Lelis Carini Aparecida, Hudson Eliara Acipreste, Ferreira Guilherme Max Dias, Ferreira Gabriel Max Dias, da Silva Luis Henrique Mendes, da Silva Maria do Carmo Hespanhol, Pinto Maximiliano Soares, Pires Ana Clarissa Dos Santos
Department of Food Technology, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Department of Chemistry, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Food Chem. 2017 Feb 15;217:52-58. doi: 10.1016/j.foodchem.2016.08.080. Epub 2016 Aug 24.
The interaction between Allura Red and bovine serum albumin (BSA) was studied in vitro at pH 7.4. The fluorescence quenching was classified as static quenching due to the formation of AR-BSA complex, with binding constant (K) ranging from 3.26±0.09 to 8.08±0.0610(4)L.mol(-1), at the warfarin binding site of BSA. This complex formation was driven by increasing entropy. Isothermal titration calorimetric measurements also showed an enthalpic contribution. The Allura Red diffusion coefficient determined by the Taylor-Aris technique corroborated these results because it reduced with increasing BSA concentration. Interfacial tension measurements showed that the AR-BSA complex presented surface activity, since interfacial tension of the water-air interface decreased as the colorant concentration increased. This technique also provided a complexation stoichiometry similar to those obtained by fluorimetric experiments. This work contributes to the knowledge of interactions between BSA and azo colorants under physiological conditions.
在pH 7.4的体外条件下研究了诱惑红与牛血清白蛋白（BSA）之间的相互作用。由于形成了AR-BSA复合物，荧光猝灭被归类为静态猝灭，其结合常数（K）在BSA的华法林结合位点处范围为3.26±0.09至8.08±0.06×10⁴ L·mol⁻¹。这种复合物的形成是由熵增加驱动的。等温滴定量热法测量也显示出焓的贡献。通过泰勒-阿里斯技术测定的诱惑红扩散系数证实了这些结果，因为它随着BSA浓度的增加而降低。界面张力测量表明，AR-BSA复合物具有表面活性，因为随着着色剂浓度的增加，水-空气界面的界面张力降低。该技术还提供了与荧光实验获得的相似的络合化学计量。这项工作有助于了解生理条件下BSA与偶氮着色剂之间的相互作用。
