purified actin-tropomyosin filaments under the experimental atpase conditions were distributed in a range of more than 10 micron in length and the addition of the 84k mr protein changed the filament length to around 1 micron at a 1/10 ( 2 ) molar ratio to actin or less than 50 nm at a 1/5 molar ratio in the presence of ca2+ .
C0025979
actin
C0001271
actin