Department of Medicinal Chemistry, Institute of Structural Biology, Drug Discovery and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, United States.
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute for Drug Discovery, Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States.
J Med Chem. 2020 Sep 10;63(17):9512-9522. doi: 10.1021/acs.jmedchem.0c00689. Epub 2020 Aug 5.
Protein N-terminal methyltransferases (NTMTs) methylate the α-N-terminal amines of proteins starting with the canonical X-P-K/R motif. Genetic studies imply that NTMT1 regulates cell mitosis and DNA damage repair. Herein, we report the rational design and development of the first potent peptidomimetic inhibitor for NTMT1/2. Biochemical and cocrystallization studies manifest that (with a half-maximal inhibitory concentration of 0.89 ± 0.10 μM) is a competitive inhibitor to the peptide substrate and noncompetitive to the cofactor S-adenosylmethionine. exhibits over 100-fold selectivity to NTMT1/2 among a panel of 41 MTs, indicating its potential to achieve high selectivity when targeting the peptide substrate binding site of NTMT1/2. Its cell-permeable analogue (IC of 54 ± 4 nM) decreases the N-terminal methylation level of the regulator of chromosome condensation 1 and SET proteins in HCT116 cells. This proof-of principle study provides valuable probes for NTMT1/2 and highlights the opportunity to develop more cell-potent inhibitors to elucidate the function of NTMTs in the future.
蛋白质 N-端甲基转移酶（NTMTs）以典型的 X-P-K/R 基序起始，甲基化蛋白质的 α-N-端胺。遗传研究表明，NTMT1 调节细胞有丝分裂和 DNA 损伤修复。在此，我们报告了针对 NTMT1/2 的首个强效肽模拟物抑制剂的合理设计与开发。生化和共结晶研究表明，（对肽底物的半数最大抑制浓度为 0.89±0.10 μM）是肽底物的竞争性抑制剂，而对辅因子 S-腺苷甲硫氨酸是非竞争性抑制剂。在 41 种 MTs 中，对 NTMT1/2 的选择性超过 100 倍，表明其在针对 NTMT1/2 的肽底物结合位点时具有实现高选择性的潜力。其可渗透细胞的类似物（IC50 为 54±4 nM）降低了 HCT116 细胞中染色体凝聚调节因子 1 和 SET 蛋白的 N-端甲基化水平。该原理验证研究为 NTMT1/2 提供了有价值的探针，并突出了未来开发更有效的细胞内抑制剂以阐明 NTMTs 功能的机会。
