Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States.
Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States.
J Med Chem. 2021 May 13;64(9):6273-6299. doi: 10.1021/acs.jmedchem.1c00339. Epub 2021 May 3.
In immunoglobulin light-chain (LC) amyloidosis, transient unfolding or unfolding and proteolysis enable aggregation of LC proteins, causing potentially fatal organ damage. A drug that kinetically stabilizes LCs could suppress aggregation; however, LC sequences are variable and have no natural ligands, hindering drug development efforts. We previously identified high-throughput screening hits that bind to a site at the interface between the two variable domains of the LC homodimer. We hypothesized that extending the stabilizers beyond this initially characterized binding site would improve affinity. Here, using protease sensitivity assays, we identified stabilizers that can be divided into four substructures. Some stabilizers exhibit nanomolar EC values, a 3000-fold enhancement over the screening hits. Crystal structures reveal a key π-π stacking interaction with a conserved tyrosine residue that was not utilized by the screening hits. These data provide a foundation for developing LC stabilizers with improved binding selectivity and enhanced physicochemical properties.
在免疫球蛋白轻链 (LC) 淀粉样变性中，LC 蛋白的瞬时去折叠或去折叠和蛋白水解使蛋白聚集，导致潜在的致命器官损伤。动力学稳定 LC 的药物可以抑制聚集；然而，LC 序列是可变的，没有天然配体，这阻碍了药物开发的努力。我们之前鉴定了能够与 LC 同源二聚体两个可变结构域之间界面上的一个位点结合的高通量筛选命中物。我们假设将稳定剂扩展到该最初表征的结合位点之外将提高亲和力。在这里，我们使用蛋白酶敏感性测定法，鉴定了可以分为四个亚结构的稳定剂。一些稳定剂具有纳摩尔 EC 值，比筛选命中物提高了 3000 倍。晶体结构揭示了与保守的酪氨酸残基的关键 π-π 堆积相互作用，而筛选命中物没有利用该相互作用。这些数据为开发具有改善的结合选择性和增强的物理化学性质的 LC 稳定剂提供了基础。
