APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 104
·期 15
·6635-6646
·
IF 3.53
Huang Kai,Zhang Shurong,Guan Xiao,Liu Jing,Li Sen,Song Hongdong
This study aims to use neutral pH optimum arginase as the catalyst for high-efficiency l -ornithine production. Sulfobacillus acidophilus arginase was firstly cloned and overexpressed in Escherichia coli . The purified enzyme was obtained, and the molecular mass determination showed that this arginase was a hexamer. S. acidophilus arginase possessed similarities with the other arginases such as the conserved sequences, purification behavior, and the necessity for Mn 2+ as a cofactor. The maximum enzyme activity was obtained at pH 7.5 and 70 °C. Thermostability and pH stability analysis showed that the arginase was stable at 30–60 °C and pH 7.0–8.5, respectively. The kinetic parameters suggested that S. acidophilus arginase could efficiently hydrolyze l -arginine. Bioconversion with this neutral pH optimum arginase had the advantages of avoiding producing by-product, high molar yield, and high-level production of l -ornithine. When the bioconversion was performed with a fed-batch strategy and a coupled-enzyme system involving S. acidophilus arginase and Jack bean urease, the final production of 2.87 mol/L was obtained with only 1.72 mmol/L l -arginine residue, and the molar yield was 99.9%. The highest production record suggests that S. acidophilus arginase has a great prospect in industrial l -ornithine production.
研究领域:
生物技术
·
酶学
·
微生物学
·
生物化工
✓ 已验证
DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2019
·Vol. 190
·期 3
·826-838
·
IF 2.14
Liu Hang,Zhou Min,Ju Xin,Shu Hang,Hu Cuiying,Li Liangzhi
β-Glucosidase (BG) hydrolyzes cellobiose into glucose, and is a vital step in converting ionic liquids (ILs)-pretreated biomass to sustainable biofuels. The inactivation mechanism of BG from Paenibacillus sp. LLZ1 induced by microcrystalline cellulose was explored in various concentrations of ILs, composed of [Emim] + cation and [DEP] − , [OAc] − , [Br] − , [Cl] − , and [BF 4 ] − anions. The FTIR analysis of inactivated BG indicated that the ILs altered its β-sheet content. Moreover, circular dichroism spectroscopy (CD) suggested that the α-helix content decreased, while the β-sheet content increased with the presence of ILs in general. Interestingly, the secondary structure of BG had almost no change after [Emim]DEP treatment, while ionic liquid [Emim]BF 4 treatment caused the irreversible denaturation of BG. Eventually, by adding 0.4 mM of Aerosol OT surfactant, the BG activity was increased by 20.1% in the presence of 25% [Emim]DEP, and the corresponding glucose yield from hydrolysis of cellobiose was increased by 23.9%.
研究领域:
生物化学
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生物技术
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酶学
·
可持续能源
✓ 已验证
DOI
PubMed
高影响因子
Journal of Analysis and Testing
·
2019
·Vol. 3
·期 3
·277-285
·
IF 0
Li Xinxue,Huang Qingwei,Li Wei,Zhang Jinli,Fu Yan
Abstract N -Acety-L-cysteine (NAC), enriched with multiple electron-rich groups involving –SH, –C=O, and –COOH, exhibits strong affinities to transition metal ions. Herein, NAC was adopted as the stabilizing agent to synthesize a series of peroxidase-like Pt nanoclusters (NCs) with different physicochemical properties. Both the cluster size and the charge state of NAC–Pt NCs are highly dependent upon the molar ratio of [K 2 PtCl 4 ]/[NAC], contributing to different peroxidase mimicking activities. The most active Pt nanozyme (~ 1.7 nm), composed of 60% metallic Pt 0 and 40% positively charged Pt 2+ respectively, exhibits the K m of 0.132 mM for 3,3′,5,5′-tetramethylbenzidine and 35 mM for H 2 O 2 . Based on the heparin-activated enzymatic activity of NAC–Pt at pH 6.0, an ultrasensitive test was established for quantitative determination of heparin, giving the linear response of 0.5–20 μg/mL as well as the limit of detection of 2 × 10 −3 μg/mL. This proposed method is also applicable in biological fluid for practical applications. Such a colorimetric method possesses several advantages involving high sensitivity, short response, eco-friendly synthesis, low consumption of material and energy, free of expensive instrument, as well as simple operation. Graphic abstract
