scholarly journals The Influence of pH and Ionic Strength on the Electrokinetic Stability of the Human Erythrocyte Membrane

1960 ◽  
Vol 43 (3) ◽  
pp. 635-654 ◽  
Author(s):  
D. H. Heard ◽  
G. V. F. Seaman
Keyword(s):  
Ionic Strength ◽  
Human Erythrocyte ◽  
Cell Injury ◽  
Hydrolytic Degradation ◽  
Stable State ◽  
Ion Association ◽  
General Term ◽  
Point Of View ◽  
Unstable State ◽  
Normal Human

The electrokinetic stability of washed normal human erythrocytes is discussed from the point of view of pH, ionic strength, and composition of the suspending medium. Many of the electrophoretic characteristics at low ionic strengths (sorbitol to maintain the tonicity), such as the isopotential points, are shown to arise principally from adsorption of hemolysate. The concept of electrokinetically stable, metastable, and unstable states for the red cell at various ionic strengths is introduced in preference to the general term "cell injury." In the stable state which exists around pH 7.4 for ionic strengths >0.007, no adsorption of hemolysate occurs, in the metastable state reversible adsorption of hemolysate occurs, and in the unstable state, in which ionic strengths and pH ranges are outside the metastable range, the membrane undergoes irreversible hemolysate adsorption or more general hydrolytic degradation. It is deduced from the equivalent binding of CNS, I, Cl, and F, the pH mobility relationships, and the conformation of the ionic strength data in the stable state to a Langmuir adsorption isotherm, that the membrane of the human erythrocyte behaves as a macropolyanion whose properties are modified by gegen ion association and in some instances by hemolysate adsorption. The experimental results are insufficient to establish conclusively the nature of the ionogenic groupings present in the membrane interphase.

Sorption of Cadmium and Lead by Chelating Ion Exchangers Ostsorb OXIN, Ostsorb DETA, and Ostsorb DTTA

1994 ◽  
Vol 59 (6) ◽  
pp. 1311-1318 ◽  
Author(s):  
Ladislav Svoboda ◽  
Petr Vořechovský
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Sodium Perchlorate ◽  
Exchange Capacity ◽  
Chloride Ions ◽  
Point Of View ◽  
Alkaline Media ◽  
Ion Exchangers ◽  
Acidic Media ◽  
Cadmium And Lead

The properties of cellulose chelating ion exchangers Ostsorb have been studied in the sorption of cadmium and lead from aqueous solutions. The Cd(II) and Pb(II) ions are trapped by the Ostsorb OXIN and Ostsorb DETA ion exchangers most effectively in neutral and alkaline media but at these conditions formation of stable hydrolytic products of both metals competes with the exchange equilibria. From this point of view, Ostsorb DTTA appears to be a more suitable sorbent since it traps the Pb(II) and Cd(II) ions in acidic media already. Chloride ions interfere with the sorption of the two metals by Ostsorb DTTA whereas the ionic strength adjusted by the addition of sodium perchlorate does not affect the exchange capacity of this ion exchanger.

Evolutionary game analysis of information sharing by institutional investors

2021 ◽  
pp. 1-9
Author(s):  
Hua Li ◽  
Qingqing Lou ◽  
Qiubai Sun ◽  
Bowen Li
Keyword(s):  
Information Sharing ◽  
Institutional Investors ◽  
Information Exchange ◽  
Evolutionary Game ◽  
Stable State ◽  
Point Of View ◽  
Game Model ◽  
Game Analysis ◽  
Relationship Network ◽  
The Relationship

In order to solve the conflict of interests of institutional investors, this paper uses evolutionary game model. From the point of view of information sharing, this paper discusses four different situations. Only when the sum of risk and cost is less than the penalty of free riding, the evolution of institutional investors will eventually incline to the stable state of information sharing. That is, the phenomenon of hugging. The research shows that the institutional investors are not independent of each other, but the relationship network of institutional investors for the purpose of information exchange. The content of this paper enriches the research on information sharing of institutional investors.

