乳腺生物反应器表达产物层析分离过程中介质的污染机理及其再生策略

Contamination mechanism and regeneration strategies of chromatographic resin in separation process for expression product from mammary gland bioreactor

摘要:

考察了磺酸基离子交换层析介质 (SP Sepharose FF) 在分离表达人乳铁蛋白的重组牛乳过程中的污染机理及其再生策略。通过层析原料及流分中各组分含量的检测分析，发现牛乳中的脂类通过堵塞效应或疏水相互作用残留在层析柱上，造成层析运行压力升高；部分酪蛋白通过静电相互作用占据介质的配基位点，导致介质的交换容量降低；乳糖与介质之间无直接相互作用。连续层析运行次数的增加以及层析-再生时间间隔的延长，均能导致残留组分和介质之间的相互作用逐渐增强，最终影响介质的再生效率。使用NaOH进行及时清洗，可以有效地清除柱上残留的脂类和蛋白，恢复离子交换介质的层析性能和微观形态。

Abstract:

This study focused on the contamination mechanism and regeneration strategies of sulfopropyl ion exchange resin (SP Sepharose FF) during the separation of recombinant human lactoferrin from transgenic bovine milk. We analyzed primary constituents’ contents in chromatorgraphic material and fractions. The results showed that the lipid in milk can clog the column or adhere to the resin through hydrophobic interaction, leading to an increase in column pressure. Some casein molecules were found to adsorb onto the resin through electrostatic interaction, therefore the adsorption capacity was decreased. There was no direct interaction between lactose and the resin in the chromatorgraphic process. Increased continuous chromatographic cycles and prolonged time interval between protein purification and column regeneration could enhance the undesirable interaction between the contaminants and resin, thus lowering the regeneration efficiency. NaOH was found to be effective in the removal of lipid and casein molecules from the column. Furthermore, normal microstructure and chromatographic performance of the ion exchanger was recovered after this cleaning procedure.