Crossbridge behaviour during muscle contraction.
A number of recent observations by probe and X-ray methods on the behaviour of crossbridges during contraction is considered in relation to the energetics of the process. It is shown that a self-consistent picture of the crossbridge cycle, compatible with these observations and involving strongly and weakly attached crossbridges, can be obtained providing that the tension-generating part of the crossbridge stroke is only about 40 A i.e. about one-third of the usually accepted value. The myosin head subunits in the tension-generating bridges could have a configuration close to that of rigor. A mechanism is suggested whereby rapid tension recovery after quick releases up to 120 A could still be produced by such a system.
Huxley
H E
HE
Kress
M
M
D000199:Actins / Q000032:analysis / Q000502:physiology; D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D005454:Fluorescence Polarization; D008954:Models, Biological; D008958:Models, Molecular; D009119:Muscle Contraction; D009132:Muscles / Q000032:analysis* / Q000502:physiology; D009218:Myosins / Q000032:analysis* / Q000502:physiology; D014961:X-Ray Diffraction
D000199:Actins; D009218:Myosins