食用合成色素胭脂红对胰蛋白酶光谱性质的影响  

Effect of ponceau 4R on the spectral properties of trypsin

作　　者：张东霞[1] 

机构地区：[1]西京学院应用统计与理学系,陕西西安710123

出　　处：《食品工业科技》2017年第13期58-63,共6页Science and Technology of Food Industry

基　　金：陕西省教育厅科研项目(15JK2184)

摘　　要：应用荧光光谱法、紫外可见吸收光谱法、傅立叶变换红外光谱和圆二色光谱法,研究了食用合成色素胭脂红与胰蛋白酶的结合性质,明确胭脂红与胰蛋白酶之间的结合常数、结合位点数(n)、作用力类型、结合距离(r)等信息。结果表明,胭脂红对胰蛋白酶内源荧光强度有较强的猝灭能力,荧光猝灭机制属于形成复合物的静态猝灭,由实验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胭脂红-胰蛋白酶复合物形成的主要作用力,胭脂红与胰蛋白酶的结合常数达到104mol/L数量级,存在中等强度的亲和力。光谱分析表明胭脂红与胰蛋白酶结合引起胰蛋白酶的氨基酸残基微环境发生改变,胰蛋白酶的二级结构α-螺旋和无规则卷曲含量增加,β-折叠和β-转角的含量降低,多肽链有所收缩。The binding characteristics between ponceau 4R and trypsin was investigated by fluorescence, UV-vis absorption, Fourier transform infrared （ FT- IR ） and circular dichroism （CD） spectroscopy, to obtain the binding constant, binding sites （ n）, the types of forces, the binding distance （r）between ponceau 4R and trypsin, and other information. The results showed that ponceau 4R had a strong ability to quench the intrinsic fluorescence of trypsin, the quenching mechanism of trypsin by the ponceau 4R was a static process. The calculated thermodynamic parameters showed that the binding process was primarily driven by hydrogen bonds and van der Waals forces.The binding constant between them was 10^4 orders of magnitude, revealing that ponceau 4R can bind to trypsin with moderate affinity.Moreover, analysis of synchronous fluorescence, UV-vis absorption, Fourier transform infrared （ FT- IR ） and CD spectra demonstrated that the binding interaction induced the microenvironment changes and conformational alteration of trypsin with increases in α-helix and random coil contents, and reduction of β-sheet and β-turn structures.resultinz in partial shrinkage of the polypeptides of protein.

关 键 词：胭脂红 胰蛋白酶 荧光猝灭 结合性质 

分 类 号：TS201.1[轻工技术与工程—食品科学]