Active elastic network: cytoskeleton of the red blood cell.
In red blood cells there is a cortical cytoskeleton; a two-dimensional elastic network of membrane-attached proteins. We describe, using a simple model, how the metabolic activity of the cell, through the consumption of ATP, controls the stiffness of this elastic network. The unusual mechanical property of active strain softening is described and compared to experimental data. As a by-product of this activity there is also an active contribution to the amplitude of membrane fluctuations. We model this membrane as a field of independent "curvature motors," and calculate the spectrum of active fluctuations. We find that the active cytoskeleton contributes to the amplitude of the membrane height fluctuations at intermediate wavelengths, as observed experimentally.
Gov
Nir S
NS
Department of Chemical Physics, The Weizmann Institute of Science, P.O.B. 26, Rehovot, Israel 76100.
D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D001703:Biophysics / Q000379:methods; D048430:Cell Shape; D003599:Cytoskeleton / Q000378:metabolism*; D004548:Elasticity; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry; D008954:Models, Biological; D008956:Models, Chemical; D015233:Models, Statistical; D008962:Models, Theoretical
D008565:Membrane Proteins; D000255:Adenosine Triphosphate