Abstract
The binding mode of a porphyrin dimer to double stranded native DNA was investigated in this study using normal electric absorption, circular dichroism (CD) and linear dichroism (LD) spectroscopies. At the time of mixing, the spectral properties of the porphyrin dimer upon its association with DNA were characterized by hypochromism and a red shift in the absorption spectrum and by complicated CD and negative LD in the Soret region. As time elapsed, the CD spectrum became a negative single band and the negative LD signal increased. These spectral changes suggested that the majority of both porphyrin moieties of the dimer intercalated between the DNA base-pairs. The changes in the spectral characteristics of the DNA bound porphyrin-dimer were similar when the minor groove of DNA was saturated by 4′,6-diamidino-2-phenylindole (DAPI), which is well-known minor groove binding molecule. The spectral properties of DAPI, which can be summarized by a large positive induced CD in the DAPI absorption region (300∼400 nm) and wavelength-independent positive reduced LD, remained intact when the porphyrin dimer was present. These observations indicated that both DAPI and porphyrin bind to DNA simultaneously, and furthermore, the bis-intercalation of the porphyrin dimer occurs in the major groove.
Original language | English |
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Pages (from-to) | 1159-1166 |
Number of pages | 8 |
Journal | Journal of Porphyrins and Phthalocyanines |
Volume | 16 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2012 Nov |
Bibliographical note
Funding Information:This study was supported by the National Research Foundation of the Republic of Korea (Grant Nos. NRF 2011–0014336).
Keywords
- DNA
- bis-intercalation
- circular dichroism
- linear dichroism
- major groove
- porphyrin
ASJC Scopus subject areas
- General Chemistry