Systems Microbiology and Biomanufacturing
·
2024
·
IF 0
Huang Yu,Li Hedan,Zhao Guihong,Hu Xiaoqing,Wang Xiaoyuan
The production of L-alanine was enhanced in Corynebacterium glutamicum ATCC13869 through metabolic engineering of the biosynthesis pathways of L-alanine and fatty acids. Strains Δ fasB , Δ fasBR , Δ fasB Δ pks13 and Δ fasBR Δ pks13 were constructed and exhibited increased L-alanine yields up to 17.29 g/L. Different from Δ fasB mutant constructed from C. glutamicum ATCC13032 in which L-glutamate production accumulated, the muatnt Δ fasB constructed from C. glutamicum ATCC13869 in this study significantly produce L-alanine without L-glutamate accumulation. Transcriptional level analysis revealed that the knockout of fasB upregulated the expression levels of the genes related to L-alanine synthesis but downregulated those associated with fatty acid synthesis, confirming the redirection of metabolic flux from fatty acid synthesis to L-alanine synthesis in these strains. L-alanine productions were further enhanced in strains Δ fasB and Δ fasBR through the combinatorial expression of heterologous genes Bacillus subtilis alaD encoding alanine dehydrogenase and Escherichia coli alaE encoding alanine export protein, and the yields reached 55.21 g/L and 54.95 g/L, respectively. Finally, 69.9 g/L L-alanine was obtained in Δ fasB /pJYW-5- alaDE after 60 h of fermentation by supplementing glucose. Our data indicate that disrupting the fatty acid biosynthesis could redirect metabolic flux towards L-alanine biosynthesis. These results provide a new strategy for increasing the production of L-alanine in C. glutamicum . Graphical Abstract
研究领域:
微生物学
·
生物工程
·
分子生物学
✓ 已验证
DOI
CRYSTENGCOMM
·
2019
·Vol. 21
·期 43
·6536-6544
·
IF 3.382
Shaozhen Wang,Biao Zang,Yueyue Chang,Hongqi Chen
Flower-shaped zeolitic imidazolate framework-L (ZIF-L) nanostructures were synthesized by a coordination control method. The various factors influencing the growth of the flower-shaped ZIF-L include the quantity of H2O2, reaction time and temperature, and the formation process and the mechanism were investigated. The results showed that H2O2 plays an induction role in the growth of crystal nuclei. Using the cleaning regulator, H2O2, flower-like ZIF-L with a high yield was produced in a short time at room temperature, and the fluorescence enhancement products were prepared at high temperature. Meanwhile, the CO2 adsorption capacity of flower-shaped ZIF-L was 1.15 mmol g−1 at room temperature and 1 bar, which was higher than that of the two-dimensional ZIF-L. This outstanding CO2 capture performance is attributed primarily to the hierarchical flower-shaped micro/nanostructure which is resistant to leaf aggregation and stacking, thus increasing the CO2 adsorption capability. These results may open a new avenue for the development of ZIF-L nanocrystals with a controlled morphology, which will be widely applied in luminescence analysis, gas sensing, separation and storage.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Boyin Yan,Zhiquan Liu,Rui Huang,Yongpeng Xu,Dongmei Liu,Wei Wang,Zhiwei Zhao,Fuyi Cui,Wenxin Shi
Cyanobacteria produce a series of secondary metabolites , one of which is beta- N -methylamino- l -alanine (BMAA). BMAA is considered to be the cause of human neurodegeneration. Compared with other cyanotoxins, the role of BMAA in cyanobacteria remains unclear. To investigate this question, six strains of cyanobacteria were cultured and tested in this experiment with an optimized and validated BMAA determination method. The results show that four strains can produce BMAA. The effects of nutrient levels on the production of BMAA by Anabaena sp. FACHB-418 were studied by changing the initial concentrations of nitrate (NaNO 3 ) and phosphate (K 2 HPO 4 ) in mediums. Bound BMAA was detected in all samples and the concentrations were within 50–100 ng/g. Free BMAA was presence when the concentration of nitrogen was lower