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A decreased hemoglobin synthesis is contemplated as a pathological indication of β-thalassemia. Recent studies show that EPZ035544 from Epizyme could induce fetal hemoglobin (HbF) levels due to its proven capability to inhibit euchromatin histone lysine methyl transferase (EHMT2). Therefore, the development of EHMT2 inhibitors is considered promising in managing β-thalassemia. Our strategy to find novel compounds that are EHMT2 inhibitors relies on the virtual screening of ligands that have a structural similarity to N2-[4-methoxy-3-(2,3,4,7-tetrahydro-1H-azepin-5-yl) phenyl]-N4,6-dimethyl-pyrimidine-2,4-diamine (F80) using the PubChem database. In silico docking studies using Autodock Vina were employed to screen a library of 985 compounds and evaluate their binding ability with EHMT2. The selection of hit compounds was based on the docking score and mode of interaction with the protein. The top two ranked compounds were selected for further investigations, including pharmacokinetic properties analysis and molecular dynamics simulations (MDS). Based on the obtained docking score and interaction analysis, N-(4-methoxy-3-methylphenyl)-4,6-diphenylpyrimidin-2-amine (TP1) and 2-N-[4-methoxy-3-(5-methoxy-3H-indol-2-yl)phenyl]-4-N,6-dimethylpyrimidine-2,4-diamine (TP2) were found to be promising candidates, and TP1 exhibited better stability in the MDS study compared to TP2. In summary, our approach helps identify potential EHMT2 inhibitors, and further validation using in vitro and in vivo experiments could certainly enable this molecule to be used as a therapeutic drug in managing β-thalassemia disease.

Hepatocellular carcinoma (HCC) is one of the life–threatening cancers in the current decade. Earlier reports suggest that protein arginine methyl transferase 5 (PRMT5) is also linked with HCC, and the symmetrically dimethylated arginine marks created by PRMT5 are read by the Staphylococcal nuclease domain-containing protein 1 (SND1), which eventually can drive HCC development. Indeed, as no inhibitors have been ascertained for SND1, we aimed to screen for new inhibitors with specificity and high affinity towards the active site of SND1. In this study, we first used the Gene Set Cancer Analysis (GSCA) dataset to evaluate the expression of SND1 in HCC. Accordingly, SND1 is the highly overexpressed gene in HCC and its overexpression affects the overall survival of HCC patients. Then, we employed a virtual screening approach to identify potential inhibitors from the ASINEX database. We utilized molecular docking to single out the potential top hits based on the docking score and mode of interaction with the SND1 active site. In the prediction, we found [4–(5,6,7,8–tetrahydro–4 H–cyclohepta[c][1,2]oxazol–3–yl)piperidin–1–yl]–[4–(trifluoromethyl)phenyl]methanone (TOP1: -10.4 kcal/mol) and 1–[2–hydroxy–2–(1–methylsulfonyl–3,4–dihydro–2 H–quinolin–6–yl)ethyl]–4–(4–methylphenyl)piperidin–4–ol (TOP2: -10.3 kcal/mol) as promising candidates than reference compound (STD: -4.6 kcal/mol). Further molecular dynamics simulations and a pharmacokinetic properties study indicate that TOP2 exhibits a more stable binding with the SND1 active site and complies with Lipinski’s rule of five for drug-likeness, with no observed toxicity and good pharmacokinetic properties.

The presence of an unbalanced gut microbiome and the dysregulation of bile acid signalling are considered pivotal causes of various inflammation-based diseases. The Takeda G protein-coupled receptor (TGR5), TGR5 is a bile acid-responsive receptor that modulates inflammatory signalling pathways, making it an enticing molecular target for the discovery of novel anti-inflammatory agents. Herein, a comprehensive in silico approach was employed to identify potential TGR5 agonists from sterol-rich phytocompounds present in Triphala, a traditional polyherbal formulation. Using in silico computational methods, such as molecular docking and molecular dynamics simulations (MDS), we screened the putative agonistic potential of 10 phytocompounds obtained from Terminalia chebula, Terminalia bellirica, and Phyllanthus emblica against the crystal structure of human TGR5 (PDB ID: 7XTQ). Based on binding energy and molecular interactions, ergosterol (−12.34 ± 0.17 kcal/mol) and stigmasterol (−10.35 ± 0.04 kcal/mol) were predicted to be the top and best compounds. Furthermore, the stability of these two compounds in the docked complex was analysed using MDS for 200 ns. The mean Cα RMSD values were 0.22 ± 0.02 nm for both ergosterol- and stigmasterol-bound complexes, compared to 0.21 ± 0.02 nm for the unbound apo protein. Further, the molecular mechanics/Poisson–Boltzmann surface area (MMPBSA) analysis revealed that ergosterol exhibited binding free energy (−139.868 ± 12.318 kJ/mol) comparable to that of the co-crystallised ligand R399 −93.424 ± 8.919 kJ/mol. In silico ADMET predictions indicated acceptable drug-like properties and low toxicity for both compounds. Collectively, these computational findings suggest that ergosterol is a promising putative TGR5 agonist, warranting further experimental validation of its potential role in modulating inflammation-related pathways.

