What question did this study set out to answer?

The aim was to investigate the interaction cycle of myosin subfragment one with actin during ATP hydrolysis.

July 27, 1976Biochemistry

Pre-steady-state kinetic evidence for a cyclic interaction of myosin subfragment one with actin during the hydrolysis of adenosine 5'-triphosphate

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Population

Complex of actin and myosin subfragment one (acto-S-1)

Design

Preclinical

Authors

SCStephen P. ChockHoward University PCP Boon ChockNational Institutes of Health EEEvan EisenbergNational Institutes of Health

Discussion

Member takes

Implication

Challenges product release as rate-limiting in acto-S-1 ATPase; leaves open validation in cardiac myosin kinetics.

Key Points

The aim was to investigate the interaction cycle of myosin subfragment one with actin during ATP hydrolysis.
Used a stopped-flow apparatus at low temperature and ionic strength for the analysis.
Monitored interactions through light scattering and fluorescence to detect intermediates.
Studied the effects of ATP addition on acto-S-1 interaction dynamics.
Confirmed a cycle where ATP causes rapid dissociation of S-1 from actin, followed by fluorescence changes.
Identified that recombination of S-1 to actin is the rate-limiting step, matching the steady-state ATPase rate.
Observed V max of 0.9 s-1 at high actin concentration, indicating the release of ADP and inorganic phosphate is not limiting.

Structured PICO

Population

Complex of actin and myosin subfragment one (acto-S-1)

Intervention

Addition of a stoichiometric concentration of adenosine 5'-triphosphate (ATP)

Outcome

Kinetics of ATP hydrolysis cycle (dissociation, fluorescence change, and recombination rates)surrogate

This kinetic study demonstrates that the rate-limiting step in acto-S-1 ATPase is a transition state prior to actin rebinding, rather than product release.

Cite This Study

Chock et al. (1976) studied this question.

synapsesocial.com/papers/6a20a8389ca8a48788f36f4a https://doi.org/10.1021/bi00660a013

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Pre-steady-state kinetic evidence for a cyclic interaction of myosin subfragment one with actin during the hydrolysis of adenosine 5'-triphosphate

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Pre-steady-state kinetic evidence for a cyclic interaction of myosin subfragment one with actin during the hydrolysis of adenosine 5'-triphosphate

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider