Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 8 October 1976:
Vol. 194. no. 4261, p. 190
DOI: 10.1126/science.194.4261.190-a
Prev | Table of Contents | Next

Articles

Muscle Crossbridges: Absence of Direct Effect of Calcium on Movement Away from the Thick Filaments

R. A. MENDELSON 1 and P. CHEUNG 1

1 Cardiovascular Research Institute, University of California, San Francisco

Fluorescence depolarization experiments show that the rotary mobility of myosin heads is hindered by the assembly of the thick filament. Calcium, with or without magnesium adenosine triphosphate, does not alter this hindrance in synthetic filaments. This implies that calcium does not directly move the crossbridges toward thin filaments on activation of muscle.

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)