三聚氰胺对DNA潜在损伤作用的研究  

Study of influences of melamine on potential trauma of DNA

作　　者：张国文[1] 汪佳蓉[1] 杨佳[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,南昌330047

出　　处：《分析试验室》2010年第2期10-13,共4页Chinese Journal of Analysis Laboratory

基　　金：科技部南昌大学国家重点实验室基金(SKLF-MB-200807);江西省自然科学基金(2007GZH1924)项目资助

摘　　要：在生理酸度条件下(pH 7.4),采用溴化乙锭(EB)为荧光探针的荧光光谱法、I-离子荧光猝灭效应、DNA熔点和粘度效应等手段,研究了三聚氰胺与DNA的相互作用。随着DNA的加入,三聚氰胺的荧光强度明显减小而且三聚氰胺能够猝灭DNA-EB复合物的荧光,说明三聚氰胺能够竞争置换EB而与DNA作用;三聚氰胺的加入使得DNA的粘度增大,DNA-EB的熔点降低;DNA的加入减小了I-对三聚氰胺荧光的猝灭程度。三聚氰胺以嵌插方式作用于DNA的亲核位点,意味着三聚氰胺进入生物体后有可能通过形成DNA加合物的形式造成DNA损伤,从而最终导致基因突变。The interaction between melamine and calf thymus DNA in physiological buffer （pH 7.4） was explored by using ethidium bromide （EB） as a fluorescence probe. The experimental phenomena showed that fluorescence intensity of melamine was greatly reduced with the addition of DNA. Moreover, fluorescence quenching of the emission peak was observed in the DNA-EB system when melamine was added, suggesting that a strong competition for DNA binding be- tween melamine and EB. The relative viscosity of DNA increased with the addition of melamine, whereas the value of melting temperature of DNA-EB system decreased in the presence of melamine. In addition, I- quenching effect on the fluorescence intensity of melamine was reduced in the presence of DNA. Based on the above experimental phenom- ena, it can be inferred that the binding mode of melamine with DNA is intercalative binding, the melamine can bind to base pairs of DNA to produce DNA adducts. The melamine might bring the chemical trauma to DNA of the organisms and induce the gene mutation through producing DNA adducts.

关 键 词：三聚氰胺 DNA 荧光光谱 DNA加合物 

分 类 号：O557.3[理学—热学与物质分子运动论]