ABSTRACT
This chapter presents the birth of glycobiology and to glycoproteins. The biological importance of glycoconjugates in general, and of glycoproteins in particular, was demonstrated through a series of crucial discoveries which pointed to the biological roles of glycans giving birth to the concept of molecular biology of glycoconjugates, that is, to glycobiology. Because of the presence in the molecule of hydroxylic and carboxylic hydrophilic functions, glycans contribute to an increase in the solubility of glycoproteins as proved by the observed decrease of solubility after enzymatic removal of most or all glycoprotein glycans. Glycans are related to immune response through both glycoprotein antigenicity and immunogenicity. Glycans may also contribute indirectly to glycoprotein antigenicity by masking peptidic epitopes by a “shield effect” identical to that implicated in the protection of peptide against proteolytic attack. Glycans often intervene in the folding of proteins during their biosynthesis.