than 1.7 mg/L (121.43 μM). Free BMAA was released from the dead and ruptured cells during the cell decline period, so dissolved BMAA cannot be detectable in the adaptation and logarithmic periods, but could be abundant in the decline periods. Statistical analyses show that free BMAA concentrations were negatively correlated with nitrogen strongly (p = 2.334 × 10 −10 and r = −0.842), but positively correlated with phosphorus weakly (p = 0.016 and r = 0.405). Moreover, the results of culture experiments indicated that exogenous BMAA could inhibit the growth of cyanobacteria that cannot produce BMAA, and the effect was enhanced as the concentration of exogenous BMAA increased. This phenomenon implies that the production of BMAA may be the stress response by some cyanobacteria to low nitrogen conditions to kill other cyanobacteria, i.e., their competitors.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Ruihong Yao,Zhijian Li,Panpan Huo,Congcong Gong,Gang Liu,Chunhong Zheng,Shouzhi Pu
In this study, we constructed zinc based metal–organic framework functionalized by L-histidine (His@ZiF-8). The His@ZiF-8 had high porosity, large surface area, abundant carboxyl and amino group, which has been found to greatly enhance the aggregation-induced emission (AIE) of tetracycline (TC). After the His@ZiF-8 enrichment with TC, the TC exhibited strong fluorescence emission peak at 565 nm based on AIE. Under the optimal conditions, the fluorescence intensity of TC exhibited a good linear relationship with TC concentration within 0.1–80 μM with a low limit of detection of 28.6 nM. Antibiotic analogs such as neomycin, chloramphenico, ampicillin, kanamycin, and erythromycin have no obvious interference. In addition, the developed method was successfully used to the detection of TC in milk, river water, and honey.
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Pharmaceutics
·
2024
·Vol. 16
·期 12
·1543
·
IF 4.9
Min Li,Wenying Li,Fang Xu,Yiping Pu,Jianguang Li
Background:L-Shikonin, an active component of Arnebia euchroma (Royle) Johnst., has remarkable pharmacological effects, particularly in its anti-tumour activity. Nonetheless, the specific targets and mechanisms of action remain to be further explored.Methods:A novel Fe3O4@L-Shikoninwas designed and synthesized in this study by linking Fe3O4andL-Shikoninthrough benzophenone. Fe3O4@L-Shikoninwas characterized using several techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and drug removal methods, to determine the content ofL-Shikoninon the surface of the magnetic particles. Target hooking technology was utilized to identify the target proteins of the compound in melanoma. The synthesized Fe3O4@L-Shikoninwas co-incubated with A375 cell lysate, followed by the target proteins, which were purified by magnetic enrichment using magnetic microspheres and identified by high-resolution mass spectrometry.Results:AutoDock Vina software was employed for molecular docking analysis, where it was found thatL-Shikonintargets RPN1, CPEB4, and HNRNPUL1 proteins. Subsequently, A375 cells were treated withL-Shikoninat different concentrations (2.5, 5.0, 10.0 μM) for 48 h, and the expressions of the three proteins were observed. The results showed a significant reduction in the relative expression of CPEB4 in the high-dose group compared to the control group (p< 0.01). Moreover, the relative expression of HNRNPUL1 was decreased in the medium- and high-dose groups (p< 0.05).Conclusions:This study initially revealed from the source thatL-Shikoninmay regulate melanoma-specific markers, melanosomes, tyrosine kinases related to abnormal tyrosine metabolism, and melanoma through multiple targets such as CPEB4 and HNRNPUL1. Proliferation and metastasis work together to exert an anti-melanoma mechanism, which provides a new idea for the follow-up study of the molecular pharmacological mechanism of the complex system of total naphthoquinones inArnebia euchroma(Royle) Johns.
