Thermal Stability of Modified i‐Motif Oligonucleotides with Naphthalimide Intercalating Nucleic Acids |
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Authors: | Ahmed Ali El‐Sayed Erik B. Pedersen Nahid Y. Khaireldin |
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Affiliation: | 1. Nucleic Acid Center, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK‐5230 Odense M;2. Photochemistry Department, Chemical Industries Division, National Research Centre, El‐Tahrir St., Dokki, Giza 12622, Egypt, (phone: +20‐2‐01008653440;3. fax: +20‐2‐33370931) |
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Abstract: | In continuation of our investigation of characteristics and thermodynamic properties of the i‐motif 5′‐d[(CCCTAA)3CCCT)] upon insertion of intercalating nucleotides into the cytosine‐rich oligonucleotide, this article evaluates the stabilities of i‐motif oligonucleotides upon insertion of naphthalimide (1H‐benzo[de]isoquinoline‐1,3(2H)‐dione) as the intercalating nucleic acid. The stabilities of i‐motif structures with inserted naphthalimide intercalating nucleotides were studied using UV melting temperatures (Tm) and circular dichroism spectra at different pH values and conditions (crowding and non‐crowding). This study indicated a positive effect of the naphthalimide intercalating nucleotides on the stabilities of the i‐motif structures compared to the wild‐type structure which is in contrast to a previous observation for a pyrene‐intercalating nucleotide showing a decrease in Tm values. |
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Keywords: | Naphthalimides i‐Motif Cytosine‐rich oligonucleotides Circular dichroism UV Melting temperature |
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