Key Points
- This study aims to investigate the properties of protein-bound ATP as an intermediate in skeletal muscle ATPase.
- Monitored formation and decay of protein-bound ATP during single turnovers of myosin subfragment 1 ATPase.
- Conducted transient kinetic studies of ATP and ATP gamma S binding to assess isomerization effects.
- Analyzed effects of ionic strength on ATP cleavage kinetics.
- In low salt conditions, the protein-ATP complex is transiently more concentrated than the protein-products complex.
- Isomerization rate constant was measured at 170 s-1 under specific conditions.
- Nucleotide binding was associated with a 50% fluorescence increase compared to magnesium-dependent ATPase activity.
Structured PICO
PPopulationmyosin subfragment 1 ATPase from rabbit skeletal muscle
IInterventionATP and adenosine 5'-(3-thiotriphosphate) [ATP (gamma S)] binding
OOutcomeTime course of formation and decay of protein-bound ATP and kinetics of the ATP cleavage stepsurrogate
The study demonstrates that a substrate-induced protein isomerization accompanies ATP binding in rabbit skeletal muscle myosin subfragment 1 ATPase.