Highly Efficient and Chemoselective Peptide Ubiquitylation

Abstract

Ein nützlicher Helfer: Mit δ‐Mercaptolysin als Hilfe bei der Isopeptidbildung zwischen ε‐NH2 des Lysinrests und dem aktivierten C‐terminalen Glycinrest von Ubiquitin (Ub) gelang eine hoch effiziente und chemoselektive Ubiquitinylierung von Peptiden.

Total Chemical Synthesis of Di‐ubiquitin Chains

“…To assemble all the di‐Ub analogues, seven parallel ligation reactions (Figure 1 D) were carried out between each Ub1 analogue and Ub2 under the NCL conditions described above. In our previous studies with the model peptides bearing δ mercaptolysine and the Ub thioester, the ligation was completed within 4 hours 9c. In this study, the ligation rate was slower and required 24 hours for completion (Figure 2 A).…”

“…Recently, several groups, including ours, have adopted chemical approaches to assemble the native isopeptide bond and allow the efficient synthesis of ubiquitinated peptides and proteins 9. Specifically, our group introduced the δ mercaptolysine to mediate the transthioesterification step of Ub thioester and subsequent S–N acyl transfer to form the isopeptide bond 9c. Subsequently, the thiol handle can be removed by applying the desulfurization reaction to furnish the unmodified isopeptide linkage.…”

Convergent Chemical Synthesis of Histone H2B Protein for the Site‐Specific Ubiquitination at Lys34

“…Hence, we divided the H2B sequence, taking into consideration the position of Ala residues, to include H2B(1–20) labeled with an HA tag, H2B(21–57), H2B(58–96), and H2B(97–125). In such an approach, ubiquitination at K34 can be achieved by incorporating δ‐mercaptolysine (K*)8 in the fragment H2B(21–57), thus enabling isopeptide native chemical ligation (ICL). We also envisioned a convergent chemical synthesis approach via a peptide hydrazide intermediate9 for the final assembly, first by ligating fragments H2B(1–20) and H2B(21–57), which bears a Ub, followed by ligation with H2B(58–125), which is prepared through ligation of fragments H2B(58–96) and H2B(97–125).…”

Towards Elucidation of the Role of Ubiquitination in the Pathogenesis of Parkinson’s Disease with Semisynthetic Ubiquitinated α‐Synuclein

“…We recently developed a highly efficient and chemoselective method to facilitate the site‐specific ubiquitination of peptides and proteins 12. In our approach, a δ‐mercaptolysine residue is used to mediate transthioesterification with an ubiquitin thioester, followed by S–N acyl transfer to form an isopeptide bond between ubiquitin and the lysine derivative.…”