title: Interaction of metallopyrazoliumylporphyrins with calf thymus DNA.
abstract: The interaction of transition metal complexes of cationic porphyrins bearing five membered rings, meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (MPzP, M=Mn(III), Ni(II), Cu(II) or Zn(II)), with calf thymus DNA (ctDNA) has been studied. Metalloporphyrins NiPzP and CuPzP are intercalated into the 5'GC3' step of ctDNA. MnPzP is bound edge-on at the 5'TA3' step of the minor groove of ctDNA, while ZnPzP is bound face-on at the 5'TA3' step of the major groove of ctDNA. The binding constants of the metalloporphyrins to ctDNA range from 1.05x10(5) to 2.66x10(6) M(-1) and are comparable to those of other reported cationic porphyrins. The binding process of the metallopyrazoliumylporphyrins to ctDNA is endothermic and entropically driven. These results have revealed that the kind of central metal ions of metalloporphyrins influences the binding characteristics of the porphyrin to DNA.
authors: Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. c02935@educ.cc.keio.ac.jp
authors: D H
authors: DH
authors: Tjahjono
authors: S
authors: S
authors: Mima
authors: T
authors: T
authors: Akutsu
authors: N
authors: N
authors: Yoshioka
authors: H
authors: H
authors: Inoue
mesh_terms: D000818:Animals; D001665:Binding Sites; D003300:Copper; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004347:Drug Interactions; D004355:Drug Stability; D007364:Intercalating Agents / Q000737:chemistry / Q000378:metabolism; D008345:Manganese; D008665:Metalloporphyrins / Q000737:chemistry / Q000378:metabolism*; D019216:Metals, Heavy / Q000737:chemistry*; D009532:Nickel; D013057:Spectrum Analysis; D013696:Temperature; D013816:Thermodynamics; D015032:Zinc
chemical_list: D007364:Intercalating Agents; D008665:Metalloporphyrins; D019216:Metals, Heavy; D008345:Manganese; D003300:Copper; D009532:Nickel; D004247:DNA; C427203:calf thymus DNA; D015032:Zinc