RNA aptamer as a molecular switch and its application
2004. 10. 12
RNA aptamer having high affnity and specificity about target molecules could be used for variable analytic application. Especially, molecular switch and sensor was developed through aptamer modification and novel design by FRET assay and electro chemical method. Complex of aptamer and ribozyme, aptazyme was used as the tool for the detection of protein without separation procedures. This molecule had high affinity for Hepatitis C virus (HCV) polymerase and HCV helicase and the increase of catalytic activity by target molecule is measured by the FRET assay. We designed allosteric ribozyme for the detection of HCV replicase and helicase using the part of aptamer binding site and the multi sensor system that could detect both HCV replicase and helicase with only one allosteric ribozyme. This multi sensor could detect not only single target but also multi targets. The catalytic activity was ~2-fold higher than one target ribozyme.
And we used the RNA aptamer instead of generally used antibody as ligand for affinity chromatography in a microchip. Oligonucleotides, RNA or DNA are more stable than protein under room temperature and site specific modification is possible on beads since oligonucleotides can be modified by tailing reaction. And photolabile linkers sensitive to UV radiation was introduced with aptamers on beads so the bound target proteins was eluted by 330nm UV radiation. Through miniaturized microfluidic affinity chromatography (BAC) system using aptamers, rather mild elution condition was applied without harsh conditions which is normally used for conventional affinity chromatography.
For protein detection by electrochemical method, we detected the thrombin specifically using aptamer with electroredox molecule, methylen blue.In this study, we introduced the variable appllication using aptamers for detection and analysis and our result showed their potential ability as RNA sensor and molecular probe for diagnosis.
1989 Ph D. Cornell University
1982 M.S. Seoul National Unviersity