Department of Biophysics, Faculty of Science, P. J. Šafárik University, Jesenna 5, 040 01 Košice, Slovakia.
Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Šafárik University, Trieda SNP 1, 040 11 Košice, Slovakia.
Biophys Chem. 2021 Aug;275:106609. doi: 10.1016/j.bpc.2021.106609. Epub 2021 May 6.
Understanding how antibodies adsorb on solid surfaces is essential for developing effective approaches to control this process. In this study, passive adsorptions on the hydrophobic solid surface of a polystyrene microparticle (MP) of two highly similar IgG1 κ-type monoclonal antibodies (mAbs), rituximab, and trastuzumab, were examined in the presence of Hofmeister salts. Except of kosmotropic salts, the screening of electrostatic interactions using salts reduces the passive adsorption of mAbs on MP. To better understand the ion-specific adsorption process, salt-dependent Langmuir isotherm parameters were obtained and correlated for two mAbs. We find that while their maximum adsorption capacities to MPs are highly correlated (r > 0.9), the salt-dependent profiles of adsorption binding constants, K, differ substantially. For rituximab, K increases >10-fold in an ion-specific manner; for trastuzumab, K remains constant. We conclude that even minor sequence variations among the mAbs can affect the adsorption, as well as the molecular forces attracting proteins to a solid surface. This difference might originate from the heterogeneous orientation of the adsorbed mAbs.
了解抗体如何在固体表面上吸附对于开发控制该过程的有效方法至关重要。在这项研究中，在Hofmeister 盐存在的情况下，研究了两种高度相似的 IgG1 κ型单克隆抗体（mAb），利妥昔单抗和曲妥珠单抗，在疏水性聚苯乙烯微球（MP）上的被动吸附。除了具有渗透作用的盐以外，使用盐来筛选静电相互作用会减少 mAb 在 MP 上的被动吸附。为了更好地理解离子特异性吸附过程，获得了盐依赖性 Langmuir 等温线参数并对两种 mAb 进行了相关性分析。我们发现，尽管它们对 MPs 的最大吸附容量高度相关（r>0.9），但吸附结合常数 K 的盐依赖性曲线却有很大差异。对于利妥昔单抗，K 以离子特异性的方式增加了>10 倍；对于曲妥珠单抗，K 保持不变。我们得出结论，即使 mAb 之间存在微小的序列差异，也会影响吸附以及吸引蛋白质到固体表面的分子力。这种差异可能源于吸附的 mAb 的不均匀取向。
