Chemical Synthesis of Ubiquitinated Peptides with Varying Lengths and Types of Ubiquitin Chains to Explore the Activity of Deubiquitinases

Adding one at a time: A general and effective synthesis yields a peptide attached to mono-, di-, tri-, and tetraubiquitin (Ub) chains (see picture for peptides with Ub and Ub4), linked through lysine residues K48 or K63. These sets of ubiquitinated peptides were prepared in good quantities, and the activity of the enzymes UCH-L3 and IsoT with these different substrates was studied.