was evaluated using a fluorescence resonance energy transfer (FRET) assay during both the cooling and heating processes. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183377DOI Listing

The effect of hydrophobic alkyl sidechains on size and solution behaviors of nanodiscs formed by alternating styrene maleamic copolymer.

Biochim Biophys Acta Biomembr 2020 May 23:183360. Epub 2020 May 23.

Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada. Electronic address:

The development of amphipathic polymers, including various formulations of styrene-maleic acid (SMA) copolymers, has allowed the purification of increasing sizes and complexities of biological membrane protein assemblies in native nanodiscs. However, the factors determining the sizes and shapes of the resulting bio-nano particles remain unclear. Here, we show how grafting on short alkyl amine sidechains onto the polar residues leads to a broad set of nanoparticle sizes with improved solution behavior. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183360DOI Listing

Molecular organization in mixed SOPC and SDPC model membranes: Water permeability studies of polyunsaturated lipid bilayers.

Biochim Biophys Acta Biomembr 2020 May 23;1862(9):183365. Epub 2020 May 23.

Department of Chemistry, Iona College, 715 North Avenue, New Rochelle, NY 10801, USA. Electronic address:

Polyunsaturated phospholipids in plasma membranes modulate order and dynamics of the lipid bilayer and influence integral membrane protein function. In this study, we investigate the effects of polyunsaturated fatty acid (PUFA) chains in phosphatidylcholine (PC) on osmotic water permeability and packing characteristics, using a droplet interface bilayer (DIB) as a model cell membrane. The lipid bilayer system is composed of mixtures of PC lipids with varying ratio of 1-stearoyl-2-oleoylphosphatidylcholine (SOPC, 18: 0-18:1 PC) to 1-stearoyl-2-docosahexaenoylphosphatidylcholine (SDPC, 18:0-22:6 PC). Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183365DOI Listing

Central residues of the amphipathic β-hairpin loop control the properties of Clostridium perfringens epsilon-toxin channel.

Biochim Biophys Acta Biomembr 2020 May 22;1862(9):183364. Epub 2020 May 22.

Institut Pasteur, Bacterial Toxins, 28 rue du Dr Roux, 75724 Paris cedex 15, France. Electronic address:

Clostridium perfringens epsilon toxin (ETX) is a heptameric pore-forming toxin of the aerolysin toxin family. ETX is the most potent toxin of this toxin family and the third most potent bacterial toxin with high cytotoxic and lethal activities in animals. In addition, ETX shows a demyelinating activity in nervous tissue leading to devastating multifocal central nervous system white matter disease in ruminant animals. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183364DOI Listing

The effects of melatonin, serotonin, tryptophan and NAS on the biophysical properties of DPPC monolayers.

Biochim Biophys Acta Biomembr 2020 May 22;1862(9):183363. Epub 2020 May 22.

Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada; Department of Biology, University of Waterloo, Waterloo, Canada. Electronic address:

Melatonin is a neurohormone that has been shown to be protective in Alzheimer's diseases against amyloid-β (Aβ) toxicity, which involves interaction of Aβ with neuronal membrane. Non-specific interactions of melatonin with cell membrane may play a physiological role in this process by preserving membrane fluidity. In the brain, melatonin is derived from the amino acid tryptophan through a pathway that includes serotonin and N-acetylserotonin (NAS). Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183363DOI Listing

Dual benefit of combined neuroprotection: Cholesterol depletion restores membrane microviscosity but not lipid order and enhances neuroprotective action of hypothermia in rat cortex nerve terminals.

Biochim Biophys Acta Biomembr 2020 May 21;1862(9):183362. Epub 2020 May 21.

Dep. of Neurochemistry of the Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, 9 Leontovicha Str., Kyiv 01054, Ukraine.

Here, both neuroprotectants, i.e. cholesterol depletion of the plasma membrane of rat brain nerve terminals (synaptosomes) using methyl-β-cyclodextrin (MβCD) and deep/propound hypothermia, were analyzed during their combined administration and regarding additive neuroprotective effect. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183362DOI Listing

Channel functions of claudins in the organization of biological systems.

Biochim Biophys Acta Biomembr 2020 May 19:183344. Epub 2020 May 19.

Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany. Electronic address:

Claudins are tight junction proteins mostly appreciated in their function of paracellular barrier-formation. Compared to a virtual absence of any tight junctions, their paracellular sealing role certainly stands out. Yet, it was recognized immediately after the discovery of the first claudins, that some members of the claudin protein family were able to convey size and charge selectivity to the paracellular pathway. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183344DOI Listing

Hyaluronic acid binding to CD44S is indiscriminate of molecular weight.

Biochim Biophys Acta Biomembr 2020 May 16;1862(9):183348. Epub 2020 May 16.

Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, United States of America; Department of Biomedical Engineering, Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, United States of America. Electronic address:

The ubiquitous presence of hyaluronic acid (HA) in the extracellular matrix (ECM) of both healthy and diseased tissues underscores its importance in human physiology. Previous studies suggest that HA can be used as a probe to qualitatively monitor cell surface levels of CD44 and other important HA receptors; however, these studies use mixtures of HA at various molecular weights. Using fluorescently labeled HA, we evaluated the apparent differences of low (25 kilodalton) and high (700 kilodalton) molecular weight HA interacting with breast cancer cell lines of varying levels of CD44. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183348DOI Listing

Synergistic inhibition mechanism of pediocin PA-1 and L-lactic acid against Aeromonas hydrophila.

Biochim Biophys Acta Biomembr 2020 May 16;1862(10):183346. Epub 2020 May 16.

Tianjin Key Laboratory of Aqua-ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, 22 Jinjing Road, 300384 Tianjin, China.

Pediocin PA-1 (PA-1) is a membrane-targeting bacteriocin from lactic acid bacteria, which shows antimicrobial activity against a wide range of Gram-positive pathogens. However, the outer membrane of Gram-negative bacteria does not allow pediocin access to its target. In this work, the synergistic inhibitory mechanism of PA-1 with L-lactic acid against Gram-negative aquaculture and food pathogen Aeromonas hydrophila (A. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183346DOI Listing

The effect of lipid phase on liposome stability upon exposure to the mechanical stress.

Biochim Biophys Acta Biomembr 2020 May 15;1862(9):183361. Epub 2020 May 15.

Lipid Systems sp. z o.o., 54-613 Wrocław, ul. Krzemieniecka 48C, Poland.

Mechanical properties of a lipid bilayer are parameters determined mainly for giant unilamellar vesicles (GUVs). It is not clear if values obtained on the GUV model can be directly translated to submicron large unilamellar vesicles (LUVs). This ambiguity is a major obstacle in exploring the effect of lipid bilayer mechanics on membrane associated processes and effectiveness of liposome-based targeted drug delivery systems. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183361DOI Listing

Regulation and function of V-ATPases in physiology and disease.

Biochim Biophys Acta Biomembr 2020 May 15:183341. Epub 2020 May 15.

Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America; Dept. of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States of America. Electronic address:

The vacuolar H-ATPases (V-ATPases) are essential, ATP-dependent proton pumps present in a variety of eukaryotic cellular membranes. Intracellularly, V-ATPase-dependent acidification functions in such processes as membrane traffic, protein degradation, autophagy and the coupled transport of small molecules. V-ATPases at the plasma membrane of certain specialized cells function in such processes as bone resorption, sperm maturation and urinary acidification. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183341DOI Listing

Magnetically aligned membrane mimetics enabling comparable chiroptical and magnetic resonance spectroscopy studies.

Biochim Biophys Acta Biomembr 2020 May 14;1862(9):183343. Epub 2020 May 14.

Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom. Electronic address:

Lipidic bicelles have been widely used for the analysis of integral membrane proteins where their spontaneous alignment in an magnetic field has been exploited for oriented sample solid-state NMR studies. Many of their physical properties however make them well suited to the analysis of membrane proteins by circular dichroism (CD) and synchrotron radiation circular dichroism (SRCD). In this paper we have identified bicelle compositions that permit comparable studies of integral membrane proteins by solid-state NMR, CD, and SRCD; complementary methods that can provide insights into protein structure and the interactions with drugs and other small molecules. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183343DOI Listing

Cholesterol and desmosterol incorporation into ram sperm membrane before cryopreservation: Effects on membrane biophysical properties and sperm quality.

