Selection of DNA aptamers that inhibit enzymatic activity of PQQGDH and its application.

We screened DNA aptamers against the water-soluble quinoprotein glucose dehydrogenase (PQQGDH) with a competitive selection method. PQQGDH is a dimeric enzyme that consists of 50-kDa subunits, and has high catalytic activity for glucose (about 5000 U/mg), therefore is used for glucose sensors in the market. PQQGDH is an excellent molecular recognition device for biosensor for diagnosis. The SELEX was performed using a competitive selection method which enables us to select aptamer having high specificity for a target molecule. After 6 rounds screening, we obtained 2 aptamers which bind to PQQGDH with high affinity and specificity. One aptamer inhibited PQQGDH activity. In addition, we constructed a dimer aptamer linked by linker sequences expecting high affinity compared to the monomer aptamer. As the result of Aptamer Blotting, the dimer aptamer showed higher affinity than the monomer.