Alexandria Engineering Journal
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2021
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IF 3.732
Yaya Wang,Yuqi Gu,Shun Yang
The reuse of support material still hamper the practical application of enzyme immobilization technology in wastewater treatment. Here, a novel strategy based on light-triggered reversible β-cyclodextrin (β-CD)-Azobenzene(Azo) host-guest interaction was developed. First, magnetic Fe 3 O 4 nanoparticles were coated with porous β-CD-containing polymers(PCDP), and then the Azo-modified enzyme was immobilized in normal condition. The immobilization would enhance the stability and catalytic performance of enzymes, and the easy separation from reaction medium could be available with external magnetic field. Over broad ranges of temperature and pH, the immobilized enzyme showed higher activity than free enzyme, and the phenol removal efficiency retained about 58.63% even after five cycles. Under UV light, the photoisomerization of Azo would lead to disassemble of β-CD-Azo interaction, resulting in the detachment of the enzyme, and phenol removal efficiency decreased to only 16%. The support materials could be recovered for continue enzyme immobilization, results based on cyclic process of enzyme immobilization and detachment strongly demonstrated the detachment of enzyme and excellent reusability of Fe 3 O 4 @PCDP. And this strategy was proved to be a practical method based on batch experiments on the removal of phenol by tyrosinase (Tyr)-based remediation.
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ACS Nano
·
2023
·
IF 17.1
Renjie Tan,Ke Zhang,Yifan Si,Shuai Zhang,Jieqiong Yang,Jinlian Hu
Long-term immobilization of joints can lead to disuse atrophy of the muscles in the joints. Oral nutrients are used clinically for rehabilitation and therapeutic purposes, but bioavailability and targeting are limited. Here, we report tea polyphenols (dietary polyphenols), sustained-release nanofilms that release tea polyphenols through slow local degradation of core–shell nanofibers in muscles. This dietary polyphenol does not require gastrointestinal consumption and multiple doses and can directly remove inflammatory factors and superoxide generated in muscle tissue during joint fixation. The quality of muscles is increased by 30%, and muscle movement function is effectively improved. Although nanofibers need to be implanted into muscles, they can improve bacterial infections after joint surgery. To investigate the biological mechanism of this core–shell nanomembrane prevention, we conducted further transcriptomic studies on muscle, confirming that in addition to achieving antioxidation and anti-inflammation by inhibiting TNF-α and NF-κB signaling pathways, tea polyphenol core–shell nanofibers can also promote muscle formation by activating the p-Akt signaling pathway.
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Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 35
·5873-5882
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IF 4.872
Jiayi Song,Ping Su,Ye Yang,Ting Wang,Yi Yang
The development of new strategies for stabilizing or improving the activities of enzymes has attracted considerable interest because of the wide range of potential applications and high cost of the native enzymes. In this study, a novel trypsin immobilization procedure in which the enzyme was immobilized using polyamidoamine (PAMAM) dendrimer modified magnetic nanoparticles as carriers through DNA-directed immobilization was developed for the first time. The optimal DNA base pairs and the optimal generation of PAMAM on the enzymatic activity were 24 bases and G3.0PAMAM, respectively. The trypsin binding capacity of the immobilized trypsin was 74.6 mg g−1, and the Km and Vmax values were 1.23 mM and 468.35 μmol min−1 mg protein−1, respectively. The immobilized trypsin reactor exhibited excellent reusability and stability properties without significant loss in enzymatic activity. Notably, the high level of enzymatic activity remained at more than 63% after 82 cycles, with only a slight decrease (above 88%) after 14 weeks of continuous use at one-week intervals. The high reversibility and reproducibility of this trypsin dynamic immobilization strategy were also investigated. The significantly improved digestion performance of the immobilized trypsin composites was further demonstrated by digesting cytochrome C, myoglobin and glycated hemoglobin, with sequence coverages of 78%, 99% and 88%, respectively, which were higher than those obtained for the free enzyme. This system therefore shows great potential in high throughput enzymatic assays and proteome analysis.
