Discovery of Bisubstrate Inhibitors of Nicotinamide <i>N</i>‑Methyltransferase (NNMT)

Nicotinamide <i>N</i>-methyltransferase (NNMT) catalyzes the N-methylation of pyridine-containing compounds using the cofactor <i>S</i>-5′-adenosyl-l-methionine (SAM) as the methyl group donor. Through the regulation of the levels of its substrates, cofactor, and products, NNMT plays an important role in physiology and pathophysiology. Overexpression of NNMT has been implicated in various human diseases. Potent and selective small-molecule NNMT inhibitors are valuable chemical tools for testing biological and therapeutic hypotheses. However, very few NNMT inhibitors have been reported. Here, we describe the discovery of a bisubstrate NNMT inhibitor MS2734 (<b>6</b>) and characterization of this inhibitor in biochemical, biophysical, kinetic, and structural studies. Importantly, we obtained the first crystal structure of human NNMT in complex with a small-molecule inhibitor. The structure of the NNMT–<b>6</b> complex has unambiguously demonstrated that <b>6</b> occupied both substrate and cofactor binding sites. The findings paved the way for developing more potent and selective NNMT inhibitors in the future

Global Profiling of Acetyltransferase Feedback Regulation

Lysine acetyltransferases (KATs) are key mediators of cell signaling. Methods capable of providing new insights into their regulation thus constitute an important goal. Here we report an optimized platform for profiling KAT–ligand interactions in complex proteomes using inhibitor-functionalized capture resins. This approach greatly expands the scope of KATs, KAT complexes, and CoA-dependent enzymes accessible to chemoproteomic methods. This enhanced profiling platform is then applied in the most comprehensive analysis to date of KAT inhibition by the feedback metabolite CoA. Our studies reveal that members of the KAT superfamily possess a spectrum of sensitivity to CoA and highlight NAT10 as a novel KAT that may be susceptible to metabolic feedback inhibition. This platform provides a powerful tool to define the potency and selectivity of reversible stimuli, such as small molecules and metabolites, that regulate KAT-dependent signaling

Sinefungin Derivatives as Inhibitors and Structure Probes of Protein Lysine Methyltransferase SETD2

Epigenetic regulation is involved in numerous physiological and pathogenic processes. Among the key regulators that orchestrate epigenetic signaling are over 50 human protein lysine methyltransferases (PKMTs). Interrogation of the functions of individual PKMTs can be facilitated by target-specific PKMT inhibitors. Given the emerging need for such small molecules, we envisioned an approach to identify target-specific methyltransferase inhibitors by screening privileged small-molecule scaffolds against diverse methyltransferases. In this work, we demonstrated the feasibility of such an approach by identifying the inhibitors of SETD2. <i>N</i>-propyl sinefungin (Pr-SNF) was shown to interact preferentially with SETD2 by matching the distinct transition-state features of SETD2’s catalytically active conformer. With Pr-SNF as a structure probe, we further revealed the dual roles of SETD2’s post-SET loop in regulating substrate access through a distinct topological reconfiguration. Privileged sinefungin scaffolds are expected to have broad use as structure and chemical probes of methyltransferases

DS_DISC766278 – Supplemental material for Discovery of Small-Molecule Antagonists of the H3K9me3 Binding to UHRF1 Tandem Tudor Domain

<p>Supplemental material, DS_DISC766278 for Discovery of Small-Molecule Antagonists of the H3K9me3 Binding to UHRF1 Tandem Tudor Domain by Guillermo Senisterra, Hugh Y. Zhu, Xiao Luo, Hailong Zhang, Guoliang Xun, Chunliang Lu, Wen Xiao, Taraneh Hajian, Peter Loppnau, Irene Chau, Fengling Li, Abdellah Allali-Hassani, Peter Atadja, Counde Oyang, En Li, Peter J. Brown, Cheryl H. Arrowsmith, Kehao Zhao, Zhengtian Yu, and Masoud Vedadi in SLAS Discovery</p