Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI
Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI
复制标题
接枝 PEG 链构象对白蛋白和溶菌酶吸附的影响：使用 QCM-D 和 DPI 的联合研究
DOI：
10.1016/j.colsurfb.2015.10.025
复制
发表时间：
2015-12-01
影响因子：
5.8
通讯作者：
Liang, Haojun
中科院分区：
文献类型：
--
作者：
Jin, Jing;Han, Yuanyuan;Liang, Haojun
本文采用双偏振干涉法（DPI）和耗散石英晶体微天平（QCM-D）研究了蛋白质在聚乙二醇（PEG）膜上的吸附行为，并对蛋白质吸附机理进行了探讨。从DPI分析，PEG 2000和PEG 5000分别显示紧密和松散的蘑菇构象。少量的LYZ可以通过氢键吸引力取代紧密的蘑菇状PEG 2000链周围的界面水，导致蛋白质吸附。PEG 5000分子链呈蘑菇状，具有较强的弹性排斥能，能阻止BSA和大部分LYZ的蛋白质吸附。从QCM分析，PEG 2000和PEG 5000显示出紧密和伸展的刷状构象。LYZ的吸附质量具有PEG 2000（0.19链/nm（2））和PEG 5000（0.16链/nm（2））接枝密度的临界区域。当PEG的接枝密度高于临界区域（刷状构象）时，PEG与LYZ之间的氢键吸引是主要因素。当PEG的接枝密度低于临界区域（蘑菇构象）时，PEG与蛋白质之间的弹性排斥是由PEG链的高构象熵驱动的，这是PEG-蛋白质体系中空间排斥的主导力。因此，BSA的吸附被PEG链的高弹性排斥能所抑制，而LYZ的吸附则被熵弹性排斥和氢键吸引的相互作用所平衡。(C)2015 Elsevier B. V.版权所有。
In this study, elucidation of protein adsorption mechanism is performed using dual polarization interferometry (DPI) and quartz crystal microbalance with dissipation (QCM-D) to study adsorption behaviors of bovine serum albumin (BSA) and lysozyme (LYZ) on poly (ethylene glycol) (PEG) layers. From the analysis of DPI, PEG2000 and PEG5000 show tight and loose mushroom conformations, respectively. Small amount of LYZ could displace the interfacial water surrounding the tight mushroomed PEG2000 chains by hydrogen bond attraction, leading to protein adsorption. The loose mushroomed PEG5000 chains exhibit a more flexible conformation and high elastic repulsion energy that could prevent protein adsorption of all BSA and most of LYZ. From the analysis of QCM, PEG2000 and PEG5000 show tight and extended brush conformations. The LYZ adsorbed mass has critical regions of PEG2000 (0.19 chain/nm(2)) and PEG5000 (0.16 chain/nm(2)) graft density. When graft density of PEG is higher than the critical region (brush conformations), the attraction of hydrogen bonds between PEG and LYZ is the dominant factor. When graft density of PEG is lower than the critical region (mushroom conformations), elastic repulsion between PEG and proteins is driven by the high conformation entropy of PEG chains, which is the dominant force of steric repulsion in PEG-protein systems. Therefore, the adsorption of BSA is suppressed by the high elastic repulsion energy of PEG chains, whereas the adsorption of LYZ is balanced by the interactions between the repulsion of entropy elasticity and the attraction of hydrogen bonds. (C) 2015 Elsevier B.V. All rights reserved.