Remarkable Microenvironmental Difference between Monolayer and Bilayer Membrane Interfaces. Dissociation Behavior of a Lysine Residue Placed on the Membrane Surface

2000 ◽  
Vol 29 (1) ◽  
pp. 82-83 ◽  
Author(s):  
Katsuhiko Ariga ◽  
Takao Abe ◽  
Jun-ichi Kikuchi
Keyword(s):  
Membrane Surface ◽  
Bilayer Membrane ◽  
Lysine Residue ◽  
Membrane Interfaces

Bilayer Membrane Bending Stiffness by Tether Formation From Mixed PC-PS Lipid Vesicles

1990 ◽  
Vol 112 (3) ◽  
pp. 235-240 ◽  
Author(s):  
J. Song ◽  
R. E. Waugh
Keyword(s):  
Present Report ◽  
Membrane Surface ◽  
Lipid Vesicles ◽  
Phosphatidyl Serine ◽  
Bilayer Membrane ◽  
Bending Stiffness ◽  
New Approach ◽  
Lipid Mixtures ◽  
Membrane Bending ◽  
Membrane Surface Charge

Recently, a new approach to measure the bending stiffness (curvature elastic modulus) of lipid bilayer membrane was developed (Biophys. J., Vol. 55; pp. 509–517, 1989). The method involves the formation of cylindrical membrane strands (tethers) from bilayer vesicles. The bending stiffness (B) can be calculated from measurements of the tether radius (Rt) as a function of the axial force (f) on the tether: B =f·Rt/2π. In the present report, we apply this method to determine the bending stiffness of bilayer membranes composed of mixtures of SOPC (1-stearoyl-2-oleoyl phosphatidyl choline) and POPS (1-palmitoyl-2-oleoyl phosphatidyl serine). Three different mixtures were tested: pure SOPC, SOPC plus 2 percent (mol/mol) POPS, and SOPC plus 16 percent POPS. The bending stiffness determined for these three different lipid mixtures were not significantly different (1.6–1.8×10-12 ergs). Because POPS carries a net negative charge, these results indicate that changes in the density of the membrane surface charge have no effect on the intrinsic rigidity of the membrane. The values we obtain are consistent with published values for the bending stiffness of other membranes determined by different methods. Measurements of the aspiration pressure, the tether radius and the tether force were used to verify a theoretical relationship among these quantities at equilibrium. The ratio of the theoretical force to the measured force was 1.12 ± 0.17.

scholarly journals A “Graft to” Electrospun Zwitterionic Bilayer Membrane for the Separation of Hydraulic Fracturing-Produced Water via Membrane Distillation

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 402
Author(s):  
Yu-Hsuan Chiao ◽  
Micah Belle Marie Yap Ang ◽  
Yu-Xi Huang ◽  
Sandrina Svetlana DePaz ◽  
Yung Chang ◽  
...  
Keyword(s):  
Crude Oil ◽  
Produced Water ◽  
Membrane Surface ◽  
Sodium Dodecyl ◽  
Bilayer Membrane ◽  
Membrane Distillation ◽  
Feed Stream ◽  
Electrospun Membrane ◽  
Salt Rejection ◽  
Zwitterionic Polymer

Simultaneous fouling and pore wetting of the membrane during membrane distillation (MD) is a major concern. In this work, an electrospun bilayer membrane for enhancing fouling and wetting resistance has been developed for treating hydraulic fracture-produced water (PW) by MD. These PWs can contain over 200,000 ppm total dissolved solids, organic compounds and surfactants. The membrane consists of an omniphobic surface that faces the permeate stream and a hydrophilic surface that faces the feed stream. The omniphobic surface was decorated by growing nanoparticles, followed by silanization to lower the surface energy. An epoxied zwitterionic polymer was grafted onto the membrane surface that faces the feed stream to form a tight antifouling hydration layer. The membrane was challenged with an aqueous NaCl solution containing sodium dodecyl sulfate (SDS), an ampholyte and crude oil. In the presence of SDS and crude oil, the membrane was stable and displayed salt rejection (>99.9%). Further, the decrease was much less than the base polyvinylidene difluoride (PVDF) electrospun membrane. The membranes were also challenged with actual PW. Our results highlight the importance of tuning the properties of the membrane surface that faces the feed and permeate streams in order to maximize membrane stability, flux and salt rejection.

Behaviour of complex oligosaccharides at a bilayer membrane surface: probed by 2H-NMR

1994 ◽  
Vol 1190 (2) ◽  
pp. 376-384 ◽  
Author(s):  
Kathryn R. Barber ◽  
Katherine S. Hamilton ◽  
Alan C. Rigby ◽  
Chris W.M. Grant
Keyword(s):  
Membrane Surface ◽  
Bilayer Membrane ◽  
2H Nmr

scholarly journals Interaction between Nanoclusters and Lipid Bilayer Membrane Surface

Hyomen Kagaku ◽  
2014 ◽  
Vol 35 (8) ◽  
pp. 404-408
Author(s):  
Hideki NABIKA ◽  
Daiki YAMAGUCHI ◽  
Kei UNOURA
Keyword(s):  
Lipid Bilayer ◽  
Membrane Surface ◽  
Bilayer Membrane ◽  
Lipid Bilayer Membrane

Structural studies of immunodeficiency viruses

1995 ◽  
Vol 53 ◽  
pp. 698-699
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
James A. Hoxie ◽  
Peter J. Bugelski
Keyword(s):  
Membrane Surface ◽  
Bilayer Membrane ◽  
Chemotherapeutic Agents ◽  
Surface Glycoprotein ◽  
Nucleocapsid Proteins ◽  
Virus Particles ◽  
P24 Protein ◽  
One Step ◽  
Viral Maturation ◽  
Structure Of Proteins

