What is the true ATPase activity of contracting myofibrils?
The ATPase activity of contracting myofibrils was obtained in a solvent of ionic contents that mimic in vivo conditions: pH 7.4 and 0.1 M potassium acetate. Contracting myofibrils are fleeting structures and their ATPase activity is of short duration: even at 4 degrees C it was over after a reaction time of 1 s and rapid reaction equipment was needed for its study. The ATPase (1.1 s-1) was very similar to that of crosslinked actoS1 (1 s-1). It was 100 x that of relaxed myofibrils.
Houadjeto
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M
INSERM U128, CNRS, Montpellier, France.
Barman
T
T
Travers
F
F
D000205:Actomyosin / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003432:Cross-Linking Reagents; D007700:Kinetics; D009119:Muscle Contraction; D009132:Muscles / Q000201:enzymology / Q000502:physiology; D009210:Myofibrils / Q000201:enzymology / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism; D011817:Rabbits
D003432:Cross-Linking Reagents; D010710:Phosphates; D000205:Actomyosin; D000251:Adenosine Triphosphatases; D002118:Calcium