Glycoprotein glycans

Carbohydrate ligands on glycoproteins, collectively known as the glycome, consist of diverse N-linked and O-linked oligosaccharide chains that decorate the surface of most secreted and membrane-bound proteins (Varki et al., 2022). These glycans serve as essential recognition elements for lectins and other glycan-binding proteins, mediating critical biological processes such as cell-cell adhesion, immune cell trafficking, and intracellular protein sorting (Moremen et al., 2012). In pathological states, particularly malignancy, glycosylation patterns undergo significant alterations, such as increased branching or sialylation, which contribute to tumor progression, metastasis, and immune evasion (Pinho & Reis, 2015). Therapeutic strategies targeting these carbohydrate ligands include the development of glycan-specific monoclonal antibodies, small molecule inhibitors of glycan-binding receptors (e.g., selectin antagonists), and the use of specific glycan motifs like mannose-6-phosphate for targeted enzyme replacement therapy (Bertozzi & Rabuka, 2009). Despite their potential, targeting glycans remains challenging due to their structural complexity, non-template-driven biosynthesis, and the potential for off-target effects on normal physiological glycosylation (Ohtsubo & Marth, 2006). Furthermore, the heterogeneity of glycan structures on a single protein backbone complicates the development of highly specific therapeutic agents.

Other names

Carbohydrate ligands on glycoproteinsProtein-linked glycansOligosaccharide ligandsTumor-associated carbohydrate antigensTACAs

Inhibition of viral neuraminidase to prevent sialic acid cleavage; Competitive inhibition of selectin-glycan interactions; Targeted delivery via mannose-6-phosphate receptor; Inhibition of glycosylation pathways; Antibody-mediated targeting of tumor-associated carbohydrate antigens (TACAs).