Characterization of N-acetyltransferase that can catalyze enantio-selectively acetylation of chiral amines.

光学活性d -2-苯甘氨酸用于合成半合成抗生素和农药的需求日益增加。本文报道了一株黄杆菌属细菌的分离，该细菌在最佳培养条件下选择性地将l型外消旋D， l -2-苯基甘氨酸转化为(2S)-2-乙酰酰胺-2-苯基乙酸，摩尔产率为49.9%，对映体过量为>99.5%，从而使培养物中保留99.0%的D-2-苯基甘氨酸纯度。对映选择性n -乙酰化反应由依赖于乙酰辅酶a的n -乙酰转移酶催化，该酶的合成由l- 2-苯基甘氨酸诱导。该酶与先前报道的细菌芳胺n -乙酰转移酶在分子质量和底物特异性上有所不同。该酶与底物l -2-苯基甘氨酸、d -2-苯基甘氨酸、2-（2-氯苯基）甘氨酸和5-氨基水杨酸（芳香胺n -乙酰基转移酶的良好底物）的相对活性比分别为100:0:56:5.49。本文报道的产n -乙酰转移酶细菌的生物转化为D， l -2-苯基甘氨酸的酶解制备提供了一条新的途径。我们克隆了黄杆菌5-3B的n -乙酰基转移酶编码基因，该基因与推测的黄杆菌ATCC35910和黄细菌的n -乙酰基转移酶高度同源。CF314。

The demand for optically active D-2-phenylglycine used to synthesize semisynthetic antibiotics and pesticides has been increasing. Here we report the isolation ofa bacterium of the genus Chryseobacteriumthat selectively transformed the L-form of racemic D,L-2-phenylglycine to (2S)-2-acetylamide-2-phenylacetic acid with a molar yield of 49.9%and an enantiomer excess of >99.5% under optimal culture conditions, consequently resulting in 99.0% pure D-2-phenylglycine remaining in the culture. The enantioselective N-acetylation was catalyzed by an acetyl-CoA-dependent N-acetyltransferase whose synthesis was induced by L-2-phenylglycine. The enzyme differed from previously reported bacterial arylamine N-acetyltransferase in molecular mass and substrate specificity. The relative activity ratio of the enzyme with the substrates L-2-phenylglycine, D-2-phenylglycine, 2-(2-chlorophenyl)glycine, and 5-aminosalicylic acid (a good substrate of arylamine N-acetyltransferase) was 100:0:56.9:5.49, respectively. The biotransformation by the N-acetyltransferase-producing bacterium reported here could constitute a new preparative route for the enzymatic resolution of D,L-2-phenylglycine. We cloned the gene encoding N-acetyltransferase of Chryseobacterium sp. 5-3B which showed high identity with putative N-acetyltransferases of Chryseobacteriumgleum ATCC35910 and Chryseobacteriumsp. CF314.