ELECTROPHORESIS
·
2020
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IF 3.081
Mengqi Li,Hao Shen,Zixin Zhou,Wenting He,Ping Su,Jiayi Song,Yi Yang
In recent years, CE-integrated immobilized enzyme reactors (IMERs) for single-enzyme immobilization have attracted considerable attention. However, there has been little research on multienzyme immobilization in CE. Here, we introduce a method for fabricating a CE-integrated IMER, using DNA-directed immobilization to fix glucose oxidase and horseradish peroxidase in the capillary, which had been functionalized with polyamidoamine dendrimer (PAMAM). Owing to the reversibility of DNA hybridization, the reactor is capable of dynamic immobilization. Moreover, by introducing the PAMAM, the loading capacity of the IMER is greatly enhanced, and the PAMAM can spontaneously form complexes with DNA and then contribute to the efficiency and stability of the reactor. After 25 days storage, the prepared IMER ultimately retained approximately 70% of its initial activity. We also used the IMER to detect glucose, and the favorable linearity was obtained over the concentration range of 0.78–12.5 mM, with an LOD of 0.39 mM, demonstrating that the CE-integrated IMER can be applied to actual samples. We believe that this strategy can be extended to other multienzyme immobilization systems, and CE-integrated IMERs are potentially useful in a wide range of biochemical research applications.
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PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 94
·期 12
·3763-3771
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IF 2.659
Weiran Li,Jiafu Shi,Yang Zhao,Yu Tian,Qian Huo,Yizhou Wu,Shaohua Zhang,Zhongyi Jiang
BACKGROUND The enzymatic process in continuous flow reactors has become attractive owing to the merits of in-line purification, improved mixing and mass transfer, etc. However, the construction of continuous flow reactors requires stable and surface-active monolithic scaffolds for enzyme immobilization. RESULTS In this study, nanofibers of linear polyethyleneimine (LPEI) are formed on the surface of poly(sodium 4-styrenesulfonate) (PSS)-treated cordierite honeycomb (named LPEI/PSS cordierite-H) as monolithic scaffold for enzyme immobilization. The controlled self-assembly of LPEI ensures the formation of nanofibers (diameters of 20–80 nm) on the surface of cordierite-H, which roughens the surface and offers many active sites for enzyme loading. The electrostatic interaction between negatively charged enzyme and positively charged LPEI helps the enzyme firmly attach on the surface. The loading capacity of LPEI/PSS cordierite-H was 1.24 mg g −1 . Horseradish peroxidase (HRP)-loaded LPEI/PSS cordierite-H (HRP@LPEI/PSS cordierite-H) exhibited activity recovery of 55.33%, 2-fold higher than that of HRP-loaded branched polyethyleneimine (BPEI)/PSS cordierite-H (HRP@BPEI/PSS cordierite-H) (23.72%). Furthermore, a silica layer was formed on the surface of HRP@LPEI/PSS cordierite-H through LPEI-induced silicification, which could prevent the enzyme from deactivation under extreme conditions. CONCLUSION These monolithic biocatalysts have great potential for applications in wastewater treatment and even in other fields such as pharmaceutical synthesis. © 2019 Society of Chemical Industry
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Wei Zhuang,Weiwei Gu,Qianqian Zhu,Jiahua Zhu,Zhenfu Wang,Huanqing Niu,Dong Liu,Jinglan Wu,Yong Chen,Ming Li,Chenjie Zhu,Hanjie Ying
