Terminal galactose on cell-surface glycans (Terminal Gal)

Terminal galactose refers to a galactose monosaccharide residue located at the non-reducing end of a glycan chain attached to proteins or lipids on the cell surface. These residues serve as critical recognition epitopes for various endogenous glycan-binding proteins, most notably the galectin family and the asialoglycoprotein receptor (ASGPR) [1.2.2, 1.5.1]. In healthy physiology, terminal galactose plays a vital role in cell adhesion, immune signaling, and the regulation of glycoprotein half-life and stability [1.3.1, 1.5.3]. Pathological alterations in galactosylation, such as the loss of terminal galactose on the Fc region of IgG (the G0 glycoform), are established biomarkers for chronic inflammatory conditions like rheumatoid arthritis [1.2.3, 1.3.2]. In oncology, terminal galactose residues on tumor-associated glycans are often exploited by cancer cells to facilitate metastasis and immune evasion through interactions with galectins [1.2.1, 1.4.2]. Therapeutic strategies targeting this molecule include the use of galectin inhibitors to block pathological binding and the development of galactose or N-acetylgalactosamine (GalNAc) conjugates for liver-specific drug delivery [1.4.3, 1.5.1].

Other names

Non-reducing terminal galactoseTerminal beta-galactosyl residueGalactose-terminated glycansTerminal Gal

Inhibition of galectin-3 binding to terminal galactose residues to prevent fibrosis and immune evasion; ASGPR-mediated endocytosis for targeted delivery of galactose/GalNAc-conjugated therapeutics; and glycoengineering of monoclonal antibodies to enhance effector functions like ADCC and CDC.