Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark.
Sci Rep. 2020 Dec 9;10(1):21574. doi: 10.1038/s41598-020-78331-0.
Histone lysine methyltransferases (KMTs) play an important role in epigenetic gene regulation and have emerged as promising targets for drug discovery. However, the scope and limitation of KMT catalysis on substrates possessing substituted lysine side chains remain insufficiently explored. Here, we identify new unnatural lysine analogues as substrates for human methyltransferases SETD7, SETD8, G9a and GLP. Two synthetic amino acids that possess a subtle modification on the lysine side chain, namely oxygen at the γ position (K, oxalysine) and nitrogen at the γ position (K, azalysine) were incorporated into histone peptides and tested as KMTs substrates. Our results demonstrate that these lysine analogues are mono-, di-, and trimethylated to a different extent by trimethyltransferases G9a and GLP. In contrast to monomethyltransferase SETD7, SETD8 exhibits high specificity for both lysine analogues. These findings are important to understand the substrate scope of KMTs and to develop new chemical probes for biomedical applications.
组蛋白赖氨酸甲基转移酶（KMTs）在表观遗传学基因调控中发挥着重要作用，已成为药物发现的有前途的靶点。然而，KMT 对具有取代赖氨酸侧链的底物的催化范围和局限性仍未得到充分探索。在这里，我们鉴定了新的非天然赖氨酸类似物作为人甲基转移酶 SETD7、SETD8、G9a 和 GLP 的底物。两种在赖氨酸侧链上进行了细微修饰的合成氨基酸，即γ位的氧（K，草酰赖氨酸）和γ位的氮（K，氮杂赖氨酸）被掺入组蛋白肽中，并作为 KMTs 底物进行测试。我们的结果表明，这些赖氨酸类似物被三甲基转移酶 G9a 和 GLP 不同程度地单甲基化、二甲基化和三甲基化。与单甲基转移酶 SETD7 不同，SETED8 对两种赖氨酸类似物都具有很高的特异性。这些发现对于理解 KMT 底物的范围以及开发用于生物医学应用的新化学探针非常重要。
