Open Accessl ‐2,4‐diaminobutyric acid decarboxylase activity responsible for the formation of 1,3‐diaminopropane in Enterobacter aerogenes
Author(s) -
Nakao Hiroshi,
Takeuchi Keiko,
Shinoda Sumio,
Yamamoto Shigeo
Publication year - 1990
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1990.tb03778.x
Subject(s) - enterobacter aerogenes , spermidine , enzyme , dithiothreitol , biochemistry , ornithine , ornithine decarboxylase , enzyme assay , substrate (aquarium) , pyridoxal phosphate , polyamine , biology , specific activity , chemistry , lysine , stereochemistry , amino acid , arginine , escherichia coli , cofactor , ecology , gene
High content of l ‐2,4‐diaminopropane (DAP), a normally minor derivative of polyamine metabolism, have been observed in cells of Enterobacter aerogenes . Supplementation of the growth medium with l ‐2,4‐diaminobutyric acid (L‐DABA) resulted in increased production of DAP, but not if supplemented with spermidine. On the basis of these observations, the biosynthetic route for DAP was evaluated. It has appeared that this bacterium possesses a novel enzyme activity catalysing the formation of DAP from L‐DABA. Lack of the activity for oxidative cleavage of spermidine yielding DAP suggests that the enzyme termed DABA decarboxylase in responsible for the formation of DAP in this bacterium. The enzyme was partially purified 360‐fold and some properties were examined. The pH optimum for the activity was 7.75–8.0, and the enzyme showed an absolute requirement for pyridoxal 5′‐phosphate with the K m value of 41 μM. The K m value for L‐DABA was 0.32 mM, and neither l ‐2,4‐diaminopropionic acid, l ‐ornithine nor l ‐lysine showed detectable substrate activity towards the partially purified enzyme. Mg 2+ and dithiothreitol greatly activated the enzyme.