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Aliquots of solution were taken and diluted for HPLC analysis every 12 h In "Abstract" under the Results section, the IPTG concentration that reads as "concentration, 0.5 mM" should read as "concentration, 0.05 mM". , should read as "The investment was carried out at varying concentration trajectories of L-Trp (0.5, 1.0, 1.5, 2.0 g/L), IPTG (0.025, 0.05, 0.075, and 0.1 mM)......." 5The effects of induction temperature, induction time, IPTG concentration and catalysis temperature on 5-HT synthesis. [Extracted from the article]

Background: l-Tryptophan (l-Trp) derivatives such as 5-hydroxytryptophan (5-HTP) and 5-hydroxytryptamine (5-HT), N-Acetyl-5-hydroxytryptamine and melatonin are important molecules with pharmaceutical interest. Among, 5-HT is an inhibitory neurotransmitter with proven benefits for treating the symptoms of depression. At present, 5-HT depends on plant extraction and chemical synthesis, which limits its mass production and causes environmental problems. Therefore, it is necessary to develop an efficient, green and sustainable biosynthesis method to produce 5-HT. Results: Here we propose a one-pot production of 5-HT from l-Trp via two enzyme cascades for the first time. First, a chassis cell that can convert l-Trp into 5-HTP was constructed by heterologous expression of tryptophan hydroxylase from Schistosoma mansoni (SmTPH) and an artificial endogenous tetrahydrobiopterin (BH4) module. Then, dopa decarboxylase from Harminia axyridis (HaDDC), which can specifically catalyse 5-HTP to 5-HT, was used for 5-HT production. The cell factory, E. coli BL21(DE3)△tnaA/BH4/HaDDC-SmTPH, which contains SmTPH and HaDDC, was constructed for 5-HT synthesis. The highest concentration of 5-HT reached 414.5 ± 1.6 mg/L (with conversion rate of 25.9 mol%) at the optimal conditions (substrate concentration,2 g/L; induced temperature, 25℃; IPTG concentration, 0.5 mM; catalysis temperature, 30℃; catalysis time, 72 h). Conclusions: This protocol provided an efficient one-pot method for converting. l-Trp into 5-HT production, which opens up possibilities for the practical biosynthesis of natural 5-HT at an industrial scale. [ABSTRACT FROM AUTHOR]

• A cocktail of chitinolytic enzymes was developed to efficiently produce GlcNAc from chitin. • An efficient and green extraction-pretreatment integrated process was established using deep eutectic solvent (DES). • The chitin extraction process from chitinous wastes using DES was proved as an universal and reusable approach. • Chitin pretreated by DES exhibited 2–6-fold hydrolysis efficiency better than raw chitinous wastes. In this study, we present an efficient and green extraction-pretreatment integrated approach for enhancing enzymatic conversion of chitinous wastes into N -acetyl- d -glucosamine (GlcNAc). Firstly, the enzyme cocktail containing a chitinase Cm Chi1 and a N-acetyl glucosaminase Cm NAGase were constructed for hydrolyzing chitin into sole GlcNAc. Secondly, deep eutectic solvent (DES), consisting of choline chloride and glycollic acid was used to treat chitinous wastes. Under optimal conditions, chitin yield reach to 72 % with a purity of 98 %. Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction analysis revealed that the crystallinity and thermal stability of the obtained chitin decreased upon DES treatment without alteration of the chemical structure or deacetylation. Finally, the concentration of GlcNAc was increased 2–6 folds by enzymatic hydrolysis of DES-treated chitinous wastes (including shrimp shell, crab shell, ganoderma spores wall, and mycelium). The process provides a promising strategy for degrading chitinous wastes to produce high valued GlcNAc. [Display omitted] [ABSTRACT FROM AUTHOR]

