A New Na super(+)-Dependent RNA-Cleaving DNAzyme with over 1000-fold Rate Acceleration by Ethanol

Enzymes working in organic solvents are important for analytical chemistry, catalysis, and mechanistic studies. Although a few protein enzymes are highly active in organic solvents, little is known regarding nucleic acid-based enzymes. Herein, we report the first RNA-cleaving DNAzyme, named EtNa, that works optimally in concentrated organic solvents containing only monovalent Na super(+). The EtNa DNAzyme has a rate of 2.0h super(-1) in 54% ethanol (with 120mm NaCl and no divalent metal ions), and a K sub(d) of 21mm Na super(+). It retains activity even in 72% ethanol as well as in DMSO. With 4mm Na super(+), the rate in 54% ethanol is >1000-fold higher than that in water. We also demonstrated the use of EtNa to measuring the ethanol content in alcoholic drinks. In total, this DNAzyme has three unique features: divalent metal independent activity, Na super(+) selectivity among monovalent metals, and acceleration by organic solvents. Accelerating science: Whereas organic solvents can denature and precipitate DNA, we report herein a new DNAzyme that is significantly accelerated by solvents. This DNAzyme requires only monovalent sodium ions and shows excellent metal specificity; we demonstrate its application for ethanol measurement in alcoholic drinks.