Investigation of the binding behavior of human serum albumin and phosphorothioate oligodeoxynucleotide

人血清白蛋白与硫代寡核苷酸的结合研究

Aim To study the binding behavior between human serum albumin （HSA） and phosphorothioate oligodeoxynucleotide （PS- ODN） and the effects of bivalent cations on the interaction. Methods Surface plasma resonance, circular dichroism and fluorescence experiments were conducted. Results （ 1 ） the binding ability was decreased along with the increase of pH; （2） Zn^2＋and Ni^2＋ enhanced the interaction between PS-ODN and HSA; （3） Upon PS-ODN binding, the conformation of HSA was changed with an increase of β - sheet. Conclusion The results provide experimental evidences to the hypothesis that PS-ODN binds with HSA in the positive potential region, and histidine residues located in the region play a crucial rule in the interaction.

目的研究二价阳离子对白蛋白与硫代寡核苷酸结合的影响以及结合硫代寡核苷酸后白蛋白构象的改变。方法应用表面等离子体共振、圆二色散以及荧光光谱法对白蛋白与硫代寡核苷酸的结合行为进行了表征。结果(1)随着pH值升高,结合能力降低;(2)锌离子能显著促进白蛋白与硫代寡核苷酸的结合, 镍离子也促进结合,但与锌离子相比作用稍弱;(3)与硫代寡核苷酸结合后,白蛋白结构发生变化,产生β-折叠构造。结论通过实验方法证明硫代寡核苷酸结合于白蛋白的正电荷密集区;表明白蛋白可能介导硫代寡核苷酸的胞吞行为。