The interaction of 4'-O-(α-L-oleandrosyl)daunorubicin( ODNR) with calf thymus DNA(ctDNA) in Tris-HCl buffer solution (pH =7.4) was studied by fluorescence and ultraviolet absorption spectroscopies. Effects of the ionic strength, KI quenching, and the ODNR binding differences between the single stranded DNA(ssDNA) and the double stranded DNA(dsDNA) were studied. The results showed that the major binding mode between ODNR and ctDNA was intercalation. The intrinsic fluorescence of ODNR was quenched by ctDNA through static quenching procedure. The binding constants ( K) and sites ( n) at different temperatures were obtained by Scatchard equation. The predominant intermolecular forces are likely the hydrophobic and electrostatic interactions according to the thermodynamic parameters.%在pH =7.4的ris-HCl介质中,利用荧光光谱和紫外吸收光谱法,研究了一种新型蒽环类抗癌药物柔红霉素衍生物(4＇-O-(α-L-夹竹桃糖基)柔红霉素,ODNR)与小牛胸腺DNA(ctDNA)的相互作用.通过离子强度的影响、KI荧光猝灭实验和单双链ctDNA作用的比较实验,分析了ODNR与ctDNA的相互作用模式.结果表明,ODNR通过嵌插方式与ctDNA发生作用.ctDNA对ODNR的荧光有明显的猝灭作用,其机理属于静态猝灭.通过Scatchard方程求得不同温度下的结合常数和结合位点数,由热力学参数确定分子间作用力为疏水作用,也可能存在静电作用.
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