EUROPIUM OXALATE ION ASSOCIATION IN WATER

1966 ◽  
Vol 44 (24) ◽  
pp. 3057-3062 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Sodium Acetate ◽  
Ion Association ◽  
Sodium Oxalate ◽  
Aqueous Sodium ◽  
Oxalate Ion

The partitioning of radiotracer 152/151Eu between aqueous sodium oxalate (Na2L) solutions and toluene solutions of thenoyltrifluoroacetone (HTTA) has been studied as a function of the oxalate concentration. The pH of the aqueous phase was controlled by means of sodium acetate – acetic acid mixtures and the ionic strength (I) by NaCl or NaClO4.At low ionic strengths (~0.05) and [L] ~10−4 M EuL+ formed, but at I = 0.95 and [L] ~10−3 M EuL2− also formed. Stability constants for the 1:1 and 1:2 (metal:ligand) complexes are reported.The magnitudes of the stepwise stability constant ratios are discussed.

scholarly journals Study of Human and Robot Social Interaction Using Artificial Cognition Methods

2020 ◽  
pp. 458-464
Author(s):  
Rupal Chaudhary
Keyword(s):  
Social Interaction ◽  
Control Systems ◽  
Mathematical Thinking ◽  
Point Of View ◽  
Wide Scope ◽  
Long Run ◽  
Normal Human ◽  
Express Information ◽  
The Individual ◽  
Human Robot Collaboration

Abstract. HRI challenges AI in numerous regards: dynamic, somewhat obscure conditions that were not initially intended for robots; a wide scope of circumstances with rich semantics to comprehend and decipher; physical associations with people that require fine, low-inactivity, yet socially satisfactory control systems; regular and multimodal correspondence. This paper is an endeavor to describe these difficulties and to introduce a lot of key dynamic issues that should be tended to for an intellectual robot to effectively impart space and assignments to a person. To begin with, we distinguish the individual and community oriented intellectual aptitudes required: mathematical thinking and circumstance appraisal dependent on point of view taking and cost-adequacy investigation; securing and the article talks about every one of these capacities, presents work executions and shows how they consolidate in a sound and unique human-robot collaboration deliberative design. Fortified by the aftereffects of the preliminary, we should in the long run exhibit how the board's express information, both symbolic and quantitative, is instrumental to more extravagant and more normal human-robot associations by squeezing for certain, human-level semantics inside the robot framework.

scholarly journals Erythrocyte membrane inhibitor of reactive lysis: effects of phosphatidylinositol-specific phospholipase C on the isolated and cell- associated protein

Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 284-289 ◽  
Author(s):  
MH Holguin ◽  
LA Wilcox ◽  
NJ Bernshaw ◽  
WF Rosse ◽  
CJ Parker
Keyword(s):  
Membrane Proteins ◽  
Phospholipase C ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Membrane Attack Complex ◽  
Human Erythrocyte Membrane ◽  
Glycosyl Phosphatidylinositol ◽  
Normal Human ◽  
Erythrocyte Membrane Proteins

Abstract The erythrocyte membrane inhibitor of reactive lysis (MIRL) is an 18-Kd protein that controls complement-mediated hemolysis by restricting the activity of the membrane attack complex. MIRL expression on the erythrocytes of paroxysmal nocturnal hemoglobinuria (PNH) is abnormally low, and the greater susceptibility of PNH erythrocytes to complement is causally related to this deficiency. Inasmuch as other proteins that are deficient in PNH are anchored to the membrane through a glycosyl phosphatidylinositol moiety, studies were undertaken to determine if MIRL shares this structural feature. Normal human erythrocytes that had been radiolabeled with 125I were incubated with phosphatidylinositol- specific phospholipase C (PIPLC), and the supernate and the solubilized membrane proteins were immunoprecipitated using anti-MIRL antiserum. The MIRL that was specifically released into the supernate had an Mr of 19 Kd, while the MIRL that remained bound to the membrane had an Mr of 18 Kd. A quantitative assay showed that approximately 10% of erythrocyte MIRL was susceptible to PIPLC; however, treatment with PIPLC had no effect on either the electrophoretic mobility or the functional activity of purified MIRL. These studies show that the effects of PIPLC on MIRL are similar to those observed for other human erythrocyte membrane proteins that are anchored by a glycosyl phosphatidylinositol moiety.

scholarly journals The human erythrocyte anion transport protein, band 3. Characterization of exofacial alkaline titratable groups involved in anion binding/translocation.

