In vitro selection of aptamers that recognize a monosaccharide

Attempts, were made to obtain RNAs that can bind to monosaccharides (galactose, glucose, and mannose) by in vitro selection. As a result, an RNA library that can bind to galactose with outstanding affinity has been obtained. Furthermore, the library was able to distinguish galactose from other monosaccharides, though they have closely similar structures. After another selection in order to obtain fast binders, a selected library tightly bound to galactose was obtained but it lost selectivity to galactose. This selectivity seemed to be derived from hydrogen bond geometry with the epimeric hydroxyl groups of monosaccharides. The results show an ability of RNAs to recognize any small molecule which consists of only carbon, hydrogen and oxygen.