In order to solve the toxic and hazardous issues of the agents in the chemical reduction process of graphene oxide (GO), disodium guanosine 5′-monophosphate (GMP-2Na) was used as an ideal reducing agent for the synthesis of functionalized GO (FGO) for lipase immobilization. At the condition of low amount adsorption of GMP-2Na indicated by the N1s spectra of X-ray photoelectron spectroscopy (XPS), the C/O atomic ratio of the FGO increased from 2.09 to 3.12, indicating the reduction of GO. As the amount of GMP-2Na increased, the intensity of the characteristic peak of GO in the XRD pattern decreased, and the I D /I G peak intensity of Raman spectra increased during the functionalization process. It was found that when the concentration of GMP-2Na is 0.20 mg/mL, the degree of hydrophobicity of FGO is conducive to the formation of optimal conformation of lipase. After immobilization, the activity of the immobilized enzyme reaches twice the value of free enzyme. At the same time, the protein loading reaches to 600 mg/g. The immobilized enzyme showed enhanced durability since no obvious decrease was observed after incubation for 8 h at pH 6.0 and pH 7.0. After storage for 35 days, the activity of GO-G@ enzyme was 54.47% higher than that of free enzyme. GO reduced by GMP-2Na provides a possibility to obtain a highly efficient lipase immobilization carrier.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
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2019
·Vol. 46
·期 1
·101-118
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IF 2.064
Li Anxia,Yang Xiaoxin,Yu Binglong,Cai Xiulan
In this study, Fe 3 O 4 /nanodiamond nanocomposites (MND) were synthesized by polyglycerol-mediated covalent bonding. The horseradish peroxidase (HRP) was successfully immobilized on PG layer of MND by interaction between functional groups of MND and HRP, where the HRP molecules became tridimensionally connected outside the MND. The physicochemical properties of MND were analyzed by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy measurements, vibrating sample magnetometer, Fourier transform infrared spectroscopy and zeta potential. The optimal conditions for the immobilization of HRP by MND are 7 mg/L, 35 °C and 3 h, respectively. Then, the effects of temperature, pH and storage time on the activity of immobilized enzyme and free enzyme were studied. The results showed that the relative activities of immobilized enzymes were higher than free enzymes at different temperatures, pH and storage time. In addition, the reusability experiments of immobilized enzymes showed that after six cycles, the immobilized HRP retained a relative activity of 75%. Applied to the removal of phenol, the effects of phenol concentration, H 2 O 2 /phenol molar concentration, immobilized HRP concentration and temperature on phenol removal were investigated. The results displayed that the removal efficiency of phenol reached a maximum when the phenol concentration was 75 mg/L, the ratio of H 2 O 2 to phenol was 1, the immobilized HRP concentration was 0.25 mg/L and the temperature was 30 °C. The above results indicate that the immobilized HRP exhibits high removal efficiency and has great potential for removing phenol.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2019
·Vol. 27
·期 2
·1888-1897
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IF 2.914
Wang Ying,Wang Luxing,Deng Xiaoyan,Gao Hongtao
Waste biomass can be recycled to prepare biochar for soil restoration, in which process soil fertility would not be lost. In this work, biochar was prepared from waste pomelo peel, combined with ZnO, to be used to immobilize Cu(II) in contaminated soil, whose maximum adsorption capacity was up to 216.37 mg g −1 . Due to combination of ZnO, the BET surface area of biochar increased from 2.39 to 18.53 m 2 g −1 . Meanwhile, the surface functional groups increased, which was conducive to fixation of metal ion on the surface of biochar. Both pseudo-second-order kinetics and Langmuir isotherm model fit the experimental data well. Adsorption was easy to happen since the adsorption site on the surface of biochar/ZnO had a strong affinity with Cu(II). In addition, mechanism investigation indicated that Cu(II) was bond with biochar/ZnO mainly by non-bioavailable state (75.6%) primarily. It inferred that biochar/ZnO was an efficient and promising passivator in reducing heavy metal risk in soil.
