Petsch D, Beeskow T C, Anspach F B, Deckwer W D
GBF, Gesellschaft für Biotechnologische Forschung mbH, Biochemical Engineering Division, Braunschweig, Germany.
J Chromatogr B Biomed Sci Appl. 1997 May 23;693(1):79-91. doi: 10.1016/s0378-4347(97)00013-3.
Surface-modified flat-sheet microfiltration membranes were functionalised with poly-L-lysine, polymyxin B, poly(ethyleneimine), L-histidine, histamine, alpha-amylase and DEAE as well as deoxycholate. Their suitability to remove endotoxin from both buffers and protein solutions was examined using bovine serum albumin, murine IgG1 and lysozyme as model proteins. In protein-free solutions reduction from 6000 EU/ml to <0.1 EU/ml was achieved with all applied ligands; only alpha-amylase as well as L-histidine and histamine, when immobilized via the non-ionic spacer bisoxirane, exhibited low clearance factors at neutral pH. The adsorption of endotoxin is mainly ruled by electrostatic interaction forces. Thus in multi-component systems, such as endotoxin-contaminated protein solutions, competing interactions take place: acidic proteins compete with endotoxin for binding sites at the membrane adsorbers, basic proteins compete with the ligands for endotoxin and act as endotoxin carriers. With properly chosen conditions the membrane adsorbers presented here show exceptional effectiveness also in the presence of proteins. They are generally superior to functionalised Sepharose chromatographic sorbents and allow fast processing. They may contribute to reduce the risks in the application of parenterals and diagnostics.
表面改性的平板微滤膜用聚-L-赖氨酸、多粘菌素B、聚乙烯亚胺、L-组氨酸、组胺、α-淀粉酶和二乙氨基乙醇以及脱氧胆酸盐进行功能化。使用牛血清白蛋白、小鼠IgG1和溶菌酶作为模型蛋白，研究了它们从缓冲液和蛋白质溶液中去除内毒素的适用性。在无蛋白溶液中，所有应用的配体都能将内毒素从6000 EU/ml降低到<0.1 EU/ml；只有通过非离子间隔物双环氧乙烷固定的α-淀粉酶以及L-组氨酸和组胺在中性pH下表现出低清除率。内毒素的吸附主要由静电相互作用力决定。因此，在多组分系统中，如被内毒素污染的蛋白质溶液，会发生竞争性相互作用：酸性蛋白质与内毒素竞争膜吸附剂上的结合位点，碱性蛋白质与配体竞争内毒素并充当内毒素载体。在适当选择的条件下，本文介绍的膜吸附剂在蛋白质存在的情况下也显示出卓越的有效性。它们通常优于功能化的琼脂糖色谱吸附剂，并允许快速处理。它们可能有助于降低肠胃外给药和诊断应用中的风险。
