Interaction of neutral polysaccharides with human erythrocyte membrane: Involvement of phospholipid bilayer

Minetti, Maurizio; Teichner, Angela; Aducci, Patrizia

doi:10.1016/0006-291x(78)91102-6

Cited by 22 publications

(9 citation statements)

References 14 publications

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“…3). The observation that polymer adsorption to the membrane surface at 0°C raises along with increasing FD molecular weights is in accordance with data previously reported with intact RBC and model membranes [ 19,23,26,27].…”

Section: Effects Of Temperature and Ionic Strength On Ghost Resealingsupporting

confidence: 92%

“…It has been suggested [19,20] that (i) the membrane components involved in the binding between neutral polysaccharides, such as dextrans, and the erythrocyte membrane are lipids, and (ii) the binding consists of polymer adsorption at the lipid-water interface. Data in Table I strengthen this hypothesis by showing that FD binding to intact erythrocytes can be reduced or abolished by phospholipase treatment of RBC.…”

Section: Fd Interaction With Erythrocyte Membrane As a Marker For Ghomentioning

confidence: 99%

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Protein‐dependent lipid lateral phase separation as a mechanism of human erythrocyte ghost resealing

Minetti¹,

Ceccarini²

1982

J of Cellular Biochemistry

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The hypothesis of a correlation between a 10 degrees-20 degrees C lipid phase transition and the resealing process of human erythrocyte membrane has been investigated. The conditions required to reseal human erythrocyte ghosts have been studied by measuring the amount of fluorescein-labeled dextran (FD) that is trapped into the membrane. Temperature per se was sufficient to induce membrane resealing: (1) at 5 mM sodium phosphate, pH 7.8 (5P8), resealing began at 12 degrees C; (2) at salt concentrations above 8 mM sodium phosphate, it occurred at lower temperature; and (3) in isotonic saline was detected just above 5 degrees C. The removal of peripheral membrane proteins from unsealed membranes by chymotrypsin at 0 degree C in 5P8 was followed by membrane resealing. This seems to imply that the presence of proteins is necessary to maintain the membrane unsealed. Protein-induced lateral phase separation of lipids may be a reasonable mechanism for the observed phenomena. In fact, the permeability of phosphatidylserine-phosphatidylcholine mixed liposomes to FD is modified by lipid lateral phase separation induced by pH or poly-L-lysine. Electron spin resonance studies of membrane fluidity by a spin labeled stearic acid showed a fluidity break around 11 degrees C, which may be due to a gel-liquid phase transition. Fluidity changes are abolished by chymotrypsin treatment. It is suggested that a lateral phase separation is responsible for the permeability of open ghosts to FD. Accordingly, disruption of phase separation apparently produces membrane reconstitution. In this respect peripheral proteins and particularly the spectrin-actin network, may play a major role in membrane resealing.

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Section: Effects Of Temperature and Ionic Strength On Ghost Resealingsupporting

confidence: 92%

Section: Fd Interaction With Erythrocyte Membrane As a Marker For Ghomentioning

confidence: 99%

Protein‐dependent lipid lateral phase separation as a mechanism of human erythrocyte ghost resealing

Minetti¹,

Ceccarini²

1982

J of Cellular Biochemistry

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“…39), it is possible that the different extents of dextran release into the supernatant may reflect their differing affinities for the erythrocyte ghosts. The higher affinity (40) and larger number of adsorption sites of the larger dextran would then explain its delayed and reduced release from the ghosts. An alternative possibility is that the presence of proteins in the erythrocyte membrane may cause cytolysins to form an incomplete prepore complex and the subsequent formation of a pore significantly smaller in size than the one observed in liposomal membranes.…”

Section: Discussionmentioning

confidence: 99%

Assembly and Topography of the Prepore Complex in Cholesterol-dependent Cytolysins