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·8458-8468
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IF 3.201
Jiayi Song,Ting Lei,Ye Yang,Nan Wu,Ping Su,Yi Yang
The major barriers to the use of enzymes in practical applications are their insufficient stability and easy inactivation under processing conditions. In this work, we developed a promising platform that allows for the simple and effective immobilization of enzymes on hydrophilic polydopamine (PDA) modified magnetic nanoparticles through DNA directed immobilization. Taking α-chymotrypsin (ChT) as an example, the well-designed immobilized enzyme in this study exhibited excellent kinetic performance, and the apparent Vmax and catalytic efficiency (kcat/Km) values of the DNA immobilized enzyme were 15.77 mM min−1 mg protein−1 and 4.05 s−1 mM−1, which were more than 6.0- and 5.9-fold enhanced compared to that of the free enzyme, respectively. The DNA immobilized enzyme exhibited promising thermal stability, which could preserve promising enzymatic activities of about 83% after 60 min incubation at 60 °C. The DNA immobilized enzyme also exhibited excellent long-term storage and incubation stability, which could preserve more than 89% of the initial activity at 4 °C for 35 days and more than 77% after 47 h of incubation, respectively. In addition, the DNA immobilized ChT exhibited excellent reusability, which showed a high degree of activity (more than 84%) after 10 cycles. Notably, the enzyme immobilization procedure exhibited high reversibility and reproducibility, and the magnetic nanoparticle surfaces were successfully regenerated and cycled through DNA strand displacement reactions for subsequent enzyme immobilization, which could retrieve more than 98% of the enzymatic activity. A significantly improved protein digestion efficiency was achieved with this immobilized ChT within 10 min, and the obtained sequence coverages were more than 1.3-fold higher when compared to that obtained by conventional in-solution digestion for 12 h. Therefore, this work exhibits a promising alternative platform for the efficient immobilization of industrially important enzymes and their broad applications.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
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IF 6.14
Liya Zhou,Jiaojiao Li,Jing Gao,Huan Liu,Saiguang Xue,Li Ma,Guangxiu Cao,Zhihong Huang,Yanjun Jiang
In this study, nickel-nitrilotriacetic acid-modified viruslike mesoporous silica nanoparticles (Ni-NTA-VMSN) were fabricated by a facile method for the first time. The Ni2+ ions on the surface of Ni-NTA-VMSN provided abundant anchoring sites for directly selective oriented immobilization of His-tagged proteins from crude enzymes. By incubation of the Ni-NTA-VMSN in the His-tagged organophosphohydrolase (OpdA)-contained cell lysates, a nanobiocatalyst, OpdA@Ni-NTA-VMSN, could be constructed. At the optimal immobilization conditions, the specific activity of OpdA@Ni-NTA-VMSN was 353.0 U/gprotein, which was slightly higher than that of free OpdA in cell lysates. The substrate’s affinity capacity of OpdA became higher after oriented immobilization, and the OpdA@Ni-NTA-VMSN exhibited excellent catalytic activity and stability. In addition, when OpdA@Ni-NTA-VMSN was applied in a plug-flow reactor, the degradation percent of methyl parathion could be maintained at more than 90% with the injection of 20 mL of reaction mixture. Thus, the Ni-NTA-VMSN will be a promising material for purifying and immobilizing His-tagged enzymes. The proposed OpdA@Ni-NTA-VMSN will be an excellent nanobiocatalyst for biodegradation of organophosphorus pesticides.
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高影响因子
MICROCHIMICA ACTA
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2018
·Vol. 185
·期 12
·1-10
·
IF 5.705
Wang Meng-Meng,Chen Shuai,Zhang Dan-Dan,Yu Yong-Liang,Wang Jian-Hua
A sorbent for selective extraction of phosphoproteins was obtained by immobilization of a Ce(IV)-substituted polyoxometalate on ethylenediamine-functionalized graphene oxide (CeEGO). The resulting composites exhibit an adsorption capacity of 981 mg g −1 for β-casein due to the synergistic effect of metal-affinity interaction between Ce(IV) and phosphate groups and π-stacking interaction between the polyoxometalate framework and the phosphate groups. The results of LC-MS and SDS-PAGE analysis show that the CeEGO composites can be applied to the extraction of phosphoproteins from protein mixture, and as little as 50 μg mL −1 of the phosphoprotein β-casein can be detected by SDS-PAGE. It was also applied to the extraction of β-casein from spiked biological samples such as drinking milk, whole blood and swine heart tissue extract.
An efficient sorbent is obtained by immobilization of a Ce(IV)-substituted polyoxometalate on ethylenediamine-functionalized graphene oxide (CeEGO). The resulting composites exhibit highly selective capture capacity towards phosphoproteins due to the synergistic effect of metal-affinity interaction between Ce(IV) and phosphate groups and π-stacking interaction between the polyoxometalate framework and the phosphate groups.
