CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2019
·Vol. 35
·期 2
·235-238
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IF 1.071
Jiang Ling,Ye Wenting,Su Weike
A series of highly functionalized 1,4-dihydropyridines was synthesized via one-pot multicomponent reactions of aromatic aldehyde, malononitrile and N -methyl-1-(methylthio)-2-nitroethenamine using Porcine pancreatic lipase(PPL) as catalyst in DMSO. This protocol is featured by mild reaction conditions, simple operation and environmental acceptability.
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BIORESOURCE TECHNOLOGY
·
2018
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IF 5.807
Youran Li,Hanrong Wang,Jiawei Lu,Alex Chu,Liang Zhang,Zhongyang Ding,Sha Xu,Zhenghua Gu,Guiyang Shi
The application of immobilized lipase in the enzymatic production of biodiesel has shown numerous advantages. In this study, surface of Polyacrylonitrile (PAN) hollow membrane was first modified using nitrile-click chemistry in order to fit for interaction with enzyme proteins. Then sodium alginate (SA) was introduced and the membrane was post-treated by CaCl 2 . When the prepared PAN-PEI-SA-CaCl 2 was used for lipase immobilization, the protein loading was 36.90 mg/g, and the enzyme activity reached up to 54.47 U/g, which was 2.5 times as much as that of Novozym® 435. As a result, the constructed immobilized lipase obtained a maximum biodiesel yield of 78.5%, which was 2.4 times that of the Novozym® 435 in transesterification reactions. Moreover, the biodiesel yield decreased by only 11% after the immobilized enzyme was continuously used for 20 times. This study exhibits that this technic has broad application prospects in the field of conversion of biomass resources.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Wenfeng Zhou,Wei Zhuang,Lei Ge,Zhenfu Wang,Jinglan Wu,Huanqing Niu,Dong Liu,Chenjie Zhu,Yong Chen,Hanjie Ying
Graphene oxide (GO) with oxygen containing functional groups can be selectively modified by small biomolecules to achieve heterogeneous surface properties. To achieve a hyper-enzymatic activity, the surface functionality of GO should be tailored to the orientation adsorption of the Thermomyces lanuginosus (TL) lipase , and the active center can be covered by a relatively hydrophobic helical lid for protection. In this work, amino acids were used to interact with GO through reduction reaction, hydrophobic forces , electrostatic forces , or hydrogen bonding to alter the surface hydrophobicity and charge density. Characterization of the structure and surface properties confirmed that the GO samples decorated with phenylalanine (Phe) and glutamic acid (Glu) exhibited superior hydrophobicity than other modifications, whereas tryptophan (Trp) and cysteine (Cys) provided weaker reduction effects on GO. Moreover, the zeta potential of the samples modified by amino acids of lysine (Lys) and arginine (Arg) is higher than other modified samples. The adsorption amount of lipase on Glu-GO reached 172 mg/g and the relative enzymatic activity reached up to 200%. The thermodynamic data and the Freundlich isotherm model fitting showed that the lipase adsorption process on modified samples was spontaneous, endothermic and entropy increase.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Haishan Qi,Yan Du,Guannan Hu,Lei Zhang
In this work, poly(carboxybetaine methacrylate) as an extremely hydrophilic polymer was modified on superparamagnetic Fe 3 O 4 nanoparticles (pCB-Fe 3 O 4 ), which were employed to immobilize porcine pancreatic lipase . The properties of immobilized lipase were investigated in comparison with the free enzyme counterpart. Enzymatic stability, reusability, and activity of the immobilized lipase were found significantly superior to that of the free lipase. In particular, at an elevated temperature of 60 °C, the immobilized lipase retained 50% of its initial activity after 150 min, while the free enzyme displayed only one-third activity of the immobilized enzyme . Besides, the immobilized lipase retained >60% of its initial activity after 7 cycles. Furthermore, the value of K cat / K m indicated the catalytic efficiency of the immobilized lipase was increased by 50% compared to that of the free one. The pCB-Fe 3 O 4 particles displayed non-cytotoxicity, while the naked Fe 3 O 4 particles caused only 50% viability of NIH 3T3 cells. These results showed that pCB-Fe 3 O 4 composite particles had higher efficiency and improved stability for lipase immobilization, which are more promising for industrial scale up of biocatalytic systems with excellent biocompatibility.
