Facile synthesis of native and protease-resistant ubiquitylated peptides.
The reversible post-translational modification of eukaryotic proteins by ubiquitin regulates key cellular processes including protein degradation and gene transcription. Studies of the mechanistic roles for protein ubiquitylation require quantities of homogenously modified substrates that are typically inaccessible from natural sources or by enzymatic ubiquitylation in vitro. Therefore, we developed a facile and scalable methodology for site-specific chemical ubiquitylation. Our semisynthetic strategy utilized a temporary ligation auxiliary, 2-(aminooxy)ethanethiol, to direct ubiquitylation to specific lysine residues in peptide substrates. Mild reductive removal of the auxiliary after ligation yielded ubiquitylated peptides with the native isopeptide linkage. Alternatively, retention of the ligation auxiliary yielded protease-resistant analogues of ubiquitylated peptides. Importantly, our strategy was fully compatible with the presence of protein thiol groups, as demonstrated by the synthesis of peptides modified by the human small ubiquitin-related modifier 3 protein.
Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195 (USA).
Caroline E
CE
Weller
Wei
W
Huang
Champak
C
Chatterjee
D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D010447:Peptide Hydrolases / Q000378:metabolism*; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism; D057149:Ubiquitinated Proteins / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D054875:Ubiquitination
D010455:Peptides; D025841:Small Ubiquitin-Related Modifier Proteins; D057149:Ubiquitinated Proteins; D010447:Peptide Hydrolases
SUMO; conjugation; peptides; protein modifications; ubiquitin