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高影响因子
International Journal of Nanomedicine
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2015
·
IF 4.383
Xiaoxiao Wen,Yudong Zheng,Jian Wu,Lu-Ning Wang,Zhenya Yuan,Jiang Peng,Haoye Meng
Bacterial cellulose (BC) is an alternative nanostructured biomaterial to be utilized for a wide range of biomedical applications. Because of its low bioactivity, which restricted its practical application, collagen and collagen hydrolysate were usually composited into BC. It is necessary to develop a new method to generate covalent bonds between collagen and cellulose to improve the immobilization of collagen on BC. This study describes a facile dialdehyde BC/collagen peptide nanocomposite. BC was oxidized into dialdehyde bacterial cellulose (DBC) by regioselective oxidation, and then composited with collagen peptide (Col-p) via covalent bonds to form Schiff’s base type compounds, which was demonstrated by the results of microstructures, contact angle, Col-p content, and peptide-binding ratio. The peptide-binding ratio was further affected by the degree of oxidation, pH value, and zeta potential. In vitro desorption measurement of Col-p suggested a controlled release mechanism of the nanocomposite. Cell tests indicated that the prepared DBC/Col-p composite was bioactive and suitable for cell adhesion and attachment. This work demonstrates that the DBC/Col-p composite is a promising material for tissue engineering and regeneration.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2014
·
IF 3.065
Meng Wang,Xu Liu,Yu-xiang Jia,Xun-liang Wang
In this work, a three-step modification scheme was devised to covalently immobilize the polyethyleneimine (PEI) multilayers for improving the comprehensive transport properties of a heterogeneous cation exchange membrane (CEM), including the grafting of carboxyl groups, the PEI immobilization by amidation reaction and glutaraldehyde-induced PEI multilayers deposition. Firstly, the changes in surface chemical composition and morphology after modification were investigated by attenuated total reflection-Fourier transform infrared spectroscopy and scanning probe microscope. Then, the membrane properties corresponding to different modification steps were comprehensively evaluated by the measurements of ion exchange capacity, water content, salt permeability coefficient, membrane electrical resistance, limiting current density and so on. Especially, in order to simulate the possible applications in the reclamation of the industrial effluents from the hydrometallurgy processes and the comprehensive utilization of seawater, respectively, some electrodialysis experiments for H + /Zn 2+ system and Na + /Mg 2+ system were performed to estimate and compare the monovalent selectivity of the membrane samples. Furthermore, the alteration of surface heterogeneity after modification was explored by current–voltage curves and chronopotentiometric curves. The experimental results showed that the modification scheme proposed in this work can make significant contributions to a heterogeneous CEM, such as the endowment of monovalent cation permselectivity, the improvement of surface homogeneity for ameliorating concentration polarization, the ability to impeding salt diffusion and even the possibility of extending membrane life-span.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Na Li,Jingjing Du,Lijian Xu,Jianxiong Xu,Tie-hong Chen
Synthesis of hollow hydridosilica nanoparticles with mesoporous shell (HMHNs) employing a mixture of cationic fluorocarbon surfactant (FC-04) and nonionic triblock copolymer surfactant (P123) as template and triethoxysilane as silica precursor is reported. It is found that the content of the FC-04 in the surfactant mixture greatly influences the aggregation state of the FC-04 and P123 surfactant template and therefore influences the morphology of the synthesized hydridosilica nanoparticles. HMHNs can be synthesized with proper amount of FC-04 surfactants due to the formation of FC-04 and P123 complex micelle, where FC-04 surfactant locates at the outer shell and the P123 constructs the inner core. Ascribed to the inherent hydride sites within the HMHNs, facile immobilization of Pd nanoparticles is achieved by using HMHNs as both the reducing agent and scaffold. The lesser processes produce some smaller Pd nanoparticles (2–3 nm) within the pore voids and relatively larger Pd nanoparticles (10–15 nm) on the outer surfaces of HMHNs. The catalytic hydrogenation of 4-nitrophenol demonstrates that the heterogeneous Pd catalyst is efficient.
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高影响因子
SOLID STATE SCIENCES
·
2014
·
IF 1.679
Lijun Dong,Chunling Ge,Peiyong Qin,Yan Chen,Qinghong Xu
In this study, MgAl-LDHs (layered double hydroxides) intercalated with sodium dodecyl sulfate and outside surface modified with (3-aminopropyl)triethoxysilane (KH550) were prepared. The existence of organic part in LDHs improved immobilization efficiency and activity recovery of candida lipolytic lipase loaded. Also the positive charge in framework of LDHs was found to be beneficial to the enzyme immobilization. An immobilization efficiency of 56.4% and an activity recovery over 69.2% of the enzyme were obtained after it was loaded on the intercalated and modified LDHs, and catalytic activity of the immobilization can be kept at least five times. Moreover, the immobilized enzyme was found to have higher temperature resistance, wider pH value and better thermostability in reactive activity.
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高影响因子
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