DNA Binding and Photocleavage Study of Cationic Metalloporphyrins by Spectral Methods |
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Authors: | Ping Zhao Jin-Wang Huang Liang-Nian Ji |
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Affiliation: | 1. School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University , Guangzhou, PR China zhaoping666@163.com;3. MOE Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University , Guangzhou, PR China |
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Abstract: | The DNA binding and photocleavage specificities of the Zn(II), Cu(II), Co(III), Mn(III) complexes of 5,10,15-tris(1-methylpyridinium-4-yl)-20-(4-propionoxyphenyl)porphyrin have been studied by using a combination of absorption, fluorescence titration, surface-enhanced Raman spectroscopy (SERS), induced circular dichroism (ICD) spectroscopy, thermal DNA denaturation as well as gel electrophoresis experiment. It is found that Cu(II) porphyrin has comparable binding ability with the free base porphyrin while the axial-coordinated Zn(II), Co(III), and Mn(III) porphyrins have lower Kb because of the molecular steric hindrance. However, those metalloporphyrins with lower Kb have similar DNA cleavage efficiencies with the free base porphyrin. This could be best understood by the enhancement of the 1O2 productivity which may also result from the steric hindrance of the axial-coordinated metalloporphyrins. |
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Keywords: | DNA binding DNA photocleavage metalloporphyrin steric hindrance |
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