The mechanical properties of actin gels. Elastic modulus and filament motions.

摘要: To address large discrepancies reported in the literature, viscoelastic properties of gels formed by purified actin filaments have been measured five different techniques and instruments using preparations separately four laboratories. These measurements consistently showed that elastic shear modulus 2 mg/ml F-actin is on order several hundred pascals, depends very strongly length history sample prior to measurement. Shortening with gelsolin mechanical perturbations reduce low values identical some indicating such account for moduli poor responsiveness filament modifying treatments previously. The structures individual within similar or those studied rheometrically were also examined dynamic light scattering fluorescence microscopy. Dynamic data analyzed a new method confirm no stable associations each other fluctuate solution at rate governed bending persistence length, determined be approximately 10 microns. Fluorescence microscopy confirmed applying even small stresses can orient rupture filaments, minimally perturbed gel, long are free diffuse limit constraints their neighbors. findings relatively isotropic networks sufficiently strong stabilize cells.