keyword
MENU ▼
Read by QxMD icon Read
search

Reconstituted lipid vesicles

keyword
https://www.readbyqxmd.com/read/28703789/capturing-suboptical-dynamic-structures-in-lipid-bilayer-patches-formed-from-free-standing-giant-unilamellar-vesicles
#1
Tripta Bhatia, Flemming Cornelius, John H Ipsen
There is accumulating evidence that the small-scale lateral organization of biological membranes has a crucial role in signaling and trafficking in cells. However, it has been difficult to characterize these features with existing methods for preparing and analyzing freestanding membranes, because the dynamics occurs below the optical resolution possible with these protocols. We have developed a protocol that permits the imaging of lipid nanodomains and lateral protein organization in membranes of giant unilamellar vesicles (GUVs)...
August 2017: Nature Protocols
https://www.readbyqxmd.com/read/28697898/fusion-domains-guide-the-oriented-insertion-of-light-driven-proton-pumps-into-liposomes
#2
Noah Ritzmann, Johannes Thoma, Stephan Hirschi, David Kalbermatter, Dimitrios Fotiadis, Daniel J Müller
One major objective of synthetic biology is the bottom-up assembly of minimalistic nanocells consisting of lipid or polymer vesicles as architectural scaffolds and of membrane and soluble proteins as functional elements. However, there is no reliable method to orient membrane proteins reconstituted into vesicles. Here, we introduce a simple approach to orient the insertion of the light-driven proton pump proteorhodopsin (PR) into liposomes. To this end, we engineered red or green fluorescent proteins to the N- or C-terminus of PR, respectively...
July 8, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28695207/peripheral-myelin-protein-22-alters-membrane-architecture
#3
Kathleen F Mittendorf, Justin T Marinko, Cheri M Hampton, Zunlong Ke, Arina Hadziselimovic, Jonathan P Schlebach, Cheryl L Law, Jun Li, Elizabeth R Wright, Charles R Sanders, Melanie D Ohi
Peripheral myelin protein 22 (PMP22) is highly expressed in myelinating Schwann cells of the peripheral nervous system. PMP22 genetic alterations cause the most common forms of Charcot-Marie-Tooth disease (CMTD), which is characterized by severe dysmyelination in the peripheral nerves. However, the functions of PMP22 in Schwann cell membranes remain unclear. We demonstrate that reconstitution of purified PMP22 into lipid vesicles results in the formation of compressed and cylindrically wrapped protein-lipid vesicles that share common organizational traits with compact myelin of peripheral nerves in vivo...
July 2017: Science Advances
https://www.readbyqxmd.com/read/28688734/first-moves-towards-photoautotrophic-synthetic-cells-in-vitro-study-of-photosynthetic-reaction-centre-and-cytochrome-bc1-complex-interactions
#4
Emiliano Altamura, Rosa Fiorentino, Francesco Milano, Massimo Trotta, Gerardo Palazzo, Pasquale Stano, Fabio Mavelli
Following a bottom-up synthetic biology approach it is shown that vesicle-based cell-like systems (shortly "synthetic cells") can be designed and assembled to perform specific function (for biotechnological applications) and for studies in the origin-of-life field. We recently focused on the construction of synthetic cells capable to converting light into chemical energy. Here we first present our approach, which has been realized so far by the reconstitution of photosynthetic reaction centre in the membrane of giant lipid vesicles...
June 26, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28648851/the-influence-of-mild-acidity-on-lysyl-phosphatidylglycerol-biosynthesis-and-lipid-membrane-physico-chemical-properties-in-methicillin-resistant-staphylococcus-aureus
#5
Reg P Rehal, Helene Marbach, Alasdair T M Hubbard, Anam A Sacranie, Federica Sebastiani, Giovanna Fragneto, Richard D Harvey
The increased biosynthesis of lysyl-phosphatidylglycerol in Staphylococcus aureus when cultured under conditions of mild acidity and the resultant increased proportion of this lipid in the plasma membrane of the bacterium, alters the physico-chemical properties of lipid bilayers in a manner which is itself dependent upon environmental pH. Clinically relevant strains of S. aureus, both methicillin susceptible and resistant, all exhibited increased lysyl-phosphatidylglycerol biosynthesis in response to mild environmental acidity, albeit to differing degrees, from ∼30% to ∼55% total phospholipid...
