[HTML][HTML] Exploring the super-relaxed state of myosin in myofibrils from fast-twitch, slow-twitch, and cardiac muscle
Muscle myosin heads, in the absence of actin, have been shown to exist in two states, the
relaxed (turnover∼ 0.05 s− 1) and super-relaxed states (SRX, 0.005 s− 1) using a simple
fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J. 100, 1969–1976).
Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we
use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of
muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 …
relaxed (turnover∼ 0.05 s− 1) and super-relaxed states (SRX, 0.005 s− 1) using a simple
fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J. 100, 1969–1976).
Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we
use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of
muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 …
