ENVIRONMENTAL POLLUTION
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2017
·
IF 5.099
Huihui Du,ChenChen Qu,Jing Liu,Wenli Chen,Peng Cai,Zhihua Shi,Xiao-Ying Yu,Qiaoyun Huang
Bacteria–phyllosilicate complexes are commonly found in natural environments and are capable of immobilizing trace metals. However, the molecular binding mechanisms of heavy metals to these complex aggregates still remain poorly understood. This study investigated Cd adsorption on Gram-positive Bacillus subtilis , Gram-negative Pseudomonas putida and their binary mixtures with montmorillonite using surface complexation model, Cd K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy and isothermal titration calorimetry (ITC). We have shown that larger amounts of Cd are adsorbed by B. subtilis than by P. putida at pH<∼6, and Cd sorption that binding to phosphate groups plays a more important role in P. putida than in B. subtilis . This remind us that we should consider the microbe species when predict the biochemical behavior of trace metals in microbe-bearing environments. The observed Cd adsorption on the binary bacteria–clay composites was more than that predicted based on the component additivity approach. When taking bacteria–clay (1:1 mass ratio) as a representative example, an approximately 68%:32% metal distribution between the bacterial and mineral fraction was found. Both the EXAFS and ITC fits showed that the binding stoichiometry for Cd-carboxyl/phosphate was smaller in the binary mixtures than that in pure bacteria. We proposed that the significant deviations were possibly due to the physical-chemical interaction between the composite fractions that might reduce the agglomeration of the clay grains, increase the negative surface charges, and provide additional bridging of metals ions between bacterial cells and clays.
研究领域:
环境科学
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微生物学
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土壤化学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Ciyuan Huang,Shasha Shi,Songlin Cai,Yue Qiao,Caiyun Wang,Linji Yang,Yuchen Wang,Hao Cheng,Tao Yang,Kai Huang,Bingsuo Zou,Tao Liu
Congo red (CR), a stable benzidine diazo dye due to its azo bonds, resists natural photodegradation and poses a significant ecological threat. Herein, organic photocatalyst material PM7:ITC-2Cl@C was integrated with natural biochar to establish a high-performance photocatalyst coupling with adsorption. PM7:ITC-2Cl@C demonstrated complete degradation of 100 mg/L CR in 10 min under indoor weak light, sustaining degradation efficiency above 99% within 20 cycles. The removal efficiency of TOC contents in simulated aquatic environment containing 100mg/ L of CR were over 81%. PM7:ITC-2Cl@C possesses broad photon utilization (450-760 nm) and sequential measurements confirm its remarkable electron-hole separation, and the catalyst surface with functional groups containing oxygen and hydrogen also aids radical generation. Additionally, the strong adsorption of biochar fosters an environment for effective interaction with active oxygen species, ensuring constant pollutant contacting. Moreover, radical quench measurements indicated h+, ·OH, and ·O2- as key reactive oxygen species. The potential degradation pathways of CR were explored via LC-MS and DFT analysis, while toxicity analysis revealed low toxicity in the intermediates, suggesting the promising prospects of this system. This approach demonstrates the high-performance PM7:ITC-2Cl@C to significantly enhance the catalytic oxidative degradation process of dying wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Hazardous Materials Advances
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2021
·
IF 0
Luo Li,Yi Li,Chunhu Tan,Tingting Zhang,Xiaoli Xin,Weihua Li,Jiansheng Li,Rui Lu
The mechanism of GO/rGO interaction with trypsin is investigated using multiple methods. UV-Vis reveals that trypsin has a maximum absorption at 278 nm, the absorption intensity increased demonstrating GO/rGO alters the solvent environment of trypsin and exposes the aromatic chromogenic groups. ITC experiments with GO and trypsin provide a negative ΔH of -25.98 KJ mol −1 and the association constant Ka of 4.829 × 10 −4 . The negative ΔS of -23.64 J mol −1 ∙K −1 is further given by the Gibbs–Helmholtz equation. Combining with the ζ potential result, the driving forces for binding include hydrogen bonding, electrostatic interaction forces and van der Waals forces. Fluorescence spectroscopy shows that GO/rGO can significantly quench the fluorescence intensities of trypsin. The equilibrium constant Kd of GO/ rGO-24h / rGO-48h is 4.41±0.07, 5.82±0.53, 7.24±0.25, respectively, which means the reduced content of oxygen-containing groups can weaken the binding forces between GO/rGO and trypsin. CD show that even low concentrations of GO/rGO affect the secondary structure of trypsin, mainly decreasing the α -helix and β -fold content while increasing the β -turn and random coil content of trypsin. Overall, GO/rGO can effectively interact with trypsin, the oxidation degree of GO/rGO can affects the combination of trypsin and further influence on protein conformation and function.