研究领域:
纳米技术
·
分析化学
·
生物化学
✓ 已验证
DOI
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2020
·Vol. 412
·期 28
·7811-7817
·
IF 3.637
Hu Yinhua,Cao Xiuping,Guo Yingshu,Zheng Xiaofei,Li Dongjiao,Chen Si-Kai,Chen Guang,You Jinmao
The fluorescent nanoprobes for reduced thiol compounds (represented by glutathione, GSH) are constructed based on the aggregation-induced emission (AIE) luminescence mechanism and endosome escape technology. First, a DNA sequence was designed with the decoration of biotin at the 5′-end, disulfide bound in the internal portion, and amino at the 3′-end. The aptamer of the MCF-7 cell was also one of the most important structures in our DNA sequence for the selectivity of MCF-7 cells. We modified streptavidin-modified magnetic beads (MB) with biotin-modified influenza virus hemagglutinin peptide (HA) and biotin-DNA-amino to form MB/DNA/HA. Carboxyl-modified tetraphenylethylene (TPE), an iconic AIE fluorogen, was bonded with amino-modified DNA by covalent interactions (TPE/DNA). Then, the TPE molecule was attached on the outer layer of MB via biotin-modified TPE/DNA to form MB/DNA/HA/TPE. Compared with traditional AIE/biomolecule conjugates, the nanoprobe had an enhanced endosome escape function, due to the assembly of HA. This construction made the intracellular fluorescence response more accurate. In the presence of reduced thiol compounds (take GSH, for example), the disulfide bond on the DNA was reduced by thiol-disulfide exchange reactions and the TPE molecule was released into the solution. The shedding TPE molecule was more hydrophobic than TPE/DNA and the conversion of TPE/DNA to shedding TPE could lead to the aggregation of the TPE fluorogen. Thus, its fluorescence was enhanced. Under the optimized condition, the fluorescence intensity increased with the increase in concentration of GSH‚ ranging from 1.0 × 10 −9 M to 1.0 × 10 −5 M‚ and the detection limit was 1.0 × 10 −9 M. The relative standard deviation (RSD) was calculated to be 3.6%. The recovery in cell homogenate was from 94.5 to 102.7%. The nanoprobe provided a way for the detection of reduced thiol compounds in MCF-7 cells. We envision that, in the near future, our strategy of DNA-instructed AIE could be widely applied for biosensing and bioimaging in vitro and even in vivo with dramatically enhanced sensitivity.
Graphical Abstract
研究领域:
生物技术
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纳米技术
·
分析化学
·
细胞生物学
·
分子生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2021
·Vol. 79
·期 8
·6409-6429
·
IF 2.87
Ding Guanjun,Wang Ao,Shi Xinming,Li Jumei,You Lijun,Wang Shaoyun
Polyphosphazene microspheres (PZS) multispectral encoded by fluorescence and surface enhanced Raman spectra (SERS) were prepared and used as solid phase carrier of capture antibody for antibody detection. A variety of fluorescent encoded polyphosphazene microspheres (FPZS) incorporating single and multiple fluorescent molecules were prepared. Multiple SERS encoded polyphosphazene microspheres (SPZS) were obtained by modification of different Raman reporters on the surface of PZS@Ag, which were fabricated with rough morphology through in situ deposition of Ag nanoparticles. Fluorescence and SERS spectral combined encoded polyphosphazene microspheres (FSPZS) were prepared by encoding of fluorescent molecules and SERS reporters. The optical signals in the two independent detection channels were separable and ensured the accuracy for the encoding method. Immunoassays of goat IgG, rabbit IgG and mouse IgG were performed by the as-prepared FPZS, SPZS and FSPZS as solid phase carrier of capture antibody and fluorescent labeled second antibody, using sandwich immunoassay method. The immunoassay results showed that the multiple-spectra encoded microspheres have stable and distinguishable encoding signals, large encoding volume and multiplexed analytical capability in sandwich immunoassays.
