Electrophoretic Mobility Of Human Erythrocytes Research Articles

Determination of Optimal Conditions for Studies of Electrophoretic Mobility of Human Erythrocytes Loaded with Cryoglobulins

For studies of the charge characteristics of human erythrocytes loaded with cryoglobulins the cells should be stored in Alsever solution with 0.1% sodium azide no longer than 1 week after blood collection. Erythrocytes should be loaded with cryoglobulins by incubation during at least 4 h, the final concentration of cryoproteins in the solution being no lower than 30 microg/ml.

Electrophoretic mobility of human erythrocytes in the presence of poly(styrene sulfonate).

The adsorption and depletion of the anionic polymer poly(styrene sulfonate) (PSS) on fresh human red blood cells (RBC) were investigated by measuring RBC electrophoretic mobility as a function of polymer molecular mass (48-2610 kDa), ionic strength (15 and 150 mM NaCl) and polymer concentration (<or= 1.5 g/dL). A subset of studies was carried out using fixed and PSS-coated cells. Our results indicate a marked increase of mobility with molecular mass and polymer concentration. Adsorption of PSS onto fresh RBC was weak, with normal mobility restored following washing cells in PSS-free buffer. Calculated zeta potentials based upon mobility and medium viscosity rose up to 618 mV for 2610 kDa PSS compared to 13 mV for control cells, thus suggesting significant polymer depletion at the cell surface; fixed and PSS-coated RBC were insensitive to medium viscosity, also validating this depletion layer hypothesis. Calculated values of increased RBC surface charge were used to estimate polymer adsorption per cell; these estimates indicated linear adsorption isotherms and binding levels consistent with studies employing neutral polymers. In overview, our results suggest the usefulness of microelectrophoresis methods for studies of RBC interactions with charged polymers or proteins, and the value of this approach for future studies using proteins known to affect RBC-RBC interactions.

Cellular electrophoretic mobility data: a first approach to a database.

Cellular electrophoretic mobility values of 288 types of eucaryotic cells were collected from literature published worldwide by a series of authors during the past forty years and arranged in a list. This list contains well-known recent electrophoretic results and also data that cannot be found anymore with modern literature retrieval systems. It will be a valuable help for scientists trying to purify cell populations. In addition, it confirms the observation that most eucaryotic cells have very similar electrophoretic mobilities, ranging from 40% above to 50% below the electrophoretic mobility of human erythrocytes, and thus reinforces the suggestion that electrophoretic mobilities of eucaryotic cells are subjected to strong biological controls.

Effect of Membrane Incorporation of 1-Palmitoylcarnitine on Surface Charge of Human Erythrocytes

1-Palmitoylcarnitine (1-PC) reduced the electrophoretic mobility of human erythrocytes bathed in low ionic strength solution. Unlike divalent cations which appear to reduce electrophoretic mobility by screening surface negative charge, cationic 1-PC does so by being incorporated into the plasma membrane. Incorporation of 1-PG was assessed directly by measurement of the partition coefficients which are 1.18 × 10 5 and 1.38 × 10 5 in sarcoplasmic reticulum vesicles and erythrocyte ghosts, respectively. The hydrophobic nature of the amphiphile interaction with erythrocyte membrane was also evident as an antihemolytic effect at 1-PC concentrations that also reduced electrophoretic mobility. Moreover, the potency and efficacy of acylcarnitines to reduce electrophoretic mobility increased as the acyl chain length increased. 1-PC also reduced the electrophoretic mobility of guinea-pig ventricular myocytes in low ionic strength solution. Estimation of the zeta potential yielded positive shifts of 4mV in myocytes and 5mV on crythrocytes at 1 μM 1-PC. These voltage shifts are essentially the same as those reported for activation and inactivation of sodium and calcium currents in myocytes. Therefore, the surface charge effect of 1-PC depends upon membrane incorporation and underlies the electrophysiological actions of the amphiphile including arrhythmias.

Electrophoretic mobility of human erythrocytes. On the applicability of the charged layer model

The limitations of previous linear electrokinetic theories are discussed. A special model of the surface charge distribution, based on the minimum condition of the interfacial electrostatic free energy, is introduced. The model describes the electrophoretic mobility, taking into account the electroosmotic flow through the surface macromolecular layer and the surface conductivity. This nonlinear electrophoretic theory describes experimental data obtained with human erythrocytes. Numerical results for an uniformly distributed space charge are also presented.

