Purification and characterization of aminobutyraldehyde dehydrogenase from Arthrobacter Sp. TMP-1.

Aminobutyraldehyde dehydrogenase was purified to essentially homogeneity from putrescine-grown cells of Arthrobacter sp. TMP-1. The molecular weights of the enzyme and its subunit were 201,000 and 51,000, respectively, suggesting that the enzyme is a tetramer of identical subunits. The apparent Michaelis constants (K(m)) for 4-aminobutyraldehyde, 3-aminopropionaldehyde and 4-guanidinobutyraldehyde were approximately 65, 150, and 85 microM, respectively. Linear fatty aldehydes also tested were less active as a substrate, while the tested succinate-semialdehyde and branched fatty aldehydes were inert. The enzyme utilized both NAD(+) and NADP(+) as coenzymes. The optimum pH was 8.0. The enzyme lost 64% of its activity when held at 40 degrees C for 10 min.