研究领域:
材料科学
·
分析化学
·
生物传感器
·
免疫学
✓ 已验证
DOI
高影响因子
3 Biotech
·
2021
·Vol. 11
·期 12
·1-13
·
IF 2.406
Tang Miaolong,Cai Jimin,Wang Yan,Huan Zhirong,Yao Hao,Xu Ce,Ge Xin,Song Sheng
Hemorrhage shock (HS) is a major threat to patients with trauma and spontaneous bleeding, resulting in multi-organ failure including the kidney. Tyrosine kinase nonreceptor 1 (TNK1) has been shown to be upregulated in the kidney of experimental HS and patients with severe trauma . The study aims to investigate the role of TNK1 and the underlying mechanism in HS-induced kidney injury. A model of HS was established with femoral artery bloodletting, followed by resuscitation in Sprague–Dawley rats. Renal expression of TNK1 was abnormally induced by HS in rats. Knockdown of TNK1 alleviated HS-induced cell apoptosis and the level of proinflammatory cytokines (TNF-α, IL-6 and IL-1β) in the kidney. The expression of M1 macrophage markers (CD86 and iNOS) and the activation of STAT1 were inhibited by TNK1 knockdown in HS rats. In vitro, human monocyte THP-1 cells were treated with 20 ng/mL interferon-gamma plus 100 ng/mL lipopolysaccharide to induce M1 polarization. TNK1 knockdown exerted inhibitory effect on macrophage M1 polarization, M1-type inflammatory cytokine production and STAT1 activation in THP-1 cells. In conclusion, downregulation of TNK1 alleviates HS-induced kidney injury by suppressing macrophage M1 polarization, inflammation and kidney cell apoptosis, in which the deactivation of STAT1 signaling may be involved.
研究领域:
医学
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免疫学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
BMC CANCER
·
2021
·Vol. 21
·期 1
·1-14
·
IF 4.43
Shi Yue,Liu Chong
Background Breast cancer (BC) is one of the major malignancies worldwide. Circular ribonucleic acids (circRNAs) are a class of conserved ribonucleic acid (RNA) molecules that play important roles in various diseases. Recently, circRNAs have been suggested to have diagnostic value and may function as potential diagnostic biomarkers for BC. Previously, hsa_circ_0043278 was found to be downregulated in human BC. However, its role in human BC has not yet been identified.Methods The levels of hsa_circ_0043278 in BC cell lines were verified by quantitative reverse transcription–polymerase chain reaction (qRT–PCR). The overexpression vector and short hairpin RNA (shRNA) of hsa_circ_0043278 were transfected into MDA-MB-231 and MCF-7 cells, respectively. The effects of hsa_circ_0043278 on tumour cell growth, migration and invasion were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), colony formation, wound healing and Transwell assays in vitro. A xenograft experiment was conducted to validate the inhibitory effect of hsa_circ_0043278 on tumour growth. The interaction between hsa_circ_0043278 and miR-455-3p was confirmed by a dual-luciferase reporter assay. Mimics and inhibitors of miR-455-3p were designed to confirm the influence of hsa_circ_0043278 on the hsa_circ_0043278/miR-455-3p/etoposide-induced gene 24 (EI24) axis.Results Hsa_circ_0043278 was downregulated in BC cell lines. Furthermore, overexpression of hsa_circ_0043278 notably decreased BC cell viability and inhibited BC cell migration and invasion in vitro and suppressed tumour growth in vivo. Downregulation of hsa_circ_0043278 led to the opposite results. Hsa_circ_0043278 expression was negatively correlated with that of miR-455-3p. In addition, mechanistic investigation proved that hsa_circ_0043278 directly bound to miR-455-3p and regulated EI24 and NF-κB expression in BC cells.Conclusion Hsa_circ_0043278 acts as a tumour suppressor gene in BC through the hsa_circ_0043278/miR-455-3p/EI24 axis and may be regarded as a new prognostic predictor or potential therapeutic target in BC.
