keyword
MENU ▼
Read by QxMD icon Read
search

Membrane curvature

keyword
https://www.readbyqxmd.com/read/28808346/evidence-that-listeria-innocua-modulates-its-membrane-s-stored-curvature-elastic-stress-but-not-fluidity-through-the-cell-cycle
#1
Samuel Furse, Martin Jakubec, Frode Rise, Huw E Williams, Catherine E D Rees, Øyvind Halskau
This paper reports that the abundances of endogenous cardiolipin and phosphatidylethanolamine halve during elongation of the Gram-positive bacterium Listeria innocua. The lyotropic phase behaviour of model lipid systems that describe these modulations in lipid composition indicate that the average stored curvature elastic stress of the membrane is reduced on elongation of the cell, while the fluidity appears to be maintained. These findings suggest that phospholipid metabolism is linked to the cell cycle and that changes in membrane composition can facilitate passage to the succeding stage of the cell cycle...
August 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28805387/polymyxin-binding-to-the-bacterial-outer-membrane-reveals-cation-displacement-and-increasing-membrane-curvature-in-susceptible-but-not-in-resistant-lps-chemotypes
#2
Denys Ewerton da Silva Santos, Laércio Pol-Fachin, Roberto D Lins, Thereza A Soares
Lipid-A is the causative agent of Gram-negative sepsis and responsible for increasingly high mortality rate among hospitalized patients. Compounds that bind Lipid-A can limit this inflammatory process. The cationic antimicrobial peptide polymyxin B (Pmx-B) is one of the simplest molecules capable of selectively bind to Lipid-A, and may serve as a model for further development of Lipid-A binding agents. Gram-negative bacteria resistance to Pmx-B relies on the upregulation of a number of regulatory systems, which promote chemical modifications of the LPS structure, and leads to major changes in the physical-chemical properties of the outer membrane...
August 14, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28804520/fast-simulation-of-lipid-vesicle-deformation-using-spherical-harmonic-approximation
#3
Michael Mikucki, Yongcheng Zhou
Lipid vesicles appear ubiquitously in biological systems. Understanding how the mechanical and intermolecular interactions deform vesicle membranes is a fundamental question in biophysics. In this article we develop a fast algorithm to compute the surface configurations of lipid vesicles by introducing surface harmonic functions to approximate the membrane surface. This parameterization allows an analytical computation of the membrane curvature energy and its gradient for the efficient minimization of the curvature energy using a nonlinear conjugate gradient method...
January 2017: Communications in Computational Physics
https://www.readbyqxmd.com/read/28794948/glucosomes-glycosylated-vesicle-in-vesicle-aggregates-in-water-from-ph-responsive-microbial-glycolipid
#4
Niki Baccile, Patrick Le Griel, Sylvain Prévost, Bernd Everaert, Inge N A Van Bogaert, Sophie Roelants, Wim Soetaert
Vesicle-in-vesicle self-assembled containers, or vesosomes, are promising alternatives to liposomes because of their possible hierarchical encapsulation and high stability. We report herein the first example of sugar-based vesicles-in-vesicles, which we baptize glucosomes. These were prepared by using a natural microbial glycolipid (branched C22 sophorolipid) extracted from the culture medium of the yeast Pseudohyphozyma bogoriensis. Glucosomes spontaneously formed in water between pH 6 and pH 4 at room temperature, without the requirement of any additive...
August 2017: ChemistryOpen
https://www.readbyqxmd.com/read/28794042/palmitoylation-contributes-to-membrane-curvature-in-influenza-a-virus-assembly-and-hemagglutinin-mediated-membrane-fusion
#5
Petr Chlanda, Elena Mekhedov, Hang Waters, Alexander Sodt, Cindi Schwartz, Vinod Nair, Paul S Blank, Joshua Zimmerberg
The highly conserved cytoplasmic tail of influenza virus glycoprotein hemagglutinin (HA) contains three cysteines, post-translationally modified by covalently bound fatty acids. While viral HA acylation is crucial in virus replication, its physico-chemical role is unknown. We used virus-like particles (VLP) to study the effect of acylation on morphology, protein incorporation, lipid composition, and membrane fusion. De-acylation interrupted HA-M1 interactions since de-acylated mutant HA fail to incorporate an M1 layer within spheroidal VLP, and filamentous particles incorporated increased numbers of neuraminidase (NA)...
