Donated Chemical Probes

Target	UCHL1
Targeted domain	Active site (covalent binding to Cys90)
Mode of action	Covalent inhibitor
Control	JYQ88
Recommended cellular usage concentration	≤ 3 µM
In vivo use	yes
Donated by	Leiden University Medical Center
Developed by Leiden University Medical Center in the Framework of:

Inhibitor/agonist potency: goal is < 100 nM (IC₅₀, K_d)	UCHL1 inhibition assay with Ub-Rho-morpholine as substrate: IC₅₀ = 320 nM Kinetic profile: k_inact = 0.01382 1/s; KI(app) = 164 µM; k_inact/KI = 84 * 1/(M*s)
Selectivity within target family: > 30-fold	No inhibition within UCH family: UCHL3 (IC₅₀ = 216 µM); UCHL5 (IC₅₀ >> 200 µM) (Inhibition assay with Ub-Rho-morpholine as substrate) No inhibition of other deubiquitylating enzymes in activity‐based protein profiling assay (ABPP) experiment
Selectivity outside target family	2‐step labelling pull‐down proteomics experiment: One off-target identified in a 2‐step labelling pull‐down proteomics experiment: PARK7 (has a cystein in the active site) PDSP scan clean with one off-target: SIGMAR1 Ki = 3429.51 nM.
On target cell activity for cell-based targets: goal is < 1 µM IC₅₀/EC₅₀	ABPP assay: Full inhibition at a 8RK64 concentration of 3 μM (1h, 37°C).
Control compound (100 times less potent than the probe)	JYQ88: UCHL1 inhibition assay with Ub-Rho-morpholine as substrate: IC₅₀ = 12.9 µM (45 times less potent); No UCHL1 inhibition observed in ABPP experiment. Binds much better to PARK7 compared to 8RK64. Clean PDSP scan.