Biochim Biophys Acta Biomembr 2020 May 13;1862(9):183357. Epub 2020 May 13.

Laboratorio Biotecnología de la Reproducción, Departamento de Producción Animal, Instituto Nacional de Tecnología Agropecuaria (INTA), EEA Balcarce, Ruta 226 km 73.5, 7620 Balcarce, Buenos Aires, Argentina. Electronic address:

Ram sperm are particularly sensitive to freeze-thawing mainly due to their lipid composition, limiting their use in artificial insemination programs. We evaluated the extent of cholesterol and desmosterol incorporation into ram sperm through incubation with increasing concentrations of methyl-β-cyclodextrin (MβCD)-sterol complexes, and its effect on membrane biophysical properties, membrane lateral organization and cryopreservation outcome. Sterols were effectively incorporated into the sperm membrane at 10 and 25 mM MβCD-sterols, similarly increasing membrane lipid order at physiological temperature and during temperature decrease. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183357DOI Listing

Characterization of lipid composition and diffusivity in OLA generated vesicles.

Biochim Biophys Acta Biomembr 2020 May 13;1862(9):183359. Epub 2020 May 13.

Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom. Electronic address:

Giant Unilamellar Vesicles (GUVs) are a versatile tool in many branches of science, including biophysics and synthetic biology. Octanol-Assisted Liposome Assembly (OLA), a recently developed microfluidic technique enables the production and testing of GUVs within a single device under highly controlled experimental conditions. It is therefore gaining significant interest as a platform for use in drug discovery, the production of artificial cells and more generally for controlled studies of the properties of lipid membranes. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183359DOI Listing

Solution NMR spectroscopy of membrane proteins.

Biochim Biophys Acta Biomembr 2020 May 13;1862(9):183356. Epub 2020 May 13.

Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada; Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2H7, Canada. Electronic address:

Integral membrane proteins (IMPs) perform unique and indispensable functions in the cell, making them attractive targets for fundamental research and drug discovery. Developments in protein production, isotope labeling, sample preparation, and pulse sequences have extended the utility of solution NMR spectroscopy for studying IMPs with multiple transmembrane segments. Here we review some recent applications of solution NMR for studying structure, dynamics, and interactions of polytopic IMPs, emphasizing strategies used to overcome common technical challenges. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183356DOI Listing

Effect of tetracaine on dynamic reorganization of lipid membranes.

Biochim Biophys Acta Biomembr 2020 May 13;1862(9):183351. Epub 2020 May 13.

College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.

To understand the intrinsic influence of a drug on lipid membranes is of critical importance in pharmacological science. Herein, we report fluorescence microscopy analysis of the interaction between the local anesthetic tetracaine (TTC) and planar supported lipid bilayers (SLBs), as model membranes. Our results show that TTC increases lipid chain mobility, destabilizes the SLBs and remarkably induces membrane disruption and solubilization. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183351DOI Listing

The SecA ATPase motor protein binds to Escherichia coli liposomes only as monomers.

Biochim Biophys Acta Biomembr 2020 May 19;1862(9):183358. Epub 2020 May 19.

Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, United States of America. Electronic address:

The essential SecA motor ATPase acts in concert with the SecYEG translocon to secrete proteins into the periplasmic space of Escherichia coli. In aqueous solutions, SecA exists largely as dimers, but the oligomeric state on membranes is less certain. Crystallographic studies have suggested several possible solution dimeric states, but its oligomeric state when bound to membranes directly or indirectly via the translocon is controversial. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183358DOI Listing

Proteasome-dependent protein quality control of the peroxisomal membrane protein Pxa1p.

Biochim Biophys Acta Biomembr 2020 May 13;1862(9):183342. Epub 2020 May 13.

Department of Cell Biochemistry, University of Groningen, the Netherlands. Electronic address:

Peroxisomes are eukaryotic organelles that function in numerous metabolic pathways and defects in peroxisome function can cause serious developmental brain disorders such as adrenoleukodystrophy (ALD). Peroxisomal membrane proteins (PMPs) play a crucial role in regulating peroxisome function. Therefore, PMP homeostasis is vital for peroxisome function. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183342DOI Listing

Optimizing the α-adrenergic receptor for solution NMR studies.

Biochim Biophys Acta Biomembr 2020 May 12:183354. Epub 2020 May 12.

Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland. Electronic address:

Sample preparation for NMR studies of G-protein coupled receptors faces special requirements: Proteins need to be stable for prolonged measurements at elevated temperatures, they should ideally be uniformly labeled with the stable isotopes C, N, and all carbon-bound protons should be replaced by deuterons. In addition, certain NMR experiments require protonated methyl groups in the presence of a perdeuterated background. All these requirements are most easily satisfied when using Escherichia coli as the expression host. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183354DOI Listing

Dynamics and structural communication in the ternary complex of fully phosphorylated V2 vasopressin receptor, vasopressin, and β-arrestin 1.

Biochim Biophys Acta Biomembr 2020 May 12;1862(9):183355. Epub 2020 May 12.

Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy; Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy. Electronic address:

G protein-coupled receptors (GPCRs) are critically regulated by arrestins, which not only desensitize G-protein signaling but also initiate a G protein-independent wave of signaling. The information from structure determination was herein exploited to build a structural model of the ternary complex, comprising fully phosphorylated V2 vasopressin receptor (V2R), the agonist arginine vasopressin (AVP), and β-arrestin 1 (β-arr1). Molecular simulations served to explore dynamics and structural communication in the ternary complex. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183355DOI Listing

The binding of the APT1 domains to phosphoinositides is regulated by metal ions in vitro.

Biochim Biophys Acta Biomembr 2020 May 11;1862(9):183349. Epub 2020 May 11.

Institute of Biochemistry and Biophysics Polish Academy of Sciences, Pawinskiego 5A, 02-106 Warsaw, Poland.

Chorein is a protein of the Vps13 family, and defects in this protein cause the rare neurodegenerative disorder chorea-acanthocytosis (ChAc). Chorein is involved in the actin cytoskeleton organization, calcium ion flux, neuronal cell excitability, exocytosis and autophagy. The function of this protein is poorly understood, and obtaining this knowledge is a key to finding a cure for ChAc. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183349DOI Listing

Potent in vitro and in vivo antimicrobial activity of semisynthetic amphiphilic γ-mangostin derivative LS02 against Gram-positive bacteria with destructive effect on bacterial membrane.

Biochim Biophys Acta Biomembr 2020 May 11;1862(9):183353. Epub 2020 May 11.

Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences & the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 511436, PR China. Electronic address:

Semisynthetic γ-mangostin derivative LS02 is a novel cationic amphiphilic peptidomimetic antimicrobial agent containing a hydrophobic scaffold and three hydrophilic and positively charged residues of arginine. LS02 showed low in vitro toxicity, potent activities against Gram-positive bacteria including MRSA (MIC = 1.56-6. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183353DOI Listing

Identifying lipids tightly bound to an integral membrane protein.

Biochim Biophys Acta Biomembr 2020 May 11:183345. Epub 2020 May 11.

Department of Physics, University of Guelph, Guelph, ON N1G 2W1, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, ON N1G 2W1, Canada. Electronic address:

Anabaena Sensory Rhodopsin (ASR) is a microbial photosensor from the cyanobacterium Anabaena sp. PCC 7120. It was found in previous studies that ASR co-purifies with several small molecules, although their identities and structural or functional roles remained unclear. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183345DOI Listing

Nanomechanical characterization of single phospholipid bilayer in ripple phase with PF-QNM AFM.

Biochim Biophys Acta Biomembr 2020 May 11;1862(9):183347. Epub 2020 May 11.

Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. Electronic address:

Topography and nanomechanical properties of the supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) single bilayer in the ripple phase were investigated by atomic force microscopy with the use of PeakForce Quantitative Nanomechanical Mapping (PF-QNM) mode under liquid conditions. The DMPC single bilayer was deposited on the mica surface by Langmuir-Blodgett and Langmuir-Schaefer techniques combined. Next, the sample was stored overnight at 4 °C under buffer solution (pH = 7. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183347DOI Listing

Structure and dynamics of phospholipids in membranes elucidated by combined use of NMR and vibrational spectroscopies.

Authors:
Hideo Akutsu

Biochim Biophys Acta Biomembr 2020 May 11;1862(9):183352. Epub 2020 May 11.

Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan; Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. Electronic address:

NMR is a sophisticated method for investigation of structure and dynamics of lipid and protein molecules in membranes. Vibrational spectroscopy is also powerful because of relatively high resolution and sensitivity, and easier access than NMR. A combined use of these spectroscopies could provide important insights into the membrane biophysics. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183352DOI Listing

A machine learning approach to estimation of phase diagrams for three-component lipid mixtures.

Biochim Biophys Acta Biomembr 2020 May 11;1862(9):183350. Epub 2020 May 11.

Department of Chemical and Biomolecular Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH 45701, USA. Electronic address:

The plasma membrane of eukaryotic cells is commonly believed to contain ordered lipid domains. The interest in understanding the origin of such domains has led to extensive studies on the phase behavior of mixed lipid systems. Three-component phase diagrams, composed of a high melting temperature (Tm) lipid, cholesterol, and a low Tm lipid have been valuable in studying lipid phase behavior. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183350DOI Listing

Ruffles and spikes: Control of tight junction morphology and permeability by claudins.

Biochim Biophys Acta Biomembr 2020 May 7;1862(9):183339. Epub 2020 May 7.

Division of Pulmonary, Allergy Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA. Electronic address:

Epithelial barrier function is regulated by a family of transmembrane proteins known as claudins. Functional tight junctions are formed when claudins interact with other transmembrane proteins, cytosolic scaffold proteins and the actin cytoskeleton. The predominant scaffold protein, zonula occludens-1 (ZO-1), directly binds to most claudin C-terminal domains, crosslinking them to the actin cytoskeleton. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183339DOI Listing

Inherited disorders of lysosomal membrane transporters.

Biochim Biophys Acta Biomembr 2020 May 8:183336. Epub 2020 May 8.

Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.

Disorders caused by defects in lysosomal membrane transporters form a distinct subgroup of lysosomal storage disorders (LSDs). To date, defects in only 10 lysosomal membrane transporters have been associated with inherited disorders. The clinical presentations of these diseases resemble the phenotypes of other LSDs; they are heterogeneous and often present in children with neurodegenerative manifestations. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183336DOI Listing

Pleiotropic effects of statins on brain cells.

Biochim Biophys Acta Biomembr 2020 May 6;1862(9):183340. Epub 2020 May 6.

Institute of Biomedical Research (BIOMED), Pontifical Catholic University of Argentina (UCA) and National Scientific and Technical Research Council (CONICET), Av. Alicia Moreau de Justo 1600, C1107AFF Buenos Aires, Argentina. Electronic address:

Starting with cholesterol homeostasis, the first part of the review addresses various aspects of cholesterol metabolism in neuronal and glial cells and the mutual crosstalk between the two cell types, particularly the transport of cholesterol from its site of synthesis to its target loci in neuronal cells, discussing the multiple mechanistic aspects and transporter systems involved. Statins are next analyzed from the point of view of their chemical structure and its impingement on their pharmacological properties and permeability through cell membranes and the blood-brain barrier in particular. The following section then discusses the transcriptional effects of statins and the changes they induce in brain cell genes associated with a variety of processes, including cell growth, signaling and trafficking, uptake and synthesis of cholesterol. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183340DOI Listing

Real-time monitoring of heat transfer between gold nanoparticles and tethered bilayer lipid membranes.

Biochim Biophys Acta Biomembr 2020 May 4;1862(9):183334. Epub 2020 May 4.

School of Life Sciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia; Institute for Biomedical Materials and Devices, University of Technology Sydney, Sydney, New South Wales 2007, Australia; ARC Research Hub for Integrated Devices for End-user Analysis at Low-levels (IDEAL), Faculty of Science, University of Technology Sydney, NSW 2007, Australia. Electronic address:

Plasmon resonance frequency irradiated gold nanoparticles (GNPs) have gained interest as a laser-targeted treatment for infections, tumors and for the controlled release of drugs in situ. Questions still remain, however, as to the efficiency of heat delivery within biological tissues and how this can be reliably determined. Here, we demonstrate how a nanomaterial-electrode interface that mimics cell membranes can detect the localized heat transfer characteristics arising from plasmon resonance frequency-matched laser excitation of GNPs. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183334DOI Listing

Characterization of BamA reconstituted into a solid-supported lipid bilayer as a platform for measuring dynamics during substrate protein assembly into the membrane.

