Rational Exploration of 2,4-Diaminopyrimidines as DHFR Inhibitors Active against and , Two Emerging Human Pathogens.

Nontuberculous mycobacteria (NTM) are emerging human pathogens linked to severe pulmonary diseases. Current treatments involve the prolonged use of multiple drugs and are often ineffective. Bacterial dihydrofolate reductase (DHFR) is a key enzyme targeted by antibiotics in Gram-negative bacterial infections.

BB0346 is an Essential, Structurally Variant LolA Homolog that is Primarily Required for Homeostatic Localization of Periplasmic Lipoproteins.

In diderm bacteria, the Lol pathway canonically mediates the periplasmic transport of lipoproteins from the inner membrane (IM) to the outer membrane (OM) and therefore plays an essential role in bacterial envelope homeostasis. After extrusion of modified lipoproteins from the IM via the LolCDE complex, the periplasmic chaperone LolA carries lipoproteins through the periplasm and transfers them to the OM lipoprotein insertase LolB, itself a lipoprotein with a LolA-like fold. Yet, LolB homologs appear restricted to γ-proteobacteria and are missing from spirochetes like the tick-borne Lyme disease pathogen , suggesting a different hand-off mechanism at the OM.

Structural and functional characterization of FabG4 from Mycolicibacterium smegmatis.

The rise in antimicrobial resistance is a global health crisis and necessitates the development of novel strategies to treat infections. For example, in 2022 tuberculosis (TB) was the second leading infectious killer after COVID-19, with multi-drug-resistant strains of TB having an ∼40% fatality rate. Targeting essential biosynthetic pathways in pathogens has proven to be successful for the development of novel antimicrobial treatments.

ACE2 acts as a novel regulator of TMPRSS2-catalyzed proteolytic activation of influenza A virus in airway cells.

The transmembrane serine protease 2 (TMPRSS2) activates the outer structural proteins of a number of respiratory viruses including influenza A virus (IAV), parainfluenza viruses, and various coronaviruses for membrane fusion. Previous studies showed that TMPRSS2 interacts with the carboxypeptidase angiotensin-converting enzyme 2 (ACE2), a cell surface protein that serves as an entry receptor for some coronaviruses. Here, by using protease activity assays, we determine that ACE2 increases the enzymatic activity of TMPRSS2 in a non-catalytic manner.

Characterization of an Monofunctional Phosphomethylpyrimidine Kinase That Is Inhibited by Pyridoxal Phosphate.

Thiamin and its phosphate derivatives are ubiquitous molecules involved as essential cofactors in many cellular processes. The biosynthesis of thiamin employs the parallel synthesis of 4-methyl-5-(2-hydroxyethyl)thiazole (THZ-P) and 4-amino-2-methyl-5(diphosphooxymethyl) pyrimidine (HMP) pyrophosphate (HMP-PP), which are coupled to generate thiamin phosphate. Most organisms that can biosynthesize thiamin employ a kinase (HMPK or ThiD) to generate HMP-PP.

Crystal structure and biophysical characterization of IspD from Burkholderia thailandensis and Mycobacterium paratuberculosis.

The methylerythritol phosphate (MEP) pathway is a metabolic pathway that produces the isoprenoids isopentyl pyrophosphate and dimethylallyl pyrophosphate. Notably, the MEP pathway is present in bacteria and not in mammals, which makes the enzymes of the MEP pathway attractive targets for discovering new anti-infective agents due to the reduced chances of off-target interactions leading to side effects. There are seven enzymes in the MEP pathway, the third of which is IspD.

Structure-Guided Discovery of N-CAIR Mutase Inhibitors.

Because purine nucleotides are essential for all life, differences between how microbes and humans metabolize purines can be exploited for the development of antimicrobial therapies. While humans biosynthesize purine nucleotides in a 10-step pathway, most microbes utilize an additional 11th enzymatic activity. The human enzyme, aminoimidazole ribonucleotide (AIR) carboxylase generates the product 4-carboxy-5-aminoimidazole ribonucleotide (CAIR) directly.

New therapeutic strategies for pulmonary diseases - untapping the mycolic acid pathway.

