Systems Microbiology and Biomanufacturing
·
2022
·Vol. 2
·期 3
·507-522
·
IF 0
Du Juanjuan,Zhang Liang
N -methyl- d -aspartic acid (NMDA), an amino acid existing in human and animal central nervous system, exerts agonist action on one of the glutamate receptor subtypes and is clinically used for treatment of diabetes, Parkinson’s and Alzheimer’s syndrome. In this study, an enzymatic protocol for the chiral resolution of N -methyl- d , l -aspartic acid was built with a predicted N -demethylase (GenBank ID: OJV90073.1) from the genome of Chloroflexi bacterium 54-19. Through sequence alignment, the enzyme shares an identity of 32.19% to 2UZZ (PDB ID) with a conserved catalytic center. Recombinantly expressed in Bacillus subtilis WB600 , the N -demethylase was characterized with optimal temperature and pH at 55 ℃ and 7.5, and adaptive temperature and pH were 40–60 ℃ and 6–8. The effects of organic solvents and metal ions were investigated as well. Compared with other previously reported sarcosine oxidases, the enzyme showed a specific N -demethylation activity against N -methyl- l -aspartic acid according to the analysis by chiral liquid chromatography, LC–MS/MS and a detection by polarimeter. The results demonstrated 76% of 4.5 mM N -methyl- d , l -aspartic acid could be chirally separated by 7 mg·L −1 enzyme after reaction of 80 min. This work provided a foundation for mild synthesis of NMDA in industry. Graphical abstract
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DOI
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2016
·Vol. 163
·期 7
·B272
·
IF 3.014
Hao Gou,Jingxian He,Zunli Mo,Xiaojiao Wei,Rere Hu,Yawen Wang,Ruibin Guo
A fast electrochemical chiral sensor based on L-lysine (L-Lys) covalent functionalize reduced graphene oxide (RGO) has been developed for electrochemical recognize of tryptophan (Trp) enantiomers. The reduced graphene oxide/L-Lys (RGO/L-Lys) chiral composites with excellent water-soluble and biocompatible is very suitable for electrochemical sensor. Meanwhile, the L-Lys retains original chirality in RGO/L-Lys composites, which progress to electrochemical chiral sensor. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) were implemented to monitor the electrochemical behavior when RGO/L-Lys simply modified on glassy carbon electrode (RGO/L-Lys/GCE). Surprisingly, the reduction of peak current was significantly different after the RGO/L-Lys composites interacted with L-Trp or D-Trp, and the testing time is very short. It suggested that the RGO/L-Lys/GCE can be used as an electrochemical chiral sensor for the discrimination of Trp enantiomers. In this electrochemical discrimination process, the three-point interaction between L-Lys and Trp enantiomers has played an important role. Further research indicated that the decreased of peak currents versus percentage of L-Trp of Trp racemic mixture exhibits a fine linear relationship, it provides opportunity to make analysis for discrimination of Trp enantiomers. The RGO/L-Lys/GCE electrochemical chiral sensor with rapid recognition, good sensitivity and high stability provided an efficient method to recognize and determine Trp enantiomers.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2020
·Vol. 31
·期 8
·1-9
·
IF 2.489
Li Wan,Hu Xueying,Chen Jiawei,Wei Zhengnan,Song Chengwu,Huang Rongzeng
The intrinsic fragility of hydroxyapatite (HAP) restricts its wider applications for local delivery of antibiotics. The composites formed by integrating HAP with hydrogels can improve the properties of HAP. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. In this study, N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels with antibacterial property and cytocompatibility was prepared by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antimicrobial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus . The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier.
Due to the intrinsic fragility of hydroxyapatite (HAP), the properties of HAP could be improved by incorporation into hydrogels. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. We prepared N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antibacterial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus . The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier.