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LWT-FOOD SCIENCE AND TECHNOLOGY
·
2022
·
IF 6.056
Jinhang Chen,Yi Zhang,Huaying Zhong,Hao Zhu,Hongxun Wang,Kheng-Lim Goh,Juntao Zhang,Mingming Zheng
Green and effective synthesis of flavor esters is a long-term interest in food, cosmetic and pharmaceutical industries. Here, an immobilized lipase microarray was prepared by immobilizing lipase CSL on hydrophobically modified ordered mesoporous silicon (CSL@OMS-C 8 ) for the enzymatic production of cinnamic esters with different flavors. The results showed that the CSL@OMS-C 8 , with an immobilization capacity of 249.3 ± 11.1 mg/g, exhibited 1.6 times higher catalytic activity than that of free lipase at the optimum temperature of 70 °C. The maximum yield of benzyl cinnamate reached 97.3% in 2 h with the corresponding CE value of 650.5 μmol/g · h, leading to the highest record compared to the current literature. Besides, the CSL@OMS-C 8 could maintain 81.4 ± 1.1% conversion for cinnamic acid after five-cycle reuse, thus revealing the high stability and reusability of immobilized lipase. Finally, the broad applicability of the immobilized lipase microarray was confirmed by its capacity to successfully catalyze the synthesis of methyl cinnamate, ethyl cinnamate, butyl cinnamate, geranyl cinnamate and isoamyl cinnamate. This study reveals new insights on the efficient and sustainable enzymatic approach to produce natural cinnamic acid flavor esters and, consequently, could pave the way for the natural and clean production in food industries.
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FOOD HYDROCOLLOIDS
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2022
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IF 11.504
Yan-Wei Liu,Qing-Hao Li,Guo-Qing Huang,Jun-Xia Xiao
The complexation between Aspergillus oryzae lipase (AOL) and chitosan (CS) was investigated as a function of phase separation pH and the resultant complexes were characterized. The results indicated that AOL and CS could assemble micron-sized complexes in pHs 5.0–6.5 and the strongest interaction occurred in pH 5.5. QCM-D analysis revealed that association in pH 5.5 generated a viscoelastic hydrated adlayer with the largest thickness. ITC analysis indicated that the interaction between AOL and CS was driven by enthalpy and the highest one-site binding stoichiometry was recorded in pH 5.5, which was 1.3 and 7.9 times higher than in pHs 5.0 and 6.0, respectively. Both electrostatic attraction and hydrophobic interaction played dominant role in AOL-CS complexation. Compared with free AOL, the interaction with CS reduced its α-helix content, increased its β-sheet content, and changed its tertiary structure; besides, the AOL-CS complex assembled in pH 5.5 exhibited the highest contact angle up to 85.5° and demonstrated enhanced lipase activity retention after incubation in pHs 3.0–9.0 and temperatures 35–75 °C. Hence, the AOL-CS complexes could be used to construct novel biphasic catalysis media based on O/W Pickering emulsions .
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MATERIALS & DESIGN
·
2022
·
IF 9.417
Meng-Dan Gong,Xin-Jiang Pei,Guang-Xu Duan,Gao-Ying Zhi,Zhi-Qin Liu,Dong-Hao Zhang
To firmly immobilize enzyme on carrier surface without covalent attachment as well as improve enzyme stability, an effective method of enzyme immobilization was developed by encapsulating enzyme into nano-molecular cages on the surface of magnetic microspheres. Compared with physical adsorption, molecular cage encapsulation could fix lipase much more firmly and make lipase more active. Then, this study focused on investigating the effects of cage hydrophobicity and cage size on lipase encapsulation respectively by adjusting the log P value (from −0.85 to 1.28) and chain length (from 2.93 to 5.41 nm) of crosslinkers. It showed that lipase activity was dependent on the hydrophobicity of cage. Moreover, the size of cage had important effect on lipase loading amount, and a big cage was conducive to house lipase molecule. The structural analysis indicated that molecular cages could retain the active conformation of lipase and increase its structural rigidity. Molecular dynamics simulation revealed the interaction between the lid domain of lipase and molecular cage, leading to the higher activity of encapsulated lipase (63.6 U/mg) than that of free lipase (50.6 U/mg). Besides, the encapsulated lipase showed more than twice higher thermal stability and almost 8 times higher tolerance to denaturant than the adsorbed lipase.
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Catalysts
·
2021
·Vol. 11
·期 12
·1463
·
IF 4.146
Honghai Wang,Wenda Yue,Shuling Zhang,Yu Zhang,Chunli Li,Weiyi Su
Silica xerogels have been proposed as a potential support to immobilize enzymes. Improving xerogels’ interactions with such enzymes and their mechanical strengths is critical to their practical applications. Herein, based on the mussel-inspired chemistry, we demonstrated a simple and highly effective strategy for stabilizing enzymes embedded inside silica xerogels by a polydopamine (PDA) coating through in-situ polymerization. The modified silica xerogels were characterized by scanning and transmission electron microscopy, Fourier tranform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and pore structure analyses. When the PDA-modified silica xerogels were used to immobilize enzymes ofCandida antarcticalipase B (CALB), they exhibited a high loading ability of 45.6 mg/gsupport, which was higher than that of immobilized CALB in silica xerogels (28.5 mg/gsupport). The immobilized CALB of the PDA-modified silica xerogels retained 71.4% of their initial activities after 90 days of storage, whereas the free CALB retained only 30.2%. Moreover, compared with the immobilization of enzymes in silica xerogels, the mechanical properties, thermal stability and reusability of enzymes immobilized in PDA-modified silica xerogels were also improved significantly. These advantages indicate that the new hybrid material can be used as a low-cost and effective immobilized-enzyme support.Keywords:Candida antarcticalipase B;silica xerogel;enzyme immobilization;polydopamine;modification
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PROCESS BIOCHEMISTRY
·
2021
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IF 3.757
Wenfeng Zhou,Xiaohong Zhou,Wei Zhuang,Rijia Lin,Ye Zhao,Lei Ge,Ming Li,Jinglan Wu,Pengpeng Yang,Hongman Zhang,Chenjie Zhu,Hanjie Ying
To effectively immobilize an enzyme while maintaining its high activity and stability, the design of supports with controlled geometric structures and heterogeneous surface properties is desirable. Towards this goal, heterogeneous titanium dioxide (TiO 2 ) surfaces with controlled pore sizes were synthesized in this study and used to efficiently immobilize lipase. The immobilized lipase activity increased by a factor of 1.31 with an increase in the TiO 2 pore size from 11.46 to 21.14 nm. The highest protein loading of 15.52 mg/g was achieved in ethenyl triethoxy silane (ETS)-modified TiO 2 (E-P25) after immobilizing the enzymes at 30 ℃, pH 7.33 for 3 h and using a protein concentration in solution of 0.176 mg/mL. Among the different surface functionalities, the highest activity yield of 428.04 % was accomplished by using TiO 2 calcinated at 650 ℃ and modified by ETS as immobilization support. The immobilized enzymes showed excellent storage stability and retained almost 95 % of their activity after being stored at 4 ℃ for 8 weeks. This research provides experimental evidence that highlights the importance of studying of enzyme immobilization on the supports with synergistically designed geometric structures and surface chemical properties.
