利用小分子DNA鉴定重金属离子对DNA的损伤

目的]利用小分子DNA鉴定重金属离子对DNA的损伤。方法]将pUC18 DNA分子暴露于Hg2+、Cr6+、Pb2+、Cd2+4种重金属离子环境中,经一定时间处理后对DNA分子进行生物活性研究,并用凝胶电泳和增色效应分析了重金属离子对分子生物活性影响机制。结果]DNA活性分析表明4,种重金属对pUC18的影响程度为Hg2+>Cr6+>Pb2+>Cd2+;凝胶电泳和增色效应结果表明4,种重金属离子主要是引起DNA分子交联导致其分子生物活性的降低,交联程度为Hg2+>Cr6+>Pb2+>Cd2+。结论]该研究表明,pUC18DNA分子可用作鉴定重金属离子对DNA损伤的依据,为评价重金属对DNA毒害作用提供了一种简捷有效的技术方法。

Identification of DNA Damage Caused by Heavy Metal Ions with Small Molecular DNA

Objective] The aim was to establish a convenient and effective method to evaluate the toxicity of heavy metal ions by using small molecular DNA.Method] pUC18 DNA which had exposed to the four heavy metal ions of Hg2+,Cr6+,Pb2+,Cd2+ was used to study the bioactivity of DNA;simultaneously,gel electrophoresis and hyperchromic effect were employed to detect the mechanism of DNA damage.Result] The bioactivity of the exposed DNA was decreased and the influence degree was Hg2+> Cr6+>Pb2+>Cd2+;the gel electrophoresis and hyperchromic effect proved the main reason leading to reduce the bioactivity was DNA cross link,the order was Hg2+> Cr6+>Pb2+> Cd2+.Conclusion] The study indicated that pUC18 DNA could be used to assay the damage of DNA causing by heavy mental ions,which may be a potential,simple and effective tool to evaluate toxicity of heavy metal ions to DNA.