基于食品蛋白—多配体复合物的活性成分载体的研究

近年来，蛋白质和配体复合物已被建议可作为活性成分的载体或复杂载体体系的组成部分。阐明它们的结合特性是基于蛋白质的载体系统开发的关键。目前，关于蛋白质和配体的研究多集中在蛋白质-单配体复合物。然而，单一成分通常不能满足实际应用的需要。随着具有多个配体结合位点的蛋白质不断被发现和不同蛋白质间相互作用的广泛研究，使得制备蛋白质-多配体复合物成为可能。本研究将选择疏水性维生素E、两亲性白藜芦醇和亲水性叶酸作为模型配体，乳球蛋白、酪蛋白和两者混合物作为模型蛋白，在对蛋白质和配体结合机制研究的基础上，制备可同时结合不同配体的蛋白质-多配体复合物，揭示复合物作为载体的优缺点；然后，通过蛋白质与多糖再组装，制备基于蛋白质-配体复合物的多功能性纳米载体。本研究结果将为蛋白质和配体作用模型和机理提供更多科学理论依据，将对基于食品蛋白的稳定化技术和活性成分在食品和保健食品领域应用具有重要的指导作用和现实意义。

It has been recently suggested that ligand-binding proteins could be potentially used as carriers or components of complex carrier systems for protection and delivery of bioactive components. To clarify the mechanism of protein-ligand interactions is of utmost importance for the development of carrier systems based on proteins. Most of the studies on protein-ligand interactions have focused on the formation and dissociation of the complexes of single ligand with different proteins. However, a single component may usually not meet the requirements in the real-world applications. Nowadays more and more proteins with multiple ligand-binding sites are being reported, which, together with interactions between different proteins, makes it possible to prepare protein-multiligand complexes. In this study, beta-lactoglobulin, casein and their mixtures will be used as model proteins to interact respectively with hydrophobic alfa-tocopherol, amphiphilic resveratrol and hydrophilic folic acid to reveal the mechanism of a single ligand binding to different proteins. On this basis, protein-multiligand complexes will be prepared by binding of multiple ligands simultaneously to the same proteins and influence of the complexes on the ligand hydrosolubility and stability will be analyzed, to discuss the characteristics of the complexes as carriers for active compounds. Finally, the complex nanoparticles will be prepared by interacting ligand-bound proteins with polysaccharides. We will analyze comprehensively influence of the protein-ligand-polysaccharide nanoparticles on the accessibility of the ligands to media and the ligand solubility and stability, in comparison with that of the protein-ligand complexes, to discuss the potential of the nanoparticles used as effective carriers of environmental stimuli-sensitive component payloads. The data gathered from the project could provide more theoretical and scientific basis for further study on the binding mode and interaction mechanism of ligands on proteins, and should help guide the development of stabilization technology based on proteins for the fortification of food and functional food with bioactive components.