Determining a novel NAD(+)-dependent amine dehydrogenase with a broad substrate range from Streptomyces virginiae IFO 12827: purification and characterization

A novel NAD(+)-dependent amine dehydrogenase (AMDH) was screened from serin ol-assimilating microorganisms and type cultures using a serinol as a subst rate. The newly found enzyme from Streptomyces virginiae IFO 12827 was stri ctly dependent on NAD(+) or NADH, and did not require artificial electron a cceptors such as phenazine methosulfate (PMS), on which all the previously reported AMDHs acted. The enzyme was purified from the cell-free extract of S. virginiae cells to homogeneity by a six-step purification procedure. Th e enzyme had a homodimeric structure consisting of 46 kDa subunits. It cata lyzed the reversible oxidative deaminations of not only amines but also ami no alcohols and amino acids. The production of 2-amino-1-propanol and aspar tic acid by the reductive amination of the corresponding keto alcohol and k eto acid in the presence of ammonium ions and NADH, and that of acetophenon e from phenethylamine by the oxidative deamination in the presence of NADwere confirmed by the AMDH reactions. (C) 2000 Elsevier Science B.V. All ri ghts reserved.