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Conformation Specific Binding of [Ru(phen) 2 (dppz)] 2+ with Mono‐ and Cluster Arylamine‐DNA Adducts
Author(s) -
Thangavel Nandhini,
Ganesan Vaidyanathan V.,
Nair Balachandran U.
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201802172
Subject(s) - adduct , chemistry , phenazine , context (archaeology) , guanine , stereochemistry , moiety , dna , conformational isomerism , crystallography , luminescence , dna adduct , nucleotide , molecule , biochemistry , biology , paleontology , optoelectronics , organic chemistry , gene , physics
Abstract The development of any probe to detect cluster adducts requires an in depth understanding on the binding affinity of probes to these adducts. In this context, we attempted to study the interaction of known DNA molecular switch [Ru(phen) 2 (dppz)] 2+ with mono‐ and cluster DNA adducts in 16‐mer Nar I sequence (5′‐CTCTC G 1 G 2 C G 3 CCATCAC‐3′) where guanine bases are modified with N ‐acetyl‐2‐aminofluorene(AAF). Luminescence studies show that [Ru(phen) 2 (dppz)] 2+ (phen: 1,10‐phenanthroline and dppz: dipyrido[3,2‐a:2′,3′‐c]phenazine) binds to AAF adduct at G 1 and G 3 which possesses minor‐groove( W ) and stacked conformation( S ) exhibit two fold enhancement while G 2 with major groove B ‐conformer exhibit 1.6 fold enhancement when compared to control. In diadducts, Ru II binds to G 2 G 3 AAF adduct lower than that of other two diadducts G 1 G 3 and G 1 G 2 . With triadducts, phenazine moiety of Ru II complex adopts canted geometry to the DNA due to the very unstable structure at the adducted site. From microscale thermophoretic data, the k d of Ru II was determined and found to be consistent with luminescence data. The present study provides an overall insight of role of conformation of AAF structure embedded in different sequence context that dictates the sensitivity of the DNA molecular light switch, in turn, facilitates in developing highly efficient probe to distinguish these cluster adducts.