Electrokinetic Behavior of Red Cells

Seaman, G. V. F.

doi:10.1016/b978-0-12-677202-9.50020-4

Cited by 86 publications

(55 citation statements)

References 193 publications

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“…EM measurements serve net quantitative data only about the cell surface potential (12). The authors have no direct evidence from this study about the chemical nature of the acidic groups responsible for the higher charge density at the new electrokinetic surface of fetal RBC.…”

Section: Discussionmentioning

confidence: 70%

“…Treatment of the TRY-digested cells with formaldehyde known to eliminate NH2 groups from the surface (12,17) increased the net negativity of the adult and fetal RBC in the same extent leaving the distance between the EM values unchanged. Similar results were found when diazonium reaction was performed for deamination.…”

Section: Resultsmentioning

confidence: 99%

“…TRY liberates sialoglycoproteins from the outer surface of the membrane unmasking charged groups originally existing too far from the surface (12). The charge density change occurring after TRY action, therefore, is complex, because, in addition to the elimination of protein-bound sialic acid molecules, TRY generates new charged groups which will contribute to the EM of these cells.…”

Section: Discussionmentioning

confidence: 99%

“…frequently, It also bears the sialic acid residues responsible for the most of the negative charge at the cell surface. Because the EM of erythrocytes NASE TREATMENT is mainly related to the peripheral sialic acid molecules of the membrane (12), glycophorin can be perceived as the main deter-…”

Section: Methodsmentioning

confidence: 99%

“…Five ml of this The EM of RBC is determined by the number and sign of the suspension (10 cells/ml) was incubated with 0.5 ml NASE (Neurionizing groups located in the outermost region of the membrane aminidase, Behringwerke AG, Marburg Lahn, West-Germany, only (12). Charged groups existing deeper in the membrane have 500 U/ml) at 37°C for 30 min.…”

Section: Methodsmentioning

confidence: 99%

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Electrokinetic Analysis of the Fetal Erythrocyte Membrane After Trypsin Digestion

Kosztolányi¹,

Jobst²

1980

Pediatr Res

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Summarvno influence on the EM, unless they become unmasked by removTreatment of intact erythrocytes with trypsin (TRY) produced a significant difference (P < 0.001) in electrophoretic mobility (EM) of fetal and adult cells. The greater net negative charge of the fetal red blood cells (RBC) at the "new electrokinetic surface" generated by TRY was further analyzed with cell-electrophoretic measurements combined with various enzymatic and chemical reactions.Formaldehyde or diazonium reaction known to eliminate positive (NH2) groups increased the net negativity of the TRY-digested adult.and fetal RBC in the same extent leaving the distance between the E M values unchanged. When the TRY digestion was followed by neuraminidase (NASE) treatment, the decrease in E M of both types of erythrocytes was of the same magnitude, and the distance between the E M values of the TRY-treated fetal and adult RBC remained unchanged, too. Phospholipase-C (PLC) digestion performed after TRY treatment did not cause any change in EM, either in adult or in fetal RBC.The results show that the greater net negativity of the fetal RBC surface after TRY digestion can be attributed to neither less positive (NH2) groups, nor more sialic acid or phosphoric acid molecules existing a t the new electrokinetic surface. It is suggested that the fetal RBC membrane may possess more acidic amino acid exposed to the outside, when TRY liberates sialoglycoprotein from the outer surface of the membrane. SpeculationGlycophorin seems to be the only major membrane protein in RBC which is readily accessible for TRY at the exterior cell surface. The new electrokinetic surface generated by TRY is characterized by the portion of glycophorin just behind the TRY splitting site. The results presented here might be explained by a supposed modification in the biogenesis of the glycophorin in fetal life. Amino acid analysis of the glycophorin fragments obtained with TRY digestion would serve a more intimate insight to the problem and would give information about the maturation from fetal to adult surface properties.ing an exterior layer of the membrane, e.g., with proteolytic enzymes. TRY digestion studies on intact RBC suggest that glycophorin is the only major membrane protein which is rcadily accessible at the exterior cell surface (1). Accordingly, electrophoretic measurements of RBC combined with proteolytic digestions and other enzymatic or chemical reactions on intact RBC would give further informations about the molecular architecture of the RBC periphery, when the results are interpreted with respect to the chemical structure and surface orientation of glycophorin.Fetal RBC have been shown to differ from those of adult not only in a number of metabolic characteristics (9), but in properties like membrane deformability (2) and lateral movement of membrane Concanavalin A receptors as well (1 l), which suggest a possible difference in membrane composition and/or structure of fetal and adult RBC. Recent studies on sodium dodecyl sulphate/ polyacrylamide gel pattern ...

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Section: Discussionmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Electrokinetic Analysis of the Fetal Erythrocyte Membrane After Trypsin Digestion

Kosztolányi¹,

Jobst²

1980

Pediatr Res

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Reduction of fibrous adhesion formation by a copolymer possessing an affinity for anionic surfaces

Elbert

Hubbell

1998

J. Biomed. Mater. Res.

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Postsurgical adhesions represent a common complication following a variety of surgical procedures. We sought to develop and evaluate a water-soluble polymer that could self-assemble onto tissue surfaces, forming a barrier on the surface. A copolymer was synthesized so as to contain two components: one component adsorbed to the tissue surface, and the other created a steric barrier, thereby preventing cell interactions with the tissue surface, and perhaps altering the wound-healing response that leads to the formation of fibrous adhesions. The component selected for tissue binding was a water-soluble polycation, poly-L-lysine, which can bind to negative sites on glycoproteins, proteoglycans, and cells; and the component selected for steric stabilization was polyethylene glycol, a nonionic polymer that interacts poorly with proteins. Efficacy of lavage with an aqueous solution of the copolymer for the prevention of postsurgical abdominopelvic adhesions was assessed following a standard electrocautery injury of the uterine horns of rats. The copolymer resulted in an 88% reduction in the extent of adhesions that formed. In vitro studies designed to investigate the mechanism of this efficacy indicated that the copolymer may both hinder cell-tissue adhesive interactions and alter the process of fibrin formation.

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Decreased Cell Surface Charge in Cystic Fibrosis Epithelia

Thethi

Duszyk

1997

Cell Biochem. Funct.

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A colloid titration technique has been used to determine the surface charge of cystic fibrosis (CF) and corresponding non-CF epithelial cells. We have shown that the negative surface charge of CF epithelial cells is significantly reduced in comparison with non-CF cells. This fact may play an important role in CF, where the increased adherence of microorganisms is known to cause chronic lung infection. Neuraminidase treatment removed approximately the same amount of surface charge in both cell lines, indicating no differences in cell surface sialylation. Similar results were obtained by direct measurements of the amount of N-acetylneuraminic acid released by neuraminidase. Therefore, our results indicate that sialic acid residues are not involved in the reduction of the negative surface charge in CF. This conclusion does not support the hypothesis that undersialylation of cell-membrane molecules occurs in cystic fibrosis.

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Electrokinetic Behavior of Red Cells

Cited by 86 publications

References 193 publications

Electrokinetic Analysis of the Fetal Erythrocyte Membrane After Trypsin Digestion

Electrokinetic Analysis of the Fetal Erythrocyte Membrane After Trypsin Digestion

Reduction of fibrous adhesion formation by a copolymer possessing an affinity for anionic surfaces

Decreased Cell Surface Charge in Cystic Fibrosis Epithelia

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