1992 ◽  
Vol 100 (2) ◽  
pp. 301-339 ◽  
Author(s):  
P J Bjerrum
Keyword(s):  
Ionic Strength ◽  
Binding Site ◽  
Transport System ◽  
Human Erythrocyte ◽  
Binding Constant ◽  
Anion Transport ◽  
High Ionic Strength ◽  
Anion Binding ◽  
Asymmetry Factor ◽  
Sensitive Group

Chloride self-exchange across the human erythrocyte membrane at alkaline extracellular pH (pHO) and constant neutral intracellular pH (pH(i)) can be described by an exofacial deprotonatable reciprocating anion binding site model. The conversion of the transport system from the neutral to the alkaline state is related to deprotonation of a positively charged ionic strength- and substrate-sensitive group. In the absence of substrate ions ([ClO] = 0) the group has a pK of approximately 9.4 at constant high ionic strength (equivalent to approximately 150 mM KCl) and a pK of approximately 8.7 at approximately zero ionic strength. The alkaline ping-pong system (examined at constant high ionic strength) demonstrates outward recruitment of the binding sites with an asymmetry factor of approximately 0.2, as compared with the inward recruitment of the transport system at neutral pHO with an asymmetry factor of approximately 10. The intrinsic half-saturation constant for chloride binding, with [Cli] = [Clo], increased from approximately 30 mM at neutral to approximately 110 mM at alkaline pHO. The maximal transport rate was a factor of approximately 1.7 higher at alkaline pHO. This increase explains the stimulation of anion transport, the "modifier hump," observed at alkaline pHO. The translocation of anions at alkaline pHO was inhibited by deprotonation of another substrate-sensitive group with an intrinsic pK of approximately 11.3. This group together with the group with a pK of approximately 9.4 appear to form the essential part of the exofacial anion binding site. The effect of extracellular iodide inhibition on chloride transport as a function of pHO could, moreover, be simulated if three extracellular iodide binding constants were included in the model: namely, a competitive intrinsic iodide binding constant of approximately 1 mM in the neutral state, a self-inhibitor binding constant of approximately 120 mM in the neutral state, and a competitive intrinsic binding constant of approximately 38 mM in the alkaline state.

scholarly journals Morin decreases acrolein-induced cell injury in normal human hepatocyte cell line LO2

2020 ◽  
Vol 75 ◽  
pp. 104234
Author(s):  
Zhao Yin ◽  
Hongyang Guo ◽  
Kaiyu Jiang ◽  
Juanying Ou ◽  
Mingfu Wang ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Injury ◽  
Human Hepatocyte ◽  
Hepatocyte Cell Line ◽  
Normal Human

scholarly journals Erythrocyte adducin: a calmodulin-regulated actin-bundling protein that stimulates spectrin-actin binding.

1987 ◽  
Vol 105 (6) ◽  
pp. 2837-2845 ◽  
Author(s):  
S M Mische ◽  
M S Mooseker ◽  
J S Morrow
Keyword(s):  
Ionic Strength ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Actin Binding ◽  
Protein 4.1 ◽  
Calcium Dependent ◽  
High Affinity ◽  
Putative Role ◽  
Cross Bridges ◽  
Dependent Mechanism

Adducin is an erythrocyte membrane skeletal phosphoprotein comprised of two related subunits of 105,000 and 100,000 Mr. These peptides form a functional heterodimer, and the smaller of the two binds calmodulin in a calcium-dependent fashion. Although this protein has been physicochemically characterized, its function remains unknown. We have examined the interaction of human adducin with actin and with human erythrocyte spectrin using sedimentation, electrophoretic, and morphologic techniques. Purified adducin binds actin at physiologic ionic strength and bundles it into arrays of laterally arranged filaments, the adducin forming cross-bridges between the filaments at 35.2 /- 3.8 (2 SD) nm intervals. The stoichiometry of high affinity adducin binding to actin at saturation is 1:7, corresponding to a dimer of adducin for every actin helical unit. Adducin also promotes the binding of spectrin to actin independently of protein 4.1. At saturation, each adducin promotes the association of one spectrin heterodimer. The formation of this ternary spectrin-actin-adducin complex is independent of the assembly path, and the complex exists in a readily reversible equilibrium with the free components. The binding of adducin to actin and its ability to stimulate spectrin-actin binding is down-regulated by calmodulin in a calcium-dependent fashion. These results thus identify a putative role for adducin, and define a calcium- and calmodulin-dependent mechanism whereby higher states of actin association and its interaction with spectrin in the erythrocyte may be controlled.

Sign in / Sign up

Export Citation Format

Share Document