β-Thalassemia is an inherited genetic disorder associated with β-globin chain synthesis, which ultimately becomes anemia. Adenosine-2,3-dialdehyde, by inhibiting arginine methyl transferase 5 (PRMT5), can induce fetal hemoglobin (HbF) levels. Hence, the materialization of PRMT5 inhibitors is considered a promising therapy in the management of β-thalassemia. This study conducted a virtual screening of certain compounds similar to 5′-deoxy-5′methyladenosine (3XV) using the PubChem database. The top 10 compounds were chosen based on the best docking scores, while their interactions with the PRMT5 active site were analyzed. Further, the top two compounds demonstrating the lowest binding energy were subjected to drug-likeness analysis and pharmacokinetic property predictions, followed by molecular dynamics simulation studies. Based on the molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) score and molecular interactions, (3R,4S)-2-(6-aminopurin-9-yl)-5-[(4-ethylcyclohexyl)sulfanylmethyl]oxolane-3,4-diol (TOP1) and 2-(6-Aminopurin-9-yl)-5-[(6-aminopurin-9-yl)methylsulfanylmethyl]oxolane-3,4-diol (TOP2) were identified as potential hit compounds, while TOP1 exhibited higher binding affinity and stabler binding capabilities than TOP2 during molecular dynamics simulation (MDS) analysis. Taken together, the outcomes of our study could aid researchers in identifying promising PRMT5 inhibitors. Moreover, further investigations through in vivo and in vitro experiments would unquestionably confirm that this compound could be employed as a therapeutic drug in the management of β-thalassemia.

Background/Objective:Staphylococcus aureus produces staphyloferrin A (Sfna) siderophores to sequester host iron during infection and rapid cell proliferation We examined drug susceptibility, siderophore production, and genome sequencing of clinical isolates of S. aureus. Methods: A total of 100 specimens, including pus, sputum, hemoculture, urine, tissue, fluid, and skin scrap specimens, were grown in iron-deprived Luria broth agar. The isolates were investigated for spectral signature using MALDI–TOF/MS, while antibiotic susceptibility and siderophore content were assessed using the chrome azurol S method. Whole genome and partial 16S rRNA DNA sequences were employed, and VITEK/MS revealed specific spectra. Results: Clindamycin, erythromycin, gentamicin, linezolid, moxifloxacin, oxacillin, trimethoprim/sulfamethoxazole, and vancomycin (100%) were the most common antibiotics to which the S. aureus isolates were susceptible. Sfna was not detectable in fluid and skin scrap isolates, which were encoded by sfnaB, sfnaD, and sfnaB/sfnaD genes. However, they were detectable in pus (73.8%), sputum (85.3%), hemoculture (50.0%), and urine (85.7%) isolates. The aureus subspecies, JKD6159, SA268, and MN8, were found to be 72.73% according to genome sequencing. Conclusion: most staphylococci in the isolates, including S. aureus JKD6159, SA268, and MN8, were sensitive to antibiotics and were detected by MALDI–TOF/MS, resulting in the production of Sfna encoded by sfna genes.

L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a significant challenge to efficiently synthesize D-tagatose using the native (wild type) L-AI at an industrial scale. Hence, it is extremely urgent to redesign L-AI to improve its catalytic efficiency towards D-galactose, and herein a structure-based molecular modification of Lactobacillus plantarum CY6 L-AI (LpAI) was performed. Among the engineered LpAI, both F118M and F279I mutants showed an increased D-galactose isomerization activity. Particularly, the specific activity of double mutant F118M/F279I towards D-galactose was increased by 210.1% compared to that of the wild type LpAI (WT). Besides the catalytic activity, the substrate preference of F118M/F279I was also largely changed from L-arabinose to D-galactose. In the enzymatic production of D-tagatose, the yield and conversion ratio of F118M/F279I were increased by 81.2% and 79.6%, respectively, compared to that of WT. Furthermore, the D-tagatose production of whole cells expressing F118M/F279I displayed about 2-fold higher than that of WT cell. These results revealed that the designed site-directed mutagenesis is useful for improving the catalytic efficiency of LpAI towards D-galactose.

