喷他脒和DNA相互作用的光谱及电化学研究

Electrochemical Studies of the Interaction between Pentamidine and DNA

应用循环伏安法,差示脉冲伏安法,紫外光谱法研究了喷他脒和DNA的相互作用。在pH 8.5的0.1 mol/L Na2HPO4-NaH2PO4缓冲溶液中,喷他脒于电位-1.56 V处有一灵敏的还原波,向其溶液中加入DNA,喷他脒峰电位稍微负移,峰电流下降;DNA使喷他脒的紫外吸收光谱发生紫移且增色,DNA和喷他脒相互作用形成1∶2非电活性缔合物,结合数为2,结合常数为3.55×106。

The electrochemical behavior of pentamidine and its interaction with DNA were studied using cyclic voltammetry, differential pulse voltammetry and UV-visible spectroscopy. In 0. 1 mol/L NaH2PO4-Na2HPO4 buffer solution （pH 8. 5）, a reduction wave of pentamidine was observed at -1.56 V. With the addition of DNA in pentamidine solutions, the reduction peak potential moved negatively little and the reduction peak current decreased. The UV spectrum showed that DNA resulted in some increase and purple shift in the absorption of pentamidine. The binding reaction of pentamidine with DNA formed a new non-electrochemical active super-molecular complex. The binding number and equilibrium constant of the complex were calculated to be 2 and 3.55 × 10^6 , respectively.