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  • was the primary pathogenic organism responsible for dental caries. (LJF) is a traditional herb in Asia and Europe and consumed as a tea beverage for thousands of years.

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  • , a Gram-positive facultative anaerobe and the causative agent of anthrax, multiplies to extraordinarily high numbers in vertebrate blood, resulting in considerable heme exposure. Heme is an essential nutrient and the preferred iron source for bacteria during vertebrate colonization, but its high redox potential makes it toxic in excess. To regulate heme homeostasis, many Gram-positive bacteria, including , rely on the two-component signaling system HssRS. HssRS comprises the heme sensing histidine kinase HssS, which modulates the activity of the HssR transcription factor to enable bacteria to circumvent heme toxicity. However, the regulation of the HssRS system remains unclear. Here we identify FapR, the transcriptional regulator of fatty acid biosynthesis, as a key factor in HssRS function. FapR plays an important role in maintaining membrane integrity and the localization of the histidine kinase HssS. Specifically, disruption of leads to increased membrane rigidity, which hinders the penetration of HssRS inducers, resulting in the inactivation of HssRS. Furthermore, deletion of affects the loading of HssS onto the cell membrane, compromising its heme sensing function and subsequently reducing endogenous heme biosynthesis. These findings shed light on the molecular mechanisms governing bacterial adaptation to heme stress and provide potential targets for antimicrobial intervention strategies.

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  • The surface protein hemagglutinin (HA) of the influenza virus plays a pivotal role in facilitating viral infection by binding to sialic acid receptors on host cells. Its conformational state is pH-sensitive, impacting its receptor-binding ability and evasion of the host immune response. In this study, we conducted extensive equilibrium microsecond-level all-atom molecular dynamics (MD) simulations of the HA protein to explore the influence of low pH on its conformational dynamics. Specifically, we investigated the impact of protonation on conserved histidine residues (His106 ) located in the hinge region of HA2. Our analysis encompassed comparisons between non-protonated (NP), partially protonated (1P, 2P), and fully-protonated (3P) conditions. Our findings reveal substantial pH-dependent conformational alterations in the HA protein, affecting its receptor-binding capability and immune evasion potential. Notably, the non-protonated form exhibits greater stability compared to protonated states. Conformational shifts in the central helices of HA2 involve outward movement, counterclockwise rotation of protonated helices, and fusion peptide release in protonated systems. Disruption of hydrogen bonds between the fusion peptide and central helices of HA2 drives this release. Moreover, HA1 separation is more likely in the fully-protonated system (3P) compared to non-protonated systems (NP), underscoring the influence of protonation. These insights shed light on influenza virus infection mechanisms and may inform the development of novel antiviral drugs targeting HA protein and pH-responsive drug delivery systems for influenza.

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  • A new type of hybrid material (NCMTs@MoO/FeNi) with a multi-layer heterostructure was designed and fabricated a one-step pyrolysis process using FeOOH/NiMoO@PDA as the precursor. FeOOH/NiMoO@PDA was prepared by the solvothermal method, followed by the nickel-ion etching method coupled with the polymerization of dopamine (DA). The as-obtained material was made of nitrogen-doped carbon nanotubes embedded with FeNi and MoO nanoparticles (NPs). Notably, the FeNi NPs exhibited significantly improved performance in the reduction of 4-nitrophenol (4-NP) and adsorption of histidine-rich protein as well as provided appropriate magnetism resources. The MoO NPs imparted a metallic nature with excellent conductivity, and the N-doped mesoporous carbon microtubes also improved conductivity and facilitated mass transfer, thus leading to enhanced performance in catalysis. Benefiting from the 1D hierarchical porous structure and compositional features, the NCMTs@MoO/FeNi composites exhibited excellent performance in 4-NP reduction and protein adsorption specific metal affinity between the polyhistidine groups of proteins and the FeNi NPs. The result presented here indicates that the strategy of combining tailored components, heterostructuring, and carbon integration is a promising way to obtain high-performance composites for other energy-related applications.

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  • Pekin ducks and Shaoxing ducks are 2 Chinese local duck breeds, both domesticated from mallard, but after domestication and long-term artificial selection, the body weight of Pekin ducks is significantly higher than that of Shaoxing ducks. It is no debate that genetic factors are the main factors responsible for this difference, but whether intestinal microbiota contribute to this difference is yet unknown. Thus, we performed comparative intestinal metagenomics and metabolomics analysis between Pekin ducks and Shaoxing ducks. We found obvious differentiation of intestinal metagenome and metabolome between the 2 breeds. Four cecal microbial genera, including Fusobacterium, Methanobrevibacter, Butyricicoccus, and Anaerotignum showed higher abundance in Pekin ducks. Among them, Methanobrevibacter and Butyricicoccus may positively correlate with fat deposition and body weight. A total of 310 metabolites showed difference between the 2 breeds. Functions of these differential metabolites were mainly enriched in amino acid metabolism, including energy metabolism-related histidine metabolism. Integrated omics analysis showed that microbial changes were closely related to altered metabolites. Especially, Butyricicoccus showing higher abundance in Pekin ducks was significantly negatively correlated with D-glucosamine-6-phosphate, which has been reported to prevent body weight gains. These findings may contribute to further understand the difference in body weight between Pekin ducks and Shaoxing ducks.

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  • Cystic echinococcosis (CE) is a parasitic zoonosis caused by the tapeworm Over the past few years, a lot of research has been done on liver illnesses using metabolomics techniques to identify biomarkers which could identify the diseases in its early stages. The present study was done to explore biomarkers in serum, urine, and cystic fluid which would help in differentiating, staging, and assessing fertility of intra-abdominal hydatid cyst by using proton nuclear magnetic resonance (H NMR) metabolomics.

