UbcH5c-IN-1 (compound 6d) is a potent and selective small-molecule inhibitor of Ubiquitin-conjugating enzyme UbcH5c, with a Kd of 283 nM for E2 UbcH5c-IN-1 by covalent binding with Cys85.
CC0651 is an allosteric inhibitor of the human Cdc34 ubiquitin-conjugating enzyme. CC0651 potently (IC50=1.72 μM) inhibits the ubiquitination of p27Kip1, as confirmed by dose-response analysis.