摘要
用电化学和光谱方法研究了溶液pH对硫堇(TH)与小牛胸腺脱氧核糖核酸(CT-DNA)相互作用方式的影响。电化学测量结果表明,在pH 7.2的磷酸盐缓冲溶液中,TH与CT-DNA之间的作用方式以嵌入结合为主,在pH6.5的磷酸盐缓冲溶液中,TH与CT-DNA之间的作用方式既存在嵌入结合也存在静电作用。荧光光谱测量结果表明,TH与DNA结合后其荧光发生猝灭,通过Stern-Volmer方程计算得到pH 6.5时TH-DNA体系的猝灭常数高于pH 7.2时的值,表明在pH 6.5的溶液中两者相互作用更强。圆二色谱(CD)实验结果也证实了这一结论。
The effect of pH of solution on the interaction between TH(thionine) and CT-DNA was studied using electrochemical and spectroscopic methods. The electrochemical results indicated that the interaction between TH and CT-DNA is in the intercalative mode in the pH 7.2 phosphate buffer solution, but both intercalative and electrostatic modes exist in the pH 6.5 phosphate buffer solution. Fluorescence spectroscopic results showed that the fluorescence intensity of TH is efficiently quenched by CT-DNA bases. The quenching constant, K-sv obtained from the Stern-Volmer equation for the pH 6.5 solution is larger than that for the pH 7.2 solution indicating that the interaction between TH and CT-DNA in the pH 6.5 solution is stronger than that in the pH 7.2 solution. The conclusion is confirmed by the results of CD spectroscopic measurements.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2003年第11期1064-1068,共5页
Acta Physico-Chimica Sinica
基金
江苏省教育厅自然科学基金(02KJB150006)
国家"211"工程重点学科建设资助项目~~
