FIGURE 5

Determination of the kinase-specific K_m(ATP) by evaluation of the Michaelis-Menten enzyme kinetic. The K_m(ATP) was assessed by performing in vitro kinase assays with different ATP-concentrations (0.5, 1, 2, 5, 10, 25, 50, 100 and 250 µM) and by analyzing the resulting Michaelis-Menten kinetics. The K_m(ATP) describes the concentration of the phosphate-donor ATP at which half of the maximal reaction velocity (V_max, marked by the dashed line) is reached. (A) Michaelis-Menten kinetic for His-DrCK1δA, K_m(ATP) = 11.97 µM. (B) Michaelis-Menten kinetic for His-DrCK1δB, K_m(ATP) = 5.31 µM. (C) Michaelis-Menten kinetic for His-DrCK1ε, K_m(ATP) = 14.45 µM. (D) Michaelis-Menten kinetic for GST-CK1ε, K_m(ATP) = 15.36 µM. K_m: Michaelis constant for ATP. Michaelis-Menten enzyme kinetic was applied to determine K_m. K_m(ATP) for GST-CK1δ was established by Roth et al. (Figure 7) and the data is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0) (Roth et al., 2021).