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

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 (K-m) for 1,3-diaminopropane was approximately 3 muM The enzyme equally used both NAD(+) and NADP(+) as coenzymes. The apparent K-m values for NAD(+) and NADP(+) were 255 muM and 108 muM. respectively. The maximum reaction rates (V-max) NAD(+) and NADP(+) were 102 and 83.3 mu mol 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. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.