Biochim Biophys Acta Biomembr 2020 May 4;1862(9):183317. Epub 2020 May 4.

Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia; Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton 3800, Australia; Infection & Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton 3800, Australia. Electronic address:

In Gram-negative bacteria, the multi-protein β-barrel assembly machine (BAM) complex is a nanomachine playing a vital role in the process of assembling β-barrel proteins into the outer membrane (OM). The core component of this multiprotein complex, BamA, is an evolutionarily conserved protein that carries five polypeptide-transport-associated (POTRA) domains that project from the outer membrane. BamA is essential for chaperoning the insertion of proteins into the OM surface of bacterial cells. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183317DOI Listing

The monomers, oligomers, and fibrils of amyloid-β inhibit the activity of mitoBK channels by a membrane-mediated mechanism.

Biochim Biophys Acta Biomembr 2020 May 4;1862(9):183337. Epub 2020 May 4.

Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS, Pasteura str. 3, Warsaw 02-093, Poland.

A causative agent of Alzheimer's disease (AD) is a short amphipathic peptide called amyloid beta (Aβ). Aβ monomers undergo structural changes leading to their oligomerization or fibrillization. The monomers as well as all aggregated forms of Aβ, i. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183337DOI Listing

FT-IR investigation of Terbinafine interaction with stratum corneum constituents.

Biochim Biophys Acta Biomembr 2020 May 3;1862(9):183335. Epub 2020 May 3.

Department of Chemistry, Newark College of Arts and Sciences, Rutgers University, Newark, NJ 07102, USA.

Terbinafine (Tbf) is a well-established anti-fungal agent used for management of a variety of dermal conditions including ringworm and athlete's foot. Both the biochemical mechanism of Tbf fungicidal action (based on squalene epoxidase inhibition) and the target region for Tbf in vivo (the stratum corneum (SC)) are well determined. However, the biochemical and pharmacokinetic approaches used to evaluate Tbf biochemistry provide no biophysical information about molecular level physical changes in the SC upon Tbf binding. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183335DOI Listing

Post-translational modifications of tight junction transmembrane proteins and their direct effect on barrier function.

Biochim Biophys Acta Biomembr 2020 May 3:183330. Epub 2020 May 3.

Institute of Biochemistry II, Jena University Hospital, Friedrich Schiller University Jena, Nonnenplan 2-4, 04473 Jena, Germany. Electronic address:

Post-translational modifications (PTMs) such as phosphorylation, ubiquitination or glycosylation are processes affecting the conformation, stability, localization and function of proteins. There is clear evidence that PTMs can act upon tight junction (TJ) proteins, thus modulating epithelial barrier function. Compared to transcriptional or translational regulation, PTMs are rapid and more dynamic processes so in the context of barrier maintenance they might be essential for coping with changing environmental or external impacts. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183330DOI Listing

Thrombocidin-1-derived antimicrobial peptide TC19 combats superficial multi-drug resistant bacterial wound infections.

Biochim Biophys Acta Biomembr 2020 Aug 3;1862(8):183282. Epub 2020 May 3.

Dept. of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, the Netherlands. Electronic address:

Antimicrobial peptides are considered promising candidates for the development of novel antimicrobial agents to combat infections by multi-drug-resistant (MDR) bacteria. Here, we describe the identification and characterization of the synthetic peptide TC19, derived from the human thrombocidin-1-derived peptide L3. Biophysical experiments into the interaction between TC19 and mimics of human and bacterial plasma membranes demonstrated that the peptide is highly selective for bacterial membranes. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183282DOI Listing

The desmosome as a model for lipid raft driven membrane domain organization.

Biochim Biophys Acta Biomembr 2020 May 3;1862(9):183329. Epub 2020 May 3.

Department of Cell Biology, Emory University, Atlanta, GA 30322, United States of America; Department of Dermatology, Emory University, Atlanta, GA 30322, United States of America. Electronic address:

Desmosomes are cadherin-based adhesion structures that mechanically couple the intermediate filament cytoskeleton of adjacent cells to confer mechanical stress resistance to tissues. We have recently described desmosomes as mesoscale lipid raft membrane domains that depend on raft dynamics for assembly, function, and disassembly. Lipid raft microdomains are regions of the plasma membrane enriched in sphingolipids and cholesterol. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183329DOI Listing

Membrane proteins in magnetically aligned phospholipid polymer discs for solid-state NMR spectroscopy.

