Elasticity of the human red blood cell skeleton.
We have measured by optical tweezers micromanipulations the area expansion and the shear moduli of spectrin skeletons freshly extracted from human red blood cells, in different controlled salinity conditions. At medium osmolarity (150 mOsm/kg), we measure KC=9.7+/-3.4 microN/m, muC=5.7+/-2.3 microN/m, KC/muC=2.1+/-0.7. When decreasing the osmolarity, both KC and muC decrease, while KC/muC is nearly constant and equal to about 2. This result is consistent with the predictions made when modeling the spectrin skeleton by a two-dimensional triangular lattice of springs. From the measured elastic moduli we estimate the persistence length of a spectrin filament: xi approximately 2.5 nm at 150 mOsm/kg.
Lenormand
G
G
Laboratoire de Biorhéologie et d'Hydrodynamique Physico-Chimique, ESA 7057, CNRS, Universités Paris 6 and Paris 7, case courrier 7056, 2, place Jussieu, F-75251 Paris cedex 05, France. henon@ccr.jussieu.fr.
Hénon
S
S
Richert
A
A
Siméon
J
J
Gallet
F
F
D004548:Elasticity; D004907:Erythrocyte Deformability / Q000502:physiology*; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D008846:Micromanipulation / Q000379:methods; D008954:Models, Biological; D009994:Osmolar Concentration; D013049:Spectrin / Q000502:physiology; D013314:Stress, Mechanical
D013049:Spectrin