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ENZYME AND MICROBIAL TECHNOLOGY
·
2021
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IF 3.493
Miao Tian,Shaowei Huang,Zhiyuan Wang,Junying Fu,Pengmei Lv,Changlin Miao,Tao Liu,Lingmei Yang,Wen Luo
The propeptide is a short sequence that facilitates protein folding. In this study, four highly active Rhizomucor miehei lipase (RML) mutants were obtained through saturation mutagenesis at three propeptide positions: Ser8, Pro35, and Pro47. The enzyme activities of mutants P35 N, P47 G, P47 N, and S8E/P35S/P47A observed at 40 °C, and pH 8.0 were 10.19, 7.53, 6.15, and 8.24 times of that wild-type RML, respectively. The S8E/P35S/P47A mutant showed good thermostability. After incubation at 40 °C for 1 h, 98.98 % of its initial activity remained, whereas wild-type RML retained only 78.76 %. This result indicated that the enhancement of hydrophilicity of 35- and 47- amino-acid residues could promote the interaction between the propeptide and the mature peptide and the enzyme activity and expression level. Highly conserved sites had a more significant impact on enzyme performance than did other sites, similar to the Pro35 and Pro47 mutants showed in this study. This study provides a new idea for protein modification: enzyme performance can be improved through propeptide regulation.
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Food Bioscience
·
2021
·
IF 4.24
Jian-Feng Zhou,Wen-Jun Wang,Zhong-Ping Yin,Guo-Dong Zheng,Ji-Guang Chen,Jing-En Li,Ling-Li Chen,Qing-Feng Zhang
The inhibitory activity of quercetin on pancreatic lipase was investigated in both vitro and vivo. Quercetin exhibited inhibitory effect on pancreatic lipase with IC 50 value of 70 μg/mL. Inhibitory kinetics indicated that quercetin was more like a mixed-type (non-competitive) inhibitor of pancreatic lipase. Quercetin induced the endogenous fluorescence quenching of lipase, which suggested the interaction between them. The binding constant and the number of the binding sites were further calculated. Molecular docking results showed that quercetin had a binding site on lipase near the active pocket. The binding of quercetin on lipase would affect its conformation, thereby decreasing the affinity between the substrate and the enzyme . In vivo studies showed that pre-administration with 5 and 10 mg/kg bwt quercetin could significantly reduce fat absorption in rat. The inhibition of quercetin on lipase can last at least 2 h in vivo. Correspondingly, quercetin significantly increased fat excretion in rat feces. The change trends of fat and quercetin content in rat feces were similar.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2021
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IF 5.268
Hongbo Suo,Moju Li,Renmin Liu,Lili Xu
In this study, imidazolium-based ionic liquid with [tf 2 N] − as the anion was successfully grafted to magnetic polydopamine nanoparticles (MPDA). The prepared materials were well characterized and used as supports for lipase immobilization. The immobilized lipase (PPL-ILs-MPDA) exhibited excellent activity and stability. The specific activity of PPL-ILs-MPDA was 2.15 and 1.49 folds higher than that of free PPL and PPL-MPDA. In addition, after 10 rounds of reuse, the residual activity of PPL-ILs-MPDA was 86.2 % higher than that of PPL-MPDA (75.4 %). Furthermore, the kinetic assay indicated that the affinity between PPL-ILs-MPDA and substrate had increased. Analysis of the secondary structure using circular dichroism was used to explain the mechanism underlying the improvement in the performance of PPL-ILs-MPDA. In addition, the immobilized lipase can be easily separated from the reaction system with a magnet. The observations regarding the development of new supports for lipase immobilization may provide new ideas regarding further studies in this field.
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