研究领域:
生物化学
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材料科学
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蛋白质组学
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JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2015
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IF 2.128
Xiaoyao Fei,Shaoyun Chen,Chunjie Huang,Dai Liu,Yongchun Zhang
Bovine carbonic anhydrase (BCA) has been immobilized on glycidoxypropyl-functionalized SBA-15 (GFS) for biomimetic carbonation reaction. GFS was characterized by N 2 adsorption–desorption, Fourier transform infrared analysis, 13 C and 29 Si CP MAS NMR spectroscopy. The immobilization time and material dose were optimized. The influences of pH value and temperature on the activity of free and immobilized BCA, storage stability and reusability of immobilized BCA were investigated using a para-nitrophenyl acetate (p-NPA) assay. The kinetic parameters K m and K cat / K m for free and immobilized BCA were found to be 2.4 mM and 896.4 M −1 s −1 , and 3.1 mM and 757.4 M −1 s −1 , respectively. It was observed that the immobilized BCA can retain around 91% of its initial activity up to 30 days at 4 °C, which showed higher storage stability than free BCA. Reusability studies suggested that immobilized BCA could keep high activity after 20 cycles of carbonation reaction. BCA immobilized on GFS (BCA-GFS) were used for hydration of CO 2 . The CO 2 sequestration capacity in terms of conversion CO 2 to calcium carbonate was quantified by organic elemental analysis. The amount of CaCO 3 precipitated over GFS-BCA was nearly the same as that precipitated over free BCA, 227 mg of CaCO 3 /mg of BCA-GFS as compared to CO 2 sequestration capacity of 241 mg of CaCO 3 /mg of BCA.
研究领域:
生物化学
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环境科学
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材料科学
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INDUSTRIAL CROPS AND PRODUCTS
·
2023
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IF 5.9
Chaozhong Xu,Liqun Sun,Shanshan Tong,Jia Ouyang,Xiaoli Gu
This study investigates the cellulase immobilization onto zeolitic imidazolate frameworks (ZIFs) to enable efficient cellulose hydrolysis at high solids loading. Different ZIF carriers (ZIF-8, ZIF-8-NH 2 , Fe 3 O 4 @ZIF-8, and Fe 3 O 4 @ZIF-8-NH 2 ) were prepared and characterized. The resulting ZIF-immobilized cellulases were subsequently analyzed for their loading capacity and enzyme activity , as well as their biochemical properties such as temperature stability, pH stability, storage stability, enzyme leaching, and enzyme kinetics . Results revealed that the cellulase immobilized on Fe 3 O 4 @ZIF-8-NH 2 exhibited an exceptional loading capacity of 359.89 mg/g and a relative enzyme activity of 69.39%. Remarkably, at a solid loading of 15% (w/w) and an enzyme dosage of 5 FPU/g cellulose, the Fe 3 O 4 @ZIF-8-NH 2 immobilized cellulase demonstrated a 20.44% higher hydrolysis yield compared to the free cellulase. Furthermore, this immobilized enzyme system displayed robust reusability, retaining 71.03% of its initial activity even after 10 cycles of reuse. A proposed mechanism of enhanced enzymatic hydrolysis by ZIF-immobilized cellulases was also presented. These findings have significant implications for the future application of ZIF-immobilized cellulases in efficient and cost-effective lignocellulosic bioconversion .
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Sustainability
·
2023
·Vol. 15
·期 18
·13382
·
IF 3.9
Qihang Dai,Ju Liu,Junjie Zheng,Bo Fu
Metal–organic frameworks (MOFs) hold great potential for efficient removal of particulate matter (PM) due to their high porosity and tunable surface groups. In this work, sustainable bacterial cellulose (BC) was employed as a substrate for Zr-based MOF (i.e., UiO-66-NH2) deposition. Specifically, the UiO-66-NH2@BC aerogel exhibits a multi-level pore structure with a specific surface area of 103 m2/g. Pristine BC aerogels indicated a removal efficiency of 50.6% for PM2.5, with a pressure drop of 22.8 Pa. While UiO-66-NH2@BC aerogels showed a PM2.5removal efficiency of 96.9%. The filtration mechanism can be assigned to the following reasons: (i) the interception/impaction of PM with the fibrous and porous aerogel network; and (ii) the presence of polar amine groups that boost electrostatic interactions between PM and MOFs. Moreover, as-prepared filters can be regenerated in a facile way with good reusability and long-term stability.
