Table 2. Leucine Inhibition Parameters^a.

enzyme	Ki (μM)	Ki* (μM)	β
WT	12 ± 3	2.3 ± 0.2	0.1
L79A	19 ± 3	4.0 ± 0.5	0
N83Ab	8.3 ± 2.2	3.2 ± 0.5	0.2
Q84A	13 ± 4	4.8 ± 0.5	0.04

^aDetermined using a standard reaction mixture of 50 mM potassium phosphate buffer (pH 7.5), 12 mM MgCl₂, 50 μM DTP, 5–10 times the K_m values of AcCoA and KIV, and varied concentrations of leucine (0–120 μM).

^bDetermined using 750 μM AcCoA.