August 9, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28790210/membrane-distribution-of-the-pseudomonas-quinolone-signal-modulates-outer-membrane-vesicle-production-in-pseudomonas%C3%A2-aeruginosa
#6
Catalina Florez, Julie E Raab, Adam C Cooke, Jeffrey W Schertzer
The Pseudomonas quinolone signal (PQS) is an important quorum-sensing molecule in Pseudomonas aeruginosa that also mediates its own packaging and transport by stimulating outer membrane vesicle (OMV) formation. Because OMVs have been implicated in many virulence-associated behaviors, it is critical that we understand how they are formed. Our group proposed the bilayer-couple model for OMV biogenesis, where PQS intercalates into the outer membrane, causing expansion of the outer leaflet and consequently inducing curvature...
August 8, 2017: MBio
https://www.readbyqxmd.com/read/28764362/the-mesoscopic-membrane-with-proteins-mesm-p-model
#7
Aram Davtyan, Mijo Simunovic, Gregory A Voth
We present the Mesoscopic Membrane with Proteins (MesM-P) model, an extension of a previously developed elastic membrane model for mesoscale simulations of lipid membranes. MesM-P employs a discrete mesoscopic quasi-particle approach to model protein-facilitated shape and topology changes of the lipid membrane on length and time scales inaccessible to all-atom and quasimolecular coarse-grained molecular dynamics simulations. We investigate the ability of MesM-P to model the behavior of large lipid vesicles as a function of bound protein density...
July 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28758651/analytical-approaches-to-study-domain-formation-in-biomimetic-membranes
#8
REVIEW
Imad Younus Hasan, Adam Mechler
Domains in biological membranes are linked to a range of biochemical life functions and thus understanding the fundamental physico-chemical drivers of domain formation is one of the key problems of biophysics and chemical biology. The phospholipid bilayer that is the structural basis of the biomembrane is a complex multicomponent mixture, and hence domain formation may be the result of thermodynamic phase equilibria, or specific sequestration of certain lipids; possibly both. There are several obstacles in the way of studying domains and thermodynamic phases in biomembranes: the complexity of the lipid mixture, the two dimensional nature of the membrane and the variety of superstructures the lipid membrane can fold into...
July 31, 2017: Analyst
https://www.readbyqxmd.com/read/28754893/salt-bridge-formation-between-the-i-bar-domain-and-lipids-increases-lipid-density-and-membrane-curvature
#9
Kazuhiro Takemura, Kyoko Hanawa-Suetsugu, Shiro Suetsugu, Akio Kitao
The BAR domain superfamily proteins sense or induce curvature in membranes. The inverse-BAR domain (I-BAR) is a BAR domain that forms a straight "zeppelin-shaped" dimer. The mechanisms by which IRSp53 I-BAR binds to and deforms a lipid membrane are investigated here by all-atom molecular dynamics simulation (MD), binding energy analysis, and the effects of mutation experiments on filopodia on HeLa cells. I-BAR adopts a curved structure when crystallized, but adopts a flatter shape in MD. The binding of I-BAR to membrane was stabilized by ~30 salt bridges, consistent with experiments showing that point mutations of the interface residues have little effect on the binding affinity whereas multiple mutations have considerable effect...
July 28, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28752207/conformational-changes-from-%C3%AE-strand-to-%C3%AE-helix-of-the-fatty-acid-binding-protein-rep1-ncxsq-in-anionic-lipid-membranes-dependence-with-the-vesicle-curvature
#10
Vanesa V Galassi, Silvina R Salinas, Guillermo G Montich
We studied the conformational changes of the fatty acid-binding protein ReP1-NCXSQ in the interface of anionic lipid membranes. ReP1-NCXSQ is an acidic protein that regulates the activity of the Na(+)/Ca(2+) exchanger in squid axon. The structure is a flattened barrel composed of two orthogonal β-sheets delimiting an inner cavity and a domain of two α-helix segments arranged as a hairpin. FTIR and CD spectroscopy showed that the interactions with several anionic lipids in the form of small unilamellar vesicles (SUVs) induced an increase in the proportion of helix secondary structure...
