Breakage of unstable protein crystals in mechanical solid-liquid separation processes

机械固液分离过程中不稳定蛋白质晶体的破碎

• 批准号: 315011332
• 负责人: Professor Dr.-Ing. Hermann Nirschl
• 金额: --
• 依托单位: Arbeitsgruppe Verfahrenstechnische Maschinen (VM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/315011332?language=en
• 关键词: Breakage; unstable; protein; crystals; mechanical

As part of the DFG priority program “Disperse, structural and phase changes of proteins and biological agglomerates in biotechnological processes (DiSP Biotech)”, the applicant is investigating the filtration and fracture behavior of mechanically labile protein crystals. The comprehensive analysis of biotechnological processes from cultivation to formulation on the micro to macro scale aims to better understand and optimize the entire process chain. Cornehl et al. showed that crystal size, shape and breakage have a strong influence on the filtration performance of lysozyme crystals. Both, protein expression and crystallization, affect crystal morphology and breakage behavior. Modifications and optimizations of the proteins or crystals have an effect on the subsequent process steps. Ultimately, it must be ensured that the target product passes the complete process chain successfully.The process functions (flux density function and compressive yield stress), which were determined by centrifugal filtration on a small scale in the first project phase, do not take any inhomogeneity of the filter cake into account. In the case of centrifugal filtration the maximum pressure is applied to the bottom of the filter cake, which leads to an inhomogeneous breakage behavior. Pressure stressed filter cakes show a shift in crystal size distribution towards smaller crystals. In addition to the compressive stress, shear stress also occurs in technical filtration processes, which results in crystal breakage and reduces the crystal size. The influence of shear stress on the cake structure and the process functions for protein crystals has to be clarified within the scope of this research project.The μCT analysis allows to investigate structural differences in the filter cake and to determine the crystal size distribution. Models for correcting and transferring process functions from a small-scale to larger filtration units do not exist for mechanically labile protein crystals. However, this is a prerequisite for the application of the process functions to calculate the filtration behavior on larger separation apparatuses. Hence, such a model has to be developed in this project. Supported by CFD simulations, the optimization of separation apparatuses under consideration of breakage mechanisms will be carried out. With 3D printing and rapid prototyping constructive improvements of the filtration apparatus can be realized and compared with regard to the filtration behavior and crystal breakage.

作为DFG优先级计划的一部分，“在生物技术过程（DISP Biotech）中，蛋白质和生物层的结构和相变”，适用的是研究机械标记蛋白质晶体的过滤和裂缝行为。从培养到微观量表上的生物技术过程的全面分析旨在更好地理解和优化整个过程链。 Cornehl等。表明晶体尺寸，形状和破裂对溶菌酶晶体的过滤性能有很大影响。蛋白质表达和结晶都会影响晶体形态和破裂行为。蛋白质或晶体的修改和优化对随后的过程步骤有影响。最终，必须确保目标产品成功通过完整的过程链。过程函数（通量密度函数和压缩屈服应力）是通过在第一个项目阶段小规模的离心过滤确定的，不要考虑过滤蛋糕的任何不均匀性。在离心过滤的情况下，将最大压力施加到过滤蛋糕的底部，这导致了不均匀的断裂行为。压力压力滤镜显示晶体尺寸分布向较小的晶体变化。除了压缩应力外，剪切应力还会在技术过滤过程中发生，从而导致晶体断裂并降低晶体尺寸。在此研究项目的范围内必须阐明剪切应力对蛋糕结构的影响和蛋白质晶体的过程功能。μCT分析允许研究过滤蛋糕中的结构差异并确定晶体尺寸分布。对于机械不稳定的蛋白质晶体而言，不存在用于校正和转移工艺功能从小尺度到较大过滤单元的模型。但是，这是应用过程函数以计算较大分离设备上的过滤行为的先决条件。因此，必须在该项目中开发这样的模型。在CFD仿真的支持下，将对正在考虑的断裂机制的分离设备进行优化。通过3D打印和快速原型制作过滤设备的建设性改进，并且可以在过滤行为和晶体破裂方面进行比较。