Basal‐like breast cancer (BLBC) is the most aggressive molecular subtype of breast cancer with worse prognosis and fewer treatment options. The underlying mechanisms upon BLBC transcriptional dysregulation and its upstream transcription factors (TFs) remain unclear. Here, among the hyperactive candidate TFs of BLBC identified by bioinformatic analysis, POU4F1 is uniquely upregulated in BLBC and is associated with poor prognosis. POU4F1 is necessary for the tumor growth and malignant phenotypes of BLBC through regulating G1/S transition by direct binding at the promoter of CDK2 and CCND1. More importantly, POU4F1 maintains BLBC identity by repressing ERα expression through CDK2‐mediated EZH2 phosphorylation and subsequent H3K27me3 modification in ESR1 promoter. Knocking out POU4F1 in BLBC cells reactivates functional ERα expression, rendering BLBC sensitive to tamoxifen treatment. In‐depth epigenetic analysis reveals that the subtype‐specific re‐configuration and activation of the bivalent chromatin in the POU4F1 promoter contributes to its unique expression in BLBC, which is maintained by DNA demethylase TET1. Together, these results reveal a subtype‐specific epigenetically activated TF with critical role in promoting and maintaining BLBC, suggesting that POU4F1 is a potential therapeutic target for BLBC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chitin/chitosan composite microspheres (CCMs) were designed with controllable DDA values. • The one-step purified and immobilization of protein was achieved using CCMs. • The CCMs realize the efficiently co-immobilization of enzyme and PLP. • The polyethyleneimine modified CCMs exhibited strong affinity of PLP. • The designed biocatalysts provided a platform technology for continuous catalysis without addition of PLP. The concomitant recycling of enzymes and co-factors is a big challenge in biocatalysis. In this study, co-immobilization of the enzyme and the co-factor pyridoxal 5′-phosphate was achieved using chitin-based microspheres as the support. Chitin/chitosan composite microspheres were prepared and then modified with polyethyleneimine. Three pyridoxal 5′-phosphate-independent enzymes were used to demonstrate that the self-sufficient biocatalysts based on chitin/chitosan composite microspheres and polyethyleneimine modified microspheres displayed good generalizability for high recycling efficiency of both enzyme and pyridoxal 5′-phosphate. Furthermore, the self-sufficient biocatalysts were applied in the continuous flow production of cadaverine and maintained good continuous catalysis without the exogenous addition of pyridoxal 5′-phosphate, suggesting that this co-immobilization platform shows promise for application in industrial biocatalysis. [ABSTRACT FROM AUTHOR]

Alzheimer’s disease (AD) is characterized by amyloid β (Aβ) peptide aggregation and cholinergic neurodegeneration. Therefore, in this paper, we examined silibinin, a flavonoid extracted from Silybum marianum , to determine its potential as a dual inhibitor of acetylcholinesterase (AChE) and Aβ peptide aggregation for AD treatment. To achieve this, we used molecular docking and molecular dynamics simulations to examine the affinity of silibinin with Aβ and AChE in silico. Next, we used circular dichroism and transmission electron microscopy to study the anti-Aβ aggregation capability of silibinin in vitro. Moreover, a Morris Water Maze test, enzyme-linked immunosorbent assay, immunohistochemistry, 5-bromo-2-deoxyuridine double labeling, and a gene gun experiment were performed on silibinin-treated APP/PS1 transgenic mice. In molecular dynamics simulations, silibinin interacted with Aβ and AChE to form different stable complexes. After the administration of silibinin, AChE activity and Aβ aggregations were down-regulated, and the quantity of AChE also decreased. In addition, silibinin-treated APP/PS1 transgenic mice had greater scores in the Morris Water Maze. Moreover, silibinin could increase the number of newly generated microglia, astrocytes, neurons, and neuronal precursor cells. Taken together, these data suggest that silibinin could act as a dual inhibitor of AChE and Aβ peptide aggregation, therefore suggesting a therapeutic strategy for AD treatment. [ABSTRACT FROM AUTHOR]

• Ru-modified Fe-Co-Ce/γ-Al 2 O 3 catalyst substantially increases abundant oxygen vacancies. • Lewis acid-base pair [Ru-O-Ce-O V ] sites enhance activity and stability for CWAO. • Rare-earth metal Ce significantly promoted the redox cycle of Fe, Co, and Ru ions. The interface of a metal oxide is one of the most pivotal defects used for reactions, but its catalytic mechanism is still unclear. In this study, we propose an excessive impregnation method to improve the physicochemical properties and performance during the catalytic wet-air oxidation (CWAO) of landfill leachate (LL) over Ru-doped cost-effective Fe-Co-Ce nanoparticles supported on γ-Al 2 O 3. In mineralization experiments, Fe 0.75 Co 0.75 Ce 3 Ru 1.5 /γ-Al 2 O 3 (Ru-1.5) exhibited outstanding performance of 89.4% for LL removal, and its kinetic constant was about 2.1 times than the catalyst without Ru. Further investigation revealed the enhanced synergism of Fe, Co, Ru, Ce, and γ-Al 2 O 3 in polymetallic oxides, and the corresponding mechanism can be explained as follows: Three-pronged approaches, activation of oxygen vacancies (O V), reversible electron transition among Fe, Co, and Ru accelerated by rare-metal Ce, and direct mineralization by adsorbing O 2 , were responsible for the CWAO of LL. Moreover, the addition of Ru not only promoted the catalytic activity, but also reduced the leaching of metals, including Fe, Co, and Ce. The spent catalyst had almost the same efficiency in maintaining high performance, indicating that the physicochemical properties strongly affect the performance of the catalyst. [ABSTRACT FROM AUTHOR]