D-allulose is a natural rare sugar with important physiological properties that is used in food, health care items, and even the pharmaceutical industry. In the current study, a novel D-allulose 3-epimerase gene (Bp-DAE) from the probiotic strain Blautia produca was discovered for the production and characterization of an enzyme known as Bp-DAE that can epimerize D-fructose into D-allulose. Bp-DAE was strictly dependent on metals (Mn2+ and Co2+), and the addition of 1 mM of Mn2+ could enhance the half-life of Bp-DAE at 55 °C from 60 to 180 min. It exhibited optimal activity in a pH of 8 and 55 °C, and the Km values of Bp-DAE for the different substrates D-fructose and D-allulose were 235.7 and 150.7 mM, respectively. Bp-DAE was used for the transformation from 500 g/L D-fructose to 150 g/L D-allulose and exhibited a 30% of conversion yield during biotransformation. Furthermore, it was possible to employ the food-grade microbial species Bacillus subtilis for the production of D-allulose using a technique of whole-cell catalysis to circumvent the laborious process of enzyme purification and to obtain a more stable biocatalyst. This method also yields a 30% conversion yield.

•Enzyme engineering using in vivo incorporation of unnatural amino acids (UAA).•Enhancing and altering enzyme activity using residue- and site-specific incorporation of UAA.•Enzyme evolution with UAA by integrating directed evolution and UAA incorporation. Traditional enzyme engineering relies on substituting one amino acid by one of the other 19 natural amino acids to change the functional properties of an enzyme. However, incorporation of unnatural amino acids (UAAs) has been harnessed to engineer efficient enzymes for biocatalysis. Residue-specific and site-specific in vivo incorporation methods are becoming the preferred approach for producing enzymes with altered or improved functions. We describe the contribution of in vivo UAA incorporation methodologies to enzyme engineering as well as the future prospects for the field, including the integration of UAAs with other new advances in enzyme engineering.

D-Arabitol is an important functional sugar alcohol, which can be used in the preparation of foods, chemicals, and medicines. Despite biological production of D-arabitol from low-cost substrates has recently been the focus of research, low yield of this technology has limited its large-scale exploitation. Optimization of this bioprocess could be a promising option to improve the yield of D-arabitol. In this study, one-factor-at-a-time (OFAT) strategy and Box-Behnken design (BBD) were used to increase D-arabitol production by Metschnikowia reukaufii CICC 31,858 through optimizing the fermentation conditions and medium composition. The OFAT optimization provided the optimal conditions for temperature, agitation speed, and fermentation time of 30℃, 220 rpm, and 6 days, respectively. Likewise, the optimum concentrations of peptone, ammonium sulfate, KH2PO4, MgSO4·7H2O, and fumaric acid in the fermentation medium were (g/L) 7.5, 1, 2, 0.5, and 7.5, respectively. Under these optimum conditions, 80.43 g/L of D-arabitol was produced from 200 g/L of glucose, with a productivity of 0.56 g/L/h. The BBD optimization with three important components of fermentation medium (KH2PO4, MgSO4·7H2O, and fumaric acid) showed that the predicted titer of D-arabitol varied from 47.21 to 89.27 g/L, and the actual titer of D-arabitol ranged from 47.36 to 89.83 g/L. The optimum concentrations (g/L) of KH2PO4, MgSO4·7H2O, and fumaric acid in the fermentation medium were found to be 1.0, 0.5, and 4.7 g/L, respectively. Under the optimum conditions, 92.45 g/L of D-arabitol was finally produced with the yield and productivity of 0.46 g/g and 0.64 g/L/h, respectively.

D-allulose is a natural rare sugar with important physiological properties that is used in food, health care items, and even the pharmaceutical industry. In the current study, a novel D-allulose 3-epimerase gene (Bp-DAE) from the probiotic strain Blautia produca was discovered for the production and characterization of an enzyme known as Bp-DAE that can epimerize D-fructose into D-allulose. Bp-DAE was strictly dependent on metals (Mn[sup.2+] and Co[sup.2+] ), and the addition of 1 mM of Mn[sup.2+] could enhance the half-life of Bp-DAE at 55 °C from 60 to 180 min. It exhibited optimal activity in a pH of 8 and 55 °C, and the Km values of Bp-DAE for the different substrates D-fructose and D-allulose were 235.7 and 150.7 mM, respectively. Bp-DAE was used for the transformation from 500 g/L D-fructose to 150 g/L D-allulose and exhibited a 30% of conversion yield during biotransformation. Furthermore, it was possible to employ the food-grade microbial species Bacillus subtilis for the production of D-allulose using a technique of whole-cell catalysis to circumvent the laborious process of enzyme purification and to obtain a more stable biocatalyst. This method also yields a 30% conversion yield.