A single Leishmania adenylate forming enzyme of the ANL superfamily generates both acetyl- and acetoacetyl-CoA.

Leishmania, a protozoan parasite, is responsible for significant morbidity and mortality worldwide, manifesting as cutaneous, mucocutaneous, and visceral leishmaniasis. These diseases pose a substantial burden, especially in impoverished regions with limited access to effective medical treatments. Current therapies are toxic, have low efficacy, and face growing resistance. Understanding the metabolic pathways of Leishmania, particularly those differing from its host, can unveil potential therapeutic targets. In this study, we investigated the acetyl-CoA synthetase (ACS) enzyme from Leishmania infantum (LiAcs1), which, unlike many organisms, also exhibits acetoacetyl-CoA synthetase (KBC) activity. This dual functionality is unique among ANL superfamily enzymes and crucial for the parasite's reliance on leucine catabolism, energy production and sterol biosynthesis. Our biochemical characterization of LiAcs1 revealed its ability to utilize both acetate and acetoacetate substrates. Additionally, LiAcs1 displayed a distinct CoA substrate inhibition pattern, partially alleviated by acetoacetate. Structural analysis provided insights into the substrate binding flexibility of LiAcs1, highlighting a more promiscuous substrate pocket compared to other ACS or KBC-specific enzymes. Substrate mimetics elucidated its ability to accommodate both small and large AMP-ester derivatives, contributing to its dual ACS/KBC functionality. These findings not only advance our understanding of Leishmania metabolism but also present LiAcs1 as a promising drug target. The dual functionality of LiAcs1 underscores the potential for developing selective inhibitors that could disrupt critical metabolic pathways across Leishmania spp. as it appears this enzyme is highly conserved across this genus. This paves the way for developing novel effective treatments against this devastating disease.

Inhibitors of Rickettsia prowazekii methionine aminopeptidase 1 identified from the Pandemic Response Box.

Methionine aminopeptidase (MetAp) enzymes catalyze the post-translational removal of the initiator methionine residue in newly synthesized proteins, a process that is often essential in the maturation of proteins. Consequently, these enzymes serve as important targets for drug development. Rickettsia prowazekii (Rp) is an obligate coccobacillus and the causative agent of the louse-borne epidemic typhus and despite adequate treatment causes a latent infection. This research aimed to identify potential anti-rickettsial agents by screening 400 compounds from the MMV Pandemic Response Box against RpMetAp1. Overall, 19 compounds were identified that possessed IC50 values from 10 µM to 340 nM. The most potent inhibitor was MMV 1580488 (17), which was observed to have an IC50 of 340 nM. The selected hits serve as chemical leads that can be used for the development of potent inhibitors of the RpMetAp1 enzyme.

Novel inhibitors of Rickettsia prowazekii methionine aminopeptidase from the Malaria Box.

Methionine aminopeptidases (MetAp) are dinuclear metalloenzymes found in both prokaryotes and eukaryotes that catalyze the hydrolysis of the N-terminal methionine residue from nascent proteins, an important post-translational modification, which makes it an attractive target for drug discovery. Rickettsia prowazekii (Rp) is an obligate pathogen and causative agent of epidemic typhus and typhus fever. In our ongoing search for anti-rickettsial agents we screened 400 compounds from the Malaria Box for inhibition of RpMetAp1 and discovered 12 compounds that inhibited the enzyme with IC50 values ranging from 800 nM to 22 µM. These inhibitors are from eleven different chemical series and represent leads that can be used to discover more potent and efficacious anti-rickettsial agents.

Structure based design, synthesis, and biological evaluation of imidazole derivatives targeting dihydropteroate synthase enzyme.

In this study, we have designed and synthesized 2-((5-acetyl-1-(phenyl)-4-methyl-1H-imidazol-2-yl)thio)-N-(4-((benzyl)oxy)phenyl) acetamide derivatives. Antimicrobial activities of all the imidazole derivatives have been examined against Gram-positive and Gram-negative bacteria and results showed that the conjugates have appreciable antibacterial activity. Besides, several analogous were evaluated for their in vitro antiresistant bacterial strains such as Extended-spectrum beta-lactamases (ESBL), Vancomycin-resistant Enterococcus (VRE), and Methicillin-resistant Staphylococcus aureus (MRSA). The SAR revealed that the 12l compound resulted in potency against all bacterial strains as well as ESBL, VRE, and MRSA strains. Lipinski's rule of five, and ADME studies were preformed for all the synthesized compounds with Staphylococcus aureus dihydropteroate synthase (saDHPS) protein (PDB ID: 6CLV) and were found standard drug-likeness properties of conjugates. Moreover, the binding mode of the ligands with the protein study has been examined by molecular docking and results are quite promising. Besides, all the analogous were tested for their in vitro antituberculosis, antimalarial, and antioxidant activity.