Abstract The aim of the study was to immobilize zinc ions by β-lactoglobulin (βLG) micelles. The investigation focused on physicochemical properties of β-lactoglobulin and zinc-β-lactoglobulin complexes as well as the stability of the obtained complex in synthetic physiological fluids. Kinetic and isothermal studies of zinc ion immobilization by βLG were conducted based on batch sorption approach, while the mechanism of binding zinc ions to βLG was determined and described by application of several kinetic and isotherm models, such as zero order, first and pseudo-first order, intraparticle Weber-Morris diffusion, Langmuir and Freundlich models. The nature of binding/immobilization of zinc ions to βLG was determined with instrumental complementary analysis by using the spectrometric, spectroscopic, microscopic, thermal and X-ray diffraction methods. The results revealed that zinc ion binding to βLG is a heterogeneous process which consists of three main stages: the stage one was associated with rapid sorption of zinc ions on the surface of βLG micelles, while stages two and three resulted from intramolecular diffusion of zinc ions. Moreover, based on instrumental and stability study it was proven that acidic (Glu, Asp) and aromatic (Tyr, Trp, Phe) amino acid groups participate in formation of Zn-βLG complex as a metallocomplex with nutraceutical potential.

中文翻译：

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β-乳球蛋白固定锌离子的研究

摘要 本研究的目的是通过β-乳球蛋白（βLG）胶束固定锌离子。研究的重点是 β-乳球蛋白和锌-β-乳球蛋白复合物的理化性质以及所得复合物在合成生理液中的稳定性。基于批量吸附方法对βLG固定锌离子的动力学和等温研究进行了研究，同时通过应用几种动力学和等温线模型，如零级、一级和伪一级来确定和描述锌离子与βLG的结合机制。顺序，粒子内 Weber-Morris 扩散，Langmuir 和 Freundlich 模型。通过使用光谱、光谱、显微、热和 X 射线衍射方法，通过仪器互补分析确定锌离子与 βLG 结合/固定的性质。结果表明，锌离子与 βLG 的结合是一个异质过程，包括三个主要阶段：第一阶段与锌离子在 βLG 胶束表面的快速吸附有关，而第二和第三阶段则是锌离子的分子内扩散。 . 此外，基于仪器和稳定性研究证明，酸性（Glu、Asp）和芳香族（Tyr、Trp、Phe）氨基酸基团作为具有营养保健潜力的金属络合物参与了 Zn-βLG 络合物的形成。