LAUSR

AbstractObjectives To characterize a novel membrane-bound d-amino acid dehydrogenase from Proteus mirabilis JN458 (PmDAD).ResultsThe recombinant PmDAD protein, encoding a peptide of 434 amino acids with a MW of 47.7 kDa, exhibited broad substrate specificity with d-alanine the most preferred substrate. The Km and Vmax values for d-alanine were 9 mM and 20 μmol min−1 mg−1, respectively. Optimal activity was at pH 8 and 45 °C. Additionally, this PmDAD generated H2O2 and exhibited 68 and 60% similarity with E. coli K12 DAD and Pseudomonas aeruginosa DAD, respectively, with low degrees of sequence similarity with other bacterial DADs.Conclusionsd-Amino acid dehydrogenase from Proteus mirabilis JN458 was expressed and characterized for the first time, DAD was confirmed to be an alanine dehydrogenase.