研究领域:
生物化学
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分子生物学
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蛋白质科学
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DOI
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
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IF 4.784
Xiaoxiao Li,Yuxiang Bai,Hangyan Ji,Jinpeng Wang,Yinglu Cui,Zhengyu Jin
Pullulanase, a typical debranching enzyme, specifically hydrolyzes α-1,6 glycosidic linkages in pullulan, starch and so on. There is accumulated knowledge about the catalysis of pullulanase, but functional roles of acceptor subsites get less attention. According to the crystal structure of pullulanase from Bacillus subtilis str. 168, stacking interaction between tryptophan437 and glycosyl unit of α-CD was found. Trp437 located in conserved region III was highly conserved in pullulanases. But functional role of this residue remains unclear. Site-directed mutagenesis was used to determine the function of Trp437. Replacement of Trp437 with glycine, phenylalanine, proline, arginine resulted in mutants with undetectable hydrolysis activity and reverse hydrolysis activity. The secondary structure of mutated proteins showed no difference from the wild-type pullulanase, but they lost the capability to bind β-CD based on the ITC measurement. Molecular docking was performed to investigate the affinity of proteins to ligands including maltotriose, 6 2 -α-D-maltotriosyl-maltotriose and α-CD, showing the affinity of mutants to ligands became weaker compared to that of PulA. And the hydrogen bond between Trp437 and Glu525 in PulA only was found in mutant W437R. These results show that Trp437 at subsite +2 plays crucial role in catalysis of PulA, and it has little tolerance to change.
研究领域:
酶学
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微生物学
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结构生物学
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DOI
PubMed
高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
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2022
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IF 5.195
Zhijia Wang,Wen Li,Jihui Lu,Zhihua Yuan,Wenmin Pi,Yaozhi Zhang,Haimin Lei,Wenguang Jing,Penglong Wang
Ethnopharmacological relevance Glycyrrhiza uralensis Fisch (RC) and Coptis chinensis Franch (RG) are traditional Chinese medicines , which are classic drug pair in prescriptions to treat gastrointestinal diseases . Multi-herb therapy is one of the most important features of traditional Chinese medicine, but due to the complex components of herbal decoctions, the substances that actually exert their medicinal effects have not been fully elucidated. The discovery of Glycyrrhiza uralensis Fisch and Coptis chinensis Franch supramolecular parts (RC-RG SA) can provide a new perspective for explaining the mechanism of drug-pair compatibility. Aim of the study The purpose of this study was to explore the active composition and identification of chemical constituents of RC-RG SA, and to explore the inhibitory effects of supramolecular parts on S. aureus and biofilm. Materials and methods The micromorphology of RC-RG SA was characterized by SEM and DLS . Intermolecular forces between Glycyrrhiza uralensis Fisch and Coptis chinensis Franch determined by ITC. The chemical constituents of RC-RG SA were systematically analyzed by UPLC-ESI-MS n . The inhibitory effect of RC-RG SA on S. aureus was determined by turbidimetric method and plate coating method. The scavenging effect of RC-RG SA supramolecular parts on S. aureus biofilm were observed by MTT method, SEM and LSCM, respectively. Results The microstructure of RC-RG SA was spherical with a particle size of 161.6 nm . ITC proved that the reaction between decoction of RC and RG was exothermic. A total of 70 compounds were preliminarily identified in RC-RG SA, including 34 flavonoids , 34 alkaloids and 2 triterpenoids . The inhibitory effect of RC-RG supramolecular parts on S. aureus proliferation and the ability to clear S. aureus biofilm were better than RC-RG co-decoction and RC-RG non-supramolecular parts. Conclusions The Glycyrrhiza uralensis Fisch and Coptis chinensis Franch co-decoctions’ supramolecular components were an important substance that exerts its medicinal effect. Current study provided supramolecular strategies to reveal the active ingredients and the medicinal effect of the traditional Chinese medicine decoction.