Biochim Biophys Acta Biomembr 2020 May 1;1862(9):183333. Epub 2020 May 1.

University of California San Diego, La Jolla, CA, USA. Electronic address:

Well-hydrated phospholipid bilayers provide a near-native environment for membrane proteins. They enable the preparation of chemically-defined samples suitable for NMR and other spectroscopic experiments that reveal the structure, dynamics, and functional interactions of the proteins at atomic resolution. The synthetic polymer styrene maleic acid (SMA) can be used to prepare detergent-free samples that form macrodiscs with diameters greater than 30 nm at room temperature, and spontaneously align in the magnetic field of an NMR spectrometer at temperatures above 35 °C. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183333DOI Listing

Lipid-nanodiscs formed by paramagnetic metal chelated polymer for fast NMR data acquisition.

Biochim Biophys Acta Biomembr 2020 May 1;1862(9):183332. Epub 2020 May 1.

Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Biophysics and Chemistry Department, The University of Michigan, Ann Arbor, MI 48109-1055, USA; Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA; Biomedical Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA. Electronic address:

Lipid-nanodiscs have been shown to be an exciting innovation as a membrane-mimicking system for studies on membrane proteins by a variety of biophysical techniques, including NMR spectroscopy. Although NMR spectroscopy is unique in enabling the atomic-resolution investigation of dynamic structures of membrane-associated molecules, it, unfortunately, suffers from intrinsically low sensitivity. The long data acquisition often used to enhance the sensitivity is not desirable for sensitive membrane proteins. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183332DOI Listing

Ionic Coulomb blockade and the determinants of selectivity in the NaChBac bacterial sodium channel.

Biochim Biophys Acta Biomembr 2020 Apr 30;1862(9):183301. Epub 2020 Apr 30.

Department of Physics, Lancaster University, Lancaster LA1 4YB, UK. Electronic address:

Mutation-induced transformations of conductivity and selectivity in NaChBac bacterial channels are studied experimentally and interpreted within the framework of ionic Coulomb blockade (ICB), while also taking account of resonant quantised dehydration (QD) and site protonation. Site-directed mutagenesis and whole-cell patch-clamp experiments are used to investigate how the fixed charge Q at the selectivity filter (SF) affects both valence selectivity and same-charge selectivity. The new ICB/QD model predicts that increasing ∣Q∣ should lead to a shift in selectivity sequences toward larger ion sizes, in agreement with the present experiments and with earlier work. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183301DOI Listing

Cell-cell junctions as sensors and transducers of mechanical forces.

Biochim Biophys Acta Biomembr 2020 Apr 28;1862(9):183316. Epub 2020 Apr 28.

Amsterdam UMC, University of Amsterdam, Location AMC, Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands. Electronic address:

Epithelial and endothelial monolayers are multicellular sheets that form barriers between the 'outside' and 'inside' of tissues. Cell-cell junctions, made by adherens junctions, tight junctions and desmosomes, hold together these monolayers. They form intercellular contacts by binding their receptor counterparts on neighboring cells and anchoring these structures intracellularly to the cytoskeleton. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183316DOI Listing

Editorial preface for SI Membrane Effectors and Actuators.

Biochim Biophys Acta Biomembr 2020 Aug 28;1862(8):183331. Epub 2020 Apr 28.

Biophysics Division, Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria. Electronic address:

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http://dx.doi.org/10.1016/j.bbamem.2020.183331DOI Listing

Evaluation of different approaches used to study membrane permeabilization by actinoporins on model lipid vesicles.

Biochim Biophys Acta Biomembr 2020 Apr 27;1862(9):183311. Epub 2020 Apr 27.

Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain. Electronic address:

Release of aqueous contents from model lipid vesicles has been a standard procedure to evaluate pore formation efficiency by actinoporins, such as sticholysin II (StnII), for the last few decades. However, regardless of the probe of choice, the results reported that StnII action was never able to empty the vesicles completely. This was hard to explain if StnII pores were to be stable and always leaky for the probes used. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183311DOI Listing

Tight junction modulation at the blood-brain barrier: Current and future perspectives.

