氯氰菊酯与DNA相互作用的光谱研究

Interaction between Cypermethrin and DNA by Spectrum Analysis

[目的]对农药氯氰菊酯与DNA的相互作用进行研究,揭示其致畸的作用机制。[方法]在pH值7.4的Tris-HCl缓冲溶液体系中,利用紫外吸收光谱法和荧光探针,对氯氰菊酯与DNA的结合方式和结合常数进行研究。[结果]氯氰菊酯在256nm处的紫外吸收峰随着DNA的加入发生了显著蓝移,同时吸光强度逐渐增大,DNA在203nm处的紫外吸收峰随着氯氰菊酯的加入发生了显著红移,同时吸光强度逐渐降低,这说明氯氰菊酯与DNA形成了复合物;固定DNA浓度(3.4×10-4mol/L),改变氯氰菊酯浓度(1×10-5～6×10-5mol/L),在203nm处测定吸光度,计算得到37℃时结合常数K为7.19×103L/mol;结合荧光探针试验证明氯氰菊酯与DNA是以沟槽方式结合。[结论]氯氰菊酯与DNA以沟槽方式结合可能是氯氰菊酯具有致畸作用的原因。

[ Objective] To observe interaction between eypermethrin pesticide and DNA and thus to reveal its mechanism of teratogenicity. [ Method] The binding methods and binding constants were studied in Tris-HC1 buffer （pH 7.4） by UV absorption spectroscopy and fluorescence probe. [ Result] The UV absorption peak at 256 nm of eypermethrin showed an obvious blue shift, and its absorption intensity increased. With the addition of eypcrmethrin, the UV absorption peak at 203 nm of DNA showed an obvious red shift, and its absorption intensity decreased. These results indicated that formation of a cypermethrin and DNA complex. With a constant DNA concentration of 3.4 ×10^-4 tool/L, Absorbance at 203 nm were measured when the cypermethrin concentration changed from 1 ×10^-5 to 6 ×10^-5 moL/L. The binding constant at 37 ℃was 7. 19 ×10^3 L/tool. Fluorescence probe also showed that cypermethrin bound to the grooves of DNA. [ Conclusion] Cypermethrin binds to grooves of DNA, which maybe the reasons for its teratogenicity.