磺胺嘧啶钠探针分析生物样品中蛋白质含量的研究

在pH 7.4的Tris-HCl缓冲溶液中,荧光猝灭光谱和三维荧光光谱显示磺胺嘧啶钠(SDS)可与人血清白蛋白(HSA)相互作用,使人血清白蛋白疏水微环境极性以及构象发生变化。考察了Δλ值、反应介质、离子强度等因素对该体系同步荧光光谱特征及强度的影响。在选定的最佳实验条件下,体系的同步荧光强度(ISF)与人血清白蛋白在1.38～276μg/mL的浓度范围内呈现良好的线性关系,线性相关系数为0.9992,从而建立了以磺胺嘧啶钠为分子探针,用固定波长同步荧光光谱分析测定蛋白质的新方法,检测限可达0.48μg/mL。用此方法对生物样品人血清、唾液和尿液中蛋白质含量进行了测定并进行加标回收实验,回收率在95.7%～103.7%之间。本文还用经典的考马斯亮蓝法对样品进行了测定,所得结果和本方法一致。同时还考察了一些常见的共存物质对蛋白质测定的影响。

Study on the determination of protein in biological samples with sulfadiazine sodium as a fluorescence probe

The interaction between sulfadiazine sodium(SDS) and human serum albumin(HSA) was investigated by the fluorescence spectra and the three-dimensional spectra in Tris-HCl buffer solution,which resulted in the changes of the conformation and hydrophobic micro-environment of HSA.The effect factors on spectral characterization and intensity of synchronous fluorescence such as the value of Δλ,pH,ionic strength,were also studied.Under the optimum conditions,based on that the synchronous fluorescence intensity(ISF) of the system was in direct proportion to the concentration of protein in the range of 1.380 - 276.0 μg/mL,a new method for the determination of the protein with sulfadiazine sodium as a fluorescence probe was proposed and the detection limit was 0.48 μg/mL.And the amount of the proteins in human serum,saliva and urine samples were detected and the recoveries were 95.74%-103.7%.The results obtained with this method were consistent with those obtained by the coomassie brilliant blue method.The effects of coexistent ions were also investigated.