Selective Covalent Inhibiting JNK3 by Small Molecules for Parkinson's Diseases

Liang Ouyang, Wen Shuai, Panpan Yang, Huan Xiao, Yumeng Zhu, Faqian Bu, Aoxue Wang, Qiu Sun, Guan Wang

Angewandte Chemie 2024 e202411037

https://doi.org/10.1002/ange.202411037

c-Jun N-terminal kinases (JNKs) including JNK1/2/3 are key members of mitogen-activated protein kinase family. Wherein JNK3 is specifically expressed in brain and emerges as therapeutic target, especially for neurodegenerative diseases. However, developing JNK3 selective inhibitors as chemical probes to investigate its therapeutic potential in diseases remains challenging. Here, we adopted the covalent strategy for identifying JNK3-selective covalent inhibitorJC16I, with high inhibitory activity against JNK3. Despite targeting a conserved cysteine the vicinity of ATP pocket in JNK family, JC16I exerted a greater than 160-fold selectivity for JNK3 over JNK1/2. Importantly, even at low concentration, JC16I showed enhanced and long-lasting inhibition against cellular JNK3. In addition, its alkyne-containing probe JC-P1 could label JNK3 in SH-SY5Y cell lysate and living cells, with goodproteome-wide selectivity. Furthermore, JC16I selectively suppressed the abnormal activation of JNK3 signaling and sufficiently exhibited neuroprotective effect in Parkinson's diseases (PD) models. Overall, our findings highlight the potential of developing isoform-selective and cell-active JNK3 inhibitors by covalent drug design strategy targeting a conserved cysteine. This work not only provides a valuable chemical probe for JNK3-targeted investigations in vitro and in vivo but also opens new avenues for the treatment of PD.

Development of ketalized unsaturated saccharides as multifunctional cysteine-targeting covalent warheads

Dong, S., Huang, H., Li, J. et al.

Commun Chem 7, 201 (2024). 

https://doi.org/10.1038/s42004-024-01279-z

Multi-functional cysteine-targeting covalent warheads possess significant therapeutic potential in medicinal chemistry and chemical biology. Herein, we present novel unsaturated and asymmetric ketone (oxazolinosene) scaffolds that selectively conjugate cysteine residues of peptides and bovine serum albumin under normal physiological conditions. This unsaturated saccharide depletes GSH in NCI-H1299 cells, leading to anti-tumor effects in vitro. The acetyl group of the ketal moiety on the saccharide ring can be converted to other carboxylic acids in a one-pot synthesis. In this way, the loaded acid can be click-released during cysteine conjugation, making the oxazolinosene a potential multifunctional therapeutic agent. The reaction kinetic model for oxazolinosene conjugation to GSH is well established and was used to evaluate oxazolinosene reactivity. The aforementioned oxazolinosenes were stereoselectively synthesized via a one-step reaction of nitriles with saccharides and conveniently converted into a series of α, β-unsaturated ketone N-glycosides as prevalent synthetic building blocks. The reaction mechanisms of oxazolinosene synthesis were investigated through calculations and validated with control experiments. Overall, these oxazolinosenes can be easily synthesized and developed as cysteine-targeted covalent warheads carrying useful click-releasing groups.

From Mechanism-Based Retaining Glycosidase Inhibitors to Activity-Based Glycosidase Profiling

 Marta Artola, Johannes M. F. G. Aerts, Gijsbert A. van der Marel, Carme Rovira, Jeroen D. C. Codée, Gideon J. Davies, and Herman S. Overkleeft

Journal of the American Chemical Society 2024

DOI: 10.1021/jacs.4c08840

Activity-based protein profiling (ABPP) is an effective technology for the identification and functional annotation of enzymes in complex biological samples. ABP designs are normally directed to an enzyme active site nucleophile, and within the field of Carbohydrate-Active Enzymes (CAZymes), ABPP has been most successful for those enzymes that feature such a residue: retaining glycosidases (GHs). Several mechanism-based covalent and irreversible retaining GH inhibitors have emerged over the past sixty years. ABP designs based on these inhibitor chemistries appeared since the turn of the millennium, and we contributed to the field by designing a suite of retaining GH ABPs modeled on the structure and mode of action of the natural product, cyclophellitol. These ABPs enable the study of both exo- and endo-acting retaining GHs in human health and disease, for instance in genetic metabolic disorders in which retaining GHs are deficient. They are also finding increasing use in the study of GHs in gut microbiota and environmental microorganisms, both in the context of drug (de)toxification in the gut and that of biomass polysaccharide processing for future sustainable energy and chemistries. This account comprises the authors’ view on the history of mechanism-based retaining GH inhibitor design and discovery, on how these inhibitors served as blueprints for retaining GH ABP design, and on some current and future developments on how cyclophellitol-based ABPs may drive the discovery of retaining GHs and their inhibitors.

SuFEx Chemistry Enables Covalent Assembly of a 280-kDa 18-Subunit Pore-Forming Complex

Lee Schnaider, Sophia Tan, Pratik R. Singh, Floriana Capuano, Alistair J. Scott, Richard Hambley, Lei Lu, Hyunjun Yang, E. Jayne Wallace, Hyunil Jo, and William F. DeGrado

Journal of the American Chemical Society 2024

DOI: 10.1021/jacs.4c07920

Proximity-enhanced chemical cross-linking is an invaluable tool for probing protein–protein interactions and enhancing the potency of potential peptide and protein drugs. Here, we extend this approach to covalently stabilize large macromolecular assemblies. We used SuFEx chemistry to covalently stabilize an 18-subunit pore-forming complex, CsgG:CsgF, consisting of nine CsgG membrane protein subunits that noncovalently associate with nine CsgF peptides. Derivatives of the CsgG:CsgF pore have been used for DNA sequencing, which places high demands on the structural stability and homogeneity of the complex. To increase the robustness of the pore, we designed and synthesized derivatives of CsgF-bearing sulfonyl fluorides, which react with CsgG in very high yield to form a covalently stabilized CsgG:CsgF complex. The resulting pores formed highly homogeneous channels when added to artificial membranes. The high yield and rapid reaction rate of the SuFEx reaction prompted molecular dynamics simulations, which revealed that the SO2F groups in the initially formed complex are poised for nucleophilic reaction with a targeted Tyr. These results demonstrate the utility of SuFEx chemistry to structurally stabilize very large (here, 280 kDa) assemblies.