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  • Lanthipeptides are a large group of ribosomally encoded peptides cyclized by thioether and methylene bridges, which include the lantibiotics, lanthipeptides with antimicrobial activity. There are over 100 experimentally characterized lanthipeptides, with at least 25 distinct cyclization bridging patterns. We set out to understand the evolutionary dynamics and diversity of lanthipeptides. We identified 977 peptides in 2785 bacterial genomes from short open-reading frames encoding lanthipeptide modifiable amino acids (C, S and T) that lay chromosomally adjacent to genes encoding proteins containing the cyclase domain. These appeared to be synthesized by both known and novel enzymatic combinations. Our predictor of bridging topology suggested 36 novel-predicted topologies, including a single-cysteine topology seen in 179 lanthionine or labionin containing peptides, which were enriched for histidine. Evidence that supported the relevance of the single-cysteine containing lanthipeptide precursors included the presence of the labionin motif among single cysteine peptides that clustered with labionin-associated synthetase domains, and the leader features of experimentally defined lanthipeptides that were shared with single cysteine predictions. Evolutionary rate variation among peptide subfamilies suggests that selection pressures for functional change differ among subfamilies. Lanthipeptides that have recently evolved specific novel features may represent a richer source of potential novel antimicrobials, since their target species may have had less time to evolve resistance.

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  • Intercropping systems have garnered attention as a sustainable agricultural approach for efficient land use, increased ecological diversity in farmland, and enhanced crop yields. This study examined the effect of intercropping on the kiwifruit rhizosphere to gain a deeper understanding of the relationships between cover plants and kiwifruit in this sustainable agricultural system. Soil physicochemical properties and bacterial communities were analyzed using the Kiwifruit-Agaricus blazei intercropping System. Moreover, a combined analysis of 16S rRNA gene sequencing and metabolomic sequencing was used to identify differential microbes and metabolites in the rhizosphere. Intercropping led to an increase in soil physicochemical and enzyme activity, as well as re-shaping the bacterial community and increasing microbial diversity. Proteobacteria, Bacteroidota, Myxococcota, and Patescibacteria were the most abundant and diverse phyla in the intercropping system. Expression analysis further revealed that the bacterial genera BIrii41, Acidibacter, and Altererythrobacter were significantly upregulated in the intercropping system. Moreover, 358 differential metabolites (DMs) were identified between the monocropping and intercropping cultivation patterns, with fatty acyls, carboxylic acids and derivatives, and organooxygen compounds being significantly upregulated in the intercropping system. The KEGG metabolic pathways further revealed considerable enrichment of DMs in ABC transporters, histidine metabolism, and pyrimidine metabolism. This study identified a significant correlation between 95 bacterial genera and 79 soil metabolites, and an interactive network was constructed to explore the relationships between these differential microbes and metabolites in the rhizosphere. This study demonstrated that Kiwifruit-Agaricus blazei intercropping can be an effective, labor-saving, economic, and sustainable practice for reshaping bacterial communities and promoting the accumulation and metabolism of beneficial microorganisms in the rhizosphere.

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  • The histidine behavior plays a crucial role in the structural and aggregation properties of protein folding and misfolding. Understanding the histidine behavior at the edge of the protein structure is critical for finding ways to disrupt fibril elongation and growth, but this impact remains poorly understood. In the current study, we used molecular dynamics simulations to investigate the edge substitution effect of histidine protonation on the structural and aggregation properties. Our data showed that Δ contributed the most to binding affinity compared to Δ and Δ. The different protonation states at the edge chain significantly impacted the secondary structure properties of the edge chain. Specifically, we found that such protonation behavior significantly affected specific regions, particularly the N-terminus (G9-Q15) and C-terminus (K28-A30). Further analysis confirmed that H6, H13, and H14 were directly involved in H-bonding networks with the C1_H14//C2_H13 interchain interactions critical for maintaining the interchain stability. Furthermore, we confirmed that H6, H13, and H14 were directly involved in the loss of the carbon skeleton contact in the N-terminus. Our findings indicate that the edge condition is more susceptible to changes in structural properties than the middle condition. The current study is helpful for understanding the histidine behavior hypothesis in related misfolding diseases.

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  • The novel mixed-ligand complexes derived from the parent antidepressant phenothiazine drug triflupromazine (TFP) were synthesized along with the secondary ligands glycine and histidine. [Cu(TFP)(Gly)Cl]·2HO (1) and [Cu(TFP)(His)Cl]·2HO (2) were examined for their in vitro biological properties. Cyclic voltammetry was used to study the binding of both complexes to CT-DNA. The two complexes were examined for antiviral, antiparasite, and anti-inflammatory applications. An in vitro cytotoxicity study on two different cancer cell lines, MCF-7, HepG2, and a normal cell line, HSF, shows promising selective cytotoxicity for cancer cells. An investigation of the cell cycle and apoptosis rates was evaluated by flow cytometry with Annexin V-FITC/Propidium Iodide (PI) staining of the treated cells. Gene expression and western blotting were carried out to determine the expression levels of the pro-apoptotic markers and the anti-apoptotic marker Bcl2. The tested complexes decreased cell viability and triggered apoptosis in human tumor cell lines. Molecular docking was also used to simulate Bcl2 inhibition. Finally, complex (2) has potent antitumor effects on human tumor cells, especially against HepG2 cells, as seen in the cellular drug uptake assay. Consequently, complex (2) may prove useful against cancer, especially liver cancer. For further understanding, it needs to be explored in vivo.

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