Abstract: Benzoate is used as food preservative widely.The interaction of bovine serum albumin (BSA) with benzoate in vitro was studied by ultraviolet (UV) absorption spectral, fluorescence spectral, and Fourier transform infrared (FT-IR) spectral methods. With the addition of benzoate, the UV absorption peak of BSA at 210nm decreased gradually and moved to longer wavelengths. FT-IR measurement indicated the decrease of the percentage of α-helix of BSA. The fluorescence of tryptoph an residue in BSA was quenched by benzoate. The experimental results showed that benzoate caused the change of conformation of BSA and 10mg benzoate in 1mg BSA damaged BSA.

Key words: benzoate, BSA, UV spectra, fluorescence spectra, FT-IR spectra

摘要： 通过紫外光谱、荧光光谱、傅里叶红外光谱的方法研究了苯甲酸钠与牛血清白蛋白(BSA)的体外相互作用。苯甲酸钠的加入使得白蛋白紫外吸收光谱中210nm处的峰值逐渐降低，峰位红移。傅里叶红外光谱的测量结果显示随着苯甲酸钠的加入白蛋白中α-螺旋的百分含量减少。白蛋白中色氨酸残基的荧光被苯甲酸钠淬灭。以上光谱结果表明苯甲酸钠引起了BSA构象的变化，1mg的BSA中加入10mg苯甲酸钠，就会造成BSA损伤。

关键词: 苯甲酸钠, 牛血清白蛋白, 紫外光谱, 荧光光谱, 傅里叶红外光谱