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Proc Natl Acad Sci U S A. 2016 Dec 20;113(51):14847-14851. doi: 10.1073/pnas.1615452113. Epub 2016 Dec 5.

Biconcave shape of human red-blood-cell ghosts relies on density differences between the rim and dimple of the ghost's plasma membrane.

Author information

1
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520 joseph.hoffman@yale.edu.

Abstract

The shape of the human red blood cell is known to be a biconcave disk. It is evident from a variety of theoretical work that known physical properties of the membrane, such as its bending energy and elasticity, can explain the red-blood-cell biconcave shape as well as other shapes that red blood cells assume. But these analyses do not provide information on the underlying molecular causes. This paper describes experiments that attempt to identify some of the underlying determinates of cell shape. To this end, red-blood-cell ghosts were made by hypotonic hemolysis and then reconstituted such that they were smooth spheres in hypo-osmotic solutions and smooth biconcave discs in iso-osmotic solutions. The spherical ghosts were centrifuged onto a coated coverslip upon which they adhered. When the attached spheres were changed to biconcave discs by flushing with an iso-osmotic solution, the ghosts were observed to be mainly oriented in a flat alignment on the coverslip. This was interpreted to mean that, during centrifugation, the spherical ghosts were oriented by a dense band in its equatorial plane, parallel to the centrifugal field. This appears to be evidence that the difference in the densities between the rim and the dimple regions of red blood cells and their ghosts may be responsible for their biconcave shape.

KEYWORDS:

biconcave discs; membrane/cytoskeletal complex; red-blood-cell ghosts; spheres

PMID:
27930321
PMCID:
PMC5187704
[Available on 2017-06-20]
DOI:
10.1073/pnas.1615452113

Conflict of interest statement

The author declares no conflict of interest.

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