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Nature Communications Jan 2024Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are...
Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism.
Topics: Animals; Humans; Plasmodium falciparum; Asparagine; Aspartate-tRNA Ligase; RNA, Transfer, Amino Acyl; Antimalarials; Mammals
PubMed: 38297033
DOI: 10.1038/s41467-024-45224-z -
Annals of Transplantation Jan 2024BACKGROUND Ischemia/reperfusion injury (IRI) is an inherent problem in organ transplantation, owing to the obligate period of ischemia that organs must endure....
BACKGROUND Ischemia/reperfusion injury (IRI) is an inherent problem in organ transplantation, owing to the obligate period of ischemia that organs must endure. Cyclosporine A (CsA), though better know as an immunosuppressant, has been shown to mitigate warm IRI in a variety of organ types, including the liver. However, there is little evidence for CsA in preventing hepatic IRI in the transplant setting. MATERIAL AND METHODS In the present study, we tested the effect of CsA on hepatic IRI in a large-animal ex vivo model of donation after circulatory death (DCD). Porcine donors were pre-treated with either normal saline control or 20 mg/kg of CsA. Animals were subject to either 45 or 60 minutes of warm ischemia before hepatectomy, followed by 2 or 4 hours of cold storage prior to reperfusion on an ex vivo circuit. Over the course of a 12-hour perfusion, perfusion parameters were recorded and perfusate samples and biopsies were taken at regular intervals. RESULTS Peak perfusate lactate dehydrogenase was significantly decreased in the lower-ischemia group treated with CsA compared to the untreated group (4220 U/L [3515-5815] vs 11 305 [10 100-11 674]; P=0.023). However, no difference was seen between controls and CsA-treated groups on other parameters in perfusate alanine or asparagine aminotransferase (P=0.912, 0.455, respectively). Correspondingly, we found no difference on midpoint histological injury score (P=0.271). CONCLUSIONS We found minimal evidence that CsA is protective against hepatic IRI in our DCD model.
Topics: Swine; Animals; Cyclosporine; Liver; Reperfusion Injury; Perfusion; Reperfusion; Organ Preservation
PubMed: 38287661
DOI: 10.12659/AOT.941054 -
Genomics Mar 2024Tibetan cashmere goats are not only served as a valuable model for studying adaptation to hypoxia and high-altitude conditions but also playing a pivotal role in...
Tibetan cashmere goats are not only served as a valuable model for studying adaptation to hypoxia and high-altitude conditions but also playing a pivotal role in bolstering local economies through the provision of premium quality cashmere yarn. In this study, we performed an integration and network analysis of metabolomic, transcriptomic and proteomic to elucidate the role of differentially expressed genes, important metabolites, and relevant cellular and metabolic pathways between the fine (average 12.04 ± 0.03 μm of mean fiber diameter) and coarse cashmere (average 14.88 ± 0.05 μm of mean fber diameter) producing by Tibetan cashmere goats. We identified a distinction of 56 and 71 differential metabolites (DMs) between the F and C cashmere groups under positive and negative ion modes, respectively. The KEGG pathway enrichment analysis of these DMs highlighted numerous pathways predominantly involved in amino acid and protein metabolism, as indicated by the finding that the most impactful pathway was the mammalian target of rapamycin (mTOR) signalling pathway. In the F group, we identified a distinctive metabolic profile where amino acid metabolites including serine, histidine, asparagine, glutamic acid, arginine, valine, aspartic acid, tyrosine, and methionine were upregulated, while lysine, isoleucine, glutamine, tryptophan, and threonine were downregulated. The regulatory network and gene co-expression network revealed crucial genes, metabolites, and metabolic pathways. The integrative omics analysis revealed a high enrichment of several pathways, notably encompassing protein digestion and absorption, sphingolipid signalling, and the synaptic vesicle cycle. Within the sphere of our integrative analysis, DNMT3B was identified as a paramount gene, intricately associated with significant proteins such as HMCN1, CPB2, GNG12, and LRP1. Our present study delineated the molecular underpinnings governing the variations in cashmere characteristics by conducting comprehensive analyses across metabolomic, transcriptomic, and proteomic dimensions. This research provided newly insights into the mechanisms regulating cashmere traits and facilitated the advancement of selective breeding programs aimed at cultivating high-quality superfine Tibetan cashmere goats.
