Synthesis of Poly-Ubiquitin Chains Using a Bifunctional Ubiquitin Monomer

An optimized large scale and highly reproducible route to orthogonally protected gamma-thiolysine is reported. Its utility in the synthesis of bifunctional ubiquitin monomers is demonstrated. These ubiquitin synthons are employed in polymerization reactions giving access to synthetic polyubiquitin chains of defined linkage.