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高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Zhen Xiang,Jiayi Zhang,Chen Zhou,Bo Zhang,Nuoya Chen,Mingyu Li,Daihua Fu,Yunbing Wang
Biodegradable occluders, which can efficiently eliminate the complications caused by permanent foreign implants, are considered to be the next-generation devices for the interventional treatment of congenital heart disease. However, the controllability of the deployment process of degradable occluders remains a challenge. In this work, a near-infrared (NIR) remotely controllable biodegradable occluder is explored by integrating poly(l-lactide-co-ε-caprolactone) (PLCL) with poly(ethylene glycol)-modified gold nanorods (GNR/PEG). The caprolactone structural units can effectively increase the toughness of poly(l-lactide) and reduce the shape-memory transition temperature of the occluder to a more tissue-friendly temperature. Gold nanorods endow the PLCL-GNR/PEG composite with an excellent photothermal effect. The obtained occluder can be easily loaded into a catheter for transport and spatiotemporally expanded under irradiation with near-infrared light to block the defect site. Both in vitro and in vivo biological experiments showed that PLCL-GNR/PEG composites have good biocompatibility, and the PEGylated gold nanorods could improve the hemocompatibility of the composites to a certain extent by enhancing their hydrophilicity. As a thermoplastic shape-memory polymer, PLCL-GNR/PEG can be easily processed into various forms and structures for different patients and lesions. Therefore, PLCL-GNR/PEG has the potential to be considered as a competitive biodegradable material not only for occluders but also for other biodegradable implants.
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高影响因子
Heliyon
·
2023
·
IF 4
Xiaoyun Liu,Xiaoze Wang,Chunyan Sun,Xiaofeng Hu,Weijun Song
Herein, we propose a simple and effective strategy for designing a zeolitic imidazolate frameworks (ZIFs) fluorescent probe with a two-dimensional leaf-like structure. By doping ZIF-L with phosphate, we developed a fluorescent probe for iron (Fe 3+ ) in systems with high salinity. The fluorescence of P-ZIF-L was quenched effectively with the presence of Fe 3+ . The physicochemical structure, surface morphology, selectivity, stability and composition of the probe were investigated. Under optimized conditions, the fluorescent probe had a detection limit of 0.5 μM. Furthermore, the results that the probe exhibited desirable salt-tolerance and was suitable for determination of Fe 3+ in brine water samples with satisfactory results.
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高影响因子
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2018
·Vol. 96
·期 1
·15-23
·
IF 1.601
Saisai Li,Yan Li,Nengbing Long,Ruifeng Zhang
Phospholipase D (PLD) was effectively immobilized on a nanocomposite support composed of ZnO nanowires and SiO 2 through in-situ co-cross-linking with poly-L-lysine (PLL). An anionic and long-chained bisepoxide cross-linker was electrostatically adsorbed on the surface of ZnO nanowires prior to co-cross-linking. Under the optimal pH, 6.5, the loading amount of PLD reached an average of 114 mg per g support for PLL concentrations in the range of 0–0.6 mg mL −1 . Co-cross-linking of PLD with PLL enhanced the activity of PLD remarkably. The highest specific activity of co-cross-linked PLD reached 25.8 U per mg protein , which was 1.62 times as high as that of the cross-linked PLD (15.9 U per mg protein ). (One unit of PLD activity [U] refers to the amount of PLD, which liberates 1 μmol of p-nitrophenol per min via hydrolysis of phosphatidyl-p-nitrophenol at pH 8.0 and 30 °C). Under the optimized conditions, the yield of phosphatidylglycerol (PtdGro) reached 98.6% within 80 min at 45 °C and pH 6.5. The co-cross-linked PLD not only exhibited good resistance to pH and heat inactivation but also improved storage stability and reusability. The yield of PtdGro remained ≥85.4% after 13 repeat uses.
