“Kinetic studies at various concentrations … inhibition by magnesium and spermine was … 2‐oxoglutarate concentrations less than 0.5 mM and NADH levels less than 0.08 mM. The presence of the … accentuated the inhibitory effect of high concentrations of 2‐oxoglutarate (>2.0 mM) and NADH (>0.32 mM).”