MNS is a tyrosine kinase inhibitor, inhibits Syk, Src, p97 with IC50 of 2.5 μM, 29.3 μM and 1.7 μM, respectively.

MLN4924 is a small molecule inhibitor of Nedd8 activating enzyme (NAE) with IC50 of 4 nM.

PYR-41 is the first cell-permeable inhibitor of ubiquitin-activating enzyme E1, with no activity at E2.

PR-619 is a non-selective, reversible inhibitor of the deubiquitinylating enzymes (DUBs) with EC50 of 1-20 μM in a cell-free assay.

P22077 is an inhibitor of ubiquitin-specific protease USP7 with EC50 of 8.6 μM, also inhibits the closely related USP47.

TCID is a DUB inhibitor for ubiquitin C-terminal hydrolase L3 with IC50 of 0.6 μM, 125-fold selective to L1.

NSC697923 is a cell-permeable and selective inhibitor of the Ub-conjugating enzyme (E2) complex Ubc13-Uev1A.

NMS-873 is an allosteric and specific p97 inhibitor with IC50 of 30 nM that demonstrates potent selectivity for VCP/p97 compared to a panel of other AAA ATPases, Hsp90, and 53 additional analyzed kinases (IC50s >10 μM).