The swinging lever-arm hypothesis of muscle contraction.
The molecular mechanism of muscle contraction is a problem that has exercised biophysicists and biochemists for many years. The common view of the mechanism is embodied in the 'cross-bridge hypothesis', in which the relative sliding of thick (myosin) and thin (actin) filaments in cross-striated muscle is brought about by the 'cross-bridges', parts of the myosin molecules which protrude from the thick filaments and interact cyclically with the actin filaments, transporting them by a rowing action that is powered by the hydrolysis of ATP. This hypothesis is, however, rather vague on the molecular details of cross-bridge movement and, in the light of the recently determined crystal structures of myosin and actin, it has evolved into the more precise 'swinging lever-arm hypothesis'.
Holmes
K C
KC
Max Planck Institute für medizinische Forschung, 69120 Heidelberg, Germany.
D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004023:Dictyostelium / Q000502:physiology; D008954:Models, Biological; D008958:Models, Molecular; D008961:Models, Structural; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology* / Q000648:ultrastructure; D009218:Myosins / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary; D014638:Vanadates / Q000378:metabolism
D000199:Actins; D014638:Vanadates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009218:Myosins