Skip to main content
. 2011 May 4;286(28):24754–24764. doi: 10.1074/jbc.M111.250779

FIGURE 1.

FIGURE 1.

Kinetic parameters for in vitro DES assay. A, conversion of C8-dhCer into C8-Cer. This scheme depicts the oxidation of C8-dhCer into C8-Cer by the enzyme dihydroceramide desaturase. The formed water is radiolabeled, and it was the target for measurements in our assays. B and C, Michaelis-Menten plots of DES activity for determination of Km and Vmax for C8-dhCer and NADH. B, determination of Km and Vmax for C8-dhCer. A fixed amount of labeled C8-dhCer and increasing amounts of unlabeled C8-dhCer starting from 0.05 μm to 10 μm were used. C, determination of Km and Vmax for NADH. Increasing amounts of NADH were used and [C8-dhCer] was 0.25 Km. Assays were performed in vitro using rat liver microsomes with an incubation time of 20 min. Values represent the mean ± S.D. of at least two separate determinations performed in triplicate. Km and Vmax values are shown in Table 1. D, table showing Km and Vmax values for NADH and C8-dhCer.