Monday, March 28, 2022

Discovery of SPH5030, a Selective, Potent, and Irreversible Tyrosine Kinase Inhibitor for HER2-Amplified and HER2-Mutant Cancer Treatment

Di Li, Yuanxiang Tu, Kaijun Jin, Lingjun Duan, Yuan Hong, Jia Xu, Na Chen, Zhihui Zhang, Hongjian Zuo, Wanchun Gong, Jing Zhang, Qian Wang, Hai Qian, Xuenan Wang, Ying Ke, and Guangxin Xia
Journal of Medicinal Chemistry 2022

DOI: 10.1021/acs.jmedchem.1c00710

Small-molecule irreversible tyrosine kinase inhibitors as high potent agents have led to improvements in disease-free and overall survival in patients with HER2-amplified cancer. The approved irreversible HER2 inhibitors, neratinib and pyrotinib, both lack HER2 selectivity, leading to off-target adverse events in patients. The development of HER2 mutation during treatment also hampers the progress of the treatment. We used a molecular hybridization strategy for structural optimizations, in conjunction with in vitro and in vivo drug-like property screening, to obtain a clinical candidate SPH5030. Overall, SPH5030 showed excellent activities against four frequent kinds of HER2 mutants and high relative HER2 selectivity compared with neratinib and pyrotinib, good pharmacokinetic characteristics with desirable bioavailabilities, and significant in vivo antitumor efficacy in xenograft mouse models, especially in a HER2 mutation A775_G776insYVMA xenograft mouse model with its potency much higher than those of neratinib and pyrotinib.



Friday, March 25, 2022

Chemical Proteomics Reveals Antibiotic Targets of Oxadiazolones in MRSA [@atbakker]

Bakker, A.; Kotsogianni, I.; Mirenda, L.; Straub, V.; Florea, B.; van den Berg, R.; Janssen, A.; Martin, N.; van der Stelt, M. ChemRxiv 2022

doi: https://doi.org/10.26434/chemrxiv-2022-7gcmd

Phenotypic screening is a powerful approach to identify novel antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) infection, but elucidation of the targets responsible for antimicrobial activity is often challenging in the case of compounds with a polypharmacological mode-of-action. Here, we show that activity-based protein profiling maps the target interaction landscape of a series of 1,3,4-oxadiazole-3-ones, identified in a phenotypic screen to have high antibacterial potency against multidrug resistant S. aureus. In situ competitive and comparative chemical proteomics with a tailor-made activity-based probe, in combination with transposon and resistance studies, revealed several cysteine and serine hydrolases as relevant targets. Our data showcase oxadiazolones as novel antibacterial chemotype with a polypharmacological mode-of-action, in which FabH, FphC and AdhE play a central role.



Monday, March 21, 2022

Structure-based design of a dual-warhead covalent inhibitor of FGFR4

  • Xiaojuan Chen, Huiliang Li, Qianmeng Lin, Shuyan Dai, Sitong Yue, Lingzhi Qu, Maoyu Li, Ming Guo, Hudie Wei, Jun Li, Longying Jiang, Guangyu Xu & Yongheng Chen 

  • Communications Chemistry volume 5,  36 (2022

  • DOI: https://doi.org/10.1038/s42004-022-00657-9

The fibroblast growth factor 19 (FGF19)/fibroblast growth factor receptor 4 (FGFR4) signaling pathways play critical roles in a variety of cancers, such as hepatocellular carcinoma (HCC). FGFR4 is recognized as a promising target to treat HCC. Currently, all FGFR covalent inhibitors target one of the two cysteines (Cys477 and Cys552). Here, we designed and synthesized a dual-warhead covalent FGFR4 inhibitor, CXF-009, targeting Cys477 and Cys552 of FGFR4. We report the cocrystal structure of FGFR4 with CXF-009, which exhibits a dual-warhead covalent binding mode. CXF-009 exhibited stronger selectivity for FGFR4 than FGFR1-3 and other kinases. CXF-009 can also potently inhibit the single cystine mutants, FGFR4(C477A) and FGFR4(C552A), of FGFR4. In summary, our study provides a dual-warhead covalent FGFR4 inhibitor that can covalently target two cysteines of FGFR4. CXF-009, to our knowledge, is the first reported inhibitor that forms dual-warhead covalent bonds with two cysteine residues in FGFR4. CXF-009 also has the potential to overcome drug induced resistant FGFR4 mutations and might serve as a lead compound for future anticancer drug discovery.



