Structural Insights into the Iodothyronine Deiodinase 2 Catalytic Core and Deiodinase Catalysis and Dimerization.

Iodothyronine deiodinases (Dio) are selenocysteine-containing membrane enzymes that activate and inactivate the thyroid hormones (TH) through reductive iodide eliminations. The three deiodinase isoforms are homodimers sharing highly conserved amino acid sequences, but they differ in their regioselectivities for the deiodination reaction and regulatory features. We have now solved a crystal structure of the mouse deiodinase 2 (Dio2) catalytic domain.

Elucidating the Unconventional Binding Mode of a DNA-Encoded Library Hit Provides a Blueprint for Sirtuin 6 Inhibitor Development.

Sirtuin 6 (Sirt6), an NAD-dependent deacylase, has emerged as a promising target for aging-related diseases and cancer. Advancing the medicinal chemistry of Sirt6 modulators is crucial for the development of chemical probes aimed at unraveling the intricate biological functions of Sirt6 and unlocking its therapeutic potential. A proprietary DNA-encoded library yielded Sirt6 inhibitor 2-Pr, displaying remarkable inhibitory activity and isoform-selectivity, and featuring a chemical structure distinct from reported Sirt6 modulators.

Specific Inhibitors of Mitochondrial Deacylase Sirtuin 4 Endowed with Cellular Activity.

Sirtuins are NAD-dependent protein lysine deacylases implicated in aging-related diseases. Mammalian Sirtuin 4 (Sirt4) is located in mitochondria and a potential therapeutic target for cancer and metabolic diseases, but no potent and selective Sirt4 inhibitors have been reported. Here, we describe the identification of potent Sirt4-specific small-molecule inhibitors.

SIRT6 Protects Against Lipopolysaccharide-Induced Inflammation in Human Pulmonary Lung Microvascular Endothelial Cells.

Inflammatory response in the pulmonary endothelium drives the pathogenesis of acute lung injury and sepsis. Sirtuin 6 (SIRT6), a member of class III NAD+-dependent deacetylases belonging to the sirtuin family, regulates senescence, metabolism, and inflammation and extends lifespan in mice and model organisms. However, the role of SIRT6 in pulmonary endothelial inflammation is unknown.

Novel 1,4-Dihydropyridines as Specific Binders and Activators of SIRT3 Impair Cell Viability and Clonogenicity and Downregulate Hypoxia-Induced Targets in Cancer Cells.

The mitochondrial SIRT3 modulates several biological pathways such as cancer, metabolism, and hypoxia-related diseases. Recently, we discovered new 1,4-dihydropyridines, compounds and , the latter being a SIRT3-specific activator. In the present work, a novel - and -related small series of compounds have been developed, with displaying the strongest SIRT3 binding and activation, with a of 29 μM and 387% of enzyme activation.

Molecular Mechanism of Sirtuin 1 Inhibition by Human Immunodeficiency Virus 1 Tat Protein.

Sirtuins are NAD-dependent protein lysine deacylases implicated in metabolic regulation and aging-related dysfunctions. The nuclear isoform Sirt1 deacetylates histones and transcription factors and contributes, e.g.

Scaffold Hopping and Optimization of Small Molecule Soluble Adenyl Cyclase Inhibitors Led by Free Energy Perturbation.

Free energy perturbation is a computational technique that can be used to predict how small changes to an inhibitor structure will affect the binding free energy to its target. In this paper, we describe the utility of free energy perturbation with FEP+ in the hit-to-lead stage of a drug discovery project targeting soluble adenyl cyclase. The project was structurally enabled by X-ray crystallography throughout.

Corrigendum: Assessing potency and binding kinetics of soluble adenylyl cyclase (sAC) inhibitors to maximize therapeutic potential.

[This corrects the article DOI: 10.3389/fphys.2022.

On-demand male contraception via acute inhibition of soluble adenylyl cyclase.

Nearly half of all pregnancies are unintended; thus, existing family planning options are inadequate. For men, the only choices are condoms and vasectomy, and most current efforts to develop new contraceptives for men impact sperm development, meaning that contraception requires months of continuous pretreatment. Here, we provide proof-of-concept for an innovative strategy for on-demand contraception, where a man would take a birth control pill shortly before sex, only as needed.

Molecular Mechanism of Sirtuin 1 Modulation by the AROS Protein.

The protein lysine deacylases of the NAD-dependent Sirtuin family contribute to metabolic regulation, stress responses, and aging processes, and the human Sirtuin isoforms, Sirt1-7, are considered drug targets for aging-related diseases. The nuclear isoform Sirt1 deacetylates histones and transcription factors to regulate, e.g.

Design, Synthesis, and Pharmacological Evaluation of Second-Generation Soluble Adenylyl Cyclase (sAC, ADCY10) Inhibitors with Slow Dissociation Rates.

Soluble adenylyl cyclase (sAC: ADCY10) is an enzyme involved in intracellular signaling. Inhibition of sAC has potential therapeutic utility in a number of areas. For example, sAC is integral to successful male fertility: sAC activation is required for sperm motility and ability to undergo the acrosome reaction, two processes central to oocyte fertilization.

Assessing potency and binding kinetics of soluble adenylyl cyclase (sAC) inhibitors to maximize therapeutic potential.

