Reaction of F-actin and the F-actin-tropomyosin complex with 20 mM glutaraldehyde for 19-22 h at 0 degrees C and 25 degrees C results in extensively cross-linked filaments, as judged by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Electron micrographs show shorter, more irregular filaments for glutaraldehyde-treated F-actin in the absence of tropomyosin as compared to the presence of tropomyosin or untreated controls. There was a 40% drop in viscosity of glutaraldehyde-treated F-actin solutions but a 90% increase in viscosity for the glutaraldehyde-treated F-actin-tropomyosin complex in solution, as compared to the untreated controls, indicating different effects of cross-linking. SDS gels indicate that intrasubunit cross-links are introduced into F-actin and that when tropomyosin is present, intramolecular cross-link formation is inhibited. Inhibition of the salt-induced G leads to F polymerization results when intramolecular cross-links are introduced into G-actin under similar or milder reaction conditions. These data indicate that, under conditions for which extensive F-actin filament cross-linking (fixing) occurs, the filaments become damaged due to the concurrent formation of intrasubunit cross-links that cause local depolymerization and distortion and that tropomyosin protects against this damage.
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Article| August 01 1981
Damage to actin filaments by glutaraldehyde: protection by tropomyosin.
S S Lehrer
Online Issn: 1540-8140
Print Issn: 0021-9525
J Cell Biol (1981) 90 (2): 459–466.
S S Lehrer; Damage to actin filaments by glutaraldehyde: protection by tropomyosin.. J Cell Biol 1 August 1981; 90 (2): 459–466. doi: https://doi.org/10.1083/jcb.90.2.459
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