Chemical Deglycosylation of Glycoproteins

Deglycosylation of glycoproteins is necessary for a number of studies such as in the structural determination of polypeptide chains, establishment of structure and function relationships of carbohydrates, 1-5 and their biosynthesis in glycoproteins. In all these studies it is important that the conditions used for chemical deglycosylation do not cause an impairment of the physicochemical integrity of the polypeptide chain. Two chemical reagents in the anhydrous form, trifluoromethanesulfonic acid (TFMS) and hydrogen fluoride (HF), have been employed for the deglycosylation of glycoproteins. TFMS by the modified procedure described herein is definitely superior to HF. It is much more potent, sensitive, convenient to use than HF because it does not require any special handling. To prevent any secondary reactions such as the alkylation of the polypeptide chains during deprotection of the protecting group, the use of anisole was made as a scavenger. This chapter discusses the chemical deglycosylation procedure by TFMS and HF in detail.