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TALANTA
·
2021
·
IF 6.057
Jia Liu,Hai-Xia Zhang,Yan-Ping Shi
With a dramatic increase in the incidence of obesity, it is significant to screen lipase inhibitors from traditional herbal medicines as drugs to treat obesity. Lipase inhibitors currently used to treat obesity possess the defects of toxicity and off-target effects. Thus, there is an urgent need to explore more safe, effective and targeted anti-obesity drugs from traditional herbal medicines. In this work, amino functionalized magnetic cellulose microsphere was employed as a novel support to immobilize lipase through covalent bonding. Characterizations from fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction demonstrated the successful preparation of the support. In comparison with the free lipase, the immobilized lipase manifested the excellent properties of a wider range for pH and temperature endurance, better pH, thermal, storage stability and reusability. Through investigating the kinetics performances of the immobilized lipase, the Michaelis-Menten constant was calculated to be 2.05 mM and its inhibition constant for orlistat was ascertained to be 40.74 μM. Eventually, the established strategy was applied to screen lipase inhibitors from 7 traditional herbal medicines and Crataegus pinnatifida Bunge was screened out due to its significant lipase inhibitory activity. To sum up, our newly established method not only developed a platform for efficiently discovering novel anti-obesity drugs from traditional herbal medicines, but also laid a solid foundation for successfully exploring undiscovered medicinal value of the traditional herbal medicines.
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PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
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2021
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IF 2.162
Shu Ye,Fan Zhang,Ying Xu,Yun Sun,Benwei Zhu,Fang Ni,Zhi Zhou,Zhong Yao
In this study, a series of acidic or alkaline polypeptide chains were designed and grafted onto DEG-AM resin using Fmoc solid-phase synthesis to study the relationship between enzyme conformation and carrier surface charge. β-d-glucosidase (βGase) was then immobilized onto these modified carriers by adsorption. Each form of immobilized βGase showed decreasing specific activity compared to that of the free. It could be attributed to both the changes in the enzyme conformation and the decrease in mass transfer efficiency. The optimum temperature of free βGase, DEG@B3-βGase is 55 °C, which of DEG@A3-βGase is 65 °C and they all have the highest activity at pH 5. The Ea values of free βGase, DEG@A3-βGase, and DEG@B3-βGase are 0.546 kJ/mol, 0.224 kJ/mol, and 0.446 kJ/mol, and the Km values were 1.30 mmol/L, 1.44 mmol/L and 2.63 mmol/L, respectively. It shows that free βGase and DEG@A3-βGase are more similar. Meanwhile, the free βGase (1.0 g/L, pH 5.0) stored at 4 °C has a shorter half-life (t1/2), which is only 9 days. However, the half-life of DEG@B3-βGase and DEG@A3-βGase is 20 days and over 60 days, indicating that the negative charged surface was conducive to maintenance of the structure and catalytic property of βGase.
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BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
·
2021
·Vol. 38
·期 2
·265-272
·
IF 1.232
Wang Jianfeng,Zhao Make,Lu Xiaoli,Gu Hongbing,Liu Baoquan
Glucose dehydrogenase, as an important biocatalyst, has been widely used in biosensors, especially in measuring blood glucose levels. The low stability of the enzyme limits its applications in clinics and industry. To improve the stability, graphene oxide nanoparticles were fabricated, characterized, and used to immobilize of glucose dehydrogenase. The nanoparticles were characterized by FTIR. The enzyme was covalently immobilized on the nanoparticles with the activation of glutaraldehyde. After optimizing the immobilization conditions, an immobilization yield of 92% and the activity recovery of 91% were achieved. The immobilized GDH was characterized and compared with the free enzyme. It showed 6.9-fold higher stability than that of the free enzyme after the immobilization. And after 25 cycles, the immobilized GDH remained 50% of the initial activity. These results indicated that the immobilization could broaden the applications of the GDH in the industry and clinic.
