Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle (Saale), Germany.
Institute of Physical and Theoretical Chemistry, University of Regensburg, 93053 Regensburg, Germany.
Mol Pharm. 2022 Feb 7;19(2):494-507. doi: 10.1021/acs.molpharmaceut.1c00587. Epub 2022 Jan 24.
Molecular interaction mechanisms in high-concentrated protein systems are of fundamental importance for the rational development of biopharmaceuticals such as monoclonal antibody (mAb) formulations. In such high-concentrated protein systems, the intermolecular distances between mAb molecules are reduced to the size of the protein diameter (approx. 10 nm). Thus, protein-protein interactions are more pronounced at high concentrations; so a direct extrapolation of physicochemical properties obtained from measurements at a low protein concentration of the corresponding properties at a high protein concentration is highly questionable. Besides the charge-charge interaction, the effects of molecular crowding, dipolar interaction, changes in protein hydration, and self-assembling tendency become more relevant. Here, protein hydration, protein dipole moment, and protein-protein interactions were studied in protein concentrations up to 200 mg/mL (= 1.3 mM) in different formulations for selected mAbs using dielectric relaxation spectroscopy (DRS). These data are correlated with the second virial coefficient, , the diffusion interaction parameter, , the elastic shear modulus, , and the dynamic viscosity, η. When large contributions of dipolar protein-protein interactions were observed, the tendency of self-assembling and an increase in solution viscosity were detected. These effects were examined using specific buffer conditions. Furthermore, different types of protein-water interactions were identified via DRS, whereby the effect of high protein concentration on protein hydration was investigated for different high-concentrated liquid formulations (HCLFs).
在单克隆抗体（mAb）制剂等生物制药的合理开发中，高浓度蛋白质体系中的分子相互作用机制至关重要。在这种高浓度蛋白质体系中，mAb 分子之间的分子间距离缩小到蛋白质直径的大小（约 10nm）。因此，在高浓度下，蛋白质-蛋白质相互作用更为明显；因此，直接推断从低浓度蛋白质测量获得的物理化学性质在高浓度蛋白质时的相应性质是非常有问题的。除了电荷-电荷相互作用外，分子拥挤、偶极相互作用、蛋白质水合变化和自组装倾向的影响变得更为相关。在这里，使用介电弛豫光谱（DRS）研究了高达 200mg/mL（=1.3mM）的不同制剂中选定 mAb 的蛋白质浓度下的蛋白质水合作用、蛋白质偶极矩和蛋白质-蛋白质相互作用。这些数据与第二维里系数、扩散相互作用参数、弹性剪切模量和动态粘度相关联。当观察到偶极子-蛋白质-蛋白质相互作用的较大贡献时，检测到自组装的趋势和溶液粘度的增加。使用特定的缓冲条件检查了这些效果。此外，通过 DRS 鉴定了不同类型的蛋白质-水相互作用，从而研究了不同高浓度液体制剂（HCLF）中高蛋白质浓度对蛋白质水合作用的影响。