Topics: Animals; Goats; Proteomics; Tibet; Phenotype; Amino Acids
PubMed: 38286347
DOI: 10.1016/j.ygeno.2024.110801 -
Amino Acids Jan 2024By affecting the ovarian pool of follicles and their enclosed oocytes, heat stress has an impact on dairy cow fertility. This study aimed to determine how heat shock...
By affecting the ovarian pool of follicles and their enclosed oocytes, heat stress has an impact on dairy cow fertility. This study aimed to determine how heat shock (HS) during in vitro maturation affected the ability of the bovine cumulus-oocyte complexes (COCs) to develop, as well as their metabolism of amino acids (AAs). In this study, COCs were in vitro matured for 23 h at 38.5 °C (control; n = 322), 39.5 °C (mild HS (MHS); n = 290), or 40.5 °C (severe HS (SHS); n = 245). In comparison to the control group, the MHS and SHS groups significantly decreased the percentage of metaphase-II oocytes, as well as cumulus cell expansion and viability. The SHS decreased the rates of cleavage and blastocyst formation in comparison to the control and MHS. Compared to the control and MHS-COCs, the SHS-COCs produced significantly more phenylalanine, threonine, valine, arginine, alanine, glutamic acid, and citrulline while depleting less leucine, glutamine, and serine. Data showed that SHS-COCs had the highest appearance and turnover of all AAs and essential AAs. Heat shock was positively correlated with the appearance of glutamic acid, glutamine, isoleucine, alanine, serine, valine, phenylalanine, and asparagine. Network analysis identified the relationship between HS and alanine or glutamic acid, as well as the relationship between blastocyst and cleavage rates and ornithine. The findings imply that SHS may have an impact on the quality and metabolism of AAs in COCs. Moreover, the use of a multistep analysis could simply identify the AAs most closely linked to HS and the developmental competence of bovine COCs.
Topics: Female; Cattle; Animals; Glutamine; Oocytes; Glutamic Acid; Alanine; Heat-Shock Response; Phenylalanine; Valine; Citrulline; Serine
PubMed: 38285159
DOI: 10.1007/s00726-023-03370-6 -
Journal of Natural Products Feb 2024The rise of multidrug resistant fungal infections highlights the need to identify and develop novel antifungal agents. Occidiofungin is a nonribosomally synthesized...
The rise of multidrug resistant fungal infections highlights the need to identify and develop novel antifungal agents. Occidiofungin is a nonribosomally synthesized glycolipopeptide that has a unique mechanism of action, disrupting actin-mediated functions and inducing cellular apoptosis. Antifungal activity has been observed in vitro against various fungal species, including multidrug resistant , and in vivo efficacy has been demonstrated in a murine vulvovaginal candidiasis model. Occidiofungin, a cyclic glycolipopeptide, is composed of eight amino acids and in previous studies, an asparagine residue was assigned at position 7 (ASN7). In this study, new structural variants of occidiofungin have been characterized which have aspartic acid (ASP7), glutamine (GLN7), or glutamic acid (GLU7) at position 7. The side chain of the ASP7 variant contains the only terminal carboxylic acid in the peptide and provides a useful site for selective chemical modifications. Analogues were synthesized at the ASP7 position and tested for antifungal activity. These analogues were shown to be more active as compared to the ASP7 variant against a panel of species. The naturally occurring variants of occidiofungin with a side chain containing a carboxylic acid at the seventh amino acid position can be used to develop semisynthetic analogues with enhanced therapeutic properties.
Topics: Mice; Animals; Antifungal Agents; Burkholderia; Carboxylic Acids; Microbial Sensitivity Tests; Glycopeptides; Peptides, Cyclic
PubMed: 38277493
DOI: 10.1021/acs.jnatprod.3c00777 -
Food Science & Nutrition Jan 2024Brownies, enriched with fiber and , hydroxytyrosol (HXT), and spirulina (encapsulated and nonencapsulated), and dietary fiber using psyllium were elaborated. For that, a...
