DNA LIGANDS THAT BIND TIGHTLY AND SELECTIVELY TO CELLOBIOSE

Cell surface oligosaccharides have been shown to play essential biolog ical roles in such diverse biological phenomena as cellular adhesion, molecular recognition, and inflammatory response. The development of h igh-affinity ligands capable of selectively recognizing a variety of s mall motifs in different oligosaccharides would be of significant inte rest as experimental and diagnostic tools, As a step toward this goal we have developed DNA ligands that recognize the disaccharide cellobio se, whether in soluble form or as the repeating unit of the polymer, c ellulose. These DNA ''aptamers'' bind with high selectivity to cellobi ose with little or no affinity for the related disaccharides lactose, maltose, and gentiobiose. Thus, the DNA ligands can discriminate sugar epimers, anomers, and disaccharide linkages.