Further evidence for a membrane potential-dependent shape transformation of the human erythrocyte membrane

1986 ◽  
Vol 6 (11) ◽  
pp. 999-1006 ◽  
Author(s):  
Peter Müller ◽  
Andreas Herrmann ◽  
Roland Glaser
Keyword(s):  
Membrane Potential ◽  
Ionic Strength ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Transmembrane Potential ◽  
Sodium Gluconate ◽  
Human Erythrocyte Membrane ◽  
Shape Transformation

The influence of various factors (pH, temperature, sodium gluconate) on the ionic strength-dependent stomatocyte-discocyte-echinocyte transformation of the human erythrocyte membrane was investigated. The results give further evidence for a correlation between shape of erythrocyte membrane and the transmembrane potential of the cells.

scholarly journals Role of the reticulum in the stability and shape of the isolated human erythrocyte membrane

1982 ◽  
Vol 92 (3) ◽  
pp. 714-721 ◽  
Author(s):  
Y Lange ◽  
RA Hadesman ◽  
TL Steck
Keyword(s):  
Ionic Strength ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Time Course ◽  
Isotonic Saline ◽  
Human Erythrocyte Membrane ◽  
Wide Range ◽  
Cell Stability ◽  
Mechanically Stabilized ◽  
Low Ionic Strength

In order to examine the widely held hypothesis that the reticulum of proteins which covers the cytoplamsic surface of the human erythrocyte membrane controls cell stability and shape, we have assessed some of its properties. The reticulum, freed of the bilayer by extraction with Triton X-100, was found to be mechanically stable at physiological ionic strength but physically unstable at low ionic strength. The reticulum broke down after a characteristic lag period which decreased 500-fold between 0 degrees and 37 degrees C. The release of polypeptide band 4.1 from the reticulum preceded that of spectrin and actin, suggesting that band 4.1 might stabilize the ensemble but is not essential to its integrity. The time-course of breakdown was similar for ghosts, the reticulum inside of ghosts, and the isolated reticulum. However, at very low ionic strength, the reticulum was less stable within the ghost than when free; at higher ionic strength, the reverse was true. Over a wide range of conditions the membrane broke down to vesicles just as the reticulum disintegrated, presumably because the bilayer was mechanically stabilized by this network. The volume of both ghosts and naked reticula varied inversely and reversibly with ionic strength. The volume of the naked reticulum varied far more widely than the ghost, suggesting that its deformation was normally limited by the less extensible bilayer. The contour of the isolated reticulum was discoid and often dimpled or indented, as visualized in the fluorescence microscope after labeling of the ghosts with fluoroscein isothiocyanate. Reticula derived from ghosts which had lost the ability to crenate in isotonic saline were shriveled, even though the bilayer was smooth and expanded. Conversly, ghosts crenated by dinitrophenol yielded smooth, expanded reticula. We conclude that the reticulum is a durable, flexible, and elastic network which assumes and stabilizes the contour of the membrane but is not responsible for its crenation.

scholarly journals Ionic-strength-dependent changes in the structure of the major protein of the human erythrocyte membrane

1977 ◽  
Vol 161 (1) ◽  
pp. 131-138 ◽  
Author(s):  
R E Jenkins ◽  
M J A Tanner
Keyword(s):  
Ionic Strength ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Polypeptide Chain ◽  
Trypsin Digestion ◽  
Major Protein ◽  
Human Erythrocyte Membrane ◽  
Extracellular Region ◽  
The Individual ◽  
Intracellular Region

The effect of ionic strength on the proteolysis by trypsin of the major membrane-penetrating protein (polypeptide 3) in the erythrocyte membrane was studied. Both the intracellular and extracellular regions of the protein are susceptible to trypsin proteolysis under hypo-osmotic conditions, whereas under iso-osmotic conditions the extracellular region of the protein is resistant to trypsin, and the intracellular region yields only two cleavage products with trypsin. Studies of the fragments obtained from polypeptide 3 by trypsin digestion under iso-osmotic conditions of ‘ghosts’ radioiodinated with lactoperoxidase confirmed our earlier conclusions that the polypeptide chain of polypeptide 3 traverses the membrane twice. Ionic-strength-dependent changes were also observed in the incorporation of iodine by lactoperoxidase into the individual extracellular tyrosine sites of the protein. These results show that polypeptide 3 undergoes ionic-strength-dependent changes in structure.

A model for the asymmetric lipid distribution in the human erythrocyte membrane

1986 ◽  
Vol 6 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Andreas Herrmann ◽  
Peter Müller
Keyword(s):  
Erythrocyte Membrane ◽  
Rate Constants ◽  
Human Erythrocyte ◽  
Human Erythrocyte Membrane ◽  
Shape Transformation ◽  
Flip Flop ◽  
Transverse Distribution ◽  
Lipid Distribution ◽  
Selective Interaction ◽  
Area Expansion

The asymmetric transverse distribution of phospholipids in the human erythrocyte membrane can be explained by differences between the rate constants of flip and flop motion of the lipids. A selective interaction between aminophospholipids and spectrin does not need to be assumed for creating and maintaining the asymmetric localization of these lipids. Shape transformation of red cells could be caused by alterations of the flip-flop rate constants leading to a change of the lipid distribution and, consequently, to a differential area expansion of the outer and inner membrane leaflet.

scholarly journals A Ceramide Pentasaccharide of Human Erythrocyte Membrane

1974 ◽  
Vol 249 (4) ◽  
pp. 1022-1025
Author(s):  
Klaus Stellner ◽  
Sen-Itiroh Hakomori
Keyword(s):  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Human Erythrocyte Membrane
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