Figure 4. Enzymatic kinetics followed by metabolomics.

Pseudo 3D plots of CBS and CSE enzymatic kinetics. The data are presented as pseudo 3D plots where the first increment of ¹³C HSQC spectra is plotted along the x (F2) and y axes. Time is plotted on the third axis. The first spectrum was obtained ~2 min after the addition of the enzyme, and subsequently 59 spectra were collected over a 300 min period. Kinetics of control isolated CBS (A) and CSE (B). Time course of CBS (C) and CSE (D) in the presence of compound 2a (250 μM). Disappearance of the resonance at 3 ppm testifies conversion of L-cysteine to L-cystathionine by CBS and to pyruvate by CSE. The spectra were recorded at 800 MHz and 37 °C using L-Cys concentrations of 250 μM. Enzyme concentrations of 20 μM.