Novel triple mutant of an extremophilic glycosyl hydrolase enables the rapid synthesis of thioglycosides

In order to expand the toolbox of enzymes available for thioglycoside synthesis, we describe here the first example of an extremophilic glycosyl hydrolase from Halothermothrix orenii (HorGH1) engineered towards thioglycosynthase activity with a novel combination of mutations. Using the triple mutant, HorGH1 M299R/E166A/E354G, a range of thioglycosides from glycosyl fluoride donors and aromatic thiols could be synthesised with exquisite stereoselectivity and good to excellent conversions (61-93%).