Impact and control of mechanical stress on protein structures during formulation in premix-emulsification

该项目的目的是量化机械应力(应力停留时间)和由此产生的工艺诱导的蛋白质和生物聚集体在预混膜乳化过程中的结构变化。在此基础上，确定了蛋白质和生物凝聚体的应激反应的潜在机制，并得出了工艺设计和控制的概念。假设蛋白质的结构变化依赖于膜上的应力停留时间。在项目的第一部分，从过程和结构水平上研究了膜中β-乳球蛋白的结构随应力停留时间的变化。在该项目即将到来的部分，将系统地研究蛋白质之间的分子间相互作用和过程环境中的相互作用，以及膜上的吸附现象。通过使用β-乳球蛋白(高压修饰蛋白、淀粉样聚集体、重组蛋白)的结构修饰变体，蛋白质结构将发生变化。采用傅立叶变换红外光谱、圆二色谱等高分辨蛋白质分析方法对复合材料的性质进行了研究。将通过渗透压法和分析超速离心法扩大分析产品组合。模拟技术将通过分子动力学的扩展方法来完成。此外，在项目的第二部分中，酶脂肪酶将被用作具有复杂的三级和四级结构的模型蛋白。将调查其活动的变化，从而产生关于生物系统中与过程相关的压力和功能损失的知识。为了实现特定项目的目标，需要不来梅莱布尼茨研究所多相流系与柏林工业大学食品技术和食品材料科学系之间的密切合作，他们在过程和结构水平上的分析和建模能力。柏林理工大学食品胶体系提供了表征分子间相互作用和吸附过程的具体能力。与优先计划内的其他合作伙伴的密切合作将导致对工艺诱导应力及其在各种不同情况下对生物系统材料特性的影响的广泛理解。这一理解将使生物系统能够更有针对性地进行工艺工程并使其适应其特定的工艺环境。

The aim of the project is to quantify the mechanical stress (stress residence time) and resulting process-induced structural changes on proteins and bio-agglomerates during premix membrane emulsification. Based hereon underlying mechanisms of stress response for proteins and bio-agglomerates are identified and concepts for process design and control are derived. It is assumed that the structural change of proteins depends on the stress residence time in the membrane.In the first part of the project, structural changes of β-lactoglobulin in the membrane as a function of the stress residence time were investigated at the process and on the structural level. In the upcoming part of the project, the intermolecular interactions of proteins and interactions within the process environment as well as sorption phenomena at the membrane will be systematically investigated. Protein structures will be varied by using structurally modified variants of β-lactoglobulin (high-pressure-modified protein, amyloid-like aggregates, recombinant proteins). The complex material properties were studied using high-resolution protein analysis such as Fourier transform infrared spectroscopy and circular dichroism. The analytical portfolio will be extended by osmometry and analytical ultracentrifugation. Simulation techniques will be completed with an extended approach of molecular dynamics. Furthermore, in the second part of the project, the enzyme lipase will be used as a model protein with complex tertiary and quaternary structure. Change in its activity will be investigated and thus knowledge about process-related stress and loss of functionality in biological systems will be generated.To fulfill the aim of the specific project, a close cooperation between the Department of Multiphase Flow of the Leibniz Institute in Bremen and the Department of Food Technology and Food Material Science of the Technical University Berlin with their competencies in analysis and modeling at the process and the structural level is required. Specific competencies on the characterization of intermolecular interactions and sorption processes are provided by the Department of Food Colloids of the Technical University Berlin. Close cooperation with other partners within the priority program will lead to a generalized understanding of process-induced stress and its impact on material properties of biological systems in a wide range of different scenarios. This understanding will allow a more targeted process engineering and adaption of biological systems to their specific process environment.