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Deuterium- and tritium-labeled pharmaceutical compounds are pivotal diagnostic tools in drug discovery research, providing vital information about the biological fate of drugs and drug metabolites. Herein we demonstrate that a photoredox-mediated hydrogen atom transfer protocol can efficiently and selectively install deuterium (D) and tritium (T) at α-amino sp³ carbon-hydrogen bonds in a single step, using isotopically labeled water (D₂O or T₂O) as the source of hydrogen isotope. In this context, we also report a convenient synthesis of T₂O from T₂, providing access to high-specific-activity T₂O. This protocol has been successfully applied to the high incorporation of deuterium and tritium in 18 drug molecules, which meet the requirements for use in ligand-binding assays and absorption, distribution, metabolism, and excretion studies.

Emergence of bacterial resistance is a major issue for all classes of antibiotics; therefore, the identification of new classes is critically needed. Recently we reported the discovery of platensimycin by screening natural product extracts using a target-based whole-cell strategy with antisense silencing technology in concert with cell free biochemical validations. Continued screening efforts led to the discovery of platencin, a novel natural product that is chemically and biologically related but different from platensimycin. Platencin exhibits a broad-spectrum Gram-positive antibacterial activity through inhibition of fatty acid biosynthesis. It does not exhibit cross-resistance to key antibiotic resistant strains tested, including methicillin-resistant Staphylococcus aureus, vancomycin-intermediate S. aureus, and vancomycin-resistant ENTEROCOCCI: Platencin shows potent in vivo efficacy without any observed toxicity. It targets two essential proteins, β-ketoacyl-[acyl carrier protein (ACP)] synthase II (FabF) and III (FabH) with IC₅₀ values of 1.95 and 3.91 μg/ml, respectively, whereas platensimycin targets only FabF (IC₅₀ = 0.13 μg/ml) in S. aureus, emphasizing the fact that more antibiotics with novel structures and new modes of action can be discovered by using this antisense differential sensitivity whole-cell screening paradigm.

GPR40 agonists are effective antidiabetic agents believed to lower glucose through direct effects on the beta cell to increase glucose stimulated insulin secretion. However, not all GPR40 agonists are the same. Partial agonists lower glucose through direct effects on the pancreas, whereas GPR40 AgoPAMs may incorporate additional therapeutic effects through increases in insulinotrophic incretins secreted by the gut. Here we describe how GPR40 AgoPAMs stimulate both insulin and incretin secretion in vivo over time in diabetic GK rats. We also describe effects of AgoPAMs in vivo to lower glucose and body weight beyond what is seen with partial GPR40 agonists in both the acute and chronic setting. Further comparisons of the glucose lowering profile of AgoPAMs suggest these compounds may possess greater glucose control even in the presence of elevated glucagon secretion, an unexpected feature observed with both acute and chronic treatment with AgoPAMs. Together these studies highlight the complexity of GPR40 pharmacology and the potential additional benefits AgoPAMs may possess above partial agonists for the diabetic patient.

Crystal structures of hGPR40, a target for treatment of type 2 diabetes, bound to a partial and an allosteric agonist explain the binding cooperativity between these ligands and present new opportunities for structure-guided drug design. Clinical studies indicate that partial agonists of the G-protein-coupled, free fatty acid receptor 1 GPR40 enhance glucose-dependent insulin secretion and represent a potential mechanism for the treatment of type 2 diabetes mellitus. Full allosteric agonists (AgoPAMs) of GPR40 bind to a site distinct from partial agonists and can provide additional efficacy. We report the 3.2-Å crystal structure of human GPR40 (hGPR40) in complex with both the partial agonist MK-8666 and an AgoPAM, which exposes a novel lipid-facing AgoPAM-binding pocket outside the transmembrane helical bundle. Comparison with an additional 2.2-Å structure of the hGPR40–MK-8666 binary complex reveals an induced-fit conformational coupling between the partial agonist and AgoPAM binding sites, involving rearrangements of the transmembrane helices 4 and 5 (TM4 and TM5) and transition of the intracellular loop 2 (ICL2) into a short helix. These conformational changes likely prime GPR40 to a more active-like state and explain the binding cooperativity between these ligands.

