FIGURE 3.
Ferricyanide reductase activities of FNRS and FNRL-PC. K3[Fe(CN)6] was premixed with 0.025–0.1 μm FNRS/L in 150 mm KP pH 8 and 5 mm MgCl2 at room temperature. The reaction was started by addition of 25–400 μm NADPH. For the FNRL-PC preparation, at least two measurements have been carried out at each given point. The data were normalized to an FNRS/L concentration of 0.1 μm and were fitted with the Henri-Michaelis-Menten equation: For FNRS (open circles) and FNRL-PC (open squares), Km(NADPH) values were 55 ± 5 μm and 40 ± 3 μm, respectively. The turnover number kcat for FNRS and FNRL-PC were 174 ± 5 s−1 and 124 ± 3 s−1, respectively.