Interaction of cyanine dyes with nucleic acids: XXVI. Intercalation of the trimethine cyanine dye cyan 2 into double-stranded DNA: study by spectral luminescence methods.
The interaction between double-stranded (ds) DNA and the cyanine dye Cyan 2 has been studied with spectral luminescence methods. Binding constant values have been determined by fluorescence titration and dye distribution in the two-phase system ethyl acetate-water (3.6 x 10(4) and 1.5 x 10(4) M(-1), respectively). Cyan 2 exhibits a small specificity for guanine-cytosine (GC) sequences in total DNA and synthetic polydeoxynucleotides poly(dA/dT) and poly(dGdC/dGdC). The DNA complexes with Cyan 2 are stable at high-ionic strength solution when NaCl is added. The dye molecule complexed with DNA is apparently shielded from the anionic quencher--iodide ion. The negative linear dichroism of the visible absorption band of aligned Cyan 2-DNA complexes indicates that the bound dye lies almost perpendicularly to the DNA helix axis. The linear dichroism of the absorption band at 260 nm suggests a considerable change in the DNA B-form. The results are consistent with an intercalative binding interaction between Cyan 2 and ds DNA.
Yarmoluk
S M
SM
Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnogo Street, 03143 Kiev, Ukraine. otava@carrier.kiev.ua
Lukashov
S S
SS
Losytskyy
M Yu
MY
Akerman
B
B
Kornyushyna
O S
OS
D002232:Carbocyanines / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D049449:Luminescence; D013057:Spectrum Analysis
D002232:Carbocyanines; C120934:cyan 2; D004247:DNA