MOLECULES
·
2016
·Vol. 21
·期 7
·895
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IF 2.465
Hui Jian,Yingwu Wang,Yan Bai,Rong Li,Renjun Gao
Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly) residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 fromSulfolobus tokodaiiwas used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ) exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570.
研究领域:
生物化学
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酶工程
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材料科学
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高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2014
·
IF 1.357
Zhirong Xin,Binbin Du,Shunjie Yan,Shanshan Du,Jiaotong Ding,Zongfeng Yang,Wanzhong Ren
Gemini surfactants (GS) with sugar-containing head-groups and different alkyl chains were successfully prepared. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer was grafted with glycidyl methacrylate (GMA) by means of UV-induced graft polymerization, and then the pGMA-grafted film was chemically immobilized with the GS. The surface graft polymerization was confirmed by ATR-FTIR and XPS. The wettability and hemocompatibility of the modified surface were characterized by means of water contact angle, protein adsorption, and platelet adhesion assays. The results showed that amphiphilic surfactant-containing polymer surfaces presented protein-resistant behavior and anti-platelet adhesion after functionalization with GS, GS1 and GS2. Besides, the hemocompatibility of the modified surface deteriorated as the length of hydrophobic chain of GS increased.
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高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2022
·
IF 4.446
Shi-Wei Zhao,Qian Zhou,Neng-Bing Long,Rui-Feng Zhang
In macropores of a melamine sponge epoxy resin was cured in ethanol solution. The produced polymer gel could uniformly deposit on the surface of melamine in either porous or nonporous morphology. The composite sponge with porous coating can be used as a large-sized and well-mass transferred support for the immobilization of cyclodextrin glucosyltransferase (CGTase, from Thermoanaerobacter sp.) through the method of adsorption and crosslinking, and a column reactor was made for the preparation of α-arbutin in a sealed circulation way. The porosity and specific surface area were 91.6 % and 46 m 2 /g, respectively. The loading amount and the specific activity of immobilized CGTase under the optimal immobilization conditions were 42 mg/g support and 651 U/g support , respectively. 5 mg/ml maltodextrin and 10 mM hydroquinone were used as a glucosyl donor and acceptor for the biosynthesis of α-arbutin, respectively. Under optimized conditions, the α-arbutin yield reached 61 % within 24 h at 40 °C. After 10 cycles, the immobilized CGTase retained 33 % of the α-arbutin yield.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Yue Wang,Wenchang Zhao,Ruixia Gao,Sameer Hussain,Yi Hao,Jiahao Tian,Shihui Chen,Yunhao Feng,Yubo Zhao,Yuyao Qu
17β-estradiol (E2), as one of the pharmaceutical and personal care product , frequently contaminates environmental water as estrogen pollutant and possesses great risk to human survival as well as the sustainable development of the ecosystem. Herein, to achieve an effective adsorbent system for the selective removal of E2 from the environmental water, Fe 3 O 4 nanoparticles are subjected to chemical etching to reduce the overall mass and then employed as carriers to prepare a novel type of lightweight daisy-like magnetic molecularly imprinted polymers (LD-MMIPs) adopting template immobilization strategy. The LD-MMIPs based etched magnetic nanoparticles not only exhibit light mass but also have plentiful imprinted sites in the etched channels, which significantly increases the adsorption capacity for E2. The daisy-like LD-MMIPs own strong magnetic responsiveness, well crystallinity , fast binding kinetics, high adsorption amount, and excellent selectivity . Moreover, combining with HPLC, the LD-MMIPs as adsorbents have been successfully used to specifically recognize and detect trace E2 in environmental water. Thus, the proposed LD-MMIPs with high adsorption capacity hold great potential in monitoring water pollution . Additionally, this work also provides an alternative strategy for improving the adsorption capacity of magnetic molecularly imprinted polymers through a convenient chemical etching technology .
