title: Myosin heads do not move on activation in highly stretched vertebrate striated muscle.
abstract: 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.
mesh_terms: 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*
chemical_list: D000199:Actins; D000251:Adenosine Triphosphatases; D009218:Myosins; D002118:Calcium