Fig. 2.

Michaelis–Menten analysis of AlkB-ΔN11 repair activity on model substrates. (A) DNA trimers and (B) pentamers were incubated at 37 °C under standard reaction conditions. AlkB was used at a concentration of 0.1 μM for the TmAT (□) and TmCT (△), 0.002 μM for CAmAAT (□) and CAmCAT (△), and 1.0 μM for TεAT (*). Reactions quenched by addition of EDTA were analyzed by reversed-phase HPLC, and the dealkylation rate was determined by quantifying substrate and product peak areas in the resulting chromatogram. Curves represent nonlinear regressions to the noncooperative Michaelis–Menten equation. Due to its substantially slower turnover rate, initial velocity of TεAT repair is plotted on the right y axis in A.