A glycoprotein is a protein molecule bearing one or more covalently attached carbohydrate chains, termed glycans. The protein component provides the polypeptide scaffold, while the glycan component consists of monosaccharide residues joined through specific glycosidic linkages and assembled at defined amino-acid sites or within particular protein regions. Protein glycosylation generates major classes of glycoproteins through N-linked glycans attached to asparagine residues, O-linked glycans attached to hydroxyl-containing amino acids such as serine or threonine, and additional linkage types including C-mannosylation and glycosylphosphatidylinositol-associated protein modification ^[1][2]. Glycan assembly is mediated by glycosyltransferases and glycosidases and occurs through compartmentalized biosynthetic pathways, especially in the endoplasmic reticulum and Golgi apparatus of eukaryotic cells ^[2][3]. A glycoprotein population may contain multiple glycoforms because glycan occupancy, monosaccharide composition, linkage, branching, and terminal modifications can vary among molecules bearing the same polypeptide sequence ^[1][4].