In mammalian cells, 10 different adenylyl cyclases produce the ubiquitous second messenger, cyclic adenosine monophosphate (cAMP). Amongst these cAMP-generating enzymes, bicarbonate (HCO )-regulated soluble adenylyl cyclase (sAC; ADCY10) is uniquely essential in sperm for reproduction. For this reason, sAC has been proposed as a potential therapeutic target for non-hormonal contraceptives for men.

Potent and Specific Activators for Mitochondrial Sirtuins Sirt3 and Sirt5.

Sirtuins are NAD-dependent protein deacylases involved in metabolic regulation and aging-related diseases. Specific activators for seven human Sirtuin isoforms would be important chemical tools and potential therapeutic drugs. Activators have been described for Sirt1 and act via a unique N-terminal domain of this isoform.

Insights into the Mechanism of Human Deiodinase 1.

The three isoenzymes of iodothyronine deiodinases (DIO1-3) are membrane-anchored homo-dimeric selenoproteins which share the thioredoxin-fold structure. Several questions regarding their catalytic mechanisms still remain open. Here, we addressed the roles of several cysteines which are conserved among deiodinase isoenzymes and asked whether they may contribute to dimerization and reduction of the oxidized enzyme with physiological reductants.

Constitutively Activating GNAS Somatic Mutation in Right Ventricular Outflow Tract Tachycardia.

[Figure: see text].

Discovery of TDI-10229: A Potent and Orally Bioavailable Inhibitor of Soluble Adenylyl Cyclase (sAC, ADCY10).

Soluble adenylyl cyclase (sAC) has gained attention as a potential therapeutic target given the role of this enzyme in intracellular signaling. We describe successful efforts to design improved sAC inhibitors amenable for interrogation of sAC inhibition to assess its potential therapeutic applications. This work culminated in the identification of TDI-10229 (), which displays nanomolar inhibition of sAC in both biochemical and cellular assays and exhibits mouse pharmacokinetic properties sufficient to warrant its use as an tool compound.

Metabolic Rewiring by Loss of Sirt5 Promotes Kras-Induced Pancreatic Cancer Progression.

Background & Aims: SIRT5 plays pleiotropic roles via post-translational modifications, serving as a tumor suppressor, or an oncogene, in different tumors. However, the role SIRT5 plays in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC) remains unknown.

Methods: Published datasets and tissue arrays with SIRT5 staining were used to investigate the clinical relevance of SIRT5 in PDAC.

Natural Glycoforms of Human Interleukin 6 Show Atypical Plasma Clearance.

A library of glycoforms of human interleukin 6 (IL-6) comprising complex and mannosidic N-glycans was generated by semisynthesis. The three segments were connected by sequential native chemical ligation followed by two-step refolding. The central glycopeptide segments were assembled by pseudoproline-assisted Lansbury aspartylation and subsequent enzymatic elongation of complex N-glycans.

Structural Basis for Activation of Human Sirtuin 6 by Fluvastatin.

Sirtuins are NAD-dependent protein lysine deacylases that are considered attractive drug targets for aging-related diseases. Sirt6 deacetylates, e.g.

Crystal structure and enzymatic characterization of the putative adenylyl cyclase HpAC1 from Hippeastrum reveal dominant triphosphatase activity.

HpAC1, a protein from Hippeastrum hybrid cultivars, was previously suggested to be a plant adenylyl cyclase. We describe a structural and enzymatic characterization of HpAC1. A crystal structure of HpAC1 in complex with a non-hydrolyzable GTP analog confirms a generic CYTH architecture, comprising a β-barrel with an internal substrate site.

The Soluble Adenylyl Cyclase Inhibitor LRE1 Prevents Hepatic Ischemia/Reperfusion Damage Through Improvement of Mitochondrial Function.

Hepatic ischemia/reperfusion (I/R) injury is a leading cause of organ dysfunction and failure in numerous pathological and surgical settings. At the core of this issue lies mitochondrial dysfunction. Hence, strategies that prime mitochondria towards damage resilience might prove applicable in a clinical setting.

Crystal structure of a class III adenylyl cyclase-like ATP-binding protein from Pseudomonas aeruginosa.

In many organisms, the ubiquitous second messenger cAMP is formed by at least one member of the adenylyl cyclase (AC) Class III. These ACs feature a conserved dimeric catalytic core architecture, either through homodimerization or through pseudo-heterodimerization of a tandem of two homologous catalytic domains, C1 and C2, on a single protein chain. The symmetric core features two active sites, but in the C1-C2 tandem one site degenerated into a regulatory center.

From PARP1 to TNKS2 Inhibition: A Structure-Based Approach.

Tankyrases (TNKSs) have recently gained great consideration as potential targets in Wnt/β-catenin pathway-dependent solid tumors. Previously, we reported the 2-mercaptoquinazolin-4-one MC2050 as a micromolar PARP1 inhibitor. Here we show how the resolution of the X-ray structure of PARP1 in complex with MC2050, combined with the computational investigation of the structural differences between TNKSs and PARP1/2 active sites, provided the rationale for a structure-based drug design campaign that with a limited synthetic effort led to the discovery of the bis-quinazolinone as a picomolar and selective TNKS2 inhibitor, endowed with antiproliferative effects in a colorectal cancer cell line (DLD-1) where the Wnt pathway is constitutively activated.