Binding of tetrakis(pyrazoliumyl)porphyrin and its copper(II) and zinc(II) complexes to poly(dG-dC)2 and poly(dA-dT)2.

Autor: Tjahjono DH; Department of Pharmacy, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132, Indonesia. daryonohadi@gerbang.fa.itb.ac.id, Kartasasmita RE, Nawawi A, Mima S, Akutsu T, Yoshioka N, Inoue H
Jazyk: angličtina
Zdroj: Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry [J Biol Inorg Chem] 2006 Jun; Vol. 11 (4), pp. 527-38. Date of Electronic Publication: 2006 Apr 22.
DOI: 10.1007/s00775-006-0105-x
Abstrakt: 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.
Databáze: MEDLINE