July 27, 2017: European Biophysics Journal: EBJ
https://www.readbyqxmd.com/read/28749896/elimination-of-anterior-corneal-steepening-with-descemet-membrane-endothelial-keratoplasty-in-a-patient-with-fuchs-dystrophy-and-keratoconus-implications-for-iol-calculation
#11
Reena Gupta, Ruta Kinderyte, Deborah S Jacobs, Ula V Jurkunas
PURPOSE: To report a case of coexistent Fuchs endothelial corneal dystrophy (FECD) and keratoconus (KCN) in which there was normalization of corneal topography after Descemet membrane endothelial keratoplasty (DMEK). METHODS: Retrospective medical record review. RESULTS: Preoperative findings revealed a best-corrected visual acuity of 20/40 with -1.00 - 2.50 × 147, topographic maximum keratometry of 50.8 D with inferior steeping, and confluent guttae in the left eye...
July 26, 2017: Cornea
https://www.readbyqxmd.com/read/28742972/stimuli-responsive-directional-vesicular-assembly-with-tunable-surface-functionality-and-impact-on-enzyme-inhibition
#12
Amrita Sikder, Debes Ray, Vinod K Aswal, Suhrit Ghosh
The article describes the self-assembly of a series of unsymmetrical bola-shaped π-amphiphiles (NDI-1, NDI-1a, NDI-2, NDI-3, and NDI-4) consisting of a hydrophobic naphthalene-diimide (NDI) chromophore attached to a nonionic hydrophilic wedge and an anionic headgroup in the two opposite arms of the central NDI. By design, only a single hydrazide group is linked either on the ionic or nonionic arm of the NDI. NDI-1 and NDI-1a are regioisomers differing only in the location of the hydrazide group, placed in the nonionic or ionic arm, respectively...
August 8, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28742022/modeling-of-axonal-endoplasmic-reticulum-network-by-spastic-paraplegia-proteins
#13
Belgin Yalçın, Lu Zhao, Martin Stofanko, Niamh C O'Sullivan, Zi Han Kang, Annika Roost, Matthew R Thomas, Sophie Zaessinger, Olivier Blard, Alex L Patto, Anood Sohail, Valentina Baena, Mark Terasaki, Cahir J O'Kane
Axons contain a smooth tubular endoplasmic reticulum (ER) network that is thought to be continuous with ER throughout the neuron; the mechanisms that form this axonal network are unknown. Mutations affecting reticulon or REEP proteins, with intramembrane hairpin domains that model ER membranes, cause an axon degenerative disease, hereditary spastic paraplegia (HSP). We show that Drosophila axons have a dynamic axonal ER network, which these proteins help to model. Loss of HSP hairpin proteins causes ER sheet expansion, partial loss of ER from distal motor axons, and occasional discontinuities in axonal ER...
July 25, 2017: ELife
https://www.readbyqxmd.com/read/28738989/membrane-curvature-and-lipid-composition-synergize-to-regulate-n-ras-anchor-recruitment
#14
Jannik B Larsen, Celeste Kennard, Søren L Pedersen, Knud J Jensen, Mark J Uline, Nikos S Hatzakis, Dimitrios Stamou
Proteins anchored to membranes through covalently linked fatty acids and/or isoprenoid groups play crucial roles in all forms of life. Sorting and trafficking of lipidated proteins has traditionally been discussed in the context of partitioning to membrane domains of different lipid composition. We recently showed that membrane shape/curvature can in itself mediate the recruitment of lipidated proteins. However, exactly how membrane curvature and composition synergize remains largely unexplored. Here we investigated how three critical structural parameters of lipids, namely acyl chain saturation, headgroup size, and acyl chain length, modulate the capacity of membrane curvature to recruit lipidated proteins...
July 21, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28735196/molecular-dynamics-simulation-of-sodium-dodecylsulfate-sds-bilayers
#15
Hongshu Zhang, Shiling Yuan, Jichao Sun, Jianqiang Liu, Haiping Li, Na Du, Wanguo Hou
Sodium dodecylsulfate (SDS) - a simple single tailed surfactant (STS) can form stable vesicles from its micellar solution without any additives under the mediation of solid surfaces. To further understand the mechanism of this transition on the molecular level, molecular dynamics simulations are performed to study segments of SDS bilayers (as part of vesicles) in the bulk solution systematically, at the moment that the lower leaflet of bilayers already detached from solid surfaces. The SDS membrane would rather keep their bilayers structure than return to micelles when the initial interdigitated degree (δi) between alkyl chains is more than 8...
