For the experiment to observe enzymatic conversion to malate, after the purification procedure, 450 µL of the purified sample was injected into a 5 mm NMR tube containing 10 µL of fumarase enzyme in 150 µL of pH 7 phosphate buffer solution. The NMR tube was immediately inserted into the benchtop magnet for C signal acquisition using 15° flip angle pulses every 7 s to monitor the hyperpolarized NMR signals over time.