Fig 7. Dependence of initial velocity (Vi) of DddW catalyzed lyase reaction on DMSP concentrations in the presence of Fe(II) and Mn(II).
Apo-DddW (2 μM) was mixed with an equimolar amount of Fe(NH4)2(SO4)2 and 300μM MnCl2. To this reaction mixture, varying concentrations (0.5–35 mM) of DMSP was added. The reactions were monitored at 205 nm. The data were fit to the Michaelis-Menten equation. The kinetic parameters are as follows. With Fe(II): Vmax = 36.50 ± 1.27 μM/s; kcat = 18.25 s-1; K m = 8.68 ± 0.73 mM; k cat/K m = 2.10 x 103 M-1s-1; With Mn(II): Vmax = 34.66 ± 1.64 μM/s; kcat = 17.33 s-1; K m = 4.50 ± 0.75 mM; k cat/K m = 3.85x103 M-1s-1.