Fig. (2) Assay optimization. (a) Titration of ADP. The Km was determined with 2 mM CP and 2.5 nM glCK as 58.3 mM. (b) Titration of CP. The Km was determined with 333 mM ADP and 1.7 nM glCK as 52.5 mM. (c) The time course of the reaction was determined with 150 mM ADP, 150 mM CP and 0.5 nM glCK. The signal is linear up to 30 min incubation at room temperature.