氟代糖在糖苷酶研究中的应用

Application of Glycosyl Fluorides in the Study on Glycosidases

近年来，氟代糖应用于糖苷酶反应研究，显示出越来越重要的作用。氟代糖可以作为糖苷酶及其突变酶的水解底物研究酶学性质；氟代糖抑制剂可以标记糖苷酶催化中心，鉴定亲核体氨基酸。尤为重要的是，氟代糖可作为糖苷酶的糖基供体来合成糖类。糖苷酶突变后，可生成糖苷合成酶和硫代糖苷合成酶，可以用与正常底物构型相反的氟代糖作为糖基供体高效合成糖类，收率一般为60％-90％，有的可达100％。糖苷酶及其突变酶以氟代糖为底物高效合成糖类的研究，必将促进生物学、糖生物学和纳米生物材料的发展。

Glycosyl fluorides are becoming increasingly important molecules for the study on glycosidases. Firstly, glycosyl fluorides act as substrates for glycosidases hydrolysis. Scecondly, the installation of fluorine elsewhere on the carbohydrate ring modifies the properties of the glycosyl fluoride so that the resultant compounds act as mechanism-based inhibitors to label enzymes in the active site, allowing identification of the catalytic nucleophile. Furthermore, glycosyl fluorides also act as donors for transglycosylation by retaining glycosides. Finally, glycosyl fluorides of the wrong anomeric configuration could be used by retaining glycosidase mutants such as glycosynthases and thioglycosynthases to synthesize carbohydrate with high yields（ normally 60% ～ 90%）. Fundamental and applied research in biology, glycobiology and nanobiotechnology would benefit from the possibility of synthesizing tailor-made oligo-/poly-saccharides.