Simultaneous binding of folic acid and lutein to β-lactoglobulin and α-lactalbumin: A spectroscopic and molecular docking study  

作　　者：Danilo C.Vidotto Guilherme M.Tavares 

机构地区：[1]Department of Food Science and Nutrition,School of Food Engineering,University of Campinas (UNICAMP),Campinas,Brazil

出　　处：《Food Bioscience》2022年第6期973-981,共9页食品生物科学（英文）

基　　金：financed by the S˜ao Paulo Research Foundation(FAPESP)(Grants 2017/09214-4 and 2018/09304-6);The authors thank the Food Chemistry Laboratory(FEA/UNICAMP)for chromatographic analysis(FAPESP multiuser equipment:grants 2018/03822-5 and 2018/23752-1);Also,this research used facilities of the Brazilian Biorenewables National Laboratory(LNBR),part of CNPEM as well.The Macromolecules facility staff is acknowledged for the assistance during CD experiments(proposal MAC-28004).

摘　　要：Whey proteins are versatile molecules with great nutritional value and multiple functionalities. One of these functionalities is the ability to bind and protect bioactive compounds. Lutein and folic acid (FA) are bioactive molecules with a remarkable relevance for developing functional foods. FA contributes in preventing the occurrence of neural tube defects during the early stages of life, while lutein is a macular pigment that contributes to the development of the retina. In this context, the aim of this work was to evaluate the ability of the main whey proteins, β-lactoglobulin and α-lactalbumin, to simultaneously bind FA and lutein. The binding was evaluated through intrinsic fluorescence quenching and molecular docking, and the impact of the binding on the secondary structure and denaturation temperature of the proteins were also evaluated through circular dichroism and differential scanning calorimetry, respectively. Both proteins had similar behavior on the performed analyses. The multi-binding ability of β-lactoglobulin and α-lactalbumin to FA and lutein was observed. The presence of the first ligand slightly reduced the association constant between the second one and the proteins;in particular for the binding of lutein in the presence of FA (reduction of around 36%–38% on the KSV values). Molecular docking indicated that both ligands interact, preferentially, on the same region of the studied protein structures. The secondary structure of the proteins, as well as their denaturation temperatures were minimally impacted by the presence of these ligands, themselves. Our results may contribute to the development of multi-functional protein-rich food products.

关 键 词：Whey proteins Multi-binding Folic acid LUTEIN Fluorescence quenching Molecular modeling 

分 类 号：O62[理学—有机化学]