Biochim Biophys Acta Biomembr 2020 Apr 27;1862(9):183298. Epub 2020 Apr 27.

Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland. Electronic address:

The blood-brain barrier (BBB) is the one of the most robust physical barriers in the body, comprised of tight junction (TJ) proteins in brain microvascular endothelial cells. The need for drugs to treat central nervous systems diseases is ever increasing, however the presence of the BBB significantly hampers the uptake of drugs into the brain. To overcome or circumvent the barrier, many kinds of techniques are being developed. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183298DOI Listing

Formation of aggregates, icosahedral structures and percolation clusters of fullerenes in lipids bilayers: The key role of lipid saturation.

Biochim Biophys Acta Biomembr 2020 Apr 25;1862(9):183328. Epub 2020 Apr 25.

Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand; Computational Biomodelling Laboratory for Agricultural Science and Technology (CBLAST), Faculty of Science, Kasetsart University, Bangkok 10900, Thailand; Thailand Center of Excellence in Physics (ThEP Center), Ministry of Higher Education, Science, Research and Innovation, Bangkok 10400, Thailand; Specialized Center of Rubber and Polymer Materials for Agriculture and Industry (RPM), Faculty of Science, Kasetsart University, Bangkok 10900, Thailand. Electronic address:

Carbon nanoparticles (CNPs) are attractive materials for a great number of applications but there are serious concerns regarding their influence on health and environment. Here, our focus is on the behavior of fullerenes in lipid bilayers with varying lipid saturations, chain lengths and fullerene concentrations using coarse-grained molecular dynamics (CG-MD) simulations. Our findings show that the lipid saturation level is a key factor in determining how fullerenes behave and where the fullerenes are located inside a lipid bilayer. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183328DOI Listing

Mechanism of polyamine induced colistin resistance through electrostatic networks on bacterial outer membranes.

Biochim Biophys Acta Biomembr 2020 Apr 24;1862(9):183297. Epub 2020 Apr 24.

Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix, Singapore 138671, Singapore; National University of Singapore, Department of Biological Sciences, Singapore; Nanyang Technological University, School of Biological Sciences, Singapore. Electronic address:

Naturally occurring linear polyamines are known to enable bacteria to be resistant to cationic membrane active peptides. To understand this protective mechanism, molecular dynamics simulations are employed to probe their effect on a model bacterial outer membrane. Being protonated at physiological pH, the amine groups of the polyamine engage in favorable electrostatic interactions with the negatively charged phosphate groups of the membrane. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183297DOI Listing

Diversity and sequence motifs of the bacterial SecA protein motor.

Biochim Biophys Acta Biomembr 2020 Apr 23:183319. Epub 2020 Apr 23.

Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, D-14195 Berlin, Germany. Electronic address:

SecA is an essential component of the Sec protein secretion pathway in bacteria. Secretory proteins targeted to the Sec pathway by their N-terminal signal peptide bind to SecA, which couples binding and hydrolysis of adenosine triphosphate with movement of the secretory protein across the membrane-embedded SecYEG protein translocon. The phylogenetic diversity of bacteria raises the important question as to whether the region of SecA where the pre-protein binds has organism-specific sequence features that might impact the reaction mechanism of SecA. Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183319DOI Listing

Negative charge of the AC-to-Hly linking segment modulates calcium-dependent membrane activities of Bordetella adenylate cyclase toxin.

Biochim Biophys Acta Biomembr 2020 Apr 22;1862(9):183310. Epub 2020 Apr 22.

Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic. Electronic address:

Two distinct conformers of the adenylate cyclase toxin (CyaA) appear to accomplish its two parallel activities within target cell membrane. The translocating conformer would deliver the N-terminal adenylyl cyclase (AC) enzyme domain across plasma membrane into cytosol of cells, while the pore precursor conformer would assemble into oligomeric cation-selective pores and permeabilize cellular membrane. Both toxin activities then involve a membrane-interacting 'AC-to-Hly-linking segment' (residues 400 to 500). Read More

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http://dx.doi.org/10.1016/j.bbamem.2020.183310DOI Listing
April 2020
3.836 Impact Factor