A cell-permeable tetrahydro-β-carbolinylbarbiturate compound that selectively inhibits the E3 ligase activity of Mdm2-MdmX hetero-complex over that of Mdm2-Mdm2 homo-complex (70.6% vs. 17.6% inhibition, respectively, with 100 µM inhibitor), without affecting Mdm2-MdmX complex formation or the activity of Roc1-Cul1 and BRCA1-BARD1, two other ligase complexes that also utilize UbcH5C as the Ub-conjugating enzyme. Effectively inhibits Mdm2-MdmX E3 ligase activity-dependent ubiquitination and proteasomal degradation of cellular Mdm2 and p53 (effective conc. = 14 µM in U2OS, RKO, and HCT116 cultures) and prevents DNA damage-induced MdmX degradation in MCF7 cells upon 50 µM etoposide treatment. Shown to induce RKO and MEF cell death in a p53- and Mdm2-dependent manner. Unlike Nutlin-3 (Cat. Nos. 444143 & 444151), MEL23 does not act by interfering Mdm2-p53 interaction.

Packaged under inert gas

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

Herman, A.G., et al. 2011. Cancer Discovery1, 312.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Toxicity: Standard Handling (A)