Bacillus cereus strain 10-L-2 produces two arylamine N-acetyltransferases that transform 4-phenylenediamine into 4-aminoacetanilide.
A bacterium, strain 10-L-2, that was isolated from soil and identified as Bacillus cereus grew well on medium containing 4-phenylenediamine and Polypepton. Strain 10-L-2 converted a wide variety of anilines, including 4-phenylenediamine, to their corresponding acetanilides. Growing cells acetylated a single amino group of 4-phenylenediamine to form 4-aminoacetanilide with a 97% molar yield, as shown by mass spectrometry and HPLC. Cell extracts exhibited arylamine N-acetyltransferase (NAT) activity toward 4-phenylenediamine. Two NATs, namely, NAT-a and NAT-b, were separated by DE52 column chromatography and were further purified and characterized. The subunit molecular masses of NAT-a and NAT-b were 31.0 and 27.5 kDa, respectively, as determined by SDS-PAGE analysis. The two enzymes had similar pH- and thermo-stabilities and were similarly affected by pH, temperature, and several reagents. The enzymes showed peak activity toward 5-aminosalicylic acid of the substrates tested, but they differed in substrate specificity. Only NAT-a had activity toward sulfamethazine. Although other wild-type bacterial cultures also synthesize NAT, the ability of strain 10-L-2 to convert and detoxify 4-phenylenediamine is much higher. This report provides the first evidence of two NATs in a eubacterium.
Mulyono
Department of Biosystems Science, Division of Biosystems Chemistry, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
Takenaka
Shinji
S
Sasano
Yasuhiro
Y
Murakami
Shuichiro
S
Aoki
Kenji
K
D000083:Acetanilides / Q000378:metabolism*; D000595:Amino Acid Sequence; D000814:Aniline Compounds / Q000737:chemistry / Q000378:metabolism; D001191:Arylamine N-Acetyltransferase / Q000737:chemistry* / Q000302:isolation & purification; D001409:Bacillus cereus / Q000201:enzymology* / Q000302:isolation & purification; D001711:Biotransformation; D008969:Molecular Sequence Data; D010655:Phenylenediamines / Q000737:chemistry* / Q000378:metabolism; D013379:Substrate Specificity
D000083:Acetanilides; D000814:Aniline Compounds; D010655:Phenylenediamines; D001191:Arylamine N-Acetyltransferase; C519644:4-aminoacetanilide; C023650:aniline; C029728:4-phenylenediamine