Tuning Intermediate Filament Mechanics by Variation of pH and Ion Charges

摘要: The cytoskeleton is formed by three types of filamentous proteins -- microtubules, actin filaments, and intermediate filaments (IFs) enables cells to withstand external internal forces. Vimentin the most abundant IF protein in humans assembles into 10 nm diameter with remarkable mechanical properties, such as high extensibility stability. It is, however, unclear which extent these properties are influenced electrostatic environment. Here, we study single vimentin employing optical trapping combined microfluidics. Force-strain curves, recorded at varying ion concentrations pH values, reveal that IFs concentration. By combination Monte Carlo simulations, relate altered mechanics interactions subunits within filaments. We thus suggest possible mechanisms allow locally tune their stiffness without remodeling entire cytoskeleton.