摘要
本实验模拟人体生理酸度(p H 7.4),应用荧光光谱法、紫外光谱法和圆二色光谱法,研究了食品着色剂柠檬黄与牛血清白蛋白(BSA)的结合性质。结果表明:柠檬黄对BSA内源荧光有较强的猝灭能力,荧光猝灭机制属于形成复合物的单一静态猝灭,计算得出的热力学参数熵变和焓变均为负值,表明氢键和范德华力是驱动柠檬黄-BSA复合物形成的主要作用力,25℃时结合常数已经达到3.04×105L·mol-1,表明柠檬黄与BSA有较强的亲合力。位点竞争实验表明:柠檬黄主要结合至BSA疏水空腔的亚域IIA,即site I位。荧光光谱、紫外光谱和圆二色光谱分析结果显示:柠檬黄与BSA结合引起BSA的表面疏水性增加,α-helix的含量减少,BSA二级结构发生了部分改变。
The binding characteristics between tartrazine and bovine serum albumin（ BSA） were investigated by fluorescence,UV-vis absorption and circular dichroism（ CD） spectroscopy under simulative physiological conditions（ pH 7. 4）. The results showed that tartrazine had a strong ability to quench the intrinsic fluorescence of BSA,the fluorescence quenching was a single static quenching process. Thermodynamic analysis of the binding data obtained at different temperatures showed that the binding process was primarily driven by hydrogen bonds and van der Waals forces. The binding constant at 298 K was calculated to be 3. 04 × 10^5L·mol^- 1,indicating that a high affinity existed between tartrazine and BSA. The site markers competitive experiments suggested that tartrazine and warfarin shared a common binding site corresponding to the subdomain IIA（ site I） of BSA. Analysis of synchronous fluorescence,UV-vis absorption and CD spectra demonstrated that the addition of tartrazine resulted in the conformational alteration of BSA with a decreasing in α-helix structure. The determination of protein surface hydrophobicity（ PSH）indicated that tartrazine binding to BSA caused an increasing in the PSH.
出处
《南昌大学学报（工科版）》
CAS
2015年第3期240-245,共6页
Journal of Nanchang University(Engineering & Technology)
基金
国家自然科学基金资助项目(31460422
21167013)
江西省自然科学基金资助项目(20143ACB20006
20142BAB204001)
江西省科技支撑资助项目(20141BBG70092)
食品科学与技术国家重点实验室基金资助项目(SKLF-ZZB-201305)
高等学校博士学科点专项科研基金联合资助项目(20123601110005)
南昌大学大学生创新创业训练计划资助项目(14001745)
关键词
柠檬黄
牛血清白蛋白
荧光猝灭
结合性质
tartrazine
bovine serum albumin
fluorescence quenching
binding characteristic
