Cell-surface N-linked glycoconjugates bearing terminal galactose

Cell-surface N-linked glycoconjugates bearing terminal galactose are a class of glycoproteins and glycolipids characterized by the presence of galactose residues at the non-reducing ends of their N-linked oligosaccharide chains. These structures typically arise following the removal of terminal sialic acid residues by neuraminidases, a process known as desialylation, which exposes the underlying galactose (Ashwell & Morell, 1974). In physiological conditions, these terminal galactose moieties serve as critical recognition signals for the asialoglycoprotein receptor (ASGPR) located on hepatocytes, facilitating the rapid clearance of aged or damaged serum proteins from the bloodstream via receptor-mediated endocytosis (D'Souza & Devarajan, 2015). In pathological contexts, such as hepatocellular carcinoma or chronic liver disease, the regulation of these glycoconjugates and their corresponding receptors is often disrupted, making them significant biomarkers for liver function and disease progression (Pinho & Reis, 2015). From a therapeutic perspective, the high affinity and specificity of the ASGPR for terminal galactose and its derivatives, such as N-acetylgalactosamine (GalNAc), have been exploited to develop liver-targeted drug delivery systems. Modern therapeutics, including siRNA-based drugs like Givosiran and Inclisiran, utilize synthetic GalNAc clusters to achieve precise delivery to hepatocytes, minimizing systemic side effects and enhancing therapeutic efficacy (Nair et al., 2014; Springer & Dowdy, 2018).

Other names

AsialoglycoproteinsDesialylated N-glycansTerminal galactosyl residuesGalactose-terminated glycoconjugatesASGPAsialoglycoprotein receptor ligands

Therapeutic agents utilize synthetic mimetics of terminal galactose (such as N-acetylgalactosamine clusters) to target the asialoglycoprotein receptor (ASGPR), facilitating receptor-mediated endocytosis and the specific delivery of payloads to hepatocytes (Nair et al., 2014; Springer & Dowdy, 2018).