不同pH条件下槲皮素与牛血清白蛋白相互作用的电化学研究

Electrochemical Studies on Interaction Between Quercetin and Bovine Serum Albumin at Different pH

应用线性扫描伏安法讨论了牛血清白蛋白(BSA)等电点pI4.8两侧,即:pH 6.2KH2PO4-NaOH缓冲液及pH4.1 HAc-NaAc缓冲液中,槲皮素(QUE)、QUE-BSA体系的电化学行为,研究了不同pH条件下QUE与BSA的相互作用。在NaOH活化玻碳电极上,QUE均产生一灵敏氧化峰,峰电流较裸玻碳电极增加显著,加入BSA后峰电流降低,峰电位移动不明显,且QUE、QUE-BSA体系的电极反应均为扩散控制的不可逆过程。计算了两种介质条件下,QUE与BSA的结合数均为2,结合常数分别为2.82×1010L/mol、7.94×107L/mol,结果表明介质条件对相互作用有很大影响。

The interaction between quercetin（QUE） and bovine serum albumin（BSA） was investigated by linear sweep voltammery in different buffer solutions of different pH.On the glass carbon electrode activated by NaOH solution,QUE yielded an irreversible oxidation peak both in pH 6.2 KH_2PO_4-NaOH and in pH 4.1 HAc-NaAc buffer solutions whose pH values were on both sides of BSA＇s isoelectric point 4.8.The peak current increased markedly comparing with bare electrode.With the addition of BSA into the QUE solution,the peak current of QUE reduced without any significant shift of the peak potential.The electrode processes of QUE and QUE-BSA system were both controlled by diffusion.The binding ratio was calculated as 2,and the binding constant were 2.82×1010 L/mol and 7.94×107 L/mol,respectively.The result showed that the interaction was influenced by the condition of the medium.