PREPARATION AND CLEAVAGE MECHANISM OF CHELATES OF METAL IONS WITH EDTA LINKED TO OLIGODEOXYRIBONUCLEOTIDES  

作　　者：Li Xiaoru(Department of Chemistry, Central South University of Technology,Changsha 410083,China)Wen Zhibin(Department of Basic Medicine,Hunan Medical University,Changsha 410078,China) 

出　　处：《Journal of Central South University》1998年第1期47-50,共4页中南大学学报（英文版）

摘　　要：The chelates of metal ions with EDTA covalently linked to the 5′end of oligodeoxyribonuclotides(ODN),i.e,ODN5′EDTA·M(Ⅱ),are prepared,in which M(Ⅱ) is Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ).The optimum pH value for forming these three chelates is calculated.For ODN5′EDTA Fe(Ⅱ) pH value is 5.8 to 8.6,pH 4.6～8.1 for ODN5′EDTA Co(Ⅱ),and pH 3.4～5.7 for ODN5′EDTA Cu(Ⅱ).Under such pH value conditions neither can Mg(Ⅱ) ion,necessary for cleavage reaction,be competitive with Fe(Ⅱ),Co(Ⅱ) or Cu(Ⅱ) to form EDTA chelate,nor can it be precipitated.The cleavage mechanism of ODN5′EDTA Fe(Ⅱ) for DNA duplex is discussed.Modified ODN binds with DNA duplex in the major groove via hydrogen bond to form triple helix.In the presense of oxygen and reducing agent dithiothreitol,hydroxyl radicals species are generated as intermediates by catalysis of metal ions,and then oxidize the ribo ring and cut the doublestranded DNA at the sites close to the EDTA· Fe(Ⅱ).

关 键 词：Oligodeoxyribonucleotide METAL IONS chelate cleavage 

分 类 号：TG115.3[金属学及工艺—物理冶金] TG115.3[金属学及工艺—金属学]