Nonlinear mechanics of entangled F-actin solutions

Using a variety of different rheological approaches, we study the nonlinear shear response of purified entangled F-actin solutions. We show that the choice of the experimental protocol is crucial. Furthermore, a transition between stress hardening and weakening can be induced even in purely entangled solutions. This transition depends on various ambient and network parameters including temperature, buffer salt concentration, filament length and density.