研究领域:
药理学
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民族药理学
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微生物学
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分析化学
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传统医学
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产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2025
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IF 7.7
Xiaona Fang,Tian Gao,Zhaofeng Luo,Renjun Pei
Vancomycin is a glycopeptide antibiotic medication employed in the treatment of various bacterial infections. In this work, we employed a novel single round high-throughput identification method based on particle display to acquire DNA aptamers specific to small molecules. Our method simplifies the traditional SELEX process for small molecule targets by enabling direct selection of affinity aptamers from the enriched library via fluorescence-activated cell sorting (FACS). Using this strategy, we obtained three aptamers for vancomycin. Notably, these aptamers were less prevalent in conventional screening library. Among them, the aptamer XN1 demonstrated a dissociation constant ( K d ) of 38.7 μM as determined by isothermal titration calorimetry. Additionally, a designed fluorescent aptamer-based biosensor (apta-sensor) exhibited a limit of detection (LOD) of 0.7 μM for vancomycin. This apta-sensor was successfully applied to quantify vancomycin in 90% wastewater samples and functioned effectively in 90% human serum.
研究领域:
分子生物学
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分析化学
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生物技术
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药学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
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2023
·Vol. 11
·期 40
·13763-13773
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IF 6.4
Yuzhu Pan,Xin Wang,Yubing Xu,Shunjie Chai,Jie Wu,Zhiwei Zhao,Qing Li,Jun Wu,Jing Chen,Zhuoya Zhu,Byung Seong Bae,Omolola Esther Fayemi,Jianming Zhou,Ying Zhu,Wei Lei
Single-crystalline perovskites with low trap density, high mobility, and long diffusion length are ideal for creating high-performance optoelectronic devices. However, growing mixed-halide single-crystalline perovskite films or wafers with arbitrary halide components and controlled thickness is challenging. Here, a liquid-phase epitaxial (LPE) method based on inverse temperature crystallization (ITC) was developed to address this issue, using orientated MAPbCl3 single crystals as substrates, resulting in a series of single-crystalline MAPbBrxCl3−x perovskite films with continuous variable bandgaps from 2.19 eV to 2.91 eV and excellent optical-electrical properties. A series of planar-type photodetectors are designed and fabricated based on the epitaxial single-crystalline MAPbBrxCl3−x films, which present a dual-mode detection ability with response in both broadband and narrowband spectra ranges by manipulating the light incident direction from top illumination and bottom illumination, respectively. Through adjusting halide compositions, these photodetectors exhibit a selective optimal response spectrum and excellent optoelectronic detection performance, demonstrating the potential for multi-functional spectral detection with epitaxial perovskite devices.
研究领域:
材料科学
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光电子学
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半导体物理
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2021
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IF 10.618
Bin Qiao,Jiakun Xu,Wenhao Yin,Wanmeng Xin,Lixin Ma,Jie Qiao,Yi Liu
Herein, we report a method that combined “aptamer-locker” DNA with CRISPR/Cas12a-based biosensing for sensitive and rapid melamine analysis. Three strategies were harnessed for designing the DNA sensors that were well characterized by circular dichroism (CD) spectroscopy and isothermal titration calorimetry (ITC) in the absence and presence of melamine. The detection parameters were optimized to achieve good analytic performance. As a result, a limit of detection (LOD) as low as 38 nM was achieved, which is below the threshold (1.0 mg/kg) of allowable melamine in infant milk products. In addition, the sensors show high selectivity for melamine against other analogues such as cyanuric acid , ammeline and ammelide . Moreover, our method was effective for rapid melamine analysis in whole milk samples, with or without sample pretreatment , in less than 20 min. Adopting a commercially available portable fluorimeter, on-site analysis of melamine in milk was accomplished. The strategies demonstrated here can expand to detect other non-nucleic-acid targets by simply replacing the aptamers.
