Computational and experimental characterization of NF023, a candidate anticancer compound inhibiting cIAP2/TRAF2 assembly

Protein-protein interactions are the basis of many important physiological processes, and are currently promising, yet difficult, targets for drug discovery. In this context, inhibitors of apoptosis (IAPs)-mediated interactions are pivotal for cancer cell survival; the interaction of the BIR1 domain of cIAP2 with TRAF2 was shown to lead the recruitment of cIAPs to the TNF-receptor, promoting the activation of NF-?B survival pathway. In this work, using a combined in silico-in vitro approach we identified a drug-like molecule, NF023, able to disrupt cIAP2 interaction with TRAF2. We demonstrated in vitro its ability to interfere with the assembly of the cIAP2-BIR1/TRAF2 complex and performed a thorough characterization of the compound's mode of action through 248 parallel unbiased molecular dynamics simulations of 300 ns (totaling almost 75 µs of all-atom sampling), which identified multiple binding modes to the BIR1 domain of cIAP2 via clustering and ensemble docking. NF023 is, thus, a promising protein-protein interaction disruptor, representing a starting point to develop modulators of NF-?B-mediated cell survival in cancer. This study represents a model-procedure that shows the use of large-scale molecular dynamics methods to typify promiscuous interactors.