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Optical differentiation between quadruplex DNA and duplex DNA with a [2.2.2]heptamethinecyanine dye
Author(s) -
Ihmels Heiko,
Mahmoud Mohamed M.A.,
Patrick Brian O.
Publication year - 2017
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.3736
Subject(s) - chemistry , cyanine , dna , intercalation (chemistry) , stacking , ligand (biochemistry) , duplex (building) , stereochemistry , crystallography , g quadruplex , fluorescence , biochemistry , organic chemistry , physics , receptor , quantum mechanics
The interactions between the trinuclear cyanine all‐ trans ‐2,2'‐[3‐[(1,3‐dihydro‐1,3,3‐trimethyl‐2H‐indol‐2‐ylidene)ethylidene]‐1,4‐pentadiene‐1,5‐diyl]‐bis[1,3,3‐trimethyl]‐3H‐indolium with representative G4‐DNA sequences, namely, 22AG [d(AG 3 T 2 AG 3 T 2 AG 3 T 2 AG 3 )], c‐myc [d(TGAG 3 TG 3 TAG 3 TG 3 TA 2 )], c‐kit [d(AG 3 AG 3 CGCTG 3 AG 2 AG 3 )], and a2 [d(ACAG 4 TGTG 4 ACAG 4 TGTG 4 )] and with double‐stranded DNA, ct DNA and ds26 [d(CA 2 TCG 2 ATCGA 2 T 2 CGATC 2 GAT 2 G)], are studied by photometric and fluorimetric titrations, CD‐spectroscopic analysis, and 1 H‐NMR spectroscopy. It is demonstrated that the heptamethine cyanine binds to quadruplex DNA by terminal π‐stacking and to duplex DNA by aggregation along the DNA backbone. The ligand does not bind selectively to quadruplex DNA as compared with duplex DNA, but the two DNA forms can be differentiated with this ligand based on the different development of its absorption and emission properties upon ligand‐DNA association.