Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, United States.
J Phys Chem Lett. 2022 Feb 10;13(5):1366-1372. doi: 10.1021/acs.jpclett.1c03669. Epub 2022 Feb 3.
Electrostatically driven attractions between proteins can result in issues for therapeutic protein formulations such as solubility limits, aggregation, and high solution viscosity. Previous work showed that a model monoclonal antibody displayed large and potentially problematic electrostatically driven attractions at typical pH (5-8) and ionic strength conditions (∼10-100 mM). Molecular simulations of a hybrid coarse-grained model (1bC/D, one bead per charged site and per domain) were used to predict potential point mutations to identify key charge changes (charge-to-neutral or charge-swap) that could greatly reduce the net attractive protein-protein self-interactions. A series of variants were tested experimentally with static and dynamic light scattering to quantify interactions and compared to model predictions at low and intermediate ionic strength. Differential scanning calorimetry and circular dichroism confirmed minimal impact on structural or thermal stability of the variants. The model provided quantitative/semiquantitative predictions of protein self-interactions compared to experimental results as well as showed which amino acid pairings or groups had the most impact.
静电驱动的蛋白质之间的吸引力可能会导致治疗性蛋白质制剂出现问题，如溶解度限制、聚集和高溶液黏度。先前的工作表明，一种模型单克隆抗体在典型的 pH（5-8）和离子强度条件（约 10-100mM）下表现出大的、潜在有问题的静电驱动吸引力。使用混合粗粒度模型（1bC/D，每个带电位点和每个结构域一个珠子）的分子模拟来预测潜在的点突变，以确定可能大大降低净吸引力的关键电荷变化（电荷到中性或电荷交换）蛋白质-蛋白质的自我相互作用。一系列变体通过静态和动态光散射进行了实验测试，以量化相互作用，并将其与低和中等离子强度下的模型预测进行比较。差示扫描量热法和圆二色性证实了变体对结构或热稳定性的影响最小。与实验结果相比，该模型对蛋白质自我相互作用进行了定量/半定量预测，并显示了哪些氨基酸对配对或基团影响最大。