研究领域:
肿瘤学
·
分子生物学
·
遗传学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 1
·1-10
·
IF 2.253
Liu Wenwen,Peng Renfu,Pan Jun
The severe recombination of photoinduced carriers is one of the major problems encountered in C 3 N 4 -based photocatalyst for hydrogen generation. Herein, PtPd/C 3 N 4 composites by in situ growth of cubic PtPd bimetallic co-catalyst on the surface of C 3 N 4 were constructed for photocatalytic hydrogen generation under visible light irradiation. The phase structure, microstructure, and optical property were characterized by X-ray diffraction, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. Photocatalytic hydrogen generation results showed that the growth of a moderate amount of cubic PtPd bimetallic co-catalyst on C 3 N 4 is excellent beneficial for enhancing hydrogen generation activity. By optimizing the loading content of cubic PtPd bimetallic co-catalyst, the PtPd/C 3 N 4 composite provided a maximum hydrogen generation rate of 54.31 μmol h −1 . The enhancement of the photocatalytic activity can be attributed to the efficient separation and transfer of photoinduced carriers. On one hand, PtPd bimetal can extract electrons from C 3 N 4 , which promotes the separation efficiency of the carriers. On the other hand, the face-to-face interface formed between PtPd cubes and C 3 N 4 nanosheets has a large contact area, resulting in lots of unique high-speed carrier transfer channels in PtPd/C 3 N 4 composite, which promotes the transfer efficiency of the carriers. The work highlights the construction of less expensive and suitable shape of co-catalyst for enhanced photocatalytic activity.
研究领域:
材料科学
·
光催化
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2021
·Vol. 11
·期 1
·1-10
·
IF 4.38
Wang Shuji,Guo Xueyong,Zhao Wanjun,Fang Hua,Wu Chengcheng,Wang Di
In order to improve the thermal decomposition performances of ammonium perchlorate (AP), the laminated AP composite was prepared by ice-template induced self-assembly method. In this study, Iron-Konjac glucomannan (Fe 3+ -KGM) hydrosol rich in AP was selected as the freezing precursor. Through directional freezing of precursor and recrystallization of AP molecules, the laminated AP composite was obtained. The results showed that the thickness of the lamellar composite structure is about 10 to 30 μm, and the recrystallized AP particles are uniformly dispersed in the gel system. The oxygen bomb test results show that the micro-/nano-layered structure can significantly improve the sample’s combustion heat value. Thermal analyses indicated that with the increasing Fe 3+ content, the peak exothermic temperature of lamellar AP composite at different heating rates both showed a decreasing trend. With 10 wt% Fe(NO 3 ) 3 ·9H 2 O added, the decomposition peak temperature decreased from 433.0 to 336.2 °C at a heating rate of 5 °C/min, and the apparent activation energy ( E a ) decreased dramatically from 334.1 kJ/mol to 255.4 kJ/mol. A possible catalytic thermal decomposition mechanism of lamellar AP composite catalyzed by Fe 3+ was proposed. This work is beneficial to the structural design of other energetic materials.
研究领域:
材料科学
·
化学工程
·
燃烧与爆炸
✓ 已验证
DOI
PubMed
高影响因子
PHARMACEUTICAL CHEMISTRY JOURNAL
·
2023
·Vol. 57
·期 5
·712-724
·
IF 0.9
Li Danqi,Li Weihong,Shi Wenhao,Wu XiaoJing,Liu Xuegui,Gao Pinyi
Depression is a common mental health disease, with the characteristics of significant and persistent low mood. Traditionally, Ziziphus jujuba Mill . was used to treat depression. However, its chemical pharmacologic profiles remain to be elucidated. The present study was aimed to explore the potential targets and mechanisms of Z. jujuba in the treatment of depression using network pharmacology and in vitro neuroprotective experiment. In this study, 11 compounds of Z. jujuba were obtained by multiple column chromatography. Based on the network pharmacology, the C-T network was established by the results of molecular docking. The information on target proteins was enriched via DAVID database, followed by the analysis of GO and KEGG. The results indicated that 10 compounds, 5 target proteins and 3 signaling pathways played important roles in treating depression. Based on the predicted result of network pharmacology, compounds 1 , 9 and 10 were identified with significant neuroprotective effects by in vitro cell experiments with human neuroblastoma cell line SH-SY5Y. This study was the first to investigate the mechanisms of Z. jujuba action in the treatment of depression from the system level, and could provide the basis of the mechanism with action of compounds for the in-depth utilization of Z. jujuba.