Heuck

Tweten

Johnson

2003

Journal of Biological Chemistry

106

142

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Cholesterol-dependent cytolysins are a family of poreforming proteins that have been shown to be virulence factors for a large number of pathogenic bacteria. The mechanism of pore formation for these toxins involves a complex series of events that are known to include binding, oligomerization, and insertion of a transmembrane ␤-barrel. Several features of this mechanism remain poorly understood and controversial. Whereas a prepore mechanism has been proposed for perfringolysin O, a very different mechanism has been proposed for the homologous member of the family, streptolysin O. To distinguish between the two models, a novel approach that directly measures the dimension of transmembranes pores was used. Pore formation itself was examined for both cytolysins by encapsulating fluoresceinlabeled peptides and proteins of different sizes into liposomes. When these liposomes were re-suspended in a solution containing anti-fluorescein antibodies, toxinmediated pore formation was monitored directly by the quenching of fluorescein emission as the encapsulated molecules were released, and the dyes were bound by the antibodies. The analysis of pore formation determined using this approach reveals that only large pores are produced by perfringolysin O and streptolysin O during insertion (and not small pores that grow in size). These results are consistent only with the formation of a prepore complex intermediate prior to insertion of the transmembrane ␤-barrel into the bilayer. Fluorescence quenching experiments also revealed that PFO in the prepore complex contacts the membrane via domain 4, and that the individual transmembrane ␤-hairpins in domain 3 are not exposed to the nonpolar core of the bilayer at this intermediate stage.Cholesterol-dependent cytolysins (CDCs) 1 are produced by a variety of pathogenic Gram-positive bacteria (reviewed in Refs.1 and 2). The monomeric forms of the CDCs are highly water soluble, but the proteins bind to cholesterol-containing membranes and then spontaneously self-associate to form large aqueous pores in the bilayer. These oligomeric complexes vary in size and may contain up to 50 individual monomers (3-5).The only crystal structure of a water soluble, monomeric form of a CDC was solved by Rossjohn et al. (6) for perfringolysin O (PFO) from Clostridium perfringens, and their data revealed that PFO is comprised of four domains. The crystal structure of a membrane-inserted oligomer of a CDC is not presently available. However, several fluorescence-based studies have identified the regions of PFO that form a transmembrane ␤-barrel and have also provided other structural information about the membrane-inserted oligomer. Domain 3 of PFO contains two stretches of amino acids (190 -217 and 288 -311) that interact with the membrane during pore formation and create an amphipathic ␤-sheet that serves as an aqueouslipid interface after insertion into the membrane (7,8). Domain 4 (residues 391-500) is involved in membrane recognition and binding, and remains close to the membrane surface in the ...

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“…Figure9. Effect of human plasma and serum on the barrier function of egg PC SUV as coated with CHAs-85-2.0 ( ), CHAp-112-1.0 (#), (A), CHP-50-1.3 ( ), and CHD-176-1.4 ( ) or without a polysaccharide coat (O) in 20 mM Tris-HCl containing 200 mM NaCl (pH 7.4) at 37.0 °C: (A) in the absence of blend fluid; (B) in the presence of 18.0% (v/v) human serum; (C) in the presence of 18.0% (v/v) human plasma.…”

mentioning

confidence: 99%

Naturally occurring polysaccharide derivatives which behave as an artificial cell wall on an artificial cell liposome

Sunamoto¹,

Sato²,

Taguchi³

et al. 1992

Macromolecules

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In order to make a liposome more mechanically stable, the liposomal surface was coated with a naturally occurring polysaccharide which bears a hydrophobic anchor such as a cholesterol or palmitoyl residue. The effect of a hydrophobic anchor on the coating efficiency of the liposomal membrane was studied from the viewpointa of the permeability of a polysaccharide-coated liposome and the membrane fluidity. Through these investigations, it was found that coating of the liposomal surface with cholesterol derivatives of the polysaccharides was much better at decreasing the membrane permeability of a water-soluble fluorescent probe (6-carboxyfluorescein) than coating with O-palmitoylpolysaccharide.

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Interaction of neutral polysaccharides with human erythrocyte membrane: Involvement of phospholipid bilayer

Cited by 22 publications

References 14 publications

Protein‐dependent lipid lateral phase separation as a mechanism of human erythrocyte ghost resealing

Protein‐dependent lipid lateral phase separation as a mechanism of human erythrocyte ghost resealing

Assembly and Topography of the Prepore Complex in Cholesterol-dependent Cytolysins

Naturally occurring polysaccharide derivatives which behave as an artificial cell wall on an artificial cell liposome

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