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高影响因子
PEST MANAGEMENT SCIENCE
·
2021
·Vol. 77
·期 5
·2576-2583
·
IF 4.845
Wei Deng,Mengting Yang,Yang Li,Zhiming Xia,Yongrui Chen,Shuzhong Yuan,Qian Yang
BACKGROUND Chinese sprangletop ( Leptochloa chinensis (L.) Nees) is one of main grass weeds invading Chinese rice fields. The target-site resistance (TSR) of cyhalofop-butyl have been widely reported in L. chinensis populations, but the non-target-site resistance (NTSR) mechanisms have not yet been well-characterized. This study aims to investigate the likely NTSR in a cyhalofop-butyl-resistant L. chinensis population (YZ-R), which was collected from Yangzhou city, Jiangsu Province, China. RESULTS Dose–response assays showed the YZ-R population exhibited 191.6-fold resistance to cyhalofop-butyl, compared to the susceptible population (YZ-S). This resistance is not target-site based, because no mutations in the two ACCase genes were detected in the YZ-R plants compared to the YZ-S plants, and the ACCase genes expression levels were similar in YZ-S and YZ-R plants. In addition, the cytochrome P450 inhibitor malathion and piperonyl butoxide (PBO), and glutathione S-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) did not significantly reverse cyhalofop-butyl resistance in the YZ-R population. However, liquid chromatography−mass spectrometry (LC–MS) analysis indicated that the metabolic rates of cyhalofop acid in YZ-R plants was significantly faster (5 to 10- fold) than in YZ-S plants. Furthermore, the YZ-R population showed no cross-resistance to other ACCase-inhibiting herbicides. CONCLUSION These results indicated that cyhalofop-butyl resistance in the YZ-R population is due to non-target-site based enhanced herbicide metabolism. Resistance in this population is likely involved in a specific detoxification enzyme, with possible high catalytic efficiency and strong substrate specificity, therefore leading to high-level and single resistance to cyhalofop-butyl. © 2021 Society of Chemical Industry
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高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2018
·
IF 3.849
Xiao-Qian Fu,Na Ma,Wei-Peng Sun,Yan-Yan Dang
In this study, a novel method of simultaneous extraction and enrichment of total polyphenol (TP) and lutein from marigold flower was developed by microwave and enzyme co-assisted aqueous two-phase extraction (ATPE) (MEAATPE). In this study, ethanol/ammonium sulfate was chosen to construct aqueous two-phase system (ATPS) due to its fine partition and recycling behaviors. The optimal MEAATPE condition was obtained, that is, 28% (w/w), ethanol/20% (w/w) ammonium sulfate, 0.45 U/g enzyme concentration, enzymolysis time of 150 min, enzymolysis temperature of 45 °C, microwave time of 120 s, and microwave power of 270 W, by investigating the effects of ATPS composition and other factors on the yield of target products. Under this optimal condition, the yields of TP and lutein reached 84.61 and 7.32 mg/g with the corresponding recovery rates of 95.35% and 99.85%, respectively. Compared with enzyme-assisted ATPE, microwave-assisted ATPE, ATPE, and Soxhlet extraction (SE), the extraction yield of TP by MEAATPE was the highest, which is 71.14% higher than that of SE. Scanning electron microscopy analysis further showed an optative pretreatment effect of marigold flower powders. Thus, MEAATPE was an efficient, rapid, and environmental-friendly method used for the extraction of natural products.
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高影响因子
PROTEIN EXPRESSION AND PURIFICATION
·
2024
·
IF 1.4
Junzhang Chang,Yuxin Zhang,Zhiwei Li,Yunfeng Ma,Xueqin Hu,Jingwen Yang,Hongbin Zhang
Chiral amino acids and their deamination products, α-keto acids, have important applications in food, medicine, and fine chemicals. In this study, two l -amino acid deaminase genes from Proteus mirabilis , PM473 of type Ⅰ and PM471 of type Ⅱ were cloned and expressed in Escherichia coli respectively, expected to achieve the chiral separation of amino acids . Extensive substrate preference testing showed that both deaminases had catalytic effects on the d -amino acid component of the D, l -amino acids, and PM473 has a wider catalytic range for amino acids. When D, L-Cys was used as the substrate, all L-Cys components and 75.1 % of D-Cys were converted to mercapto pyruvate , and the remaining D-Cys was a single chiral enantiomer . Molecular docking analysis showed that the interaction between the substrate and the key residues affected the stereoselectivity of enzymes . The compatibility of hydrophobicity between the binding pocket and substrate may be the basic factor that affects the substrate selectivity. This work provides an alternative method for the production of α-keto acids and the resolution of chiral amino acids.
