N-linked terminal galactose residues on cell-surface glycans (Terminal Gal)

N-linked terminal galactose residues are carbohydrate structures found at the distal ends of N-glycan chains on cell-surface and secreted glycoproteins. These residues are typically masked by terminal sialic acids; their exposure, often termed desialylation, serves as a key biological signal for protein turnover and cell-cell interactions (Stockert, 1995). The primary physiological receptor for these residues is the Ashwell-Morell receptor (asialoglycoprotein receptor, ASGPR) located on hepatocytes, which facilitates the endocytosis and degradation of desialylated proteins (Ashwell & Harford, 1982). In pathological contexts, such as cancer, aberrant glycosylation leads to the overexposure of terminal galactose, which can promote metastasis by interacting with galectins or facilitate immune evasion (Pinho & Reis, 2015). From a pharmacological perspective, terminal galactose residues are targeted for liver-specific drug delivery systems and are the binding targets for potent toxins like ricin, as well as various diagnostic lectins (Lord et al., 2003).

Other names

Terminal beta-galactoseAsialoglycansGalactose-terminated N-glycansTerminal Gal residuesAsialoglycoprotein receptor ligand

Binding to asialoglycoprotein receptors (ASGPR) for hepatic clearance, or interaction with galectins to modulate cell signaling and adhesion (Stockert, 1995; Johannes et al., 2018).