Bacillus cereus strain 10-L-2 produces two arylamine N-acetyltransferases that transform 4-phenylenediamine into 4-aminoacetanilide
Bacillus cereus strain 10-L-2 produces two arylamine N-acetyltransferases that transform 4-phenylenediamine into 4-aminoacetanilide
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DOI：
10.1263/jbb.103.147
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发表时间：
2007-02-01
影响因子：
2.8
通讯作者：
Aoki, Kenji
中科院分区：
文献类型：
--
作者：
Mulyono;Takenaka, Shinji;Aoki, Kenji
从土壤中分离到一株蜡样芽孢杆菌（Bacilluscereus），命名为10-L-2，能在含有4-苯二胺和聚蛋白胨的培养基上生长。菌株10-L-2将多种苯胺（包括4-苯二胺）转化为它们相应的乙酰苯胺。生长中的细胞乙酰化4-苯二胺的单个氨基形成4-氨基乙酰苯胺，摩尔产率为97%，如质谱和HPLC所示。细胞提取物对4-苯二胺表现出芳胺N-乙酰转移酶（NAT）活性。经DE 52柱层析分离得到两种NAT，即NAT-a和NAT-b，并对其进行了纯化和表征。经SDS-PAGE分析，NAT-a和NAT-b的亚基分子量分别为31.0和27.5kDa。这两种酶具有相似的pH和热稳定性，并且受pH、温度和几种试剂的影响相似。酶对5-氨基水杨酸的底物测试显示出峰值活性，但他们在底物特异性不同。只有NAT-a对磺胺二甲嘧啶有活性。虽然其他野生型细菌培养物也合成NAT，但菌株10-L-2转化和解毒4-苯二胺的能力要高得多。这份报告提供了真细菌中存在两个NAT的第一个证据。
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.