研究领域:
中药学
·
神经科学
·
生物信息学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 14
·8871-8886
·
IF 4.22
Pi Menghan,Jiang Lichao,Wang Zhisen,Cui Wei,Shi Lingying,Ran Rong
As a new two-dimensional material, MXene has caused extensive research in field of supercapacitor, electromagnetic shielding, strain sensing field due to its excellent mechanical properties and electrical conductivity. MXene with good water dispersibility can be used as an ideal nano-material to enhance the conductivity of hydrogels. However, MXene is easy to accumulate in the hydrogel system, and there are rare articles on MXene hydrogels. In this paper, we combine cellulose nanocrystals (CNCs) and MXene to prepare CNC/MXene nanosheets and take advantage of CNC’s excellent dispersibility in water and the electrostatic repulsion between CNCs to avoid the accumulating of MXene and enhance the mechanical properties of the hydrogel. Based on it, we prepared a physical–chemical double crosslinking and double-network CNC/MXene hydrogel by in situ polymerization and cycle freeze-thaw method. The CNC/MXene hydrogel we prepared exhibited excellent mechanical properties; it could be stretched to 7 times its original length and could reach 1.025 MPa tensile stress. When the compression strain was 80%, the compression stress could reach 1.1 MPa. After unloading the compression pressure, it could rapidly return to its original length within 0.17 s, which would impact greatly on the practical application of CNC/MXene hydrogel. What's more, the conductivity of it was up to 0.4 S/m and the thermal conductivity was 0.38 W/mK. So, the hydrogel prepared by us has a wide range of application prospects in the fields of human motion monitoring, electronic skin, man–machine interface, etc.
研究领域:
材料科学
·
传感器技术
·
生物医学工程
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 3
·1715-1729
·
IF 5.044
Liu Hongyu,Yang Lin,Zhan Yifei,Lan Jianwu,Shang Jiaojiao,Zhou Mi,Lin Shaojian
In this work, a durable and sunlight-driven self-cleaning superhydrophobic cotton fabric was developed as a multifunctional oil/water separation material. First of all, Ag/AgCl was successfully deposited on the polydopamine modified cotton fabric surface by electrostatic adsorption, then the Ag/AgCl loaded fabric was coated by the polydimethylsiloxane (PDMS) via simple dip-coating method. The as-prepared cotton fabric (PDMS-Ag/AgCl@CF) presented the superhydrophobic property with water contact angle about 155°. Meanwhile, the prepared PDMS-Ag/AgCl@CF exhibited great tolerance and resistance to broad pH and various organic solvents, and it can also withstand 50 cycles of abrasion or 60 min of ultrasound treatment without an apparent decrease of superhydrophobicity, indicating its outstanding mechanical durability. As expected, this durable superhydrophobic fabric can availably separate various oil/water mixtures by gravity-driven force with high separation efficiency (over 97.8%), and it possessed good reusability. Additionally, the PDMS-Ag/AgCl@CF exhibited an outstanding self-cleaning performance under sunlight irradiation, due to visible light photocatalytic performance of Ag/AgCl. Finally, the resultant cotton fabric displayed good antibacterial activity. Therefore, in consideration of its prominent comprehensive performances, it is expected that the PDMS-Ag/AgCl@CF can be used as a promising material for oily water remediation.
研究领域:
材料科学
·
环境科学
·
光催化
·
抗菌材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）