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PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Xiaofeng Yi,Shenhua Huang,Lu Chang,Zhaoshou Wang,Yuanpeng Wang
The redistribution process of arsenate (As(V)) and the variation in As(V) content in different locations must be clarified to ensure low mobility of As(V) during microbial ferrihydrite reduction. In this study, we investigated As(V) immobilization and redistribution processes when ferrihydrite was incubated with Geobacter sulfurreducens in the presence of titanium dioxide (TiO 2 ) nanoparticles . Our study results showed that, As(V) in the aqueous phase and ferrihydrite were redistributed on light minerals (goethite), heavy minerals (ferrihydrite and magnetite), and extracellular polymeric substances (EPS) induced by G. sulfurreducens during ferrihydrite reduction. Interestingly, we found that As(V) in the form of arsenate ion (AsO 4 3- ) was adsorbed by the functional groups of the EPS, while the formed Fe II 3 (As V O 4 ) 2 was wrapped in the network structure of EPS. Moreover, the addition of TiO 2 nanoparticles did not promote but delayed the entire ferrihydrite reduction, As(V) immobilization and redistribution processes. Furthermore, changes in the aqueous arsenic and iron concentrations are closely related to the formation time of secondary minerals. Our study findings provide new insights into the As(V) immobilization process mediated by G. sulfurreducens under anaerobic conditions .
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PubMed
高影响因子
Biotechnology for Biofuels
·
2021
·Vol. 14
·期 1
·1-12
·
IF 6.04
Zhou Zi-Wen,Cai Chun-Xian,Xing Xiu,Li Jun,Hu Zu-E.,Xie Zong-Bo,Wang Na,Yu Xiao-Qi
Background Production of biodiesel from renewable sources such as inedible vegetable oils by enzymatic catalysis has been a hotspot but remains a challenge on the efficient use of an enzyme. COFs (Covalent Organic Frameworks) with large surface area and porosity can be applied as ideal support to avoid aggregation of lipase and methanol. However, the naturally low density limits its application. In this work, we reported a facile synthesis of core–shell magnetic COF composite (Fe 3 O 4 @COF-OMe) to immobilize RML ( Rhizomucor miehei lipase), to achieve its utilization in biodiesel production. Result This strategy gives extrinsic magnetic property, and the magnetic COFs is much heavier and could disperse in water medium well, facilitating the attachment with the enzyme. The resultant biocomposite exhibited an excellent capacity of RML due to its high surface area and fast response to the external magnetic field, as well as good chemical stability. The core–shell magnetic COF-OMe structure not only achieved highly efficient immobilization and recovery processes but also maintained the activity of lipase to a great extent. RML@Fe 3 O 4 @COF-OMe performed well in practical applications, while free lipase did not. The biocomposite successfully achieved the production of biodiesel from Jatropha curcas Oil with a yield of about 70% in the optimized conditions. Conclusion Magnetic COFs (Fe 3 O 4 @COF-OMe) for RML immobilization greatly improved catalytic performance in template reaction and biodiesel preparation. The magneticity makes it easily recovered and separated from the system. This first successful attempt of COFs-based immobilized enzyme broadened the prospect of biodiesel production by COFs with some inspiration.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2021
·
IF 5.302
Yongchang Guo,Ying Zhang,Mathieu Allix,Shaowei Feng,Hong Sun,Cécile Genevois,Emmanuel Véron,Jianqiang Li
Pyrochlore-based glass-ceramics are attracting attention as a promising host material for immobilizing minor actinide in high-level wastes. However, the loading capacity of pyrochlore-based materials for actinide elements is to be improved, and only conventional synthetic approaches of powder sintering and glassy bulk crystallization were reported. Here, new (La,Y) 2 (Zr,Ti) 2 O 7 pyrochlore-based glass-ceramics were subtly designed and successfully prepared through a rapid melting and solidification process. The solidification behavior of samples with different cooling rates was investigated, the dense and crack-free (La,Y) 2 (Zr,Ti) 2 O 7 pyrochlore-based glass-ceramics were prepared at the cooling rate of 500 °C/s (within 1.5 s). The present amorphous La 2 O 3 -TiO 2 -Al 2 O 3 phase demonstrates the outstanding thermal stability compared with the currently used borosilicate glass for high-level waste immobilization due to the lack of conventional glass-forming components. The results show the great feasibility of this novel synthesis route for glass-ceramics by direct solidification and its good potential for immobilizing high-level wastes.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-9
