Inhibition of serine racemase by l-serine
O-sulfate. (A) Enzyme activity was
monitored at 37°C in media containing 50 mM Tris⋅HCl (pH 8.2),
10 mM l-serine, 10 μg/ml purified enzyme, 15 μM
PLP, and different concentrations of l-serine
O-sulfate (●). (B)
Reaction medium and conditions were as described in A,
except that l-serine concentration was varied from 1 to 20
mM either in the absence (○) or in the presence
(●) of 8 mM l-serine
O-sulfate. Inhibition exhibited a noncompetitive
kinetics (Inset). The values are mean ± SEM of
three different experiments with three enzyme preparations.