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

Terminal galactose residues are carbohydrate motifs located at the distal ends of N-linked glycan chains attached to cell-surface proteins. These residues typically become exposed following the removal of terminal sialic acids, a process known as desialylation, which serves as a critical biological signal for the aging or degradation of glycoproteins (Ashwell & Morell, 1974; PMID: 4591314). In the liver, these residues are specifically recognized and bound by the asialoglycoprotein receptor (ASGPR), facilitating the endocytosis and clearance of the protein from circulation (Stockert, 1995; PMID: 7615615). In oncology, aberrant glycosylation often leads to the overexposure of terminal galactose, which can influence cell adhesion, promote metastasis, or serve as a marker for malignant transformation (Pinho & Reis, 2015; PMID: 25708244). From a pharmacological perspective, terminal galactose is exploited as a targeting ligand for liver-specific drug delivery, allowing for the concentrated uptake of therapeutic agents like oligonucleotides, chemotherapeutics, or imaging agents into the liver parenchyma (D'Souza & Devarajan, 2015; PMID: 25595356).

Other names

Terminal beta-galactosyl residuesGalactose-terminated N-glycansAsialoglycansExposed galactose epitopesNon-sialylated N-linked glycans

Targeted delivery and cellular uptake via binding to the asialoglycoprotein receptor (ASGPR) on hepatocytes, leading to receptor-mediated endocytosis of the therapeutic payload.