Minimum structural unit required for energy transduction in muscle.
The sliding of actin filaments was directly measured along single-headed myosin filaments on which the density of the heads was widely varied, using video-fluorescence microscopy. The results showed that the double-headed structure of myosin is not essential for inducing the sliding movement of actin filaments. The minimum number of myosin heads required for supporting movement of actin filaments at a maximum velocity of 5 micron/s at 23 degrees C was estimated to be 4, at most 16. This led to the conclusion that the sliding distance of actin filaments induced during a single ATP hydrolysis cycle is probably 160 nm or more, at least 40 nm under unloaded conditions.
Yanagida
T
T
Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University, Japan.
Harada
Y
Y
D008841:Actin Cytoskeleton / Q000502:physiology*; D000199:Actins / Q000502:physiology*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003599:Cytoskeleton / Q000502:physiology*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009132:Muscles / Q000502:physiology*; D009218:Myosins / Q000502:physiology*; D011817:Rabbits
D000199:Actins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009218:Myosins