Metal complexes of modified cyclen as catalysts for hydrolytic restriction of plasmid DNA
                                
                                    
                                        作者:Joel A. Krauser、Aarti L. Joshi、Ismail O. Kady                                    
                                    
                                        DOI:10.1016/j.jinorgbio.2010.04.007
                                    
                                    
                                        日期:2010.8
                                    
                                    Simple and novel nuclease models have been synthesized. These involve metal-binding ligand 1,4,7,10-tetraazlcyclododecane (cyclen) tethered to an acridine ring (a DNA-binding group) by amide linkers of various lengths. Binding of these probes to DNA was studied by monitoring changes in their UV-visible spectra affected by the presence of DNA. Titration of these compounds with increasing amounts of pBR322 DNA caused hypochromic effects and shifted the acridine absorption at 360 nm to a longer wavelength. Under biologically relevant conditions (37 degrees C and pH 7.4), specific transition metal complexes of these compounds are found to be highly effective catalysts toward the hydrolysis of plasmid DNA. This is demonstrated by their ability to convert the super-coiled DNA (form I) to open-circular DNA (form II). Structure-activity correlation studies show that hydrolytic activity depends on both the structure of ligand (L-1>L-2>L-3) and the nature of metal ion cofactor (Co3+>Zn2+>Cr2+>Ni2+>Cu2+>Fe3+). (C) 2010 Elsevier Inc. All rights reserved.