Document Detail

The role of Ca2+ in cross-bridge kinetics in chemically skinned rabbit psoas fibers.
MedLine Citation:
PMID:  6234757     Owner:  NLM     Status:  MEDLINE    
The sinusoidal analysis method is applied to chemically skinned rabbit psoas preparations, and the effect of Ca ions on exponential processes is determined. The results are compared to the predictions of two classes of models, those in which the binding of Ca2+ to the thin filaments acts as a switch to fully activate a segment of the filament (switch hypothesis), and those in which the binding of Ca2+ results in a graded increase in activity in proportion to the fraction of sites occupied (graded hypothesis). Although qualitative features of our results are in accord with the switch hypothesis, quantitative examination of the results shows that there is an extra process (B'), which produces a W-shaped phase-frequency plot during partial activation. This result is consistent with the assumption that there are two activated states available to the thin filaments of structured muscle.
M Kawai; P W Brandt; R N Cox
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Advances in experimental medicine and biology     Volume:  170     ISSN:  0065-2598     ISO Abbreviation:  Adv. Exp. Med. Biol.     Publication Date:  1984  
Date Detail:
Created Date:  1984-07-27     Completed Date:  1984-07-27     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0121103     Medline TA:  Adv Exp Med Biol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  657-72     Citation Subset:  IM    
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MeSH Terms
Adenosine Triphosphatases / metabolism*
Calcium / metabolism*
Contractile Proteins / metabolism*
Models, Biological
Muscle Contraction*
Muscles / physiology*
Grant Support
Reg. No./Substance:
0/Contractile Proteins; 7440-70-2/Calcium; EC 3.6.1.-/Adenosine Triphosphatases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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