Dynamics of counterion-induced attraction between vimentin filaments followed in microfluidic drops

摘要: Intermediate filaments (IFs) are fiber-forming proteins and part of the cytoskeleton eukaryotes. In vitro network formation purified IF systems is mediated, for example, by interaction with multivalent ions. The understanding these mechanisms increases knowledge on a fundamental level. Here, we employ time-lapse fluorescence microscopy to directly image evolution vimentin IFs upon addition divalent We thus able follow process starting few seconds after first encounter free ions up several minutes when networks in equilibrium. local protein density compacted can reach factor 45 higher than original solution concentration. competition between mono- ion condensation onto explains our observations reveals polyelectrolyte nature as reason attraction presence small cations. method studies microfluidic drops presented here be generalized other dynamic systems.