Results from kinetic
analysis of inhibitor candidates with the
hCBS truncated dimer. (a) Lineweaver–Burk plot for hCBS inhibition
with 6S, detecting H2S production in the presence
Pb(OAc)2. (b) Secondary-plot of bis-α-hydrazino acid
(6S) inhibition of H2S production by hCBS
yielding a Ki value of 48 ± 2 μM.
(c) UV/vis spectroscopic profile of model PLP-inhibitor adducts formed
nonenzymatically. Conditions: 0.26 mM hydrazino acid 6S, 0.2 mM PLP, 50 mM KPO4 (pH 8.0), scans every 10 min,
isosbestic point = 355 nm, t1/2 = 7 min
(left spectrum); conditions: 0.33 mM aminooxy acid 9S,
0.2 mM PLP, 50 mM KPO4 (pH 8.0), scans recorded every 10
min, isosbestic point = 360 nm, t1/2 =
15 min (right spectrum).