·
IF 6.232
Pu Chenlu,Zhao Hongli,Gu Qinying,Zheng Yu,Lan Minbo
A selectively modified porous metal/carbon nanocomposite was fabricated to enhance the enrichment of low-abundance phosphopeptides from biological samples. The carbon matrix derived from the metal-organic framework provides a suitable pore size to allow the diffusion of peptides, while the deliberately modified metal nanoparticles within the pores enhance their interaction with the phosphopeptides. This nanocomposite shows extremely high enrichment selectivity for phosphopeptides in the MALDI-TOF MS detection, even when the molar ratio of α-casein digests versus bovine serum albumin digests was up to about 1:20,000. By combining such nanocomposite with nano-LC-MS/MS, 4556 unique phosphopeptides were identified with high selectivity (95.2%) from HeLa cell extracts. Furthermore, phosphopeptides from prostate tissue digests were also determined. A total of 277 and 1242 phosphopeptides were identified from normal and tumor tissues of a patient with prostate cancer, respectively. This indicates that phosphorylation and prostate cancer can be related to each other.
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PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
·
IF 7.489
Qing Shao,Fei Lu,Long Yu,Xirong Xu,Xinghao Huang,Yudong Huang,Zhen Hu
The surface of poly (p-phenylene benzobisoxazole) (PBO) fibers with self-healing and ultraviolet (UV)-resistance performance play the key role in prolonging their service lifespan. Although great advances have been made in the single aspect of above two properties, integration of self-healing and anti-UV performance into the surface of PBO fiber is still a challenge. In this study, the coagulation strategy mediated by metal-organic framework (MOF) is proposed to construct the multifunctional surface of PBO fibers. The spindle-like iron (III)-based MOF (MIL-88B-NH 2 ) nanocrystals are firstly immobilized onto the surface of PBO-COOH through hydrothermal reaction , then serving as the medium layer to further immobilize sufficient graphene oxide (GO) nanosheets . Benefitting from the favorable near-infrared (NIR, 808 nm) photothermal conversion performance of GO nanolayers, the monofilament composite-PBO@Fe-MIL-88B-NH 2 -GO-TPU (thermoplastic polyurethane) exhibited a stable and high self-healing efficiency (approximately 80%) within five cycle times. Meanwhile, the cooperative adsorption and shielding weaken effects of MOF-GO nanolayers enabled PBO fibers with excellent anti-UV properties that are superior to much reported literatures after 96 h aging time and eventually increased by 75% compared with untreated PBO fiber. In view of the varieties and multifunctionalities of MOFs and carbon nanomaterials , MOF-mediated coagulation strategy would provide guidance for preparing multifunctional composite materials.
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PubMed
高影响因子
PROCESS BIOCHEMISTRY
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2020
·
IF 2.952
Farid Shakerian,Jing Zhao,Shao-Ping Li
A simple method for immobilization of amylase (Am) on montmorillonite (Mt) was developed. Direct immobilization of crude commercial Am was initially evaluated by size exclusion chromatography by considering Am peaks (in comparison to the pure enzyme from the same source), while the immobilized enzyme performance was monitored by anion exchange chromatography. The immobilized Am showed approximately 55.6 ± 0.7 % (n = 3) of the activity of the free enzyme. Both free and immobilized Am showed maximum performance in neutral pH (pH ∼ 7). The immobilized Am maintained more than 60 % of its initial activity after 10 reuse cycles. The immobilized enzyme was successfully applied for starch removal in crude carbohydrates extracted from medicinal plant samples.
