Project description:GAS41 is an emerging oncogene overexpressed and implicated in multiple cancers, including non-small cell lung cancer (NSCLC). GAS41 is a dimeric protein that contains the YEATS domain, which is involved in the recognition of lysine-acylated histones. Here, we report the development of GAS41 YEATS inhibitors by employing a fragment-based screening approach. These inhibitors bind to GAS41 YEATS domain in a channel constituting a recognition site for acylated lysine on histone proteins. To enhance inhibitory activity, we developed a dimeric analog with nanomolar activity that blocks interactions of GAS41 with acetylated histone H3. Our lead compound engages GAS41 in cells, blocks proliferation of NSCLC cells, and modulates expression of GAS41-dependent genes, validating on-target mechanism of action. This study demonstrates that disruption of GAS41 protein-protein interactions may represent an attractive approach to target lung cancer cells. This work exemplifies the use of bivalent inhibitors as a general strategy to block challenging protein-protein interactions.
Project description:Anion-transport proteins are central to all of physiology, for processes ranging from regulating bone-density, muscle excitability, and blood pressure, to facilitating extreme-acid survival of pathogenic bacteria. 4,4-Diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) has been used as an anion-transport inhibitor for decades. In this study, we demonstrate that polythiourea products derived from DIDS hydrolysis inhibit three different CLC chloride-transport proteins, ClC-ec1, ClC-0, and ClC-Ka, more effectively than DIDS itself. The structures of the five major products were determined by NMR spectroscopy, mass spectrometry, and chemical synthesis. These compounds bind directly to the CLC proteins, as evidenced by the fact that inhibition of ClC-0 occurs only from the intracellular side and inhibition of ClC-Ka is prevented by the point mutation N68D. These polythioureas are the highest affinity inhibitors known for the CLCs and provide a new class of chemical probes for dissecting the molecular mechanisms of chloride transport.
Project description:Enzymes are instrumental to life and key actors of pathologies, making them relevant drug targets. Most enzyme inhibitors consist of small molecules. Although efficient, their development is long, costly and can come with unwanted off-targeting. Substantial gain in specificity and discovery efficiency is possible using biologicals. Best exemplified by antibodies, these drugs derived from living systems display high specificity and their development is eased by harnessing natural evolution. Aptamers are nucleic acids sharing functional similarities with antibodies while being deprived of many of their limitations. Yet, the success rate of inhibitory aptamer discovery remained hampered by the lack of an efficient discovery pipeline. In this work, we addressed this issue by introducing an ultrahigh-throughput strategy combining in vitro selection, microfluidic screening and bioinformatics. We demonstrate its efficiency by discovering a modified aptamer that specifically and strongly inhibits SPM-1, a beta-lactamase that remained recalcitrant to the development of potent inhibitors.
Project description:Monoacylglycerol lipase (MGL) is a serine hydrolase involved in the biological deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). Previous efforts to design MGL inhibitors have focused on chemical scaffolds that irreversibly block the activity of this enzyme. Here, we describe two naturally occurring terpenoids, pristimerin and euphol, which inhibit MGL activity with high potency (median effective concentration, IC(50) = 93 nM and 315 nM, respectively) through a reversible mechanism. Mutational and modeling studies suggest that the two agents occupy a common hydrophobic pocket located within the putative lid domain of MGL, and each reversibly interacts with one of two adjacent cysteine residues (Cys(201) and Cys(208)) flanking such pocket. This previously unrecognized regulatory region might offer a molecular target for potent and reversible inhibitors of MGL.
Project description:Ice recrystallization is the main contributor to cell damage and death during the cryopreservation of cells and tissues. Over the past five years, many small carbohydrate-based molecules were identified as ice recrystallization inhibitors and several were shown to reduce cryoinjury during the cryopreservation of red blood cells (RBCs) and hematopoietic stems cells (HSCs). Unfortunately, clear structure-activity relationships have not been identified impeding the rational design of future compounds possessing ice recrystallization inhibition (IRI) activity. A set of 124 previously synthesized compounds with known IRI activities were used to calibrate 3D-QSAR classification models using GRid INdependent Descriptors (GRIND) derived from DFT level quantum mechanical calculations. Partial least squares (PLS) model was calibrated with 70% of the data set which successfully identified 80% of the IRI active compounds with a precision of 0.8. This model exhibited good performance in screening the remaining 30% of the data set with 70% of active additives successfully recovered with a precision of ~0.7 and specificity of 0.8. The model was further applied to screen a new library of aryl-alditol molecules which were then experimentally synthesized and tested with a success rate of 82%. Presented is the first computer-aided high-throughput experimental screening for novel IRI active compounds.
