Direct Measurement of the Area Expansion and Shear Moduli of the Human Red Blood Cell Membrane Skeleton - Archive ouverte HAL Access content directly
Journal Articles Biophysical Journal Year : 2001

Direct Measurement of the Area Expansion and Shear Moduli of the Human Red Blood Cell Membrane Skeleton

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Abstract

The area expansion and the shear moduli of the free spectrin skeleton, freshly extracted from the membrane of a human red blood cell (RBC), are measured by using optical tweezers micromanipulation. An RBC is trapped by three silica beads bound to its membrane. After extraction, the skeleton is deformed by applying calibrated forces to the beads. The area expansion modulus KC and shear modulus μC of the two-dimensional spectrin network are inferred from the deformations measured as functions of the applied stress. In low hypotonic buffer (25 mOsm/kg), one finds KC = 4.8 ± 2.7 μN/m, μC = 2.4 ± 0.7 μN/m, and KC/μC = 1.9 ± 1.0. In isotonic buffer, one measures higher values for KC, μC, and KC/μC, partly because the skeleton collapses in a high-ionic-strength environment. Some data concerning the time evolution of the mechanical properties of the skeleton after extraction and the influence of ATP are also reported. In the Discussion, it is shown that the measured values are consistent with estimates deduced from experiments carried out on the intact membrane and agree with theoretical and numerical predictions concerning two-dimensional networks of entropic springs.

Dates and versions

hal-03876197 , version 1 (28-11-2022)

Licence

Attribution - CC BY 4.0

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Cite

Guillaume Lenormand, Sylvie Hénon, Alain Richert, Jacqueline Siméon, François Gallet. Direct Measurement of the Area Expansion and Shear Moduli of the Human Red Blood Cell Membrane Skeleton. Biophysical Journal, 2001, 81 (1), pp.43-56. ⟨10.1016/S0006-3495(01)75678-0⟩. ⟨hal-03876197⟩
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