La(Ⅲ)与脱氧核糖核苷酸的相互作用

Interaction of La(Ⅲ) with Deoxyribonucleotide

用高效液相色谱解析Ｌａ（Ⅲ）分别与单个脱氧核糖核苷酸反应、与碱基对互补的５′－ｄＡＭＰ和５′－ｄＴＭＰ、５′－ｄＣＭＰ和５′－ｄＧＭＰ反应、与４种脱氧核糖核苷酸共存体系反应的产物．从色谱峰的变化，证明了在ｐＨ６．５、室温条件下，Ｌａ（Ⅲ）可与单个的５′－ｄＧＭＰ作用；不与单个的５′－ｄＡＭＰ、５′－ｄＴＭＰ、５′－ｄＣＭＰ相作用，但在５′－ｄＡＭＰ和５′－ｄＴＭＰ共存时，Ｌａ（Ⅲ）使５′－ｄＡＭＰ和５′－ｄＴＭＰ的色谱峰面积大大减小并有新峰产生；当四种脱氧核糖核苷酸同时存在时除５′－ｄＣＭＰ峰不变外，５′－ｄＡＭＰ、５′－ｄＴＭＰ和５′－ｄＧＭＰ的峰面积都明显减小．这一结果表明：Ｌａ（Ⅲ）可与５′－ｄＡＭＰ和５′－ｄＴＭＰ相互交联，从而为稀土离子与ＤＮＡ双链进行链间交联的推测提供了有力的证据．

We analysed products of reaction of La(Ⅲ) with monodeoxyribo nucleotide 5′ dNMP,2 kind base complement monodeoxyribonucleotide 5′ dAMP+5′ dTMP and 5′ dGMP+5′ dCMP,and 4 kind monodeoxyribonucleotidecoexistent system by HPLC.The experiment shown that at pH 6.5 and commontemperature La(Ⅲ)can react with 5′ dGMP,but can′t react with 5′ dTMP,5′ dAMP,and 5′ dCMP.When base complement 5′ dAMP+5′ dTMP coexistent,La(Ⅲ) can react with 5′ dAMP and 5′ dTMP,4 kind monodeoxyribonucleotide coexistent,all can interact with La(Ⅲ) except 5′ dCMP.From the results,it is demonstrated that La(Ⅲ) can interact with DNA by crosslinking.