483-LM

483-LM is a novel, selective small molecule inhibitor of the anti-apoptotic protein Mcl-1 (Induced myeloid leukemia cell differentiation protein), developed by researchers at the University of Michigan. It belongs to a class of compounds designed to restore apoptosis in cancer cells by targeting the dysregulated apoptotic machinery common in aggressive malignancies like metastatic melanoma. 483-LM exhibits low-nanomolar binding affinity for Mcl-1 and demonstrates high selectivity (over 300-fold) compared to other Bcl-2 family members such as Bcl-2 and Bcl-xL. Mechanistically, the compound disrupts the protein-protein interactions between Mcl-1 and pro-apoptotic proteins (Bax, Bak, and Bim), leading to mitochondrial outer membrane depolarization, caspase activation, and PARP cleavage. Preclinical studies have shown that 483-LM effectively inhibits tumor growth in vivo and induces massive up-regulation of the pro-apoptotic protein Noxa, particularly in Mcl-1-dependent melanoma cell lines.