荧光法测定四种肾上腺素药物与牛血清白蛋白的相互作用

Determination of interaction between four adrenaline drugs and bovine serum albumin by fluorescence method

运用荧光光谱法研究生理pH条件下四种肾上腺素药物与牛血清白蛋白(BSA)在不同温度下的相互作用。固定BSA浓度,梯度变化药物浓度,混合溶液分别在25℃及37℃水浴中温浴2h后进行荧光强度测定,运用Stern-Volmer方程及改进的双对数方程求出不同温度下药物与BSA的结合常数(K)和结合位点数(n)。结果表明,四种肾上腺素药物均与BSA形成结合物,对BSA荧光猝灭机制均为静态猝灭;不同温度下与BSA的K值顺序为硫酸沙丁胺醇>重酒石酸去甲肾上腺素>酒石酸美托洛尔>盐酸肾上腺素,37℃时的结合常数(K)和结合位点数(n)均大于25℃时的结果;热力学参数表明四种肾上腺素药物与BSA之间的结合均为自发过程,与BSA分子间主要作用力类型为疏水作用力。分子对接结果和实验结果符合较好。

The interaction between four epinephrine drugs and bovine serum albumin(BSA)at different temperatures under physiological pH conditions was studied by fluorescence spectroscopy.BSA and drug with different concentration was incubated for 2h at 25℃and 37℃respectively.Subsequently,the fluorescence intensity of the mixture of was determined.The binding constant(K)and the number of binding sites(n)of the drug with BSA at different temperatures were calculated using the Stern-Volmer equation and the modified double logarithmic equation.The results showed that the four kinds of epinephrine drugs all formed a complex with BSA,and the fluorescence quenching mechanism was static quenching.The order of K value at different temperatures is as follows,salbutamol sulfate>norepinephrine bitartrate>metoprolol tartrate>epinephrine hydrochloride.The values of K and n at 37℃are greater than those at 25℃.Thermodynamic parameters showed that the binding between the four epinephrine drugs and BSA is a spontaneous process,and the main type of intermolecular interaction with BSA is hydrophobic interaction.