Purification and characterization of aminopropionaldehyde dehydrogenase from Arthrobacter sp. TMP-1

Abstract Aminopropionaldehyde dehydrogenase was purified to apparent homogeneity from 1,3-diaminopropane-grown cells of Arthrobacter sp. TMP-1. The native molecular mass and the subunit molecular mass of the enzyme were approximately 205 000 and 52 000, respectively, suggesting that the enzyme is a tetramer of identical subunits. The apparent Michaelis constant (Km) for 1,3-diaminopropane was approximately 3 μM. The enzyme equally used both NAD+ and NADP+ as coenzymes. The apparent Km values for NAD+ and NADP+ were 255 μM and 108 μM, respectively. The maximum reaction rates (Vmax) for NAD+ and NADP+ were 102 and 83.3 μmol min−1 mg−1, respectively. Some tested aliphatic aldehydes and aromatic aldehydes were inert as substrates. The optimum pH was 8.0–8.5. The enzyme was sensitive to sulfhydryl group-modifying reagents.