Brief Description

ML323 is a reversible, potent USP1-UAF1 inhibitor with IC50 of 76 nM in a Ub-Rho assay and 174 nM and 820 nM in orthogonal gel-based assays using K63-linked diubiquitin (di-Ub) and monoubiquitinated PCNA (Ub-PCNA) as substrates, respectively.
IC50 Value: 76 nM(in Ub-Rho assay)
Target: USP1-UAF1
in vitro: ML323 probably exerts its inhibitory effect through an allosteric mechanism. The measured inhibition constants of ML323 for the free enzyme (Ki) and the enzyme-substrate complex (K′i) were 68 nM and 183 nM, respectively, which is in accordance with the IC50 determination. ML323 showed little to no inhibition against the USPs tested, including USP2, USP5, USP7, USP8, USP10, USP11, USP14 and USP21. Notably, ML323 did not inhibit the USP46-UAF1 complex that contains the same UAF1 subunit as the USP1-UAF1 complex and demonstrated little inhibition against USP1 alone (IC50 > 200 μM) in a Ub-Rho assay in which USP1-UAF1 and USP1 demonstrated similar Km values. Furthermore, ML323 displayed little to no inhibition against DUBs in the ubiquitin C-terminal hydrolase (UCH), ovarian tumor protease (OTU) and Machado-Joseph domain (MJD) families and did not inhibit a deSUMOylase, SENP1, and a deneddylase, NEDP1. ML323 inhibits USP1-UAF1 through a mixed inhibition mechanism. inhibition of cellular USP1-UAF1 activity by ML323 compromises Polη-mediated TLS of UV-induced DNA damage. ML323 led to a similar decrease in LD50 in both PD20 and PD20 + D2 cells (to 2.8 and 3.4 J m?2, respectively).

Solubility

DMSO

Melting point

Boiling point

Density

Formula Weight:

Flash point

Storage conditions

Store at -20°C 2 years

Appearance:

White to off-white solid