CARBOHYDRATE-CARBOHYDRATE INTERACTION INVOLVED IN CELL RECOGNITION AND ADHESION

摘要

Recent advances in glycobiology revealed the existence of biologically significant carbohydrate-carbohydrate interactions, and this type of interaction could have a general, fundamental character for cell biology. A typical example is the report of Hakomori who proposed that carbohydrate-carbohydrate interaction is responsible for the initial step of cell adhesion. Embryogenesis, metastasis, and other proliferation processes are, according to Hakomori, mediated by carbohydrate-carbohydrate interactions. One of the structures involved in this novel mechanism is the Lewis~x trisaccharide determinant (Galβ1->4[Fucal->3]GlcNAcβ1). The Lewis~x antigen - previously defined as the Stage-Specific Embryonic Antigen 1 (SSEA-1) - is found in a wide variety of system such as human cancers, pre-implantation mouse embryos, embryonic carcinoma cells, and human erythrocytes. Characteristic features of carbohydrate-carbohydrate interactions are a strong dependency on divalent cations (such as Ca~(2+)), a variable specificity, and an extremely low affinity that is compensated in nature by a multivalent presentation of the carbohydrate ligands at the cell surface.