Possible uncoupling of the mechanochemical process in the actomyosin system by covalent crosslinking of F-actin.
It has been speculated that F-actin depolymerizes during muscle contraction. In order to test this speculation, G-actin in F-actins were immobilized by crosslinking. While this did not affect activation of myosin ATPase, superprecipitation could be abolished. Sedimentation, light scattering, electron microscope, electrophoresis and homodyne spectra measurements seem to indicate that the average size of crosslinked segments increases with time of treatment with the crosslinking agent. At the same time, the amounts of dimers and trimers decreased. It appears that crosslinking makes F-actin filaments less flexible. The possible reasons for the loss of the capability to exhibit superprecipitation are discussed.
Gadasi
H
H
Department of Polymer Research, The Weizmann Institute of Science, Rehovot, Israel.
Oplatka
A
A
Lamed
R
R
Hochberg
A
A
Lowe
W
W
D000199:Actins / Q000378:metabolism* / Q000648:ultrastructure; D003432:Cross-Linking Reagents / Q000378:metabolism; D005976:Glutaral / Q000378:metabolism; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D009218:Myosins / Q000378:metabolism*
D000199:Actins; D003432:Cross-Linking Reagents; D009218:Myosins; D005976:Glutaral