Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, Gudelsky Way, Rockville, MD, USA.
Biomolecular Labeling Laboratory, Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, Gudelsky Way, Rockville, MD, USA.
J Biomol Struct Dyn. 2024;42(22):12571-12579. doi: 10.1080/07391102.2023.2270749. Epub 2023 Oct 28.
The crystallizable fragment (Fc) domain of immunoglobulin subclass IgG1 antibodies is engineered for a wide variety of pharmaceutical applications. Two important structural variables in Fc constructs are the hinge region connecting the Fc to the antigen binding fragments (Fab) and the glycans present in various glycoforms. These components affect receptor binding interactions that mediate immune activation. To design new antibody drugs, a robust in silico method for linking stability to structural changes is necessary. In this work, all-atom simulations were used to compare the dynamic behavior of the four structural variants arising from presence or absence of the hinge and glycans. We expressed the simplest of these constructs, the 'minimal Fc' with no hinge and no glycans, in and report its crystal structure. The 'maximal Fc' that includes full hinge and G0F/G1F glycans is based on a previously reported structure, Protein Data Bank (PDB) ID: 5VGP. These, along with two intermediate structures (with only the glycans or with only the hinge) were used to independently measure the stability effects of the two structural variables using umbrella sampling simulations. Principal component analysis (PCA) was used to determine free energy effects along the Fc's dominant mode of motion. This work provides a comprehensive picture of the effects of hinge and glycans on Fc dynamics and stability.Communicated by Ramaswamy H. Sarma.
免疫球蛋白 IgG1 亚类的可结晶片段（Fc）结构域被用于各种药物应用。Fc 结构中的两个重要结构变量是连接 Fc 与抗原结合片段（Fab）的铰链区和各种糖型中的聚糖。这些成分影响介导免疫激活的受体结合相互作用。为了设计新的抗体药物，需要一种强大的、将稳定性与结构变化联系起来的计算方法。在这项工作中，我们使用全原子模拟来比较由铰链和聚糖的存在或缺失引起的四种结构变体的动态行为。我们表达了这些结构变体中最简单的一种，即没有铰链和聚糖的“最小 Fc”，并报告了其晶体结构。包含完整铰链和 G0F/G1F 聚糖的“最大 Fc”基于之前报道的结构，PDB ID：5VGP。这些结构，以及两个中间结构（只有聚糖或只有铰链），被用于使用伞形采样模拟来独立测量这两个结构变量对稳定性的影响。主成分分析（PCA）用于确定 Fc 主要运动模式下的自由能影响。这项工作全面描述了铰链和聚糖对 Fc 动力学和稳定性的影响。由 Ramaswamy H. Sarma 交流。