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Molecular Catalysis
·
2021
·
IF 5.062
Fei Peng,Qing-Sheng Chen,Min-Hua Zong,Wen-Yong Lou
Sequential immobilization of multiple enzymes can not merely improve the enzymatic activity and enzyme stability but also facilitate the recovery for reuse, well imitating the natural enzyme complexes. Here, we developed a novel approach of preparing sequential multienzyme nanomachineries based on chemical crosslinking and protein assembly, and then characterized the nanodevice. In the preparation process, Kg BDH-SC (SpyCatcher-fused (2 R ,3 R )-2,3-butanediol hydrogenase) was firstly immobilized onto the functionalized silicon dioxide nanoparticles with glutaraldehyde, and then FDH-ST (SpyTag-fused formate hydrogenase) was immobilized by the spontaneous protein reaction between SpyTag and SpyCatcher to achieve the sequential co-immobilized enzymes FDH-ST-SC- Kg BDH@SiO 2 , which can asymmetrically reduce 2-hydroxyacetophenone to ( R )-1-phenyl-1,2-ethanediol by cofactor regeneration. In comparison to the mixture of free enzymes, the sequential co-immobilized enzymes created under the design conditions performed around 50% activity recovery. Furthermore, FDH-ST-SC- Kg BDH@SiO 2 presented wider pH tolerance and greater organic solvents tolerance than the mixture of free enzymes as well as retained 51.7% of overall activity after being recycled eight times. Finally, the sequential co-immobilized enzyme enabled the biosynthesis of ( R )-1-phenyl-1,2-ethanediol from 80 mM 2-hydroxyacetophenone in the phosphate buffer reaction system, with 87.4% yield and over 99% optical purity.
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ANNALS OF NUCLEAR ENERGY
·
2020
·
IF 1.378
Guilin Wei,Fen Luo,Bingsheng Li,Yi Liu,Jingjun Yang,Zhentao Zhang,Yi Liu,Xiaoyan Shu,Yi Xie,Xirui Lu
This study mainly investigated the Bi 2 O 3 -B 2 O 3 -ZnO ternary glass to immobilize the iodine waste forms under low sintering temperatures (≤600 °C). Based on the results of Molecular Dynamic (MD) code GULP and amorphous fraction, the Bi 2 O 3 -B 2 O 3 -ZnO ternary glass with 20 mol% Bi 2 O 3 to be chosen to immobilize the sliver-coated silica gel with 10 wt%, 20 wt% and 30 wt% iodine loadings (total content of iodine is 8 wt%). The results show that the amorphous fraction are increased with temperature rising and the composition has dominant effect on determining the density results. The specimen with 20 wt% sintered at 600 °C has the highest amorphous fraction as 0.71. The SEM-EDS results reveal that part of iodine had been physically solidified in the form of white spots and the rest chemically solidified in the glassy phase. Our findings demonstrate the potential of Bi 2 O 3 -B 2 O 3 -ZnO ternary glass to immobilize iodine waste forms.
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ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Jianguo Liu,Nan Wang,Jianan Liu,Ming Li,Ying Xu,Chenguang Wang,Yanzhi Wang,Haoquan Zheng,Longlong Ma
Highly selective catalytic hydrogenation of alkynes to alkenes is a highly important reaction owing to its industrial and commercial application. Specifically, semihydrogenation of terminal alkynes has been more challenging than internal alkenes even using Lindlar catalysts. Also, the high reduction degree state metal-supported catalysts like Pd0/C, Pt0/C, and Ru0/C have been well-known to be used widely in hydrogenation due to their super activity. However, charcoal can absorb a large amount of water; Pd/C with 50% water is convenient on a large-scale synthesis. Charcoal generally bears oxygen groups on its surface, which are responsible for low selectivity and undesired products. Even typically, only 10–60% of the Pd metal atoms are exposed, they still suffer from poor stability in acids owing to leaching. Herein, we intend to design active and stable metal catalysts with features as the following to avoid leaching: having strong interaction with the support and coordinatively unsaturated metal sites or low valence state metals physically isolated from the acid environment. Herein, a highly efficient semihydrogenation of terminal alkynes to produce alkenes has been realized using a heterogeneous Pd(II)/POP-GIEC catalyst, imine-linked, crystalline, and porous organic polymer supporter modified by coordination of Pd(OAc)2 to its walls under mild conditions. Surprisingly, for the first time, modified POP-supported low reduction degree PdII catalysts were synthesized efficiently, and they were successfully used in semihydrogenation of terminal alkynes. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the para, ortho, and meta position of aromatic alkynes. The substrate having a substituent with the functionality of fluoro protected at the meta position was semihydrogenated with a high alkyne conversion of 100% and olefin selectivity (up to 99%).
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