Tjahjono Daryono H, Kartasasmita Rahmana E, Nawawi As'ari, Mima Shunsuke, Akutsu Takehiro, Yoshioka Naoki, Inoue Hidenari
Department of Pharmacy, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132, Indonesia.
J Biol Inorg Chem. 2006 Jun;11(4):527-38. doi: 10.1007/s00775-006-0105-x. Epub 2006 Apr 22.
Interactions of cationic porphyrins bearing five-membered rings at the meso position, meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (MPzP; M is H2, Cu(II) or Zn(II)), with synthetic polynucleotides poly(dG-dC)2 and poly(dA-dT)2 have been characterized by viscometric, visible absorption, circular dichroisim and magnetic circular dichroism spectroscopic and melting temperature measurements. Both H2PzP and CuPzP are intercalated into poly(dG-dC)2 and are outside-bound to the major groove of poly(dA-dT)2, while ZnPzP is outside-bound to the minor groove of poly(dA-dT)2 and surprisingly is intercalated into poly(dG-dC)2. The binding constants of the porphyrin and poly(dG-dC)2 and poly(dA-dT)2 are on the order of 10(6) M(-1) and are comparable to those of other cationic porphyrins so far reported. The process of the binding of the porphyrin to poly(dG-dC)2 and poly(dA-dT)2 is exothermic and enthalpically driven for H2PzP, whereas it is endothermic and entropically driven for CuPzP and ZnPzP. These results have revealed that the kind of the central metal ion of metalloporphyrins influences the characteristics of the binding of the porphyrins to DNA.
对中位带有五元环的阳离子卟啉，即中位-四(1,2-二甲基吡唑鎓-4-基)卟啉（MPzP；M为H₂、Cu(II)或Zn(II)）与合成多核苷酸聚(dG-dC)₂和聚(dA-dT)₂的相互作用，已通过粘度测定、可见吸收、圆二色性和磁圆二色性光谱以及解链温度测量进行了表征。H₂PzP和CuPzP都嵌入到聚(dG-dC)₂中，并在外围结合到聚(dA-dT)₂的大沟，而ZnPzP在外围结合到聚(dA-dT)₂的小沟，且令人惊讶地嵌入到聚(dG-dC)₂中。卟啉与聚(dG-dC)₂和聚(dA-dT)₂的结合常数约为10⁶ M⁻¹，与迄今报道过的其他阳离子卟啉的结合常数相当。卟啉与聚(dG-dC)₂和聚(dA-dT)₂的结合过程对H₂PzP来说是放热的且由焓驱动，而对CuPzP和ZnPzP来说是吸热的且由熵驱动。这些结果表明金属卟啉中心金属离子的种类会影响卟啉与DNA结合的特性。
