Selection of structure-induced aptamer targeting small molecule based on capillary sieving electrophoresis

In this study, a structure-induced aptamer targeting small molecules was selected using capillary sieving electrophoresis (CSE). CSE was conducted using a capillary filled with a background solution containing hydroxypropyl cellulose as a sieving matrix to separate the aptamer candidates by changing their structures via complexation. Before aptamer selection, the original random-sequence DNA library was used to create structure-not-preorganized DNA sub-library containing straight-chain-like structures using CSE. Next, a structure-induced aptamer targeting l-tyrosinamide was selected from the prepared sub-library. Six aptamer candidates were selected, one of which showed a binding ability comparable to that of the reported l-tyrosinamide aptamer and selectivity toward the analogs. These results indicated that the proposed method can be applied to select structure-induced aptamers that target small molecules.