β-环糊精-4-苄氧基苯酚包合物与DN A的相互作用

摘要

以溴化乙锭（EB）为分子探针，生理pH＝7.4环境下，分别采用荧光光谱法、化学热力学法和黏度法等手段研究了β-环糊精-4-苄氧基苯酚（β-CD-PBP）包合物与鲱鱼精DNA （hsDNA）的相互作用。利用摩尔比法测定β-环糊精（β-CD）与4-苄氧基苯酚（PBP）的包合比nβ-CD∶nPBP ＝1∶1，其包合常数Kf＝7.39×103 L· mol-1。β-CD-PBP包合物与hsDNA的结合比nDNA∶nβ-CD-PBP ＝1∶9，结合常数为K300.15K ＝2.86×103 L/mol，K310.15K＝2.69×104 L/mol。热力学函数ΔrHmθ＝1.44×105 J/mol，ΔrGmθ300.15K ＝-1.97×104 J/mol，ΔrSmθ＝549.32 J/（mol·K），结果表明β-CD-PBP包合物与DNA作用是熵驱动，β-CD-PBP与hsDNA的作用方式为静电和部分嵌插的作用方式。%Ethidium bromide (EB) was used as molecule probe,the interaction between β-cyclodex-trin-4-Benzyloxypheno (β-CD-PBP)and herring-sperm DNA was studied in physiological buffer solution (pH=7.4)by fluorescence spectroscopy,thermodynamic analysis and viscosity method.Based on the mole ratio method and linear method,the parameters were determined as follows:the binding ratio nβ-CD∶nPBP=1∶1 and binding constant Kf=7.39 ×1 03 L·mol-1 .The binding ratio was nDNA∶nβ-CD-PBP=1∶9,the thermodynamic perameters were ΔrHmθ=1.44 ×1 05 J/mol,ΔrGmθ300.15K=-1.97 ×1 04 J/mol,ΔrSmθ=549.32 J/mol·K. ΔrSmθwas the primary driven power of this interaction,the binding constants were K300.15K=2.86 ×1 03L/mol,K310.15K=2.69 ×1 04L/mol.These results indicated that the interaction between β-CD-PBP and herring-sperm DNA belonged to electrostatic and part intercalation.