Tanaka H, Tanizawa K, Arai T, Saito K, Arai T, Soda K
FEBS Lett. 1986 Feb 17;196(2):357-60. doi: 10.1016/0014-5793(86)80279-4.
The tryptophan synthase alpha 2 beta 2 complex from Escherichia coli has been found to catalyze the beta-replacement reaction of L-serine with indazole, an indole analog which has a nitrogen atom at the 2-position (pyrazole ring). The reaction product was isolated and identified as beta-indazolealanine by mass spectrometric, elemental and NMR analyses. Careful assignment of 1H- and 13C-signals with several NMR techniques revealed that the beta-carbon of the product alanine moiety was bound to the 1-N-position of the indazole ring. This is the first example of the beta-replacement reaction catalyzed by tryptophan synthase occurring at any other position than the 3-position of indole analogs.
已发现来自大肠杆菌的色氨酸合成酶α2β2复合物可催化L-丝氨酸与吲唑的β-取代反应，吲唑是一种在2位（吡唑环）具有氮原子的吲哚类似物。通过质谱、元素分析和核磁共振分析对反应产物进行分离并鉴定为β-吲唑丙氨酸。使用多种核磁共振技术对1H和13C信号进行仔细归属，结果表明产物丙氨酸部分的β-碳与吲唑环的1-N位相连。这是色氨酸合成酶催化的β-取代反应在吲哚类似物的3位以外的任何其他位置发生的首个实例。
