Relative inhibitory effects of selected known and newly tested compounds against ADC.[a]

[a]The measurements were performed using 1 mM L-aspartate, 3 µM ADC, and 1 mM compound (potential inhibitor) in D2O at 25°C.[b]The conversion percentage corresponds to the product formed by integration of the 1H NMR signals corresponding to substrate and product of the enzymatic reaction after ca. 30 min upon addition of the enzyme. The time was adjusted to correspond to 50% conversion in the absence of inhibitor (reference). The absolute values were averaged from at least two independent assays.[c]The relative inhibitory effect, krel, was calculated as the ratio of the conversion percentages in the presence and absence of compound.[d]While full inhibition was also observed when using double the enzyme concentration, i.e., 6 µM, only a small nhibitory effect could be detected (krel = 0.9) when the assay was performed with 100 µM oxaloacetate, i.e., at a 10-fold lower inhibitor concentration.[e]A smaller krel value of 0.74, suggesting moderate inhibition, was observed upon preincubation with ADC for 1 h at ambient temperature.