荧光光谱结合多元曲线分辨-交替最小二乘法研究十二烷基三甲基溴化铵与牛血清白蛋白的相互作用

模拟pH=7.4的人体生理条件,用荧光光谱法结合多元曲线分辨-交替最小二乘法(MCR-ALS),研究表面活性剂十二烷基三甲基溴化铵(CTAB)与牛血清白蛋白(BSA)的相互作用。为增加实验数据的信息量,本实验采用顺序不同的两种滴加方式得到扩展的荧光光谱数据矩阵;进而采用渐进因子分析法(EFA)得到作用体系中各组分浓度变化曲线的初值,再应用MCR-ALS对该扩展荧光光谱矩阵进行迭代计算,较好地分辨出动态作用中各种物质的浓度变化趋势图,并由此曲线推断出CTAB与BSA的表观结合常数和结合比。

Spectroscopic Studies on the Interaction between Cetyltrimethylammoninm Bromide and Bovine Serum Albumin Using MCR-ALS Approach

Under the imitated physiological conditions(pH=7.4),the interaction between cetyltrimethylammonium bromide(CTAB) and bovine serum albumin(BSA) was investigated by fluorescence spectroscopy using the multivariate curve resolution-alternating least-squares method(MCR-ALS).Two different kinds of titration mode were carried out and the obtained spectral data matrices were augmented.The evolving factor analysis(EFA) was utilized to this data matrix to gain the number of components and the initial estimate of the concentration profiles,and MCR-ALS constrained optimization was applied to treat the data matrix.The concentration profiles of the species,the molar ratio of the complex of ∶ and the apparent equilibrium constant Kapp were extracted.The binding constants Ka and the number of binding sites n were also evaluated from the double-logarithm curve.The obtained information from MCR-ALS was compared with the one gained by conventional method,the results showed that the application of the chemometrics approach could lead to satisfactory spectral data interpretation and quantitative information.