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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
15
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pubmed:dateCreated |
1976-10-29
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pubmed:abstractText |
A single cycle of adenosine 5'-triphosphate (ATP) hydrolysis by a complex of actin and myosin subfragment one (acto-S-1) was studied in a stopped-flow apparatus at low temperature and low ionic strength, using light scattering to monitor the interaction of S-1 with actin and fluorescence to detect the formation of fluorescent intermediates. Our results show that the addition of a stoichiometric concentration of ATP to the acto-S-1 causes a cycle consisting of first, a rapid dissociation of the S-1 from actin by ATP; second, a slower fluorescence change in the S-1 that may be related to the initial phosphate burst; and third, a much slower rate limiting recombination of the S-1 with actin. This latter step equals the acto-S-1 steady-state adenosine 5'-triphosphatase (ATPase) rate at both low and high actin concentrations, and like the steady-state ATPase levels off at a V max of 0.9s-1 at high actin concentration. Therefore, the release of adenosine 5'-diphosphate and inorganic phosphate is not the rate-limiting step in the acto-S-1 ATPase. Rather, a slow first-order step corresponding to the previously postulated transition from the refractory to the nonrefractory state precedes the rebinding of the S-1 to the actin during each cycle of ATP hydrolysis.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Actins,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphatases,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Myosins,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphates
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
27
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pubmed:volume |
15
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3244-53
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:133714-Actins,
pubmed-meshheading:133714-Adenosine Diphosphate,
pubmed-meshheading:133714-Adenosine Triphosphatases,
pubmed-meshheading:133714-Adenosine Triphosphate,
pubmed-meshheading:133714-Kinetics,
pubmed-meshheading:133714-Models, Chemical,
pubmed-meshheading:133714-Myosins,
pubmed-meshheading:133714-Nephelometry and Turbidimetry,
pubmed-meshheading:133714-Peptide Fragments,
pubmed-meshheading:133714-Phosphates,
pubmed-meshheading:133714-Protein Binding,
pubmed-meshheading:133714-Scattering, Radiation,
pubmed-meshheading:133714-Spectrometry, Fluorescence
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pubmed:year |
1976
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pubmed:articleTitle |
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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pubmed:publicationType |
Journal Article
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