Glycosidases and glycosynthases in enzymatic synthesis of oligosaccharides. An overview

Retaining glycosidases have been extensively studied for the synthesis of oligosaccharides and glycoconjugates as a convenient enzymatic approach to achieve the required regio- and stereoselectivity in glycoside bond formation as compared to chemical methods which require tedious protection, activation and deprotection steps. This paper reviews the different methodologies developed for enzymatic synthesis of glycoconjugates: classical transglycosylation reactions catalyzed by wild-type glycosidases outlining the recent developments in reaction conditions technology, and novel glycosynthases, engineered glycosidases lacking hydrolytic activity but efficiently catalyzing condensation reactions that are emerging as promising tools in the field.