L-半胱氨酸二肽与DNA的相互作用研究  

Study on the Interaction of L-Cysteine Dipeptide with DNA

作　　者：卢奎[1,2] 成红丽[1] 马丽[1] 赵东欣[1] 杨亮茹[1] 赵玉芬[3] 

机构地区：[1]河南工业大学化学化工学院,河南郑州450001 [2]河南工程学院,河南郑州451191 [3]清华大学化学系,生命有机磷化学与化学生物学教育部重点实验室,北京100084

出　　处：《光谱学与光谱分析》2010年第1期146-149,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20572016,20772023);河南省教育厅科技计划项目(2006KYCX017)资助

摘　　要：以溴化乙锭(EB)为荧光探针,利用紫外-可见光谱法和荧光分光光度法等手段研究了L-半胱氨酸二肽(Cys-Cys)与DNA的相互作用,并推测了其相互作用机理和作用模式。结果表明:随着二肽浓度的增加,DNA-Cys-Cys体系的紫外光谱先呈减色效应,继续增大其浓度时又呈增色效应;盐效应实验表明此相互作用容易受环境中离子强度的影响;随着二肽浓度的增加,EB-DNA复合体系的荧光猝灭,Stern-Volmer方程说明此过程为静态猝灭,通过Lineweaver-Burk方程计算得到两者作用的结合常数为1.640×10~4L·mol^(-1)。综合以上结果可知:Cys-Cys与DNA的作用方式主要为静电结合。这一实验结果为进一步在分子水平上研究寡肽类小分子与DNA的作用提供一定的理论依据。In the present paper the interaction mechanism and mode of biologically active cysteine dipeptide （Cys-Cys） with DNA was studied by UVVis spectrophotometry and fluorescence spectroscopy using ethidium bromide as a fluorescence probe. The results showed that in the buffer solution of Tris-HCl （pH 7.20）, at low concentration of Cys-Cys, the ultraviolet spectrum of DNA-Cys-Cys system produced hypochromic effect with increasing the concentration of Cys-Cys. When the concentration of Cys-Cys increased to some high extent, the ultraviolet spectrum of DNA-Cys-Cys system produced hyperchromic effect. Salt-effect experiment showed that the interaction is liable to be affected by the ionic strengths, suggesting the existence of electrostatic binding between Cys-Cys and DNA. The fluorescence of EB-DNA had quenching effect with increasing the concentration of Cys-Cys, and the Stern Volmer equation indicated that the quenching process was a static one. According to the Lineweaver-Burk equation the binding constant was determined to be 1. 640× 10^4 L· mol^- 1. From the above results it can be concluded that the interaction mode of Cys-Cys with DNA was mainly electrostatic binding. These findings could contribute to further investigation on the mechanism of oligopeptides interaction with DNA.

关 键 词：紫外-可见光谱法 荧光分光光度法 半胱氨酸二肽 脱氧核糖核酸 相互作用 

分 类 号：O657.3[理学—分析化学]