Cheng Chien-Chung, Huang-Fu Wei-Chun, Hung Kuo-Chan, Chen Po-Jui, Wang Wen Jwu, Chen Yu-Ju
Department of Chemistry, Tamkang University, Taipei, Taiwan 251, Republic of China.
Nucleic Acids Res. 2003 Apr 15;31(8):2227-33. doi: 10.1093/nar/gkg323.
A novel octahedral complex CoII(HAPP)(TFA)2 [hexaazaphenantholine-cyclophane (HAPP), trifluoroacetate (TFA)] is a DNA bulge-specific probe with single-strand DNA cleavage activity in the presence of H2O2. This complex exhibits low affinity towards double-stranded DNA and low reactivity toward single-stranded DNA. Metal-HAPP complexes with different coordination number and ring size were synthesized and their selectivity and reactivity for DNA bulges were compared. The DNA sequence at the bulge site influences the intensity of cleavage at the bulge and the flanking sites after piperidine treatment. Cleavage specificity of CoII(HAPP)(TFA)2 was characterized extensively using scavenger reagents to quench the cleavage reaction and high-resolution polyacrylamide gel electrophoresis. In addition, 3'-phosphoglycolate cleavage products were trapped and analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. These data were used to deduce that the DNA cleavage pathway for CoIIHAPP2+ in the presence of H2O2 involves 4'-H abstraction of the deoxyribose moiety.
一种新型八面体配合物CoII(HAPP)(TFA)2 [六氮杂菲咯啉环番(HAPP),三氟乙酸盐(TFA)] 是一种在H2O2存在下具有单链DNA切割活性的DNA凸起特异性探针。该配合物对双链DNA亲和力低,对单链DNA反应性低。合成了具有不同配位数和环大小的金属-HAPP配合物,并比较了它们对DNA凸起的选择性和反应性。凸起位点的DNA序列影响哌啶处理后凸起处和侧翼位点的切割强度。CoII(HAPP)(TFA)2的切割特异性通过使用清除剂淬灭切割反应和高分辨率聚丙烯酰胺凝胶电泳进行了广泛表征。此外,通过基质辅助激光解吸电离飞行时间质谱对3'-磷酸乙醇酸切割产物进行了捕获和分析。这些数据用于推断在H2O2存在下CoIIHAPP2+的DNA切割途径涉及脱氧核糖部分的4'-H提取。