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Can A Denaturant Stabilize DNA? Pyridine Reverses DNA Denaturation in Acidic pH
Author(s) -
Portella Guillem,
Terrazas Montserrat,
Villegas Núria,
González Carlos,
Orozco Modesto
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201503770
Subject(s) - chemistry , dna , pyridine , stacking , ionic strength , solvent , nucleobase , osmolyte , denaturation (fissile materials) , base pair , nuclear magnetic resonance spectroscopy , crystallography , biophysics , stereochemistry , organic chemistry , biochemistry , aqueous solution , nuclear chemistry , biology
The stability of DNA is highly dependent on the properties of the surrounding solvent, such as ionic strength, pH, and the presence of denaturants and osmolytes. Addition of pyridine is known to unfold DNA by replacing π–π stacking interactions between bases, stabilizing conformations in which the nucleotides are solvent exposed. We show here experimental and theoretical evidences that pyridine can change its role and in fact stabilize the DNA under acidic conditions. NMR spectroscopy and MD simulations demonstrate that the reversal in the denaturing role of pyridine is specific, and is related to its character as pseudo groove binder. The present study sheds light on the nature of DNA stability and on the relationship between DNA and solvent, with clear biotechnological implications.