scholarly journals Origin of subdiffusion of water molecules on cell membrane surfaces

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Eiji Yamamoto ◽  
Takuma Akimoto ◽  
Masato Yasui ◽  
Kenji Yasuoka
Keyword(s):  
Cell Membrane ◽  
Water Molecules ◽  
Membrane Surfaces

scholarly journals 2P131 Aging of water molecules on cell membrane surfaces(07. Water & Hydration & Electrolyte,Poster)

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S180
Author(s):  
Eiji Yamamoto ◽  
Takuma Akimoto ◽  
Masato Yasui ◽  
Kenji Yasuoka
Keyword(s):  
Cell Membrane ◽  
Water Molecules ◽  
Membrane Surfaces

scholarly journals 1PT004 Mean Exit Time Analysis about Water Molecules around Membrane Surfaces(The 50th Annual Meeting of the Biophysical Society of Japan)

2012 ◽  
Vol 52 (supplement) ◽  
pp. S84
Author(s):  
Eiji Yamamoto ◽  
Takuma Akimoto ◽  
Yoshinori Hirano ◽  
Masato Yasui ◽  
Kenji Yasuoka
Keyword(s):  
Annual Meeting ◽  
Exit Time ◽  
Water Molecules ◽  
Time Analysis ◽  
Membrane Surfaces ◽  
Mean Exit Time ◽  
Biophysical Society

DISEASED RED BLOOD CELLS STUDIED BY ATOMIC FORCE MICROSCOPY

2002 ◽  
Vol 01 (05n06) ◽  
pp. 683-688 ◽  
Author(s):  
YONG CHEN ◽  
JIYE CAI ◽  
JINGXIAN ZHAO
Keyword(s):  
Lung Cancer ◽  
Atomic Force Microscopy ◽  
Cell Membrane ◽  
Erythrocyte Membrane ◽  
Mammalian Cells ◽  
Membrane Surface ◽  
Force Microscopy ◽  
Membrane Surfaces ◽  
Atomic Force ◽  
Mean Width

In recent years, many mammalian cells, especially erythrocytes because of simpleness of their membrane surfaces, were widely studied by atomic force microscopy. In our study, diseased erythrocytes were taken from patients of lung cancer, myelodisplastic syndrome (MDS), and so on. We obtained many clear topographical images of numerous erythrocytes, single erythrocyte, and ultramicrostructure of erythrocyte membrane surfaces from normal persons and patients. By studying the red cells of lung cancer patients, we found that many erythrocytes of lung cancer patient have changed into echinocytes. One erythrocyte has 10–20 short projections, most of which, with a mean width of 589.0 nm and a length of 646.7 nm, are on the edge of cell. The projections in the center of echinocytes are lodged and embedded, but in conventional model of echinocytes, the projections in the center stretch outside cell membrane, so a novel model of erythrocytes was designed in our paper. After observation of microstructure of MDS patient's erythrocyte membrane surface, we found that many apertures with different diameters of tens to hundreds nanometers appeared on the surface of cell membrane. It can be concluded that AFM may be widely applied in clinic pathological inspection.

scholarly journals Platelet Membrane Actin and Myosin

1977 ◽  
Author(s):  
H. Horák ◽  
P.G. Barton ◽  
C.M. Gibbs
Keyword(s):  
Cell Membrane ◽  
Membrane Vesicles ◽  
Two Dimensional ◽  
Con A ◽  
Whole Cells ◽  
Two Dimensional Electrophoresis ◽  
Membrane Surfaces ◽  
Sds Page ◽  
Inside Out ◽  
Dimensional Electrophoresis

Horse platelet membranes isolated by the glycerol lysis technique and subjected to SDS-PAGE showed large amounts of actin and variable amounts of myosin relative to other membrane proteins and glycoproteins. [14C]-2-dinitrothioadenosine diphosphate, when briefly incubated with whole cells, rapidly labeled the membrane actin component. Retention of myosin by the membranes during their isolation was optimized by lysing the cells and resuspending the membranes in Tris-HC1, pH 7.35, with 0.13 M KCl, 0.01 M NaCl, 2 mM MgCl2 and 0.01 mM CaCl2. Subsequently, significant amounts of actin and myosin could be eluted from the membranes with 10-3 M ADP but not with CDP, GDP or UDP. Actin was also eluted effectively from membranes prepared in Tris-NaCl, pH 7.35, by washing with 0.1 mM EDTA (in presence or absence of ADP). Despite repeated washings with either elution system, more than 50% of the actin remained associated with the membranes. When membrane vesicles with right side out (RO) and inside out (IO) orientation, separated by chromatography on Con A-Sepharose, were similarly washed identical results were obtained. Two dimensional electrophoresis of the membrane protein of IO vesicles separated two major actin components, one of which was differentially removed by prior treatment of the vesicles with 10-3 M ADP. It is concluded that (1) platelet myosin and two forms of platelet actin are associated with the cell membrane and that myosin and one form of actin can be displaced by ADP or EDTA while the second form of actin is more firmly attached, and (2) some actin is present on both membrane surfaces.

scholarly journals A web-accessible computer program for calculating electrical potentials and ion activities at cell-membrane surfaces

2013 ◽  
Vol 375 (1-2) ◽  
pp. 35-46 ◽  
Author(s):  
Peter M. Kopittke ◽  
Peng Wang ◽  
Neal W. Menzies ◽  
Ravi Naidu ◽  
Thomas B. Kinraide
Keyword(s):  
Cell Membrane ◽  
Computer Program ◽  
Electrical Potentials ◽  
Membrane Surfaces ◽  
Ion Activities

scholarly journals Power-Law Trappings Cause Anomalous Diffusions of Water Molecules on Membrane Surfaces

2013 ◽  
Vol 104 (2) ◽  
pp. 172a
Author(s):  
Eiji Yamamoto ◽  
Takuma Akimoto ◽  
Yoshinori Hirano ◽  
Masato Yasui ◽  
Kenji Yasuoka
Keyword(s):  
Power Law ◽  
Water Molecules ◽  
Membrane Surfaces

scholarly journals Structural changes in the membrane of vero cells infected with a paramyxovirus.