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PubMed
高影响因子
CRYSTENGCOMM
·
2012
·Vol. 15
·期 9
·1729-1738
·
IF 3.842
L. Z. Pei,Y. Q. Pei,Y. K. Xie,C. G. Fan,H. Y. Yu
Manganese vanadate nanorods with a single crystalline triclinic Mn2V2O7 phase have been synthesized through a hydrothermal process using sodium lauryl sulfonate (SDS) as the surfactant. The manganese vanadate nanorods have a typical length in the range of 5 to 20 μm and a diameter of about 50 to 300 nm. The morphology of the manganese vanadate products is influenced by SDS concentration, hydrothermal temperature and duration time. SDS promotes the phase transformation of the products from irregular particles with an orthorhombic MnV2O5 phase to nanorods with a triclinic Mn2V2O7 phase. The growth process has been proposed as a nucleation and SDS adsorption growth process based on the analysis of the influence of growth conditions on the morphology of the manganese vanadate products. The manganese vanadate nanorods are used as glassy carbon electrode modified materials to analyze the electrochemical responses of L-cysteine. The manganese vanadate nanorod modified glassy carbon electrode exhibits a good analytical performance for the electrochemical determination of L-cysteine with a detection limit of 0.026 μM and linear range of 0.00005–2 mM.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Jingqiu Li,Yi Feng,Lvye Yang,Jianfeng Yao
Metal ion-induced etching can effectively convert zeolitic imidazolate frameworks (ZIFs) to CoNi-layered double hydroxides (LDH). Here, different metal-ion-assisted etching methods are utilized to convert Co-ZIF-L to CoNi-LDH with various morphologies and electrochemical properties . The resultant CoNi-LDH (CoNi-1) with a composition of Co 0.7 Ni 0.3 (OH) 2 displayed a high electrochemical performance when Co-ZIF-L was treated in N, N -dimethylformamide-ethanol solution containing Co 2+ ions followed by Ni 2+ ion-induced etching under hydrothermal condition. The improved electrochemical performance of CoNi-1 can be attributed to structural advantages, where the well-dispersed ultrathin CoNi-LDH layers favor the exposure of surface active sites and promote ion diffusion to maximize electrochemical properties.
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高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2021
·
IF 8.528
Xiao Wu,Yunxiao Liu,Haipeng Wu,Yongxin Duan,Jianming Zhang
Owing to the renewable/biodegradable characters, cellulose nanomaterials have been proposed to modify poly (L-lactic acid) (PLLA) for producing fully green, high performance fused deposition modeling (FDM) consumables. However, to realize the industrial application, the efficient dispersion of hydrophilic cellulose nanofillers in hydrophobic PLLA matrix by industrial melt compounding route rather than solution compounding remains a challenge. Herein, by using polyvinyl acetate (PVAc) modified cellulose nanocrystals (CNCs) powder (CNCs-PVAc) containing mixture of CNCs grafted by PVAc and PVAc homopolymer latex, the homogeneous dispersion of CNCs in PLLA has been achieved by simple melt blend. The results show that the addition of CNCs-PVAc with 5 wt% loading enhances both the melt processibility and inter-fuse adhesion of PLLA remarkably, which in turn results in the improvement of tensile breaking energy by 257%, inter-layer adhesion strength and notched impact toughness by 103% and 57.0%, respectively, as well as good dimensional stability. This work provides an industrial route to prepare PLLA/CNCs-PVAc nanocomposites with high performance for meeting the requirements of strength and dimensional accuracy of FDM parts for end applications.
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高影响因子
危险品化学品经营许可证（带存储）