Glycosylation of Recombination Proteins - Problems and Prospects

Glycosylation, the addition of sugar residues to a peptide backbone, is the most extensive posttranslational modifica- tion made to proteins by eukaryotic cells. The majority of recombinant proteins manufactured for human therapy are glycoproteins derived from animal cells, and it is essential to fully characterize and, if possible, control the glycosylation profile of these products. Indeed, the Food and Drug Ad- ministration (FDA) in the United States and the Commit- tee for Proprietary Medical Productions (CPMP) of the European Community are demanding increasingly sophis- ticated carbohydrate analysis on all new glycoproteins des- tined for human therapy.

A complete survey of protein glycosylation is beyond the scope of this article, and the reader is referred to the excel- lent reviews recently published on glycoprotein biosyn- thesis, 2-7 regulation of biosynthetic pathways, 1,8-13 biolog- ical functions of glycan structures, 1.14-19 and glycoprotein analysis. 2°-29 This review will focus on the aspects of glyco- protein research that are of direct relevance to the biotech- nology industry, i.e., the reasons and methods for defining the glycosylation patterns of recombinant glycoproteins