Liquid Crystal ordering of DNA Dickerson Dodecamer duplexes with different 5’- Phosphate terminations |
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| Authors: | Marco Todisco Gregory P Smith Tommaso P Fraccia |
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| Institution: | 1. Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Fratelli Cervi 93, I-20090 Segrate (MI), Italy;2. Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO, 80309-0390;3. Institute Pierre-Gilles de Gennes, ESPCI Paris, PSL Research University, 6 rue Jean Calvin, 75005 Paris, France |
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| Abstract: | AbstractThe onset of liquid crystal (LC) phases in concentrated aqueous solutions of DNA oligomers crucially depends on the end-to-end interaction between the DNA duplexes, which can be provided by the aromatic stacking of the terminal base-pairs or by the pairing of complementary dangling-ends. Here we investigated the LC behavior of three blunt-end 12-base-long DNA duplexes synthesized with hydroxyl, phosphate and triphosphate 5’-termini. We experimentally characterized the concentration-temperature phase diagrams and we quantitatively estimated the end-to-end stacking free energy, by comparing the empirical data with the predictions of coarse-grained linear aggregation models.The preservation of LC ordering, even in presence of the bulky and highly charged triphosphate group, indicates that attractive stacking interactions are still present and capable of induce linear aggregation of the DNA duplexes. This finding strengthens the potential role of chromonic like self-assembly for the prebiotic formation of linear polymeric nucleic acids. |
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