研究领域:
药理学
·
肿瘤学
·
分子生物学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Xingmao Zhang,Hang Wang,Ruxin Yao,Longyu Wang,Pengfei Zhao,Yiting Li,Lin Wang,Qi Wang,Qiang Lyu,Zhuangjun Fan
Designing and synthesizing membranes with fast and selective cation transport remains extremely challenging. Herein, ZGO membranes are conceived via a two-dimensional zeolitic imidazolate framework (ZIF-L) in situ grown on graphene oxide (GO), with ZIF-L as an interlayer that increases both vertical interlayer spacing and lateral tortuous path spacing of GO, thus improving the stability, selectivity, and ion permeation of the ZGO lamellar membrane. Structural analyses reveal that GO surfaces with abundant oxygen functional groups favored the formation of ZIF-L with 316 crystal planes and offered a high ion-accessible surface area. More importantly, the ZGO membrane delivers an excellent K + permeability of 86.9 mmol m −2 h −1 and K + /Mg 2+ selectivity up to 266, outperforming state-of-the-art GO-based membranes. Furthermore, molecular simulations confirm that the hydrogen bonding between hydrated cations and polar functional groups of ZGO membranes substantially restricted the dynamical transport of bivalent cation, and thus led to excellent cation selectivity. These results open a pathway to developing membranes for fast and highly selective ion separations in the future.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xuanqi Hao,Xiao Zhang,Jianrong Wang,Chenchen Liu,Chuanhao Li,Ping Yang
To create fluorescent sensors for Cr (VI) and l-arginine detection, blue-emitting carbon dots (CDs, named as M-CDs) were prepared via a solvothermal synthesis by using m-phenylenediamine. The introduction of sulfuric acid changed the blue-emitting of CDs into green-emitting (named as S-CDs), in which the photoluminescence (PL) peak wavelengths of samples M-CDs and S-CDs were 450 and 540 nm, while their PL efficiencies were 21.7 and 84.2 % respectively. Sulfuric acid resulted in the average fluorescent lifetime of the CDs was prolonged into 8.19 from 4.65 ns. The photo and thermal stable tests demonstrated that theses CDs revealed excellent stability. Meanwhile, CDs flexible films with bright blue- and green-emitting were prepared utilizing the favorable solubility of CDs in polar solvents. Mono-dispersed CDs as luminescent materials demonstrated it promising prospects in luminescent devices field. Furthermore, M-CDs exhibited excellent selectivity towards Cr(VI) and l-arginine. The detected limit (0.86 μM for Cr(VI) and 0.43 μM for l-arginine) was determined by assessing the response of M-CDs to various concentrations of Cr(VI) ion and l-arginine solutions. These bright CDs revealed great potential for accurate detection of Cr(VI) and l-arginine.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Marine Drugs
·
2022
·Vol. 20
·期 11
·688
·
IF 6.085
Jingmin Cui,Yan Sun,Linqing Wang,Qin Miao,Wenqiang Tan,Zhanyong Guo
We successfully prepared a series ofl-arginine Schiff bases acylated chitosan derivatives, aiming to improve the antioxidant activity and antimicrobial activity of chitosan by introducing a furan ring, pyridine ring, andl-arginine structure. The accuracy of the structures of ten compounds was characterized by FT-IR and1H NMR. In terms of DPPH radical scavenging activity, except for compound CR3PCA, the scavenging rate of other compounds was higher than chitosan, especially CRCF and CRBF had strong scavenging abilities. At the same time, in the superoxide-radical scavenging activity assay, CRCF, CRBF, CR3PCA, CR2C3PCA, and CR2B3PCA were comparable to positive control at 1.60 mg/mL. Simultaneously, CRFF, CRCF, and CRBF had a certain inhibitory effect onBotrytis cinerea. Furthermore, the inhibitory effect of CRFF, CRCF, and CR3PCA onStaphylococcus aureuswas very well, close to the positive control at 1.00 mg/mL. CRCF and CR2B3PCA showed better inhibitory effects onEscherichia colithan other compounds. The MTT assay was used to determine the cytotoxicity of the chitosan derivatives, which proved their safety to fibroblast cells. In summary, the study indicated that some of these compounds have the potential for further development and utilization in the preparation of antioxidants and antimicrobial agents.Keywords:chitosan;l-arginine Schiff bases;heterocyclic compounds
研究领域:
生物化学
·
食品科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
E-POLYMERS
·
2021
·Vol. 21
·期 1
·420-427
·
IF 2.025
Benxiang Hu,Yuanbing Zhou,Ming-Chao Luo,Yan-Chan Wei,Gui-Xiang Liu,Shuangquan Liao,Yanfang Zhao
Nonrubber components (NRCs) play an important role in the outstanding mechanical property of natural rubber (NR). The main inositol component of NRCs in natural rubber latex (NRL) is l -quebrachitol. In this study, the influence of l -quebrachitol on the properties of centrifuged natural rubber (CNR) was investigated. The NRL was centrifuged twice to remove most of the NRCs. After that, l -quebrachitol was added in the latex with per hundreds of rubber (phr) vary from 0% to 0.8%, and the vulcanized CNR were prepared. It is shown that the properties of vulcanized CNR were greatly changed, with T
90 reduced from 19 to 15 min, the tensile strength increased from 5 to 9 MPa, T
g reduced by about 2°C, and the ability for strain-induced crystallization was enhanced. It was proved by FTIR results that l -quebrachitol was linked to the CNR crosslinking network with ester bond.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2017
·
IF 3.154
Sihua Cheng,Xiumin Fu,Xiaoqin Wang,Yinyin Liao,Lanting Zeng,Fang Dong,Ziyin Yang
Tea (Camellia sinensis) is the most widely consumed beverage aside from water. The flavor of tea is conferred by certain metabolites, especially l-theanine, in C. sinensis. To determine why more l-theanine accumulates in C. sinensis than in other plants, we compare l-theanine contents between C. sinensis and other plant species (Camellia nitidissima, Camellia japonica, Zea mays, Arabidopsis thaliana, and Solanum lycopersicum) and use a stable isotope labeling approach to elucidate its biosynthetic route. We quantify relevant intermediates and metabolites by mass spectrometry. l-Glutamic acid, a precursor of l-theanine, is present in most plants, while ethylamine, another precursor of l-theanine, specifically accumulates in Camellia species, especially C. sinensis. Most plants contain the enzyme/gene catalyzing the conversion of ethylamine and l-glutamic acid to l-theanine. After supplementation with [2H5]ethylamine, all the plants produce [2H5]l-theanine, which suggests that ethylamine availability is the reason for the difference in l-theanine accumulation between C. sinensis and other plants.
