Myosin heads do not move on activation in highly stretched vertebrate striated muscle.
Highly stretched muscles in which thick and thin filaments no longer overlap produce little or no tension on activation. In preparations producing no tension, the 42.9-nanometer myosin layer line shown in x-ray diffraction patterns does not become weaker. This suggests that myosin heads do not move from their resting positions in the absence of actin.
D000199:Actins / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001001:Anura; D002118:Calcium / Q000502:physiology; D009038:Motion; D009119:Muscle Contraction; D009132:Muscles / Q000648:ultrastructure; D009218:Myosins / Q000502:physiology*
D000199:Actins; D000251:Adenosine Triphosphatases; D009218:Myosins; D002118:Calcium