Enzymatic glycosyl transfer: mechanisms and applications

Glycosylated compounds have numerous applications in the food, pharmaceutical and personal care industries. Their synthesis is, however, far from trivial. Because chemical glycosylation reactions suffer from low yields and lack of selectivity, biocatalytic routes have received increasing attention as efficient and 'green' alternatives. Several types of biocatalysts can be used for this purpose, each with its own advantages and disadvantages. The applications of glycoside hydrolases, glycoside phosphorylases, transglycosidases and glycosyl transferases are discussed in light of the most recent insights into the mechanistic features of the enzymes. A thorough understanding of their structure function relationships should also allow a more efficient engineering of the activity and specificity of these enzymes. Several strategies to enhance the glycosylation potential of natural biocatalysts are presented