Viscoelastic properties of red cell membrane in hereditary elliptocytosis.
The viscoelastic properties of the RBC membrane are in part determined by a submembrane network of proteins consisting of spectrin alpha beta heterodimers (SpD) assembled head-to-head to form spectrin tetramers (SpT) and spectrin oligomers (SpO). SpT, in turn, are connected into a two-dimensional network by the linkage of distal ends of SpT to protein 4.1 and actin. With the micropipette technique, we determined the membrane viscoelastic properties of RBCs from a subset of patients with hereditary elliptocytosis (HE); these RBCs exhibit membrane skeletal instability, defective SpD self-association, and a molecular defect in the alpha I domain of spectrin, which is involved in the SpD-SpD contact (HE SpD alpha-SpD). The elastic modulus and viscosity of the membrane were significantly higher for the HE RBCs than for the control cells. Incubation of normal cells with N-ethyl-maleimide (NEM) produced a similar defective SpD self-association and a significant increase in the viscoelastic parameters of the membrane. The data provide evidence that the mode of assembly of membrane spectrin in the cytoskeletal protein network plays a major role in determining the rheologic behavior of erythrocyte membrane.
Chabanel
A
A
Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York.
Sung
K L
KL
Rapiejko
J
J
Prchal
J T
JT
Palek
J
J
Liu
S C
SC
Chien
S
S
D004548:Elasticity; D004612:Elliptocytosis, Hereditary / Q000097:blood*; D004907:Erythrocyte Deformability; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D009994:Osmolar Concentration; D012212:Rheology; D013049:Spectrin / Q000502:physiology; D014783:Viscosity
D013049:Spectrin