July 15, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28729947/associations-between-optic-nerve-head-related-anatomical-parameters-and-refractive-error-over-the-full-range-of-glaucoma-severity
#16
Neda Baniasadi, Mengyu Wang, Hui Wang, Mufeed Mahd, Tobias Elze
PURPOSE: To evaluate the associations between optic disc (OD)-related anatomical parameters (interartery angle [IAA] between superior and inferior temporal retinal arteries, OD tilt [TL], rotation [ROT], and torsion [TO], OD surface curvature [CUR], and central retinal vessel trunk entry point location [CRVTL] on OD) and the spherical equivalent of refractive error (SE), and to assess the impact of glaucoma severity on these relationships. METHODS: Cirrus optical coherence tomography (OCT) fundus images and 24-2 visual fields of 438 patients were included...
July 2017: Translational Vision Science & Technology
https://www.readbyqxmd.com/read/28716920/vamp3-and-snap23-mediate-the-disturbed-flow-induced-endothelial-microrna-secretion-and-smooth-muscle-hyperplasia
#17
Juan-Juan Zhu, Yue-Feng Liu, Yun-Peng Zhang, Chuan-Rong Zhao, Wei-Juan Yao, Yi-Shuan Li, Kuei-Chun Wang, Tse-Shun Huang, Wei Pang, Xi-Fu Wang, Xian Wang, Shu Chien, Jing Zhou
Vascular endothelial cells (ECs) at arterial branches and curvatures experience disturbed blood flow and induce a quiescent-to-activated phenotypic transition of the adjacent smooth muscle cells (SMCs) and a subsequent smooth muscle hyperplasia. However, the mechanism underlying the flow pattern-specific initiation of EC-to-SMC signaling remains elusive. Our previous study demonstrated that endothelial microRNA-126-3p (miR-126-3p) acts as a key intercellular molecule to increase turnover of the recipient SMCs, and that its release is reduced by atheroprotective laminar shear (12 dynes/cm(2)) to ECs...
August 1, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28710286/how-tetraspanins-shape-endothelial-and-leukocyte-nano-architecture-during-inflammation
#18
REVIEW
Jonas Franz, Marco Tarantola, Christoph Riethmüller
Tetraspanins are ubiquitous membrane proteins that induce local membrane curvature and hence co-ordinate cell-to-cell contacts. This review highlights their role in inflammation, which requires control of the nano-architecture of attachment sites between endothelial cells and leukocytes. The active role of endothelial cells in preparing for transmigration of leukocytes and determining the severity of an inflammation is often underscored. A clear hint to endothelial pre-activation is their ability to protrude clustered adhesion proteins upward prior to leukocyte contact...
August 15, 2017: Biochemical Society Transactions
https://www.readbyqxmd.com/read/28709244/chiral-edge-fluctuations-of-colloidal-membranes
#19
Leroy L Jia, Mark J Zakhary, Zvonimir Dogic, Robert A Pelcovits, Thomas R Powers
We study edge fluctuations of a flat colloidal membrane comprised of a monolayer of aligned filamentous viruses. Experiments reveal that a peak in the spectrum of the in-plane edge fluctuations arises for sufficiently strong virus chirality. Accounting for internal liquid crystalline degrees of freedom by the length, curvature, and geodesic torsion of the edge, we calculate the spectrum of the edge fluctuations. The theory quantitatively describes the experimental data, demonstrating that chirality couples in-plane and out-of-plane edge fluctuations to produce the peak...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28707721/contractile-actin-belt-and-mesh-structures-provide-the-opposite-dependence-of-epithelial-stiffness-on-the-spontaneous-curvature-of-constituent-cells
#20
Satoru Okuda, Katsuyuki Unoki, Mototsugu Eiraku, Ken-Ichi Tsubota
Actomyosin generates contractile forces within cells, which have a crucial role in determining the macroscopic mechanical properties of epithelial tissues. Importantly, actin cytoskeleton, which propagates actomyosin contractile forces, forms several characteristic structures in a 3D intracellular space, such as a circumferential actin belt lining adherence junctions and an actin mesh beneath the apical membrane. However, little is known about how epithelial mechanical property depends on the intracellular contractile structures...
July 14, 2017: Development, Growth & Differentiation
keyword
keyword
51578
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"