Laboratory of Engineering Thermodynamics, University of Kaiserslautern, Kaiserslautern, Germany.
Langmuir. 2012 Aug 7;28(31):11376-83. doi: 10.1021/la302239e. Epub 2012 Jul 25.
Adsorption of native as well as mono-, di-, and tri-PEGylated lysozyme on Toyopearl PPG-600M, a mildly hydrophobic resin is studied by isothermal titration calorimetry and by independent adsorption equilibrium measurements in sodium phosphate buffer at pH 7.0 and 25 °C. For PEGylation two different PEG sizes are used (5 and 10 kDa) which leads to six different forms of PEGylated lysozyme all of which are systematically studied. Additionally, the adsorption of five pure PEGs is explored. The ammonium sulfate concentration is varied from 600 to 1200 mM. The molar enthalpy of adsorption Δh(p)(ads) is determined from the calorimetric and the adsorption equilibrium data. It is found to be endothermic in all experiments. The comparison of the adsorption of different PEGylated forms shows that the adsorption of PEGylated lysozyme is driven by the adsorption of the PEG chain. The results provide insight into the adsorption mechanisms of polymer-modified proteins on hydrophobic chromatographic resins.
采用等温滴定微量热法和独立吸附平衡测量法，在 pH 7.0 和 25°C 的磷酸钠缓冲液中，研究了天然以及单、二和三聚乙二醇化溶菌酶在 Toyopearl PPG-600M 这种弱疏水性树脂上的吸附。对于 PEGylation，使用了两种不同的 PEG 大小（5 和 10 kDa），这导致了六种不同形式的 PEGylated 溶菌酶，所有这些都进行了系统研究。此外，还探索了五种纯 PEG 的吸附。硫酸铵浓度从 600 到 1200 mM 变化。从量热和吸附平衡数据确定摩尔吸附焓Δh(p)(ads)。在所有实验中，它都是吸热的。不同 PEGylated 形式的吸附比较表明，PEGylated 溶菌酶的吸附是由 PEG 链的吸附驱动的。这些结果提供了对聚合物修饰蛋白在疏水性色谱树脂上吸附机制的深入了解。
