title: DNA binding and cleaving activity of the new cleft molecule N,N'-Bis(guanidinoethyl)-2,6-pyridinedicarboxamide in the absence or in the presence of copper(II).
abstract: Novel cleft molecule pyridine-2,6-dicarboxamide appending two guanidinoethyl group side arms (Gua) was synthesized. The interactions of the cleft molecule in the absence of copper(II) (Gua) or in the presence of copper(II) (Cu2+-Gua) with calf thymus DNA were studied by fluorescence and CD spectroscopy. The results indicate that the DNA binding affinity of Cu2+-Gua is stronger than that of Gua, and the binding constants of Cu2+-Gua and Gua are 1.61 x 10(6) M(-1) and 2.86 x 10(5) M(-1), respectively. Agarose gel electrophoresis was used to assess the plasmid pUC 19 DNA cleavage activities in the presence of Gua and Cu2+-Gua. Kinetic data of DNA cleavage promoted by Cu2+-Gua under physiological conditions fit a saturation kinetic profile with k(max) of 0.0173 +/- 0.0011 h(-1), which gave a aproximately 10(6)-fold rate acceleration over uncatalyzed supercoiled DNA, while the catalyst concentration is lower than 0.0625 mM. The hydrolysis pathway was proposed as the possible mechanism for DNA cleavage promoted by Cu2+-Gua. The acceleration is due to efficient cooperative catalysis of the copper cation center and the functional groups (bis(guanidinium) groups).
authors: Department of Chemistry, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China.
authors: Ying
authors: Y
authors: Shao
authors: Xin
authors: X
authors: Sheng
authors: Ying
authors: Y
authors: Li
authors: Zhao-Li
authors: ZL
authors: Jia
authors: Jing-Jing
authors: JJ
authors: Zhang
authors: Fang
authors: F
authors: Liu
authors: Guo-Yuan
authors: GY
authors: Lu
mesh_terms: D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D053837:DNA Cleavage; D019791:Guanidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D011728:Pyridones / Q000138:chemical synthesis*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002413:Cations, Divalent; C533574:N,N'-bis(guanidinoethyl)-2,6-pyridinedicarboxamide; D011728:Pyridones; D003300:Copper; D004247:DNA; C427203:calf thymus DNA; D019791:Guanidine