 

Wednesday, March 16, 2022

Single Mutation on Trastuzumab Modulates the Stability of Antibody–Drug Conjugates Built Using Acetal-Based Linkers and Thiol-Maleimide Chemistry

Xhenti Ferhati, Ester Jiménez-Moreno, Emily A. Hoyt, Giulia Salluce, Mar Cabeza-Cabrerizo, Claudio D. Navo, Ismael Compañón, Padma Akkapeddi, Maria J. Matos, Noelia Salaverri, Pablo Garrido, Alfredo Martínez, Víctor Laserna, Thomas V. Murray, Gonzalo Jiménez-Osés, Peter Ravn, Gonçalo J. L. Bernardes, and Francisco Corzana

Journal of the American Chemical Society 2022

DOI: 10.1021/jacs.1c07675

Antibody-drug conjugates (ADCs) are a class of targeted therapeutics used to selectively kill cancer cells. It is important that they remain intact in the bloodstream and release their payload in the target cancer cell for maximum efficacy and minimum toxicity. The development of effective ADCs requires the study of factors that can alter the stability of these therapeutics at the atomic level. Here, we present a general strategy that combines synthesis, bioconjugation, linker technology, site-directed mutagenesis, and modeling to investigate the influence of the site and microenvironment of the trastuzumab antibody on the stability of the conjugation and linkers. Trastuzumab is widely used to produce targeted ADCs because it can target with high specificity a receptor that is overexpressed in certain breast cancer cells (HER2). We show that the chemical environment of the conjugation site of trastuzumab plays a key role in the stability of linkers featuring acid-sensitive groups such as acetals. More specifically, Lys-207, located near the reactive Cys-205 of a thiomab variant of the antibody, may act as an acid catalyst and promote the hydrolysis of acetals. Mutation of Lys-207 into an alanine or using a longer linker that separates this residue from the acetal group stabilizes the conjugates. Analogously, Lys-207 promotes the beneficial hydrolysis of the succinimide ring when maleimide reagents are used for conjugation, thus stabilizing the subsequent ADCs by impairing the undesired retro-Michael reactions. This work provides new insights for the design of novel ADCs with improved stability properties.



Friday, March 11, 2022

Identification and In Silico Binding Study of a Highly Potent DENV NS2B-NS3 Covalent Inhibitor

Xincheng Lin, Jiawei Cheng, Yuming Wu, Yaoliang Zhang, Hailun Jiang, Jian Wang, Xuejun Wang, and Maosheng Cheng

ACS Medicinal Chemistry Letters  2022

DOI: 10.1021/acsmedchemlett.1c00653

Dengue virus (DENV), an arthropod-borne flavivirus, has developed rapidly in the past few decades and becoming the most widespread arbovirus in the world. The vital role of NS2B-NS3 in virus replication and maturation of viral proteins makes it the most promising target for anti-DENV drug discovery. In the current work, a potent NS2B-NS3 covalent inhibitor 23 (IC50 = 6.0 nM, kinac/Ki = 1581 M–1 s–1) was discovered through the chemical modification of a published covalent inhibitor 1 (IC50 = 500 nM, kinac/Ki = 156.1 M–1 s–1), followed by in vitro assay. Further comprehensive structure–activity relationship analysis through covalent docking and molecular dynamics simulation provides informative understanding of the binding modes of covalent inhibitors targeting NS2B-NS3.

Discovery of Potent and Selective Inhibitors against Protein-Derived Electrophilic Cofactors

Xie Wang, Zongtao Lin, Katelyn A. Bustin, Nate R. McKnight, William H. Parsons, and Megan L. Matthews