研究领域:
分析化学
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分子生物学
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生物技术
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食品安全
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DOI
PubMed
高影响因子
PHYTOMEDICINE
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2024
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IF 6.7
Zhenxiu Liu,Lin Chen,Mingyun Chen,Lang Linghu,Zhihua Liao,Min Chen,Guowei Wang
Background Farnesoid X receptor (FXR) is a vital receptor for bile acids and plays an important role in the treatment of cholestatic liver disease. In addition to traditional bile acid-based steroidal agonists, synthetic alkaloids are the most commonly reported non-steroidal FXR agonists. Sarmentol H is a nor-sesquiterpenoid obtained from Sedum sarmentosum Bunge, and in vitro screening experiments have shown that it might be related to the regulation of the FXR pathway in a previous study. Purpose To investigate the therapeutic effects of sarmentol H on cholestasis and to determine whether sarmentol H directly targets FXR to mitigate cholestasis. Furthermore, this study aimed to explore the key amino acid residues involved in the binding of sarmentol H to FXR through site-directed mutagenesis. Methods An intrahepatic cholestasis mouse model was established to investigate the therapeutic effects of sarmentol H on cholestasis. In vitro experiments, including Co-Ip and FXR-EcRE-Luc assays, were performed to assess whether sarmentol H activates FXR by recruiting the receptor coactivator SRC1. CETSA, SIP, DARTS, and ITC were used to determine the binding of sarmentol H to FXR protein. The key amino acid residues for sarmentol H binding to FXR were analyzed by molecular docking and site-directed mutagenesis. Finally, we conducted in vivo experiments on wild-type and Fxr −/− mice to further validate the anticholestatic target of sarmentol H. Results Sarmentol H had significant ameliorative effects on the pathological conditions of cholestatic mice induced with ANIT. In vitro experiments suggested that it is capable of activating FXR and regulating downstream signaling pathways by recruiting SRC1. The target validation experiments showed that sarmentol H had the ability to bind to FXR as a ligand (K D = 2.55 μmol/L) and enhance the stability of its spatial structure. Moreover, site-directed mutagenesis revealed that THR292 and TYR365 were key binding sites for sarmentol H and FXR. Furthermore, knockout of the Fxr gene resulted in a significantly higher degree of ANIT-induced cholestatic liver injury than that in wild-type cholestatic mice, and the amelioration of cholestasis or regulatory effects on FXR downstream genes by sarmentol H also disappeared in Fxr −/− cholestatic mice. Conclusion Sarmentol H is an FXR agonist. This is the first study to show that it exerts a significant therapeutic effect on cholestatic mice, and can directly bind to FXR and activate it by recruiting the coactivator SRC1.
研究领域:
药理学
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肝病学
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分子生物学
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生物化学
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Fuyun Ji,Huihui Liu,Chuyan Wang,Na Guo,Yizhong Shen,Shuizhong Luo,Shaotong Jiang,Zhi Zheng
Curcumin (Cur) and (−)-Epigallocatechin gallate (EGCG) have synergistic bioactivity in several terms, but their polar differences and environmental sensitivity make co-utilization challenging. Soy protein fibrils (UF) have sparked broad attention as outstanding carriers for bioactive substances. In this study, EGCG was applied to remodel the structure of Cur-loaded UF complex (UFC) to form novel UF-based hydrogels co-encapsulated Cur and EGCG (UFCE). The fluorescence spectroscopy, ITC , and FTIR analysis demonstrated that EGCG absorbed and deposited on the surface of UFC through hydrophobic and electrostatic interactions. The binding of EGCG led to the formation of UFCE, which constructed a stable and uniform gel network during heat treatment. UFCE gels formed with varying EGCG/protein concentration ([E]/[F]) ratios showed different structural properties with different encapsulation effects. At 2.5% protein concentration, UFCE gels formed at [E]/[F] ratio of 0.08 (UFCE 0.08 ) exhibited better gelling properties. The encapsulation efficiency of Cur and EGCG in UFCE 0.08 gel was up to 97.71% and 91.02%, respectively. Moreover, UFCE 0.08 gel exhibited significantly enhanced stability of Cur (95.27%) and EGCG (70.27%) than that of free Cur (53.13%) and free EGCG (13.32%) after thermal treatment at 85 °C for 120 min. UFCE 0.08 gel was also effective in improving the UV light stability of Cur (88.70%) and EGCG (72.96%). Furthermore, the binding of EGCG had pronouncedly boosted the anticancer activity of Cur in the UFCE 0.08 gel against Caco-2 cells. This study provides new perspectives into the fibril-polyphenol hydrogel systems for the co-encapsulation of EGCG and Cur, which has substantial potential for health-promoting applications.
