Thionine Interaction to DNA: Comparative Spectroscopic Studies on Double Stranded Versus Single Stranded DNA
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Thionine Interaction to DNA: Comparative Spectroscopic
Studies on Double Stranded Versus Single Stranded DNA
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| Creator |
Paul, Puja
Kumar, G Suresh |
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| Subject |
Chemistry
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| Description |
Interaction of thionine with double stranded and
single stranded calf thymus DNA has been studied by
absorbance, fluorescence, competition dialysis, circular
dichroism and isothermal titration calorimetry. Binding to
the native double stranded DNA conformation induced
strong quenching in fluorescence spectrum of thionine.
Linear Scatchard plots indicated the binding to be of one
type and the affinity values evaluated to be of the order of
105 M−1 with double stranded DNA. Fluorescence quenching
was much weaker with single stranded DNA and the
binding affinity was about one order lower. Ferrocyanide
quenching studies revealed that the fluorescence emission
of dye molecules bound to the double stranded DNA was
quenched much less compared to those bound to the single
stranded DNA. Furthermore, there was significant emission
polarization for the bound dye molecules and strong energy
transfer from the DNA base pairs to the dye molecules
indicating intercalative binding to ds DNA. Salt dependence
of the binding phenomenon revealed that electrostatic
forces played a significant role in the binding process. The
intercalation of the dye molecules to double stranded DNA
and simple stacking to single strands was proved from these
fluorescence techniques. Support to the fluorescence results
have been derived from absorption, circular dichroic and
dialysis results. Calorimetric studies suggested that the
binding to ds DNA conformation was both enthalpy and entropy favoured while that to ss DNA was predominantly
entropy favoured.
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| Date |
2012
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/1484/1/APPLIED_BIOCHEMISTRY_AND_BIOTECHNOLOGY___166(_8_)1991%2D2006;2012[26].pdf
Paul, Puja and Kumar, G Suresh (2012) Thionine Interaction to DNA: Comparative Spectroscopic Studies on Double Stranded Versus Single Stranded DNA. Journal of Fluorescence, 22 (1). pp. 71-80. |
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| Relation |
http://dx.doi.org/10.1007/s10895-011-0931-2
http://www.eprints.iicb.res.in/1484/ |
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