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应用光谱手段研究了在pH值7.4的生理酸度条件下氟氯氰菊酯(CF)与牛血清白蛋白(BSA)之间的相互作用。测定了不同温度下的猝灭常数,证实了在0.35~4.16μmol/L的浓度范围内氟氯氰菊酯对BSA的内源荧光有较强的猝灭作用,机理为静态猝灭。计算了热力学参数,由焓变(ΔH)和熵变(ΔS)值推断氟氯氰菊酯与BSA之间主要靠疏水作用力结合,生成自由能变ΔG小于0,表明此作用过程是一个自发过程。结合过程中BSA构象的变化通过同步荧光和圆二色谱实验得以证实。圆二色谱实验的结果显示BSA中的α-螺旋结构损失了,说明其微环境及构象均发生了变化。
The interaction between cyfluthrin (CF) and bovine serum albumin (BSA) was studied spectrophotometrically at physiological pH of 7.4. The quenching constants at different temperatures were measured. It was confirmed that cyfluthrin strongly quenched endogenous fluorescence of BSA in the concentration range of 0.35 ~ 4.16μmol / L, the mechanism of which is static quenching. The thermodynamic parameters were calculated. From the enthalpy change (ΔH) and entropy change (ΔS) value, it was concluded that the interaction between cyfluthrin and BSA mainly depends on the hydrophobic force, and the free energy change ΔG is less than 0, indicating that this process is a spontaneous process. The conformational changes of BSA during the binding process were confirmed by synchronous fluorescence and circular dichroism. The results of circular dichroism showed that the α-helical structure in BSA was lost, indicating that the microenvironment and conformation of the BSA changed.