Kalmode Hanuman P, Podsiadly Izabella, Kabra Ashish, Boulton Adam, Reddy Prabhakar, Gao Yan, Li Christopher, Bushweller John H
Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22903, United States.
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.
ACS Med Chem Lett. 2022 Jul 7;13(8):1363-1369. doi: 10.1021/acsmedchemlett.2c00198. eCollection 2022 Aug 11.
The CXXC domain is a reader of DNA methylation which preferentially binds to unmethylated CpG DNA motifs. Chromosomal translocations involving the gene produce in-frame fusion proteins in which the N-terminal portion of the MLL1 protein harboring its CXXC domain is fused to the C-terminal portion of multiple partners. For the MLL-AF9 fusion, mutations which disrupt CXXC domain-DNA binding abrogate the ability to cause leukemia in mice. Based on this, we initiated an effort to develop small-molecule inhibitors of the MLL1 CXXC domain as a novel approach to therapy. We developed a fluorescence polarization-based assay for MLL CXXC domain-DNA binding and screened a library of Cys-reactive molecules. For the most potent hit from this screen, we have synthesized a library of analogs to explore the structure-activity relationship, defined the binding site using chemical shift perturbations in NMR spectra, and explored the selectivity of compounds across the CXXC domain family.
CXXC结构域是一种DNA甲基化阅读器，它优先结合未甲基化的CpG DNA基序。涉及该基因的染色体易位产生框内融合蛋白，其中含有CXXC结构域的MLL1蛋白的N端部分与多个伙伴的C端部分融合。对于MLL-AF9融合蛋白，破坏CXXC结构域与DNA结合的突变消除了在小鼠中引发白血病的能力。基于此，我们开始努力开发MLL1 CXXC结构域的小分子抑制剂，作为一种新的治疗方法。我们开发了一种基于荧光偏振的MLL CXXC结构域与DNA结合的检测方法，并筛选了一个半胱氨酸反应性分子库。对于该筛选中最有效的命中物，我们合成了一个类似物库，以探索构效关系，利用核磁共振光谱中的化学位移扰动确定结合位点，并探索化合物在CXXC结构域家族中的选择性。
