Comparison of the Binding Geometry of Free-Base and Hexacoordinated Cationic Porphyrins to A- and B‑Form DNA
| Autor: | Ye Sol Oh, Maeng-Joon Jung, Young-Ae Lee, Seog K. Kim |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Circular dichroism Aqueous solution Absorption spectroscopy Chemistry General Chemical Engineering Free base 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Linear dichroism Fluorescence Porphyrin Article lcsh:Chemistry 03 medical and health sciences Crystallography chemistry.chemical_compound 030104 developmental biology lcsh:QD1-999 Emission spectrum 0210 nano-technology |
| Zdroj: | ACS Omega, Vol 3, Iss 1, Pp 1315-1321 (2018) ACS Omega |
| ISSN: | 2470-1343 |
| Popis: | Although the transition from B-DNA to the A-form is essential for many biological concerns, the properties of this transition have not been resolved. The B to A equilibrium can be analyzed conveniently because of the significant changes in circular dichroism (CD) and absorption spectrum. CD and linear dichroism (LD) methods were used to examine the binding of water-soluble meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) and its derivatives, Co-TMPyP, with B- and A-calf thymus DNA. B- to A-transitions occurred when the physiological buffer was replaced with a water-ethanol mixture (∼80 v/v %), and the fluorescence emission spectra of TMPyP bound to DNA showed a different pattern under ethanol–water conditions and water alone. The featureless broad emission bands of TMPyP were split into two peaks near at 658 and 715 nm in the presence of DNA under an aqueous solution. In the case of an ethanol–water system, however, the emission bands are split in two peaks near at 648 and 708 nm and 656 and 715 nm with and without DNA, respectively. This may be due to a change in the solution polarity. On the basis of the CD and LD data, TMPyP interacts with B-DNA via intercalation at a low ratio under a low ionic strength, 1 mM sodium phosphate. On the other hand, the interaction with A-DNA (80 v/v % ethanol–water system) occurs in a nonintercalating manner. This difference might be because the structural conformations, such as the groove of A-DNA, are not as deep as in B-DNA and the bases are much more tilted. In the case of Co-TMPyP, porphyrin binds preferably via an outside self-stacking mode with B- and A-DNA. |
| Databáze: | OpenAIRE |
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