Effect of 3'-end capping of aptamer with various 2',4'-bridged nucleotides: Enzymatic post-modification toward a practical use of polyclonal aptamers.

The capping of the 3'-ends of thrombin binding aptamers (TBAs) with bridged nucleotides increased the nuclease resistances and the stabilities in human serum. The binding abilities of the aptamers were not affected by the capping. The capping could be simply executed via a one step enzymatic process using 2',4'-bridged nucleoside 5'-triphosphate and terminal deoxynucleotidyl transferase.