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

[a]<p>The measurements were performed using 1 mM L-aspartate, 3 µM ADC, and 1 mM compound (potential inhibitor) in D₂O at 25°C.</p>[b]<p>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 <i>absence</i> of inhibitor (reference). The absolute values were averaged from at least two independent assays.</p>[c]<p>The relative inhibitory effect, <i>k</i>_rel, was calculated as the ratio of the conversion percentages in the presence and absence of compound.</p>[d]<p>While full inhibition was also observed when using double the enzyme concentration, i.e., 6 µM, only a small nhibitory effect could be detected (<i>k</i>_rel = 0.9) when the assay was performed with 100 µM oxaloacetate, i.e., at a 10-fold lower inhibitor concentration.</p>[e]<p>A smaller <i>k</i>_rel value of 0.74, suggesting moderate inhibition, was observed upon preincubation with ADC for 1 h at ambient temperature.