A duplexed high-throughput mass spectrometry assay for bifunctional POLB polymerase and lyase activity.

Polymerase β (POLB), with dual functionality as a lyase and polymerase, plays a critical role in the base excision repair (BER) pathway to maintain genomic stability. POLB knockout and rescue studies in BRCA1/2-mutant cancer cell lines revealed that inhibition of lyase and polymerase activity is required for the synthetic lethal interaction observed with PARP inhibitors, highlighting POLB as a valuable therapeutic target. Traditional biochemical assays to screen for enzyme inhibitors focus on a single substrate to product relationship and limit the comprehensive analysis of enzymes such as POLB that utilize multiple substrates or catalyze a multi-step reaction.

Design and Discovery of a Potent and Selective Inhibitor of Integrin αvβ1.

Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvβ1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvβ1 relative to several other integrin isoforms measured. Azabenzimidazolone demonstrated antifibrotic efficacy in an rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvβ1 inhibition.

Biochemical and Cellular Profile of NIK Inhibitors with Long Residence Times.

Two different signaling pathways lead to the activation of the transcription factor NF-κB, initiating distinct biological responses: The canonical NF-κB pathway activation has been implicated in host immunity and inflammatory responses, whereas the noncanonical pathway activation has been involved in lymphoid organ development and B-cell maturation, as well as in the development of chronic inflammatory diseases and some hematologic cancers. The NF-κB-inducing kinase (NIK) is a cytoplasmic Ser/Thr kinase and is a key regulator of the noncanonical pathway. NIK activation results in the processing of the p100 subunit to p52, leading to the formation of the RelB/p52 complex and noncanonical pathway activation.

Structure-guided optimization of a novel class of ASK1 inhibitors with increased sp character and an exquisite selectivity profile.

Apoptosis Signal-Regulating Kinase-1 (ASK1) is a known member of the Mitogen-Activated Protein Kinase Kinase Kinase (MAP3K) family and upon stimulation will activate the p38- and JNK-pathways leading to cardiac apoptosis, fibrosis, and hypertrophy. Using Structure-Based Drug Design (SBDD) in parallel with deconstruction of a published compound, a novel series of ASK1 inhibitors was optimized, which incorporated a saturated heterocycle proximal to the hinge-binding motif. This yielded a unique chemical series with excellent selectivity across the broader kinome, and desirable drug-like properties.