June 23, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/28616949/monitoring-atpase-induced-ph-changes-in-single-proteoliposomes-with-the-lipid-coupled-fluorophore-oregon-green-488
#6
Miriam Schwamborn, Johannes Schumacher, Jeremias Sibold, Nikolas K Teiwes, Claudia Steinem
Monitoring the proton pumping activity of proteins such as ATPases in reconstituted single proteoliposomes is key to quantify the function of proteins as well as potential proton pump inhibitors. However, most pH-detecting assays available are either not quantitative, require well-adapted reconstitution protocols or are not appropriate for single vesicle studies. Here, we describe the quantitative and time-resolved detection of F-type ATPase-induced pH changes across vesicular membranes doped with the commercially available pH sensitive fluorophore Oregon Green 488 DHPE...
July 10, 2017: Analyst
https://www.readbyqxmd.com/read/28592883/the-lateral-distance-between-a-proton-pump-and-atp-synthase-determines-the-atp-synthesis-rate
#7
Johannes Sjöholm, Jan Bergstrand, Tobias Nilsson, Radek Šachl, Christoph von Ballmoos, Jerker Widengren, Peter Brzezinski
We have investigated the effect of lipid composition on interactions between cytochrome bo 3 and ATP-synthase, and the ATP-synthesis activity driven by proton pumping. The two proteins were labeled by fluorescent probes and co-reconstituted in large (d ≅ 100 nm) or giant (d ≅ 10 µm) unilamellar lipid vesicles. Interactions were investigated using fluorescence correlation/cross-correlation spectroscopy and the activity was determined by measuring ATP production, driven by electron-proton transfer, as a function of time...
June 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28536532/phase-partitioning-of-gm1-and-its-bodipy-labeled-analog-determine-their-different-binding-to-cholera-toxin
#8
Sami Rissanen, Michal Grzybek, Adam Orłowski, Tomasz Róg, Oana Cramariuc, Ilya Levental, Christian Eggeling, Erdinc Sezgin, Ilpo Vattulainen
Driven by interactions between lipids and proteins, biological membranes display lateral heterogeneity that manifests itself in a mosaic of liquid-ordered (Lo) or raft, and liquid-disordered (Ld) or non-raft domains with a wide range of different properties and compositions. In giant plasma membrane vesicles and giant unilamellar vesicles, specific binding of Cholera Toxin (CTxB) to GM1 glycolipids is a commonly used strategy to label raft domains or Lo membrane environments. However, these studies often use acyl-chain labeled bodipy-GM1 (bdGM1), whose headgroup accessibility and membrane order or phase partitioning may differ from those of GM1, rendering the interpretation of CTxB binding data quite problematic...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28476622/green-fluorescence-protein-based-content-mixing-assay-of-snare-driven-membrane-fusion
#9
Paul Heo, Byoungjae Kong, Young-Hun Jung, Joon-Bum Park, Jonghyeok Shin, Myungseo Park, Dae-Hyuk Kweon
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins mediate intracellular membrane fusion by forming a ternary SNARE complex. A minimalist approach utilizing proteoliposomes with reconstituted SNARE proteins yielded a wealth of information pinpointing the molecular mechanism of SNARE-mediated fusion and its regulation by accessory proteins. Two important attributes of a membrane fusion are lipid-mixing and the formation of an aqueous passage between apposing membranes. These two attributes are typically observed by using various fluorescent dyes...
