Carbohydrate (CHO) structures on a cell surface serves as interaction sites between cells and their environment. Cellular carbohydrate-binding proteins such as lectins bind to specific CHO to facilitate cell-cell contact. Lectins commonly have 2 or more CHO binding sites that can form oligomeric structures.
Sugar-Immobilized Gold Nano-Particles (SGNP) is structurally defined sugar chains bound to a gold bead. The SGNP mimic CHO on a cell surface. Carbohydrate-binding proteins with multiple receptors sites attach to several SGNPs forming an aggregate of particles giving an appearance of a precipitation that can be visually observed. Carbohydrate-protein interactions are reversible allowing easy retrieval of the protein for further characterization.