A novel fungal metabolite, apicidin [cyclo(N-O-methyl-L-tryptophanyl-L-isoleucinyl-D-pipecolinyl-L-2- amino-8-oxodecanoyl)], that exhibits potent, broad spectrum antiprotozoal activity in vitro against Apicomplexan parasites has been identified. It is also orally and parenterally active in vivo against Plasmodium berghei malaria in mice. Many Apicomplexan parasites cause serious, life-threatening human and animal diseases, such as malaria, cryptosporidiosis, toxoplasmosis, and coccidiosis, and new therapeutic agents are urgently needed. Apicidin's antiparasitic activity appears to be due to low nanomolar inhibition of Apicomplexan histone deacetylase (HDA), which induces hyperacetylation of histones in treated parasites. The acetylation-deacetylation of histones is a thought to play a central role in transcriptional control in eukaryotic cells. Other known HDA inhibitors were also evaluated and found to possess antiparasitic activity, suggesting that HDA is an attractive target for the development of novel antiparasitic agents.

Microbial natural products have long been a rich source of human therapeutics. While the chemical diversity encoded in the genomes of microbes is large, this modality has waned as fermentation-based discovery methods have suffered from rediscovery, inefficient scaling, and incompatibility with target-based discovery paradigms. Here, we leverage a metagenomic partitioning strategy to sequence soil microbiomes at unprecedented depth and quality. We then couple these data with target-focused, in silico search strategies and synthetic biology to discover multiple novel natural product inhibitors of human methionine aminopeptidase-1 (HsMetAP1), a validated oncology target. For one of these, metapeptin B, we demonstrate sub-micromolar potency, strong selectivity for HsMetAP1 over HsMetAP2 and elucidate structure-activity relationships. Our approach overcomes challenges of traditional natural product methods, accesses vast, untapped chemical diversity in uncultured microbes, and demonstrates computationally-enabled precision mining of modulators of human proteins.

Microbial natural products are specialized metabolites that have long been a rich source of human therapeutics. While the chemical diversity encoded in the genomes of microbes is believed to be large, the productivity of this modality has waned as traditional fermentation-based discovery methods have been plagued by high-rates of rediscovery, inefficient scaling, and incompatibility with target-based drug discovery. Here, we demonstrate a scalable discovery platform that couples dramatically improved assembly of deep-sequenced metagenomic samples with highly efficient, target-focused, in silico search strategies and synthetic biology to discover multiple novel inhibitors of human methionine aminopeptidase-1 (HsMetAP1), a validated oncology target. For one of these novel inhibitors, metapeptin B, we demonstrate sub-micromolar potency, strong selectivity for HsMetAP1 over HsMetAP2 and leverage natural congeners to rapidly elucidate key SAR elements. Our 'next-gen' discovery platform overcomes many of the challenges constraining traditional methods, implies the existence of vast, untapped chemical diversity in nature, and demonstrates computationally-enabled precision discovery of modulators of human proteins of interest. Competing Interest Statement Multiple authors are/were employees of Zymergen, Inc.

To assess disease activity, steroid-free remission, and other clinical outcome assessments among pediatric patients with ulcerative colitis (UC) and Crohn's disease (CD) in the ImproveCareNow (ICN) registry. Patients aged 2-17 years diagnosed with UC or CD between June 1, 2013 and December 31, 2019 were enrolled if they initiated a biologic after enrollment in the ICN registry and completed at least 12 months follow-up after first maintenance dose. Baseline (at biologic initiation) demographics were summarized using descriptive statistics. Pediatric UC Activity Index (PUCAI), partial Mayo score, and Physician Global Assessment (PGA) were assessed for UC; and the Short Pediatric Crohn's Disease Activity Index (sPCDAI) and PGA were assessed for CD at first maintenance dose, 1- and 3-year time points. Kappa coefficients were used to assess the level of agreement between the outcome measures. A total of 1887 patients (UC = 350; CD = 1537) were included. Baseline demographics were similar across groups. For UC patients, mean PUCAI scores decreased and the proportion of patients in steroid-free remission, quiescent state based on PGA, and remission based on partial Mayo score increased from first maintenance dose to 1 and 3 years. For CD patients, mean sPCDAI score of CD patients decreased and the proportion of patients in steroid-free remission by sPCDAI and in quiescent state based on PGA increased from first maintenance dose to 1 and 3 years. Kappa coefficients showed only modest correlation between disease activity assessments. Disease activity scores improved over time, with more pediatric patients with UC and CD achieving steroid-free remission at 1 and 3 years after first biologic maintenance dose.

In recent surveys, employers of forestry graduates have indicated that interpersonal skills as well as technical competencies are essential for long-term success in forestry. These employers find that many recent graduates fall short in their ability to work in teams, listen to and address public questions, and solve problems collaboratively. New classroom approaches that embed interactive skills within a disciplinary framework can assist students in developing those necessary social skills and at the same time enhance students' learning and retention of technical information. A six-course sequence for Iowa State University sophomores illustrates the concept of cooperative learning as an alternative to individual and competitive learning models. Instructors find that supervised practice of interactive skills in a classroom environment develops the professional competencies employers want.