June 17, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28472750/effect-of-the-presence-of-cholesterol-in-the-interfacial-microenvironment-on-the-modulation-of-the-alkaline-phosphatase-activity-during-in-vitro-mineralization
#10
B F Favarin, M A R Andrade, M Bolean, A M S Simão, A P Ramos, M F Hoylaerts, J L Millán, P Ciancaglini
Mineralization of the skeleton starts within cell-derived matrix vesicles (MVs); then, minerals propagate to the extracellular collagenous matrix. Tissue-nonspecific alkaline phosphatase (TNAP) degrades inorganic pyrophosphate (PPi), a potent inhibitor of mineralization, and contributes Pi (Phosphate) from ATP to initiate mineralization. Compared to the plasma membrane, MVs are rich in Cholesterol (Chol) (∼32%) and TNAP, but how Chol influences TNAP activity remains unclear. We have reconstituted TNAP in liposomes of dipalmitoylphosphatidylcholine (DPPC) or dioleoylphosphatidylcholine (DOPC) combined with Chol or its derivatives Cholestenone (Achol) and Ergosterol (Ergo)...
April 26, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28415454/development-of-a-dna-liposome-complex-for-gene-delivery-applications
#11
M Rasoulianboroujeni, G Kupgan, F Moghadam, M Tahriri, A Boughdachi, P Khoshkenar, J J Ambrose, N Kiaie, D Vashaee, J D Ramsey, L Tayebi
The association structures formed by cationic liposomes and DNA (Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cationic liposomes were prepared using a modified lipid film hydration method consisting of a lyophilization step for gene delivery applications. The obtained results demonstrated that the mean particle size had no significant change while the polydispersity (PDI) increased after lyophilization. The mean particle size slightly reduced after lyophilization (520±12nm to 464±25nm) while the PDI increased after lyophilization (0...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28408867/visualization-of-snare-mediated-hemifusion-between-giant-unilamellar-vesicles-arrested-by-myricetin
#12
Paul Heo, Joon-Bum Park, Yeon-Kyun Shin, Dae-Hyuk Kweon
Neurotransmitters are released within a millisecond after Ca(2+) arrives at an active zone. However, the vesicle fusion pathway underlying this synchronous release is yet to be understood. At the center of controversy is whether hemifusion, in which outer leaflets are merged while inner leaflets are still separated, is an on-pathway or off-pathway product of Ca(2+)-triggered exocytosis. Using the single vesicle fusion assay, we recently demonstrated that hemifusion is an on-pathway intermediate that immediately proceeds to full fusion upon Ca(2+) triggering...
2017: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/28377464/stard3-mediates-endoplasmic-reticulum-to-endosome-cholesterol-transport-at-membrane-contact-sites
#13
Léa P Wilhelm, Corinne Wendling, Benoît Védie, Toshihide Kobayashi, Marie-Pierre Chenard, Catherine Tomasetto, Guillaume Drin, Fabien Alpy
StAR-related lipid transfer domain-3 (STARD3) is a sterol-binding protein that creates endoplasmic reticulum (ER)-endosome contact sites. How this protein, at the crossroad between sterol uptake and synthesis pathways, impacts the intracellular distribution of this lipid was ill-defined. Here, by using in situ cholesterol labeling and quantification, we demonstrated that STARD3 induces cholesterol accumulation in endosomes at the expense of the plasma membrane. STARD3-mediated cholesterol routing depends both on its lipid transfer activity and its ability to create ER-endosome contacts...
May 15, 2017: EMBO Journal
https://www.readbyqxmd.com/read/28356285/exosome-production-and-its-regulation-of-egfr-during-wound-healing-in-renal-tubular-cells
#14
Xiangjun Zhou, Wei Zhang, Qisheng Yao, Hao Zhang, Guie Dong, Ming Zhang, Yutao Liu, Jian-Kang Chen, Zheng Dong
Kidney repair following injury involves the reconstitution of a structurally and functionally intact tubular epithelium. Growth factors and their receptors, such as EGFR, are important in the repair of renal tubules. Exosomes are cell-produced small (~100 nm in diameter) vesicles that contain and transfer proteins, lipids, RNAs, and DNAs between cells. In this study, we examined the relationship between exosome production and EGFR activation and the potential role of exosome in wound healing. EGFR activation occurred shortly after scratch wounding in renal tubular cells...