Immunodeficiency viruses (IV) are retroviruses belonging to the subfamily Lentivirinae and include human (HIV) and simian (SIV) immunodeficiency viruses. In this study, we focus on the structure of proteins in SIV isolated from macaques (SIVmac). IV form by budding through the surface of an infected cell, where viral proteins and RNA are enveloped by the host cell bilayer membrane. Immature virions consist of this outer membrane studded with surface glycoprotein projections and a thick sub-envelope protein plaque composed of unprocessed Pr55gag protein. Viral maturation is marked by cleavage of this protein by a viral protease into the structural proteins p17, p24 and p15. Mature virus particles are icosahedral, approximately 120 nm in diameter, consisting of membrane surface glycoprotein projections, a thin submembrane p17 protein layer, a centrally located core capsid composed of p24 protein subunits surrounding the viral ribonucleic acid, and nucleocapsid proteins p7 and p6, derived from processed p15. One step in the development of anti-IV treatments is to understand the organization of the proteins in order to determine specific sites to target chemotherapeutic agents.

Molecular cytochemistry of freeze-fractured cells

1986 ◽  
Vol 44 ◽  
pp. 894-897
Author(s):  
Pedro Pinto da Silva
Keyword(s):  
Membrane Proteins ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Biological Membranes ◽  
Bilayer Membrane ◽  
Integral Membrane Proteins ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
Freeze Etching

I will describe four approaches that combine cytochemistry with freeze-fracture: 1) FREEZE-ETCHING; 2) FRACTURE-LABEL; 3) FRACTURE-PERMEATION; and 4) LABEL-FRACTURE. These techniques, in particular fracture-label, involve delicate points of interpretation and numerous validating controls. In the publications listed at the end, these issues have been addressed in detail.1. FREEZE-ETCHING. I developed freeze-etching as a cytochemical approach to prove that membranes were split by freeze-fracture and to show that biological membranes were comprised of a bilayer membrane continuum interrupted by integral membrane proteins.1 - 4 In freeze-etching, the distribution of the marker over the membrane surface exposed by sublimation is compared to that of the intramembrane particles exposed by fracture. It is often required to aggregate the particles into domains larger than the labeling molecules (Fig. 1). This, and the need for freezing in distilled water, severely limits the application of freeze-etching.

Liposomal Nanotechnology for Cancer Theranostics

2018 ◽  
Vol 25 (12) ◽  
pp. 1397-1408 ◽  
Author(s):  
Xiuli Yue ◽  
Zhifei Dai
Keyword(s):  
Fluorescent Dyes ◽  
Multimodality Imaging ◽  
Membrane Surface ◽  
Bilayer Membrane ◽  
Chemotherapeutic Agents ◽  
Core Domain ◽  
Self Assembling ◽  
Biomimetic Nanoparticles ◽  
Aqueous Core

Liposomes are a type of biomimetic nanoparticles generated from self-assembling concentric lipid bilayer enclosing an aqueous core domain. They have been attractive nanocarriers for the delivery of many drugs (e.g. radiopharmaceuticals, chemotherapeutic agents, porphyrin) and diagnostic agents (e.g. fluorescent dyes, quantum dots, Gadolinium complex and Fe3O4) by encapsulating (or adsorbing) hydrophilic one inside the liposomal aqueous core domain (or on the bilayer membrane surface), and by entrapping hydrophobic one within the liposomal bilayer. Additionally, the liposome surface can be easily conjugated with targeting molecules. Liposomes may accumulate in cancerous tissues not only passively via enhanced permeability and retention (EPR) effect, but also actively by targeting cancer cell or angiogenic marker specifically. The multimodality imaging functionalization of liposomal therapeutic agents makes them highly attractive for individualized monitoring of the in vivo cancer targeting and pharmacokinetics of liposomes loading therapeutic drugs, and predicting therapeutic efficacy in combination with the helpful information from each imaging technique. The present review article will highlight some main advances of cancer theranostic liposomes with a view to activate further research in the nanomedicine community.

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

1978 ◽  
Vol 36 (2) ◽  
pp. 328-329
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston
Keyword(s):  
Conformational Changes ◽  
Human Erythrocyte ◽  
Shape Change ◽  
Membrane Surface ◽  
Slight Modification ◽  
Active Role ◽  
Main Role ◽  
Bank Blood ◽  
Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

Role of PKC isozymes in water transport in toad urinary bladder

1991 ◽  
Vol 49 ◽  
pp. 302-303
Author(s):  
A.J. Mia ◽  
L.X. Oakford ◽  
T. Yorio
Keyword(s):  
Urinary Bladder ◽  
Apical Membrane ◽  
Membrane Surface ◽  
Protein A ◽  
Cell Types ◽  
Leukemic Cells ◽  
Toad Urinary Bladder ◽  
Pkc Isozymes ◽  
Antibody Labeling

Protein kinase C (PKC) isozymes, when activated, are translocated to particulate membrane fractions for transport to the apical membrane surface in a variety of cell types. Evidence of PKC translocation was demonstrated in human megakaryoblastic leukemic cells, and in cardiac myocytes and fibroblasts, using FTTC immunofluorescent antibody labeling techniques. Recently, we reported immunogold localizations of PKC subtypes I and II in toad urinary bladder epithelia, following 60 min stimulation with Mezerein (MZ), a PKC activator, or antidiuretic hormone (ADH). Localization of isozyme subtypes I and n was carried out in separate grids using specific monoclonal antibodies with subsequent labeling with 20nm protein A-gold probes. Each PKC subtype was found to be distributed singularly and in discrete isolated patches in the cytosol as well as in the apical membrane domains. To determine if the PKC isozymes co-localized within the cell, a double immunogold labeling technique using single grids was utilized.

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