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高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 11
·1-11
·
IF 6.232
Zou Jiao,Lan Xi-Wen,Zhao Guo-Qing,Huang Zhao-Ning,Liu Yi-Ping,Yu Jin-Gang
A novel chiral sensing platform, 6-O-α-maltosyl-β-cyclodextrin (Mal-βCD)-based film, is proposed for selective electrochemical recognition of tyrosine ( Tyr ) enantiomers. Black phosphorus nanosheets (BP NSs) and Mal-βCD modified glassy carbon electrode (Mal-βCD/BP NSs/GCE) were prepared by a layer-to-layer drop-casting method, and the platform was easy to fabricate and facile to operate. It is proposed that the amino and hydroxyl groups of the Tyr enantiomers and the chiral hydroxyl groups of Mal-βCD selectively form intermolecular hydrogen bonds to dominate effective chiral recognition. Two linear equations of Ip (μA) = 11.40 C L-Tyr (mM) + 0.28 ( R 2 = 0.99147) and Ip (μA) = 7.96 C D-Tyr (mM) + 0.22 ( R 2 = 0.99583) in the concentration range 0.01–1.00 mM have been obtained. The limits of detection (S/N=3) for L- Tyr and D- Tyr were 4.81 and 6.89 µM, respectively. An interesting phenomenon was that the value of I L- Tyr /I D- Tyr (1.51) in this work was slightly higher than the value of I L- Trp /I D- Trp (1.49) reported in our previous study, where tryptophan ( Trp ) enantiomers were electrochemically recognized by Nafion (NF)-stabilized BPNSs-G2-β-CD composite. The two similar sensors fabricated by different methods showed different recognition ability toward either Tyr or Trp enantiomers, and the underlying mechanism was discussed in detail. More importantly, the proposed chiral sensor enables prediction of the percentages of D- Tyr in racemic Tyr mixtures. The chiral sensor may provide a novel approach for the fabrication of novel chiral platforms in the practical detection of L- or D- enantiomer in racemic Tyr mixtures. Graphical abstract
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CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yongkui Li,Xianjin Qi,Guohua Li,Hua Wang
Nonferrous smelting wastewaters containing high levels of arsenic and sulfuric acid threaten human health and ecological environments due to insufficient disposal technologies and/or possible leakages during transportation to long-term storage facilities. Chemical precipitation is one important route for arsenic removal and immobilization via the formation of arsenic-stabilized minerals. In this study, we propose a new strategy for the treatment of wastewaters containing high levels of arsenic using pyrite as an in situ S and Fe source to prepare environmentally friendly scorodite and As 2 S 3 precipitates. Dissolved pyrite release (S-II) and Fe (II) ions in highly acidic wastewater, both of which drive arsenic precipitation. Sulfide ions readily react with As(III) to generate the stable As 2 S 3 while Fe(II)/As(III) were oxidized to Fe(III)/As(V) by H 2 O 2 . The reaction between Fe(III) and As(V) took place on the pyrite surface as a nucleation site to form amorphous ferric arsenate that ultimately transformed into crystalline scorodite. Sulfide ions were oxidized to H 2 SO 4 that further promoted pyrite dissolution. Up to 99.4% of arsenic was successfully removed from copper smelting wastewaters with an initial arsenic concentration of 11200 mg/L. The concentration of leached As from the As-bearing precipitate was 1.78 mg/L under optimized conditions, which were: a 1.4 FeS 2 /As molar ratio, an initial solution pH of 2, an H 2 O 2 /As molar ratio of 1%, a reaction temperature of 90 °C, and a reaction time of 12 h. In summary, a prospective process successfully shows arsenic removal and immobilization from smelting wastewater, and further demonstrates the potential for the efficient and affordable disposal of wastewater.
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危险品化学品经营许可证（带存储）