Inhibition of ATP binding to myofibrils and acto-myosin subfragment 1 by caged ATP

The bonding of Mg(2+)-ATP and myofibrils in the presence of P3-(1-(2-nitrophenyl)ethyl)adenosine 5'-triphosphate (caged ATP) was studied using a quench flow technique. The observation of single turnovers of (gamma-32P)ATP hydrolysis revealed that ADP had an inhibition constant of 145 micromoles. The study revealed a lower rate of ATP binding caused by the preventive effects of caged ATP on bonding of ATP and fibers.