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, vol.18, no.1, pp.139-147, 2008 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 1
  • Publication Date: 2008
  • Doi Number: 10.1007/s10895-007-0252-7
  • Journal Name: JOURNAL OF FLUORESCENCE
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.139-147

Abstract

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.