Calculation of the Electrophoretic Mobility of a Particle Bearing Bound Polyelectrolyte Using the Nonlinear Poisson-Boltzmann Equation

A numerical method for determining the electrophoretic mobility of a polyelectrolyte-coated particle is presented. The particle surface is modeled as having a permeable layer of polyelectrolyte molecules anchored to its surface. Fluid flow within the polyelectrolyte layer is subject to Stokes drag arising from the polyelectrolyte segments. The method allows arbitrary distribution of polymer segments and charge density normal to the surface to be used. The hydrodynamic plane of shear may also be varied. The potential profile is determined by a numerical solution to the nonlinearized Poisson-Boltzmann equation. The potential profile is then used in a numerical solution to the Navier-Stokes equation to give the required mobility. The use of the nonlinearized Poisson-Boltzmann equation extends the results to higher charge density/lower ionic strength conditions than previous treatments. The surface potentials and mobilities for three limiting charge distributions are compared for both the linear and nonlinear treatments to delimit the range of validity of the linear treatment. The utility of the numerical, nonlinear treatment is demonstrated by an improved fit to the electrophoretic mobility of human erythrocytes as a function of ionic strength in the range 10 to 150 mM.

Electrophoretic mobility of erythrocytes exposed to accelerated helium nuclei or to gamma-rays, as modified by adeturone.

The electrophoretic mobility of human erythrocytes exposed in whole blood or in cell suspensions to relatively low doses (0.7-2.5 Gy) of accelerated helium nuclei (4.6 GeV/nucleon) or of gamma-rays was found to diminish with increase in radiation dose, as measured at 3 h post-irradiation. Pre-treatment with a radioprotectant, adeturone (S-2-aminoethylisothiuronium adenosine-5'-triphosphate), allowed electrophoretic mobility to be maintained within normal limits, with more stable values in the case of alpha-irradiations. The experimental evidence is discussed in terms of the protectant's involvement in repair of radiation-induced conformational changes in surface membrane components.

Experimental results contradicting claimed 1009-MHz influence on erythrocyte mobility.

AbstractAn attempt was made to detect the influence of ultrahigh frequency radiation (1009 MHz) on the electrophoretic mobility of human erythrocytes. Ines. In contradiction to an earlier report by Ismailov no effect was observed.

309 - Electrostatic and structural properties of the surface of human erythrocytes. I-cell-electrophoretic studies following neuraminidase treatment

Following neuraminidase treatment the electrophoretic mobility of human erythrocytes was measured in dependence on the ionic strength. It could be shown that neuraminic acid groups are the only charge carriers within the ranges of the surface coat passed by the electro-osmotic flow. A quantitative comparison of the measured ionic-strength dependences of neuraminidase-treated and non-treated erythrocytes showed a structural change of the surface coat accompanied by charge reduction. The degradation of neuraminic acid led to colayering of the surface coat molecules. The total charge was determined to be 1.8×10 7 negative elementary charges/erythrocyte. In deeper layers of the surface coat there were 2×10 6 negative elementary charges which could not be reduced by neuraminidase. The theoretical concept of the influence of the three-dimensional charge distribution of the cell surface on the electrophoretic mobility [1, 2] could be checked in qualitative and quantitative terms. There was a considerably better correlation of surface charge density to biochemical data than that so far obtained by electrophoretic studies.

Electrostatic and structural properties of the surface of human erythrocytes. I-cell-electrophoretic studies following neuraminidase treatment

Following neuraminidase treatment the electrophoretic mobility of human erythrocytes was measured in dependence on the ionic strength. It could be shown that neuraminic acid groups are the only charge carriers within the ranges of the surface coat passed by the electro-osmotic flow. A quantitative comparison of the measured ionic-strength dependences of neuraminidase-treated and non-treated erythrocytes showed a structural change of the surface coat accompanied by charge reduction. The degradation of neuraminic acid led to colayering of the surface coat molecules. The total charge was determined to be 1.8×10 7 negative elementary charges/erythrocyte. In deeper layers of the surface coat there were 1×10 6 negative elementary charges which could not be reduced by neuraminidase. The theoretical concept of the influence of the three-dimensional charge distribution of the cell surface on the electrophoretic mobility [1,2] could be checked in qualitative and quantitative terms. There was a considerably better correlation of surface charge density to biochemical data than that so far obtained by electrophoretic studies.

Effect of Hæmagglutinating Viruses on the Electrophoretic Mobility of Human Erythrocytes

THE enzymic activity of influenza viruses, recently characterized in chemical terms for the substrate ovomucin1, was first suggested by Hirst2, who showed that, following the agglutination of erythrocytes, the virus was eluted spontaneously, leaving the cells inagglutinable by the same strain. Burnet, McCrea and Stone3 found that cells from which one strain had become eluted were still agglutinable by certain other strains. The arrangement of influenza A and B, mumps and Newcastle disease viruses in the order of their progressive action on cellular receptors was termed the ‘receptor gradient’. Elucidation of this unique enzyme-substrate relationship, characterized by the varying extent of interaction, is limited by the qualitative nature of the biological method. The finding of Hanig4 that, following treatment with the PR8 strain of influenza virus, the electrophoretic mobility of human erythrocytes was markedly reduced, suggested a biophysical approach to the problem.