Introduction: Treatment options against infections are very limited. New compounds are needed to cure pulmonary diseases. While the mycolic acid biosynthetic pathway has been largely exploited for the treatment of tuberculosis, this metabolic process has been overlooked in , although it offers many potential drug targets for the treatment of this opportunistic pathogen.

and Efficacy of NITD-916 against Mycobacterium fortuitum.

Mycobacterium fortuitum represents one of the most clinically relevant rapid-growing mycobacterial species. Treatments are complex due to antibiotic resistance and to severe side effects of effective drugs, prolonged time of treatment, and co-infection with other pathogens. Herein, we explored the activity of NITD-916, a direct inhibitor of the enoyl-ACP reductase InhA of the type II fatty acid synthase in Mycobacterium tuberculosis.

Efficacy and Mode of Action of a Direct Inhibitor of InhA.

There is an unmet medical need for effective treatments against pulmonary infections, to which cystic fibrosis (CF) patients are particularly vulnerable. Recent studies showed that the antitubercular drug isoniazid is inactive against due to the incapacity of the catalase-peroxidase to convert the pro-drug into a reactive metabolite that inhibits the enoyl-ACP reductase InhA. To validate InhA as a druggable target in , we assayed the activity of NITD-916, a 4-hydroxy-2-pyridone lead candidate initially described as a direct inhibitor of InhA that bypasses KatG bioactivation in .

Structural characterization of aspartate-semialdehyde dehydrogenase from Pseudomonas aeruginosa and Neisseria gonorrhoeae.

Gonorrhoea infection rates and the risk of infection from opportunistic pathogens including P. aeruginosa have both risen globally, in part due to increasing broad-spectrum antibiotic resistance. Development of new antimicrobial drugs is necessary and urgent to counter infections from drug resistant bacteria.

Crystal structures of glutamyl-tRNA synthetase from Elizabethkingia anopheles and E. meningosepticum.

Elizabethkingia bacteria are globally emerging pathogens that cause opportunistic and nosocomial infections, with up to 40% mortality among the immunocompromised. Elizabethkingia species are in the pipeline of organisms for high-throughput structural analysis at the Seattle Structural Genomics Center for Infectious Disease (SSGCID). These efforts include the structure-function analysis of potential therapeutic targets.

Genetic Interaction Analysis Reveals that Cryptococcus neoformans Utilizes Multiple Acetyl-CoA-Generating Pathways during Infection.

Cryptococcus neoformans is an important human fungal pathogen for which the external environment is its primary niche. Previous work has shown that two nonessential acetyl-CoA metabolism enzymes, ATP-citrate lyase () and acetyl-CoA synthetase (), play important roles in C. neoformans infection.

Structure-Guided Synthesis of FK506 and FK520 Analogs with Increased Selectivity Exhibit Therapeutic Efficacy against Cryptococcus.

Calcineurin is an essential virulence factor that is conserved across human fungal pathogens, including Cryptococcus neoformans, Aspergillus fumigatus, and Candida albicans. Although an excellent target for antifungal drug development, the serine-threonine phosphatase activity of calcineurin is conserved in mammals, and inhibition of this activity results in immunosuppression. FK506 (tacrolimus) is a naturally produced macrocyclic compound that inhibits calcineurin by binding to the immunophilin FKBP12.

Crystal structure of a hypothetical protein from Giardia lamblia. Corrigendum.

The name of one of the authors in Beard et al. [(2022), Acta Cryst. F78, 59-65] is corrected.

Crystal structure of an inorganic pyrophosphatase from Chlamydia trachomatis D/UW-3/Cx.

Chlamydia trachomatis is the leading cause of bacterial sexually transmitted infections globally and is one of the most commonly reported infections in the United States. There is a need to develop new therapeutics due to drug resistance and the failure of current treatments to clear persistent infections. Structures of potential C.

Crystal structure of a hypothetical protein from Giardia lamblia.

Giardiasis is the most prevalent diarrheal disease globally and affects humans and animals. It is a significant problem in developing countries, the number one cause of travelers' diarrhea and affects children and immunocompromised individuals, especially HIV-infected individuals. Giardiasis is treated with antibiotics (tinidazole and metronidazole) that are also used for other infections such as trichomoniasis.