Brownies, enriched with fiber and , hydroxytyrosol (HXT), and spirulina (encapsulated and nonencapsulated), and dietary fiber using psyllium were elaborated. For that, a commercial control (CTRL) and an experimental control (CTRL) (without antioxidants) were compared. Color, nutritional composition, pH, antioxidant capacity, total phenolic compounds, as well as sensory properties were evaluated. The results showed the brownies developed with psyllium and the different extracts increased total dietary fiber compared to CTRL Commercial and CTRL, with E-spirulina (14.93 g/100 g) and Moringa (11.91 g/100 g) being the most prominent samples. However, with regard to soluble fiber, the highest content of NE-spirulina and the lowest content of HXT were observed. In addition, brownies enriched with extracts showed higher antioxidant capacity and higher phenolic compounds than controls, with HXT standing out at 299.25 μM Trolox/g in ABTS, 1470.08 μM Trolox/g in DPPH, and 18.15 μM Trolox/g in FRAP. However, a high level of phenolic compounds was found in E-Spirulina (604.71 mg/L). In reference to fatty acids, monounsaturated fatty acids (MUFA) (70%) were the predominant fatty acids, followed by polyunsaturated fatty acids (PUFA) (19%) and saturated fatty acids (SFA) (10%). Glutamic acid and asparagine were the predominant amino acids. As for mineral content, N-spirulina and E-spirulina were the brownies with the highest iron bioaccessibility; Si, Na, B, Al, P, Fe, Zn, Bi, Ca, Cu, Mg, Mn, Rb, S, and Sr being the most abundant elements in the brownies of this study. In addition, the HXT and Moringa samples scored higher in overall acceptability compared to the controls. The findings suggest that the incorporation of psyllium, quinoa flour, and antioxidant extracts in brownies could be a viable approach to produce a healthy brownie enriched with fiber, antioxidants and, therefore, considering the nutritional, physicochemical, and organoleptic characteristics, HTX is the ideal compound to enrich bakery products.
PubMed: 38268863
DOI: 10.1002/fsn3.3778 -
Molecules (Basel, Switzerland) Jan 2024Dye-decolorizing peroxidases (DyPs) are heme proteins with distinct structural properties and substrate specificities compared to classical peroxidases. Here, we...
Dye-decolorizing peroxidases (DyPs) are heme proteins with distinct structural properties and substrate specificities compared to classical peroxidases. Here, we demonstrate that DyP from the extremely radiation-resistant bacterium is, like some other homologues, inactive at physiological pH. Resonance Raman (RR) spectroscopy confirms that the heme is in a six-coordinated-low-spin (6cLS) state at pH 7.5 and is thus unable to bind hydrogen peroxide. At pH 4.0, the RR spectra of the enzyme reveal the co-existence of high-spin and low-spin heme states, which corroborates catalytic activity towards HO detected at lower pH. A sequence alignment with other DyPs reveals that DyP possesses a Methionine residue in position five in the highly conserved GXXDG motif. To analyze whether the presence of the Methionine is responsible for the lack of activity at high pH, this residue is substituted with a Glycine. UV-vis and RR spectroscopies reveal that the resulting DyPM190G is also in a 6cLS spin state at pH 7.5, and thus the Methionine does not affect the activity of the protein. The crystal structures of DyP and DyPM190G, determined to 2.20 and 1.53 Å resolution, respectively, nevertheless reveal interesting insights. The high-resolution structure of DyPM190G, obtained at pH 8.5, shows that one hydroxyl group and one water molecule are within hydrogen bonding distance to the heme and the catalytic Asparagine and Arginine. This strong ligand most likely prevents the binding of the HO substrate, reinforcing questions about physiological substrates of this and other DyPs, and about the possible events that can trigger the removal of the hydroxyl group conferring catalytic activity to DyP.
