Nonenzymatic Polymerization of Ubiquitin: Single-Step Synthesis and Isolation of Discrete Ubiquitin Oligomers


  • We thank Prof. A. Hoskins for use of the fluorescent imager and Prof. M. Mahanthappa for critical reading of the manuscript. The deubiquitinases IsoT, OTUB1, USP7, and AMSH were a kind gift from LifeSensors Inc. Financial support was provided by UW-Madison, the Greater Milwaukee Shaw Scientist Program, Susan G. Komen for Cure, NSF (graduate fellowship awarded to V.H.T.), the Wisconsin Partnership Fund for the establishment of the University of Wisconsin Human Proteomics Program (Y.G.), and NIH (R01HL096971 awarded to Y.G.). The NSF (9520868) is also acknowledged for support of the UW-Madison Chemistry Instrumentation Center.


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Linked: A method based on thiol-ene chemistry enables the synthesis and purification of ubiquitin oligomers with ≥4 units. This approach, which employs free-radical polymerization, can be applied towards the synthesis of homogeneous Lys6-linked ubiquitin oligomers currently inaccessible by enzymatic methods. By using these chains, one can study their roles in the ubiquitin proteasome system and the DNA damage response pathway.