scholarly journals Contributions of lipids and proteins to the surface charge of membranes. An electron microscopy study with cationized and anionized ferritin.

1979 ◽  
Vol 82 (3) ◽  
pp. 726-741 ◽  
Author(s):  
R W Burry ◽  
J G Wood
Keyword(s):  
Electron Microscope ◽  
Surface Charge ◽  
Membrane Surface ◽  
Lipid Vesicles ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Chemical Fixation ◽  
Glutaraldehyde Fixation ◽  
Membrane Surface Charge ◽  
Model Reactions

The surface charge of cultured neurons was investigated with the electron microscope markers anionized ferritin (AF) and cationized ferritin (CF). To determine which membrane components could react with the markers, model reactions were used. Both protein-coated Sepharose beads and lipid vesicles were reacted at physiological pH. Results with these model reactions indicate that the following groups may contribute to the surface charge: acidic groups--the sialic acid of both glycoproteins and gangliosides, the carboxyl group of proteins, and the phosphates of phospholipids; basic groups--the amines of proteins. The effect of chemical fixation on the surface charge was investigated. Glutaraldehyde fixation was shown to increase the charge of neutral proteins but not by a mechanism involving unbound aldehydes. Glutaraldehyde fixation of phospholipid vesicles in the presence of CF showed that amine-containing phospholipids were cross-linked to CF. This cross-linkage was seen with the electron microscope as the clumping of CF and the burying of CF in the membrane. Paraformaldehyde fixation had a lesser effect on the charge of proteins but did react with phospholipids as did glutaraldehyde. It is concluded that at physiological pH: (a) most of the charged proteins and lipids on cell surface can contribute to the membrane surface charge, and (b) the membrane surface charge of cells can be greatly changed by chemical fixation.

scholarly journals Theoretical Considerations and the Microelectrophoresis Experiment on the Influence of Selected Chaotropic Anions on Phosphatidylcholine Membrane Surface Charge Density

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 132
Author(s):  
Joanna Kotyńska ◽  
Monika Naumowicz
Keyword(s):  
Charge Density ◽  
Surface Charge ◽  
Surface Charge Density ◽  
Membrane Surface ◽  
Quantitative Description ◽  
Theoretical Data ◽  
Lipid Vesicles ◽  
Hofmeister Series ◽  
Chaotropic Anions ◽  
Membrane Surface Charge

Influence of sodium salts of selected chaotropic anions from the Hofmeister series (NaCl, NaBr, NaNO3, NaI) on the surface charge density of phosphatidylcholine membranes was studied. Small unilamellar lipid vesicles were used as a model system in the investigations. The theoretical and experimental approach to the interactions between inorganic anions and phosphatidylcholine membranes is presented. Experimental membrane surface charge densities data were determined as a function of pH of the aqueous electrolytes using microelectrophoresis method. The quantitative description of the interactions between zwitterionic phosphatidylcholine membrane and monovalent anions is presented. The equilibria constants of the binding of solution ions onto phospholipid surface were calculated. Knowledge of these parameters was essential to determine the theoretical membrane surface charge density values. The theoretical data were compared to the experimental ones in order to verify the mathematical model. Both approaches indicate that the anion-phosphatidylcholine membrane interaction increases with the size of the anion. The adsorption of chaotropic anions to membranes was found to follow the Hofmeister series I− > NO3− > Br− > Cl−.

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.

Impact of ion exchange membrane surface charge and hydrophobicity on electroconvection at underlimiting and overlimiting currents

2017 ◽  
Vol 523 ◽  
pp. 36-44 ◽  
Author(s):  
K.A. Nebavskaya ◽  
V.V. Sarapulova ◽  
K.G. Sabbatovskiy ◽  
V.D. Sobolev ◽  
N.D. Pismenskaya ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Surface Charge ◽  
Membrane Surface ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Membrane Surface Charge

Effects of Natural Organic Matter and Ionic Species on Membrane Surface Charge

2002 ◽  
Vol 36 (17) ◽  
pp. 3864-3871 ◽  
Author(s):  
Yongki Shim ◽  
Hong-Joo Lee ◽  
Sangyoup Lee ◽  
Seung-Hyeon Moon ◽  
Jaeweon Cho
Keyword(s):  
Organic Matter ◽  
Surface Charge ◽  
Natural Organic Matter ◽  
Membrane Surface ◽  
Ionic Species ◽  
Membrane Surface Charge

scholarly journals The Phosphoinositide Phosphatase SopB Manipulates Membrane Surface Charge and Trafficking of the Salmonella-Containing Vacuole

2010 ◽  
Vol 7 (6) ◽  
pp. 453-462 ◽  
Author(s):  
Malina A. Bakowski ◽  
Virginie Braun ◽  
Grace Y. Lam ◽  
Tony Yeung ◽  
Won Do Heo ◽  
...  
Keyword(s):  
Surface Charge ◽  
Membrane Surface ◽  
Phosphoinositide Phosphatase ◽  
Membrane Surface Charge
Sign in / Sign up

Export Citation Format

Share Document