研究领域:
材料科学
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药学
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生物技术
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食品科学
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Lianshun Zhang,Mengqing Jia,Xi Wang,Lei Gao,Bo Zhang,Lei Wang,Jinming Kong,Lianzhi Li
It is of great significance to sensitively and selectively detect uranyl ion (UO 2 2+ ) in environmental and biological samples due to the high risks of UO 2 2+ to human health. However, such suitable sensors are still scarce. A novel fluorescence sensor based on a dansyl-modified peptide, Dansyl-Glu-Glu-Pro-Glu-Trp-COOH (D-P5), was efficiently synthesized by Fmoc solid phase peptide synthesis. As the first linear peptide-based fluorescence sensor for UO 2 2+ , D-P5 exhibited high selectivity and sensitivity to UO 2 2+ over 27 metal ions (UO 2 2+ , Cr 3+ , Cu 2+ , Ba 2+ , Hg 2+ , Pb 2+ , Co 2+ , Ag + , Fe 3+ , Ca 2+ , K + , Mg 2+ , Mn 2+ , Na + , Ni 2+ , Cd 2+ , Zn 2+ , Al 3+ , Dy 3+ , Er 3+ , Gd 2+ , Ho 3+ , La 3+ , Lu 3+ , Pr 3+ , Sm 3+ , Tm 3+ ) by a turn-off fluorescence response in 10 mM HEPES buffer (pH 6.3). The effects of anions such as S 2− , NO 3 – , SO 4 2− CO 3 2– , HCOO – , antioxidant ascorbic acid and 4-nitrophenyl acetate on the selectivity for UO 2 2+ detection were also studies. D-P5 sensor could be used for detecting UO 2 2+ in a good linear relationship with concentration in the range of 0–8.0 μM with a low limit of detection of 83.2 nM. Furthermore, the interaction of the sensor with UO 2 2+ was characterized by ESI-MS, IR, XPS and ITC measurements. The 1:1 binding stoichiometry between the sensor and UO 2 2+ was measured by the job’s plot and further verified by ESI-MS. The binding constant of the sensor with UO 2 2+ was calculated to be 9.8 × 10 4 M −1 by modified Benesi-Hildebrand equation. ITC results showed that the ΔH θ and ΔS θ for the interaction of D-P5 with UO 2 2+ were −(7.167 ± 1.25) kJ·mol −1 and 66.5 J·mol −1 ·K −1 , respectively. Time-resolved fluorescence spectroscopy indicated that the mechanism of fluorescence quenching of D-P5 by UO 2 2+ ion was static quenching process. In addition, this sensor displayed a good practicality for UO 2 2+ detection in lake water sample without tedious sample pretreatment.
研究领域:
分析化学
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环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2024
·
IF 11
Xingran Kou,Xiwei Xu,Nan Gao,Yunchong Zhang,Xin Huang,Feng Chen,Qinfei Ke,Qingran Meng
Supramolecular chemistry of cyclodextrins (CDs) inclusion complexes is a hot research topic at present, but current studies often focus on the host-guest interaction between CDs and hydrophobic substances, while ignoring the self-assembly behavior of the host and guest during the inclusion process. Based on the spatial structures, six representative terpenes were selected in this study, and the stoichiometric ratio between terpenes and β-cyclodextrin (β-CD) was investigated by isothermal titration calorimetry (ITC) method. Meanwhile, the constructed inclusion complexes (ICs) were characterized by nuclear magnetic resonance , X-ray diffraction, scanning electron microscope , etc. On this basis, the assembly process of β-CD and terpenes was investigated firstly by molecular simulation method, and the inclusion process between β-CD and terpenes was further studied in terms of the formation of individual ICs and ICs aggregates. Results showed that hydrophobic interaction and van der Waals force were the main driving forces of the reaction between terpenes and β-CD, and the formation of ICs, β-CD molecule aggregation, terpene aggregation, and ICs aggregation occurred simultaneously during the inclusion process of terpenes and β-CD. To sum up, this study may provide certain thinking and reference for the subsequent supramolecular chemical research on CDs.
研究领域:
超分子化学
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环糊精化学
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主客体化学
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自组装
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物理化学
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分子识别
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有机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）