Very High Concentration Solubility and Long-Term Stability of DNA in an Ammonium-Based Ionic Liquid: A Suitable Medium for Nucleic Acid Packaging and Preservation
Nripat Singh, Mukesh Sharma, Dibyendu Mondal, Matheus M. Pereira, Kamalesh Prasad
ACS Sustainable Chemistry & Engineering
Packaging as well as preservation of DNA in nonaqueous media at ambient conditions for long durations is an important research endeavor considering the biomacromolecule as nanoscale substrate for functional biomaterial design and for biotechnological applications. From this perspective, the present work reports both very high concentration dissolution and packaging of DNA in an ionic liquid (IL) without affecting the structural integrity of the biopolymer upon long-term storage. 2-Hydroxyethylammonium formate (2-HEAF), which is an ammonium based IL was able to solubilize 25% w/w of DNA (salmon testes) within 12 h at 25 °C. The solubilized DNA in the IL showed long-term chemical and structural stability upon storage under ambient conditions for more than 1 year, which makes the IL a suitable medium for nucleic acid preservation. From isothermal calorimetric (ITC) studies it was evident that the hydrogen bond formed between the IL and DNA was responsible for the high concentration solubility and extended stability, unlike earlier observations for choline based ILs, where both the electrostatic interactions and hydrogen bond were collectively found to be responsible for the phenomenon. Upon auto DNA docking analyses, higher preference for minor-groove over major-groove binding on DNA structure was observed for the IL, and it showed strong ability to promote hydrogen bonding with nucleic acids.
Circular dichroism, DNA structure, Chemical stability, Biochemistry