摘要
农用化学物质残留可能会与DNA结合形成加和物,从而对动物和人类造成危害。文章利用紫外光谱和荧光光谱研究了溴鼠灵(BDF)与小牛胸腺DNA(ct-DNA)的作用机理。结果表明,低浓度的ct-DNA可使BDF的吸收光谱发生减色,ct-DNA对BDF的稳态荧光有明显的的猝灭作用,属于静态猝灭方式,27℃时KSV=1.21×104L·mol-1;根据热力学参数推测BDF与ct-DNA之间的相互作用主要是范德瓦耳斯力作用;猝灭试验发现ct-DNA对BDF无明显保护作用;离子强度改变时,BDF/ct-DNA体系的荧光强度也随之改变;ct-DNA对β-CD/BDF包络物的荧光也有猝灭,但猝灭程度比游离的BDF有所降低,表明β-CD对BDF具有保护作用,也说明BDF与ct-DNA或β-CD的结合具有竞争性。各试验结果一致表明BDF与ct-DNA之间主要是以沟区结合方式发生作用。另外,试验结果也表明BDF与ct-DNA之间还存在静电作用。范德瓦耳斯力和静电作用的共同作用,为BDF在沟区与DNA的相互结合提供了更好条件。
The interaction between brodifacoum （3-[3-（4＇-bromophenyl-4） 1,2,3,4-tetralin-10]-4-hydroxyl-coumarin） （BDF）, an anticoagulant rodenticide, and calf thymus DNA （ct-DNA） was studied by UV spectrum and fluorescence spectrum. The results were summarized as follows： There was a hypochromic effect of low concentration ct-DNA on the UV spectra. The fluorescence quenching studies showed a regular decrease in the fluorescence intensity after addition of ct-DNA by the static quenching mode with a quenching constant （Ksv） of 1.21×10^4 L·mol^-1 at 27℃. The BDF possibly bonded to ct-DNA mainly via Van der Waals forces by the corresponding thermodynamics parameter. K_1 quenching experiment found that there was not obvious protection of ct-DNA to BDF. The fluorescence intensity of BDF/ct-DNA system changed with the variation in ionic strength. Quenching of ct-DNA on the fluorescence of BDF/β-CD inclusion complex was reduced in contrast with the free BDF, which showed that β-CD could provide BDF with protection. So the comprehensive interaction mode of BDF with ct-DNA may be the groove binding by the above results. It was indicated that there had been static-electro interaction between BDF and ct-DNA at the same time. The conjunct action of Van der Waals forces and electrostatic attraction favorably provide BDF bonding interaction in the groove of ct-DNA.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2009年第4期999-1003,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(20575076)
山西高校科技研究开发基金项目(20051223)资助
