Evolved Thermostable Transketolase for Stereoselective Two-Carbon Elongation of Non-Phosphorylated Aldoses to Naturally Rare Ketoses
作者:Marion Lorillière、Romain Dumoulin、Mélanie L’enfant、Agnès Rambourdin、Vincent Thery、Lionel Nauton、Wolf-Dieter Fessner、Franck Charmantray、Laurence Hecquet
DOI:10.1021/acscatal.9b01339
日期:2019.6.7
TKgst for conversion of two tetroses (d-threose, l-erythrose), two pentoses (d-xylose, d-ribose), and two hexoses (d-allose, d-glucose), respectively. These six Cn aldoses as acceptor and HPA as donor substrates were transformed by the TKgst variants at 60 °C with practically complete conversion. The corresponding Cn+2 ketoses, including two hexuloses (d-tagatose, l-psicose), two heptuloses (d-altro-heptulose
我们建议使用羟基丙酮酸(HPA)作为一种步骤,一步一步地将非磷酸化醛糖(C 4 –C 6)的碳原子延伸成相应的C n +2酮糖(C 6 –C 8)的一种环保,高效,立体选择性的方法。酮醇供体底物和来自嗜热脂肪热地芽孢杆菌(TK gst)的演化的热稳定转酮醇酶作为生物催化剂。与野生型TK gst相比,TK gst活性位点中两个或三个关键位置的同时位点饱和诱变(SSM)产生了有效的变体L382F / F435Y,R521Y / S385 / H462N和R521V / S385D / H462S。用于分别转化两个四糖(d-苏糖,l-赤藓糖),两个戊糖(d-木糖,d-核糖)和两个己糖(d-阿洛糖,d-葡萄糖)。这六种C n醛糖为受体,HPA为供体底物,在60°C被TK gst变体转化,几乎完全转化。相应的C n +2酮糖,包括两个己糖(d-塔格糖,l-庚糖),两个庚糖(d-硝基-庚糖,d - i