Analytical Sciences

Abstract − Analytical Sciences, 24(1), 167 (2008).

Arginine-modified DNA Aptamers That Show Enantioselective Recognition of the Dicarboxylic Acid Moiety of Glutamic Acid
Kazuomi OHSAWA,* Toshiyuki KASAMATSU,* Jun-ichi NAGASHIMA,* Kazuo HANAWA,* Masayasu KUWAHARA,*,** Hiroaki OZAKI,* and Hiroaki SAWAI*
*Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Gunma 376-8515, Japan
**PRESTO, Japan Science and Technology Agency (JST), Chiyoda, Tokyo 102-0075, Japan
We have screened glutamic acid-binding aptamers from a modified DNA pool containing arginine residues using the method of systematic evolution of ligands by exponential enrichment (SELEX). Thirty-one modified DNA molecules were obtained from the enriched pool after the 17th round of selection, and their binding affinities for the target were evaluated by binding assays using affinity gels. Three modified DNA molecules having higher affinity were sequenced and we determined their affinity and specificity for the target by surface plasmon resonance (SPR) measurements. The SPR studies indicated that two of these three aptamers distinguished the dicarboxylic acid moiety of the D-isomer from that of the L-isomer; however, the third aptamer did not show enantioselectivity.