The interactions between an aza-cyclic cerium (III) complex and pUC19 DNA

A new biomimetic catalyst (M-CYC) is formed from the combination of CYC (a derivative of 1,4,7,10,13,16,19,22,25,28,31-undecaaza-cyclotritriacontane-2,5,8,11,14,17,20,23,26,29,32-undeca acyl) and Ce(III, M) in aqueous solution. The interaction between this complex and DNA was studied using electronic absorption spectroscopy, fluorescence spectroscopy, and gel electrophoresis. The results indicated that M-CYC and calf thymus DNA (pUC19 DNA) interacted via intercalation. The apparent binding constant of the complex with DNA was determined to be 2.0×104 L/mol at pH 8.16. Based on gel electrophoresis analysis, M-CYC was shown to nick the circular plasmid pUC19 DNA in the presence of a free radical scavenger. The nicking of DNA serves as a model of hydrolyzed cleavage.

Graphical AbstractA new biomimetic catalyst M-CYC made from Ce(III) metal ion and cyclosporin was constructed and used as a catalyst in the cleavage of plasmid pUC19 DNA. The interactions between M-CYC and DNA were investigated by UV-Vis absorption and fluorescence spectroscopy.Figure optionsDownload as PowerPoint slide