Sugar-assisted ligation for the synthesis of glycopeptides.

Chemical synthesis of glycoproteins from readily available materials is a powerful method for obtaining a pure product with full control of its atomic structure. Sugar-assisted ligation (SAL) is an emerging approach that allows the synthesis of a large glycopeptide from two unprotected fragments. Contrary to other ligation methods that are limited to the use of a cysteine residue or depend on external auxiliary, SAL takes advantage of the existing sugars in glycopeptides to promote proximity between the two peptides to facilitate an amide bond formation.