Modulation of DNA triplex stability through nucleobase modifications

Article abstract of DOI:10.1080/07328319708006169

Spermine conjugation at N⁴ of 5-Me-dC in oligonucleotides (sp-ODNs) reduces the net negative charge and these as HG strands form triplexes with foremost stability at neutral pH (7.3), in contrast to unmodified ODNs which form stable triplexes at pH 5.5. The stability of sp-ODN triplexes is shown to arise from improved association with duplex caused by electrostatic interaction of polycationic spermine sidechain with anionic phosphate backbone of DNA and N3 protonation is not a pre-requirement for triplexes constituted from sp-ODNs. The amplification of electrostatic component of interaction can be achieved by transformation of primary amine group of polyamines to corresponding guanidinium functions leading to improved binding and stabilization of DNA triplexes even at pH 7.0. %-Amino-dU ODNs are shown to be compatible as a central strand in formation of triplexes in which pyrimidine would be in the middle position of a triad.

Full text of DOI:10.1080/07328319708006169

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Nucleosides and Nucleotides
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Modulation of DNA Triplex Stability
Through Nucleobase Modifications
Krishna N. Ganesh a , Kallanthottathil G. Rajeev a , Pradeep S.
Pallan a , Vipul S Rana a , Dinesh A. Barawkar a & Vaijayanti A.
Kumar a
a Division of Organic Chemistry , National Chemical Laboratory ,
Pune, 411008, India
Published online: 16 Aug 2006.
To cite this article: Krishna N. Ganesh , Kallanthottathil G. Rajeev , Pradeep S. Pallan , Vipul
S Rana , Dinesh A. Barawkar & Vaijayanti A. Kumar (1997) Modulation of DNA Triplex Stability
Through Nucleobase Modifications, Nucleosides and Nucleotides, 16:7-9, 1271-1278, DOI:
10.1080/07328319708006169
To link to this article: http://dx.doi.org/10.1080/07328319708006169
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