Ir and Raman spectroscopic studies on coulombic interaction between water-soluble porphyrins and nucleic acids
✍ Scribed by Y. Nonaka; D. S. Lu; A. Dwivedi; D. P. Strommen; K. Nakamoto
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 471 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
We have shown previously that the N‐methylpridyl group vibrations of water‐soluble porphyrins, M(TMpy‐P4), are shifted to lower frequencies (0.5–2.6 cm^−1^) as a result of coulombic interaction between the N^+^‐CH~3~ group of M(TMpy‐P4) and the PO~2~ group of a nucleic acid. We have now turned over our attention to the effect of this coulombic interaction on the PO~2~ group vibrations of nucleic acids. Using Fourier transform ir and Raman spectroscopy, we found that the ν~a~(PO~2~) at 1221 cm^−1^ is shifted 12 ∼ 17 cm^−1^ to higher frequencies, whereas the ν~s~(PO~2~) at 1087 cm~−1~ is shifted 18 ∼ 26 cm^−1^ to lower frequencies, when DNA is mixed with M(TMpy‐P4). These results indicate that the N^+^‐CH~3~ group of M(TMpy‐P4) interacts preferentially with one of the two oxygen atoms of the PO~2~ group of the DNA duplex.