重金属与鲑鱼精DNA作用的比较研究

Interaction Between Heavy Metals and the DNA from Salmon Sperm

用紫外光谱法、循环伏安法和黏度测定等方法,对Cd2+、Pb2+与鲑鱼精DNA的作用机理进行了研究。结果表明,随着Cd2+、Pb2+浓度的增大,DNA表现出增色效应,当加入不同浓度的CO23-溶液时,DNA的增色效应降低,即Cd2+对DNA的损伤程度降低;当加入不同浓度的PO34-溶液时,DNA的损伤修复作用不明显;而在CO23-、PO43-存在的情况下,与Pb2+具有协同作用,加速Pb2+对DNA的破坏。而且,Cd2+能与DNA形成了一种电惰性化合物,致使阴极峰电流下降,说明Cd2+与DNA的作用是插入式的沟槽结合;Pb2+能与DNA发生缔合作用,使DNA的结构发生改变。当Cd2+、Pb2+浓度增大时,DNA溶液的黏度逐渐减小。光谱研究、循环伏安法和黏度法的结果均说明Cd2+、Pb2+都是以插入方式与DNA作用的。

The mechanism of interaction between heavy metals Cd^2＋, pb^2＋nd Salmon Sperm DNA by was researched using the ultraviolet spectral method, cyclic volt-ampere method and viscosity determination method. As concentration of Cd^2＋, Pb^2＋ increased, the DNA repre- sented hyper chromic effect. Added different concentrations of CO3^2＋ solutions, the hyper chromic effects of DNA reduced, i.e. the level of DNA damaged by Cd2＋ lowered. When added different concentrations of PO4^3- solutions, the damage restoration of DNA was not obvious. While CO3^2- and PO4^3- existed, they exhibited synergistic effect together with Pb^2＋, thus accelerated the DNA damage by Pb^2＋. Moreover, Cd^2＋ and DNA could form an electro inert compound, resulting in the decrease of the peak electric current of cathode, indicating that the interaction between Cd2＋ and DNA was groove combination of insert mode. Pb^2＋ and DNA could produce conclusion effect, changing the structure of DNA. When concentration of Cd^2＋ and Pb^2＋ increased, the viscosity of the DNA solution gradually reduced. Based on the study with ultraviolet spectral method, cyclic volt-ampere method and viscosity determination method, both Cd^2＋ and Pb^2＋ interacted with DNA by the means of insert mode.