Document Detail

Modification of myofibrils by fluorophore-induced photo-oxidation.
MedLine Citation:
PMID:  1829462     Owner:  NLM     Status:  MEDLINE    
The excitation of fluorophores in the vicinity of a myofibril stops both shortening in the presence of ATP and Ca2+, and the extraction of the A-band by NaCl in the presence of Mg pyrophosphate. Shortening is more quickly affected than extraction. These effects can be induced by fluorescently-tagged antibodies bound in the A-band. Both depolymerization of the thick filament and the interaction between the myosin head and actin appear to be modified. Enzymatic lowering of the oxygen concentration in the bathing solution during excitation reduces these effects, indicating that they are due to photo-oxidation catalysed by excitation of the fluorophore. The results suggest that care needs to be exercised to minimize the consequences of these changes on the outcome of fluorescence-based assays of activity. Irradiated myofibrils that do not shorten, hydrolyse ATP at a rate comparable to those that contract, so they may be useful as a model system for the study of crossbridge activity in the ordered array of proteins of the myofibril.
P Knight; N Parsons
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Journal of muscle research and cell motility     Volume:  12     ISSN:  0142-4319     ISO Abbreviation:  J. Muscle Res. Cell. Motil.     Publication Date:  1991 Apr 
Date Detail:
Created Date:  1991-08-02     Completed Date:  1991-08-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8006298     Medline TA:  J Muscle Res Cell Motil     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  183-91     Citation Subset:  IM    
Muscle Biology Department, Agricultural and Food Research Council Institute of Food Research, Bristol Laboratory, Langford, Avon, UK.
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MeSH Terms
Actins / radiation effects
Adenosine Triphosphate / metabolism
Ca(2+) Mg(2+)-ATPase / metabolism
Calcium / metabolism
Calcium-Transporting ATPases / metabolism
Fluoresceins / pharmacology
Fluorescent Antibody Technique*
Fluorescent Dyes / pharmacology*
Microscopy, Fluorescence / methods*
Muscle Contraction / drug effects*,  radiation effects
Myofibrils / drug effects*,  radiation effects
Oxygen / metabolism
Rhodamines / pharmacology*
Ultraviolet Rays
Reg. No./Substance:
0/Actins; 0/Fluoresceins; 0/Fluorescent Dyes; 0/Rhodamines; 2321-07-5/Fluorescein; 56-65-5/Adenosine Triphosphate; 7440-70-2/Calcium; 7782-44-7/Oxygen; EC 3.6.1.-/Ca(2+) Mg(2+)-ATPase; EC ATPases

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

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