Posttranslational modifications of histone proteins, which form nucleosome cores, play an important role in gene regulation. Ubiquitination is one such modification. We previously reported on the synthesis of ubiquitinated histone H3 with an isopeptide mimetic structure. In this report, we describe the preparation of ubiquitinated histone H3 peptides with a native isopeptide structure, which showed a slightly weaker effect on the enzymatic activity of DNA methyltransferase 1 than the previous ubiquitinated H3 peptide analogs. These findings show that a native structure is important for determining the mechanism of the function, although ubiquitinated H3 peptide analogs can mimic the role of the original ubiquitinated H3. We also report on the successful preparation of the ubiquitinated full length histone H3.

中文翻译：

---

组蛋白H3泛素化形式的化学合成及其对DNA甲基转移酶1的影响

组蛋白形成核小体核心的翻译后修饰在基因调控中起重要作用。泛素化就是这样一种修饰。我们先前曾报道过具有异肽模拟结构的泛素化组蛋白H3的合成。在此报告中，我们描述了具有天然异肽结构的泛素化组蛋白H3肽的制备，该结构对DNA甲基转移酶1的酶活性的影响比以前的泛素化H3肽类似物稍弱。这些发现表明，尽管泛素化的H3肽类似物可以模仿原始泛素化的H3的作用，但天然结构对于确定功能的机制很重要。我们还报告了成功制备泛素化全长组蛋白H3的信息。