Journal of the American Chemical Society 2021
DOI: 10.1021/jacs.1c12748

Electrophilic cofactors are widely distributed in nature and play important roles in many physiological and disease processes, yet they have remained blind spots in traditional activity-based protein profiling (ABPP) approaches that target nucleophiles. More recently, reverse-polarity (RP)-ABPP using hydrazine probes identified an electrophilic N-terminal glyoxylyl (Glox) group for the first time in secernin-3 (SCRN3). The biological function(s) of both the protein and Glox as a cofactor has not yet been pharmacologically validated because of the lack of selective inhibitors that could disrupt and therefore identify its activity. Here, we present the first platform for analyzing the reactivity and selectivity of an expanded nucleophilic probe library toward main-chain carbonyl cofactors such as Glox and pyruvoyl (Pyvl) groups. We first applied the library proteome-wide to profile and confirm engagement with various electrophilic protein targets, including secernin-2 (SCRN2), shown here also to possess a Glox group. A broadly reactive indole ethylhydrazine probe was used for a competitive in vitro RP-ABPP assay to screen for selective inhibitors against such cofactors from a set of commercially available nucleophilic fragments. Using Glox-containing SCRN proteins as a case study, naphthyl hydrazine was identified as a potent and selective SCRN3 inhibitor, showing complete inhibition in cell lysates with no significant cross-reactivity detected for other enzymes. Moving forward, this platform provides the fundamental basis for the development of selective Glox inhibitors and represents a starting point to advance small molecules that modulate electrophile-dependent function.


Tuesday, March 8, 2022

Discovery of Potent PROTACs Targeting EGFR Mutants through the Optimization of Covalent EGFR Ligands

Hong-Yi Zhao, Hai-Peng Wang, Yu-Ze Mao, Hao Zhang, Minhang Xin, Xiao-Xiao Xi, Hao Lei, Shuai Mao, Dong-Hui Li, and San-Qi Zhang

Journal of Medicinal Chemistry 2022
DOI: 10.1021/acs.jmedchem.1c01827

Drug resistance caused by epidermal growth factor receptor (EGFR) mutation has largely limited the clinical use of EGFR tyrosine kinase inhibitors (EGFR-TKIs) for the treatment of non-small-cell lung cancer (NSCLC). Herein, to overcome the intractable problem of drug resistance, proteolysis targeting chimeras (PROTACs) targeting EGFR mutants were developed by optimizing covalent EGFR ligands. Covalent or reversible covalent pyrimidine- or purine-containing PROTACs were designed, synthesized, and evaluated. As a consequence, covalent PROTAC CP17, with a novel purine-containing EGFR ligand, was discovered as a highly potent degrader against EGFRL858R/T790M and EGFRdel19, reaching the lowest DC50 values among all reported EGFR-targeting PROTACs. Furthermore, CP17 exhibited excellent cellular activity against the H1975 and HCC827 cell lines with high selectivity. Mechanism investigation indicated that the lysosome was involved in the degradation process. Importantly, the covalent binding strategy was proven to be an effective approach for the design of PROTACs targeting EGFRL858R/T790M, which laid the practical foundation for further development of potent EGFR-targeting PROTACs.



Saturday, March 5, 2022

SP3-enabled Rapid and High Coverage Chemoproteomic Identification of Cell-State Dependent Redox-Sensitive Cysteines [@Keribackus]

Heta S. Desai,Tianyang Yan,Fengchao Yu,Alexander W. Sun,Miranda Villanueva,Alexey I. Nesvizhskii,Keriann M. Backus

Molecular & Cellular Proteomics, 2022

https://doi.org/10.1016/j.mcpro.2022.100218

Proteinaceous cysteine residues act as privileged sensors of oxidative stress. As reactive oxygen and nitrogen species (ROS and RNS) have been implicated in numerous pathophysiological processes, deciphering which cysteines are sensitive to oxidative modification and the specific nature of these modifications is essential to understanding protein and cellular function in health and disease. While established mass spectrometry-based proteomic platforms have improved our understanding of the redox proteome, the widespread adoption of these methods is often hindered by complex sample preparation workflows, prohibitive cost of isotopic labeling reagents, and requirements for custom data analysis workflows. Here, we present the SP3-Rox redox proteomics method that combines tailored low cost isotopically labeled capture reagents with SP3 sample cleanup to achieve high throughput and high coverage proteome-wide identification of redox-sensitive cysteines. By implementing a customized workflow in the open-source FragPipe computational pipeline, we achieve accurate MS1-based quantitation, including for peptides containing multiple cysteine residues. Application of the SP3-Rox method to cellular proteomes identified cysteines sensitive to the oxidative stressor GSNO and cysteine oxidation state changes that occur during T cell activation.



Thiol Reactivity of N-Aryl α-Methylene-γ-lactams: Influence of the Guaianolide Structure [@KayBrummond]

 Daniel P. Dempe, Chong-Lei Ji, Peng Liu, and Kay M. Brummond The Journal of Organic Chemistry, 2020 DOI: 10.1021/acs.joc.2c01530 The α-meth...