Project description:The proteolytic activity of the enzyme ADAMTS7 was recently shown to enhance the progression of atherosclerosis, in line with human genetic findings suggesting that ADAMTS7 has a role in the pathophysiology of coronary heart disease. Targeting the active site of ADAMTS7 with a small molecule inhibitor, therefore, has therapeutic potential. Here, we report the design and synthesis of a novel hydroxamate-based arylsulfonamide that is a potent and selective ADAMTS7 inhibitor. In silico studies guided the hit optimization process aiming to improve selectivity of the previously reported (non-selective) inhibitor EDV33. Our lead compound is a p-trifluoromethyl biphenyl sulfonamide, which displayed a 12-fold selectivity for ADAMTS7 (K i = 9 nM) over ADAMTS5 (K i = 110 nM) and an 8-fold increase in inhibition of ADAMTS7 compared to EDV33 (K i = 70 nM). The substitutions switched selectivity and produced a new potent ADAMTS7 inhibitor that can be taken forward for further characterisation.
Project description:The mitogen-activated kinases JNK1/2/3 are key enzymes in signaling modules that transduce and integrate extracellular stimuli into coordinated cellular response. Here, we report the discovery of irreversible inhibitors of JNK1/2/3. We describe two JNK3 cocrystal structures at 2.60 and 2.97 Å resolution that show the compounds form covalent bonds with a conserved cysteine residue. JNK-IN-8 is a selective JNK inhibitor that inhibits phosphorylation of c-Jun, a direct substrate of JNK, in cells exposed to submicromolar drug in a manner that depends on covalent modification of the conserved cysteine residue. Extensive biochemical, cellular, and pathway-based profiling establish the selectivity of JNK-IN-8 for JNK and suggests that the compound will be broadly useful as a pharmacological probe of JNK-dependent signal transduction. Potential lead compounds have also been identified for kinases, including IRAK1, PIK3C3, PIP4K2C, and PIP5K3.
Project description:A high-throughput screen based on a viral replication assay was used to identify inhibitors of the human cytomegalovirus. Using this approach, hit compound 1 was identified as a 4 ?M inhibitor of HCMV that was specific and selective over other herpes viruses. Time of addition studies indicated compound 1 exerted its antiviral effect early in the viral life cycle. Mechanism of action studies also revealed that this series inhibited infection of MRC-5 and ARPE19 cells by free virus and via direct cell-to-cell spread from infected to uninfected cells. Preliminary structure-activity relationships demonstrated that the potency of compound 1 could be improved to a low nanomolar level, but metabolic stability was a key optimization parameter for this series. A strategy focused on minimizing metabolic hydrolysis of the N1-amide led to an alternative scaffold in this series with improved metabolic stability and good pharmacokinetic parameters in rat.
Project description:The mixed-lineage leukemia (MLL) protein, also known as MLL1, is a lysine methyltransferase specifically responsible for methylation of histone 3 lysine 4. MLL has been pursued as an attractive therapeutic target for the treatment of acute leukemia carrying the MLL fusion gene or MLL leukemia. Herein, we report the design, synthesis, and evaluation of an S-adenosylmethionine-based focused chemical library which led to the discovery of potent small-molecule inhibitors directly targeting the MLL SET domain. Determination of cocrystal structures for a number of these MLL inhibitors reveals that they adopt a unique binding mode that locks the MLL SET domain in an open, inactive conformation.
Project description:Herein, we report a novel series of highly potent and selective triazolothiadiazole c-Met inhibitors. Starting with molecule 5, we have applied structure-based drug design principles to identify the triazolothiadiazole ring system. We successfully replaced the metabolically unstable phenolic moiety with a quinoline group. Further optimization around the 5,6 bicyclic moiety led to the identification of 21. Compound 21 suffered from PDE3 selectivity issues and subsequent, structurally informed design led to the discovery of compound 23. Compound 23 has exquisite kinase selectivity, excellent potency, favorable ADME profile, and showed dose-dependent antitumor efficacy in a SNU-5 gastric cancer xenograft model.