研究领域:
植物代谢
·
生物化学
·
植物生理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER TESTING
·
2020
·
IF 3.275
Tao Zhou,Hang Xiao,Weifeng Peng,Bo Liang,Yao Liu,Jiangbo Lv,Jianghuai Hu,Ke Zeng,Gang Yang
The pyrolysis behaviors of l -tyrosine-based phthalonitrile(TPN) resin were investigated by thermogravimetric-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The small molecules produced during pyrolysis process of TPN resin were tracked in real time by TG-FTIR-MS. The larger molecules ( m / z > 40) from fast pyrolysis at 900 °C of the TPN resin using Py-GC/MS were identified. From TG-FTIR-MS and Py-GC/MS results, the production pathways of pyrolysis products such as CO 2 , CO, NH 3 , benzonitrile and phenol were analyzed. The possible pyrolysis mechanism of TPN resin under non-oxidizing gaseous environment was proposed. The results of this study provide the useful information for designing the molecular structure of l -tyrosine-based polymers which possessing high thermal stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
PHYTOMEDICINE
·
2025
·
IF 8.3
Junsong Jing,Yi Sun,Yiyang Shui,Junyi Wang,Wenjing Ye,Ranran Chen,Lianhao Wu,Lijuan Xing,Rongrong Huang,Ting Zhou,Wenwen Zhu,Yueguo Wu,Sheng Zhang,Jing Shi,Yuanyuan Li,Yan Liu,Zhenqiang You
Background Viral pneumonia is an infection of the lungs caused by numerous different viruses, which can lead to severe respiratory distress and even life-threatening conditions. In the absence of specific treatments for viral pneumonia, natural traditional medicines offer an alternative in terms of innovative drug therapies. Morus alba L. (common name mulberry leaf) is a Chinese medicine that has been used clinically as an antiviral. Purpose The therapeutic effect of M. alba on viral pneumonia was investigated along with its mechanism of action. Methods Network pharmacology and molecular docking were used to analyze the mechanism of action of M. alba in the treatment of viral pneumonia. Histology, immunofluorescence, Western blotting, qPCR, and flow cytometry were used to evaluate the protective effect of MLE (the ethanol extract of Morus alba L. ) on PR8 (A/Puerto Rico/8/1934 H1N1, a murine lung-adapted influenza A virus strain)-induced viral pneumonia. SiRNA was used to validate the relationship between the therapeutic effects of MLE on viral pneumonia and the target Syk (a crucial non-receptor tyrosine kinase). Results MLE alleviated PR8-induced viral pneumonia by reducing inflammatory factor expression in the lungs, decreasing NF-κB pathway activation, slowing oxidative damage in the lungs, and inhibiting lung tissue cell apoptosis. Meanwhile, MLE for viral pneumonia was significantly associated with Syk targets. Notably, knockdown of the Syk gene not only reduced the therapeutic effect of MLE, but also suppressed PR8-induced viral pneumonia. Conclusion MLE can alleviate PR8-induced viral pneumonia through inhibiting the Dectin-1/Syk pathway.
研究领域:
药理学
·
分子生物学
·
病毒学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）