Targeted Protein Localization by Covalent 14–3–3 Recruitment

 Qian Shao, Tuong Nghi Duong, Inji Park, Lauren M. Orr, and Daniel K. Nomura

Journal of the American Chemical Society 2024

DOI: 10.1021/jacs.3c12389

14–3–3 proteins have a unique ability to bind and sequester a multitude of diverse phosphorylated signaling proteins and transcription factors. Many previous studies have shown that interactions of 14–3–3 with specific phosphorylated substrate proteins can be enhanced through small-molecule natural products or fully synthetic molecular glue interactions. However, enhancing 14–3–3 interactions with both therapeutically intractable transcription factor substrates and potential neo-substrates to sequester and inhibit their function remains elusive. One of the 14–3–3 proteins, 14–3–3σ or SFN, has cysteine C38 at the substrate-binding interface, near the sites where previous 14–3–3 molecular glues have been found to bind. In this study, we screen a fully synthetic cysteine-reactive covalent ligand library to identify molecular glues that enhance the interaction of 14–3–3σ with not only druggable transcription factors such as estrogen receptor (ERα) but also challenging oncogenic transcription factors such as YAP and TAZ, which are part of the Hippo transducer pathway. We identify a hit EN171 that covalently targets both C38 and C96 on 14–3–3 to enhance 14–3–3 interactions with ERα, YAP, and TAZ, leading to impaired estrogen receptor and Hippo pathway transcriptional activity. We further demonstrate that EN171 could not only be used as a molecular glue to enhance native protein interactions but could also be used as a covalent 14–3–3 recruiter in heterobifunctional molecules to sequester nuclear neo-substrates such as BRD4 and BLC6 into the cytosol. Overall, our study reveals a covalent ligand that acts as a novel 14–3–3 molecular glue for challenging transcription factors such as YAP and TAZ and demonstrates that these glues can be potentially utilized in heterobifunctional molecules to sequester nuclear neo-substrates out of the nucleus and into the cytosol to enable targeted protein localization.

Aminomethyl Salicylaldehydes Lock onto a Surface Lysine by Forming an Extended Intramolecular Hydrogen Bond Network

Jacqueline Weaver, Gregory B. Craven, Linh Tram, Hao Chen, and Jack Taunton

Journal of the American Chemical Society 2024

DOI: 10.1021/jacs.4c04314

The development of electrophilic ligands that rapidly modify specific lysine residues remains a major challenge. Salicylaldehyde-based inhibitors have been reported to form stable imine adducts with the catalytic lysine of protein kinases. However, the targeted lysine in these examples is buried in a hydrophobic environment. A key unanswered question is whether this strategy can be applied to a lysine on the surface of a protein, where rapid hydrolysis of the resulting salicylaldimine is more likely. Here, we describe a series of aminomethyl-substituted salicylaldehydes that target a fully solvated lysine on the surface of the ATPase domain of Hsp90. By systematically varying the orientation of the salicylaldehyde, we discovered ligands with long residence times, the best of which engages Hsp90 in a quasi-irreversible manner. Crystallographic analysis revealed a daisy-chain network of intramolecular hydrogen bonds in which the salicylaldimine is locked into position by the adjacent piperidine linker. This study highlights the potential of aminomethyl salicylaldehydes to generate conformationally stabilized, hydrolysis-resistant imines, even when the targeted lysine is far from the ligand binding site and is exposed to bulk solvent.

Discovery of a Covalent Inhibitor of Pro-Caspase-1 Zymogen Blocking NLRP3 Inflammasome Activation and Pyroptosis

Dongyi Cao, Ruiying Xi, Hongye Li, Zhonghui Zhang, Xiaoke Shi, Shanshan Li, Yujie Jin, Wanli Liu, Guolin Zhang, Xiaohua Liu, Shunxi Dong, Xiaoming Feng, and Fei Wang

Journal of Medicinal Chemistry 2024

DOI https://doi.org/10.1021/acs.jmedchem.4c01558

Caspase-1 plays a central role in innate immunity, as its activation by inflammasomes induces the production of proinflammatory cytokines and pyroptosis. However, specific inhibition of the enzymatic activity of this protease is not effective in suppressing inflammation, owing to its enzyme-independent function. Herein, we identified a cyclohexenyl isothiocyanate compound (CIB-1476) that potently inhibited caspase-1 activity and suppressed the assembly and activation of the NLRP3 inflammasome and gasdermin-D-mediated pyroptosis. Mechanistically, CIB-1476 directly targeted pro-caspase-1 as an irreversible covalent inhibitor by binding to Cys285 and Cys397, resulting in more durable anti-inflammatory effects in the suppression of enzyme-dependent IL-1β production and enzyme-independent nuclear factor κB activation. Chemoproteomic profiling demonstrated the engagement of CIB-1476 with caspase-1. CIB-1476 showed potent therapeutic effects by suppressing inflammasome activation in mice, which was abolished in Casp1–/– mice. These results warrant further development of CIB-1476 along with its analogues as a novel strategy for caspase-1 inhibitors.