荧光探针法研究色氨酸二肽与DNA的相互作用  

Study on the interaction of trp-trp and DNA by fluorescence probe

作　　者：卢奎[1] 冯业振[1] 赵东欣[1] 任海平[1] 赵玉芬[2] 

机构地区：[1]河南工业大学化学化工学院,郑州450001 [2]清华大学化学系,生命有机磷化学及化学生物学教育部重点实验室,北京100084

出　　处：《分析试验室》2009年第1期1-4,共4页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(20272055，20572016);河南省杰出青年基金(0312000900)项目资助

摘　　要：以溴化乙锭(EB)为荧光探针,对色氨酸二肽(Trp-Trp)与小牛胸腺DNA的作用机制进行了研究,考查了酸度、离子强度及磷酸根离子对Trp-Trp与DNA相互作用的影响;结果表明,在pH 7.2的模拟体液条件下,Trp-Trp可与DNA发生相互作用;向DNA-EB体系中加入Trp-Trp时荧光逐渐减弱,这说明Trp-Trp能与DNA发生作用。通过Scatchard方程进一步分析发现,Trp-Trp对DNA-EB的影响表现为混合模式:一方面,Trp-Trp能中和DNA上的磷氧负离子,导致DNA链收缩,从而影响DNA的构象,使嵌入的EB从DNA中部分游离出来,荧光减弱;另一方面,Trp-Trp与EB也存在静电位点竞争。The interaction between tryptophan dipeptide （Trp-Trp） and ct-DNA was studied by fluorescence spectroscopy using ethidium bromide （EB） as fluorescence probe, the effect factors such as acidity, salt effect and phosphoric acid ion on the interaction are investigated; It is showed that in Tris-HCl （pH 7.2）, Trp-Trp can react with DNA. The fluorescence intensity of DNA-EB quenched with the increase of Trp-Trp. According to the equation of scatchard, influence of Trp-Trp on interaction of DNA-EB belongs to mixed model. On the one hand, the oxyphosphate anion of DNA can be neutralized by Trp-Trp partially, which induced the contraction of DNA and the conformational change of DNA, leading to release of EB from DNA partially; on the other hand, the Trp-Trp can also compete the electrostatic sites with EB directly.

关 键 词：荧光光谱 色氨酸二肽 小牛胸腺DNA 相互作用 

分 类 号：O629.7[理学—有机化学] O657.3[理学—化学]