1975 ◽  
Vol 67 (3) ◽  
pp. 551-565 ◽  
Author(s):  
M Dubois-Dalcq ◽  
T S Reese
Keyword(s):  
Cell Membrane ◽  
Measles Virus ◽  
Structural Changes ◽  
Vero Cells ◽  
Small Particles ◽  
Freeze Fracturing ◽  
Viral Antigens ◽  
Viral Budding ◽  
Membrane Surfaces ◽  
Viral Maturation

Vero cells productively infected with the Halle strain of measles virus have been studied by means of surface replication, freeze-fracturing, and surface labeling with horseradish peroxidase-measles antibody conjugate in order to examine changes in the structure of the cell membrane during viral maturation. Early in infection, the surfaces of infected cells are embossed by scattered groups of twisted strands, and diffuse patches of label for viral antigens cover regions marked by these strands. At later stages, when numerous nucleocapsids become aligned under the plasmalemmal strands, the strands increase in number and width and become more convoluted. At this stage, label for viral antigens on the surface of the cell membrane is organized into stripes lying on the crests of strands. Finally, regions of the membrane displaying twisted strands protrude to form ridges or bulges, and the freeze-fractured membrane surrounding these protrusions is characterized by an abundance of particles small than those found on the rest of the cell membrane. The fractured membranes of viral buds are continuous sheets of these small particles, and the spacing between both nucleocapsids and stripes of surface antigen in buds is less than in the surrounding cell membrane. Detached virus is covered with a continuous layer of viral antigen, has unusually large but no small particles on its membrane surfaces exposed by freeze-fracturing, and no longer has nucleocapsids aligned under its surface. Thus, surface antigens, membrane particles, and nucleocapsids attached to the cell membrane are mobile within the plane of the membrane during viral maturation. All three move simutaneously in preparation for viral budding.

scholarly journals Free energy landscapes of sodium ions bound to DMPC–cholesterol membrane surfaces at infinite dilution

2016 ◽  
Vol 18 (13) ◽  
pp. 9036-9041 ◽  
Author(s):  
Jing Yang ◽  
Massimiliano Bonomi ◽  
Carles Calero ◽  
Jordi Martí
Keyword(s):  
Free Energy ◽  
Infinite Dilution ◽  
Sodium Ion ◽  
Water Molecules ◽  
Sodium Ions ◽  
Energy Landscapes ◽  
Membrane Surfaces ◽  
Additional Water ◽  
Free Energy Landscapes ◽  
Typical Configuration

Typical configuration of two DMPC lipids and one cholesterol molecule solvating one sodium ion, together with two additional water molecules.

scholarly journals Theory for Ligand Rebinding at Cell Membrane Surfaces

1998 ◽  
Vol 74 (3) ◽  
pp. 1215-1228 ◽  
Author(s):  
B. Christoffer Lagerholm ◽  
Nancy L. Thompson
Keyword(s):  
Cell Membrane ◽  
Membrane Surfaces ◽  
Ligand Rebinding

scholarly journals A method for detection of permeation events in Molecular Dynamics simulations of lipid bilayers

2021 ◽  
Author(s):  
Carlos R. S. Camilo ◽  
J. Roberto Ruggiero ◽  
Alexandre S. de Araujo
Keyword(s):  
Molecular Dynamics ◽  
Cell Membrane ◽  
Lipid Bilayers ◽  
Complex Structure ◽  
Phospholipid Bilayer ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Human Knowledge ◽  
Crossing Time ◽  
Dynamics Simulations

The cell membrane is one of the most important structures of life. Understanding its functioning is essential for several human knowledge areas, mainly how it controls the efflux of substances between the cytoplasm and the environment. Being a complex structure, composed of several classes of compounds such as lipids, proteins, sugars, etc., a convenient way to mimic it is through a phospholipid bilayer. The Molecular Dynamics simulation of lipid bilayers in solution is the main computational approach to model the cell membrane. In this work, we present a method to detect permeation events of molecules through the lipid bilayer, characterizing its crossing time and trajectory. By splitting the simulation box into well-defined regions, the method distinguishes the passage of molecules through the bilayer from artifacts produced by crossing molecules through the simulation box edges when using periodic boundary conditions. We apply the method to study the spontaneous permeation of water molecules through bilayers with different lipid compositions and modeled with different force fields. Our method successfully characterizes the permeation events, and the results obtained show that the frequency and time of permeation are independent of the force field used to model the phospholipids. Besides, it is observed that the increase in the concentration of cholesterol molecules in lipid bilayers induces the reduction of permeation events due to its compacting action on the bilayer, making it denser and, therefore, hindering the diffusion of water molecules inside it. The computational tool to perform the method discussed here is available on https://github.com/crobertocamilo/MD-permeation.

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