June 1, 2017: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/28320948/highly-oriented-photosynthetic-reaction-centers-generate-a-proton-gradient-in-synthetic-protocells
#15
Emiliano Altamura, Francesco Milano, Roberto R Tangorra, Massimo Trotta, Omar Hassan Omar, Pasquale Stano, Fabio Mavelli
Photosynthesis is responsible for the photochemical conversion of light into the chemical energy that fuels the planet Earth. The photochemical core of this process in all photosynthetic organisms is a transmembrane protein called the reaction center. In purple photosynthetic bacteria a simple version of this photoenzyme catalyzes the reduction of a quinone molecule, accompanied by the uptake of two protons from the cytoplasm. This results in the establishment of a proton concentration gradient across the lipid membrane, which can be ultimately harnessed to synthesize ATP...
April 11, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28301741/mechanisms-of-autophagy-initiation
#16
REVIEW
James H Hurley, Lindsey N Young
Autophagy is the process of cellular self-eating by a double-membrane organelle, the autophagosome. A range of signaling processes converge on two protein complexes to initiate autophagy: the ULK1 (unc51-like autophagy activating kinase 1) protein kinase complex and the PI3KC3-C1 (class III phosphatidylinositol 3-kinase complex I) lipid kinase complex. Some 90% of the mass of these large protein complexes consists of noncatalytic domains and subunits, and the ULK1 complex has essential noncatalytic activities...
June 20, 2017: Annual Review of Biochemistry
https://www.readbyqxmd.com/read/28274844/phosphatidylserine-lipids-and-membrane-order-precisely-regulate-the-activity-of-polybia-mp1-peptide
#17
Dayane S Alvares, João Ruggiero Neto, Ernesto E Ambroggio
Polybia-MP1 (IDWKKLLDAAKQIL-NH2) is a lytic peptide from the Brazilian wasp venom with known anti-cancer properties. Previous evidence indicates that phosphatidylserine (PS) lipids are relevant for the lytic activity of MP1. In agreement with this requirement, phosphatidylserine lipids are translocated to the outer leaflet of cells, and are available for MP1 binding, depending on the presence of liquid-ordered domains. Here, we investigated the effect of PS on MP1 activity when this lipid is reconstituted in membranes of giant or large liposomes with different lipid-phase states...
June 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28255696/reconstitution-of-tcr-signaling-using-supported-lipid-bilayers
#18
Xiaolei Su, Jonathon A Ditlev, Michael K Rosen, Ronald D Vale
Biochemical reconstitution has served as an important tool for understanding the mechanisms of many cellular processes including DNA replication, transcription, translation, vesicle trafficking, and ubiquitin-mediated proteolysis. Here, we demonstrate that biochemical reconstitution can be applied to studying a complex signaling pathway involving as many as 12 proteins or protein complexes acting at the surface of model membranes. We show that a temporal sequence of events in activated T cells beginning with phosphorylation of the T cell receptor and culminating in the activation of actin polymerization can be replicated in vitro...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28253967/in-vitro-reconstitution-of-atg8-conjugation-and-deconjugation
#19
D Fracchiolla, B Zens, S Martens
Macroautophagy, hereafter autophagy, is a major degradation pathway in eukaryotic systems that allows the removal of large intracellular structures such as entire organelles or protein aggregates, thus contributing to the homeostasis of cells and tissues. Autophagy entails the de novo formation of an organelle termed autophagosome, where a cup-shaped structure called isolation membrane nucleates in proximity of a cytoplasmic cargo material. Upon elongation and closure of isolation membranes, the mature autophagosome delivers the sequestered cargo into the lysosomal system for degradation...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28202656/durable-vesicles-for-reconstitution-of-membrane-proteins-in-biotechnology
#20
REVIEW
Paul A Beales, Sanobar Khan, Stephen P Muench, Lars J C Jeuken
The application of membrane proteins in biotechnology requires robust, durable reconstitution systems that enhance their stability and support their functionality in a range of working environments. Vesicular architectures are highly desirable to provide the compartmentalisation to utilise the functional transmembrane transport and signalling properties of membrane proteins. Proteoliposomes provide a native-like membrane environment to support membrane protein function, but can lack the required chemical and physical stability...
February 8, 2017: Biochemical Society Transactions
keyword
keyword
58872
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"