Viscoelasticity of actin-gelsolin networks in the presence of filamin.
Cross-linking of actin filaments by filamin by means of frequency-dependent rheology yields an increase in the filament's elasticity and stiffness. Higher cross-linker (filamin) ratios are required for mean actin-filament lengths of 5-6 microm than for random-length distribution of actin filaments. The loss modulus (i.e. the viscous portion) in the region of the internal-chain dynamics [G"(omega) approximately omega(alpha)] is influenced by the cross-linking of filaments, and with an increasing molar ratio of filamin/actin a reduction of alpha is observed. Rheological measurements reveal that actin networks are already formed at the polymerizing stage at a molar ratio of filamin/actin of less than 1:100, and electron micrographs show phase separation of actin/filament networks of low density and of actin/filament bundles.
Goldmann
W H
WH
Surgery Research Laboratories, Massachusetts General Hospital, Harvard Medical School, Charlestown 02129, USA. goldman@helix.mgh.harvard.edu
Tempel
M
M
Sprenger
I
I
Isenberg
G
G
Ezzell
R M
RM
D000199:Actins / Q000737:chemistry*; D001704:Biopolymers; D003285:Contractile Proteins / Q000737:chemistry*; D064448:Filamins; D018260:Gelsolin / Q000737:chemistry*; D008840:Microfilament Proteins / Q000737:chemistry*; D008854:Microscopy, Electron
D000199:Actins; D001704:Biopolymers; D003285:Contractile Proteins; D064448:Filamins; D018260:Gelsolin; D008840:Microfilament Proteins