The mechanism of benzothiazole styrylcyanine dyes binding with dsDNA: Studies by spectral-luminescent methods


Akbay N. , LOSYTSKYY M. Y. , KOVALSKA V. B. , BALANDA A. O. , YARMOLUK S. M.

JOURNAL OF FLUORESCENCE, cilt.18, ss.139-147, 2008 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 18 Konu: 1
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1007/s10895-007-0252-7
  • Dergi Adı: JOURNAL OF FLUORESCENCE
  • Sayfa Sayısı: ss.139-147

Özet

In the presented work studies of the interaction mode of monomer and two homodimer benzothiazole styryl dyes containing spermine-like linkage/tail group with the double stranded (ds) DNA are reported. For these dyes, equilibrium constant of dye binding to DNA (K-b), as well as the number of dsDNA base pairs occupied by one bound dye molecule (n) were determined. The data obtained show that the presence of spermine-like group containing quaternary nitrogen (Bos-5) results in increase of K (b) value as compared to this of unsubstituted analogue (Sbt). Besides, for the dimer dyes containing benzothiazole styryl chromophores, the K-b value is either five times higher (DBos-13) or almost the same (DBsu-10) as compared to this of corresponding monomer Sbt, depending on the position in the benzothiazole ring where the linker is attached. Moreover, the n values for both dimers are significantly different as well, pointing to the bis-intercalative binding mechanism for DBos-13 and for the groove-binding one for DBsu-10. The conclusion about the dimer dyes-dsDNA binding mechanisms is also supported by the study of the fluorescent response of these dyes on the presence of AT- and GC-containing polynucleotides.