RT Journal Article SR Electronic(1) A1 Yamamoto, Shigeo A1 Tsuzaki, Yukari A1 Tougou, Katsuhiko A1 Shinoda, SumioYR 1992 T1 Purification and characterization of L-2,4-diaminobutyrate decarboxylase from Acinetobacter calcoaceticus JF Microbiology, VO 138 IS 7 SP 1461 OP 1465 DO https://doi.org/10.1099/00221287-138-7-1461 PB Microbiology Society, SN 1465-2080, AB Acinetobacter calcoaceticus ATCC 23055 produces a large amount of 1,3-diaminopropane under normal growth conditions. The enzyme responsible, L-2,4-diaminobutyrate (DABA) decarboxylase (EC 4.1.1.-), was purified to electrophoretic homogeneity from this bacterium. The native enzyme had an M r of approximately 108000, with a pl of 5.0, and was a dimer composed of identical or nearly identical subunits with apparent M r 53000. The enzyme showed hyperbolic kinetics with a K m of 1.59 mM for DABA and 14.6 μM for pyridoxal 5'-phosphate as a coenzyme. The pH optimum was in the range 8.5–8.75, and Ca2+gave a much higher enzyme activity than Mg2+as a cationic cofactor. N-γ-AcetyIDABA, 2,3-diaminopropionic acid, ornithine and lysine were inert as substrates. The enzyme was different in subunit structure, N-terminal amino acid sequence and immunoreactivity from the DABA decarboxylase of Vibrio alginolyticus previously described., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-138-7-1461