Topics: Deinococcus; Extremophiles; Hydrogen Peroxide; Methionine; Racemethionine; Heme; Peroxidases
PubMed: 38257271
DOI: 10.3390/molecules29020358 -
Molecules (Basel, Switzerland) Jan 2024In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the...
In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the study was to examine the ability of soluble oat fiber to reduce the amount of acrylamide formed in the process of obtaining rusks. The effect of the concentration of β-glucans in oat fiber preparations at 20% and 30% and the amount of preparations used at 10%, 15%, and 20% was investigated. On the basis of the obtained test results, it was shown that the most optimal concentration of oat fiber preparation in rusks recipe is at 15%, regardless of the content of β-glucan in it. This concentration makes it possible to reduce the amount of acrylamide formed in baked goods and rusks by ~70% and ~60%, respectively, while maintaining the desired physical and chemical properties of the product. In addition, it was shown that the browning index and water activity strongly correlate with the content of acrylamide in rusks, which makes them good markers of this compound in rusks. The use of hydrocolloids in the form of oat fiber preparations with different contents of β-glucan as a tool for reducing the amount of acrylamide in rusks, at the same time, offers the possibility of enriching these products with a soluble dietary fiber with health properties.
Topics: Bread; Acrylamide; beta-Glucans; Avena; Colloids
PubMed: 38257219
DOI: 10.3390/molecules29020306 -
Metabolomics Reveals Rubiadin Accumulation and the Effects of Methyl Jasmonate Elicitation in Calli.Plants (Basel, Switzerland) Jan 2024Callus suspension techniques have been considered attractive for improving bioactive metabolite productivity; methyl jasmonate (MeJA) is a widely used elicitor for...
Callus suspension techniques have been considered attractive for improving bioactive metabolite productivity; methyl jasmonate (MeJA) is a widely used elicitor for stimulating synthetic pathways. In this study, a multivariate analysis-based metabolomics approach was employed to investigate the primary and specialized metabolites in the leaves, unelicited calli, and 100 or 200 μM MeJA elicited calli of . Rubiadin, a powerful anthraquinone with various therapeutic properties, was only identified in calli, accumulating in a MeJA elicitation concentration-dependent manner. Callus cultures also contained high levels of amino acids, sugars, and phenolic compounds, indicating energy metabolism and metabolic adaptation responses for proliferation and stabilization. Regarding MeJA application, elicited calli contained higher amounts of quinic acid, kaempferol, and glucose with lower amounts of sucrose and raffinose than those in the unelicited control, which were closely related to protective mechanisms against MeJA. Moreover, excessive elicitation increased the asparagine, fructose, and raffinose levels and decreased the glucose and sucrose levels, which was ascribed to increased activation of the aminoacyl-tRNA biosynthesis pathway and wider utilization of glucose than of fructose after sucrose degradation. These results will be useful for optimizing plant cell culture techniques to achieve high production rates for valuable specialized metabolites.
PubMed: 38256721
DOI: 10.3390/plants13020167 -
Biomolecules Dec 2023is an obligate intracellular parasite that has numerous interactions with different hosts during its elaborate life cycle. This is also the case for the other parasites...
is an obligate intracellular parasite that has numerous interactions with different hosts during its elaborate life cycle. This is also the case for the other parasites belonging to the same phylum . In this study, we bioinformatically identified the components of the multi-synthetase complexes (MSCs) of several parasites and modelled their assembly using AlphaFold2. It appears that none of these MSCs resemble the two MSCs that we have identified and characterized in . Indeed, tRip, the central protein involved in the association of the two MSCs is different from its homologues, suggesting also that the tRip-dependent import of exogenous tRNAs is not conserved in other apicomplexan parasites. Based on this observation, we searched for obvious differences that could explain the singularity of protein synthesis by comparing tRNA genes and amino acid usage in the different genomes. We noted a contradiction between the large number of asparagine residues used in proteomes and the single gene encoding the tRNA that inserts them into proteins. This observation remains true for all the strains studied, even those that do not contain long asparagine homorepeats.
Topics: Asparagine; Plasmodium; Amino Acids; Protein Biosynthesis; RNA, Transfer
PubMed: 38254646
DOI: 10.3390/biom14010046