Objectives: To characterize a novel membrane-bound D -amino acid dehydrogenase from Proteus mirabilis JN458 (PmDAD).
Results: The 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 K m and V max 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.
Conclusions: D-Amino acid dehydrogenase from Proteus mirabilis JN458 was expressed and characterized for the first time, DAD was confirmed to be an alanine dehydrogenase.
Keywords: Characterization; D -amino acid; D -amino acid dehydrogenase; Proteus mirabilis.