ENZYME AND MICROBIAL TECHNOLOGY
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2023
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IF 3.4
Shuaifeng Liu,Meng Zhang,Dengwang Hong,Zemin Fang,Yazhong Xiao,Wei Fang,Xuecheng Zhang
β-Glucosidases with high catalytic activity and glucose tolerant properties possess promising applications in lignocellulose-based industries. To obtain enzymes possessing these properties, a semi-rational strategy was employed to engineer the glucose-stimulating β-glucosidase Bgl2A for high cellobiose hydrolysis activity. A total of 18 mutants were constructed. A22S, V224D, and A22S/V224D exhibited high specific activities of 272.06, 237.60, and 239.29 U/mg toward cellobiose, which were 2.5- to 2.8-fold of Bgl2A. A22S, V224D, and A22S/V224D exhibited increased k cat values, which were 2.7- to 3.1-fold of Bgl2A. A22S and V224D maintained glucose-stimulating property, whereas A22S/V224D lost it. Using 150 g/L cellobiose as the substrate, the amount of glucose produced by A22S was the highest, yielding 129.70 g/L glucose after 3 h reaction at 35 °C. The synergistic effects of the engineered enzymes with commercial cellulase on hydrolyzing cellulose were investigated. Supplemented with the commercial cellulase and A22S, the highest glucose amount of 23.30 g/L was yielded from cellulose with hydrolysis rate of 21.02 %. Given its high cellobiose hydrolysis activity and glucose-stimulating properties, A22S can be used as a component of enzyme cocktail to match mesophilic cellulases for efficient cellulose hydrolysis.
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EUROPEAN POLYMER JOURNAL
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2023
·
IF 6
Yang Liu,Chuang Lang,Yaping Ding,Siyu Sun,Guangwei Sun
Chitosan (CS)/β-sodium glycerophosphate (β-GP) gels have low temperature sensitivity, which limits their biomedical application. The protonation and deprotonation of the CS amino groups are regulated by pH. It is possible to accelerate thermosensitive gelation by increasing the pH of the CS solution to maximize the degree of CS amino deprotonation and enhance hydrophobic interactions. In this study, a CS solution with a higher pH (HpHCS; pH 6.19, close to pKa 6.2) was obtained by means of the consumption of hydrogen ions using excessive chitosan. Raman spectroscopy showed that strong hydrogen bonds might exist in HpHCS. Gelation was accelerated significantly at 37 °C using HpHCS due to the decreased sol–gel transition temperature. Support vector machine and t-distributed stochastic neighbor embedding analyses confirmed that the gel derived from HpHCS was significantly different from that of the other groups. In addition, the HpHCS gel exhibited a low degradation rate and low cytotoxicity. Furthermore, a mathematical equation was established to predict the gelation time of HpHCS/β-GP at 37 °C. A better concentration of HpHCS for in vivo injection was obtained due to the shorter gelation time and lower viscosity. We found that human mesenchymal stem cells survived and proliferated in vitro in the HpHCS/β-GP hydrogel. Therefore, this study provides an optimized HpHCS solution with enhanced deprotonation for accelerated thermosensitive gelation with β-GP.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Mengmeng Jia,Wen-Hai Zhang,Xuehong Zhang,Ming-Jie Yin,Shuo Gu,Xinmiao Hu,Hongxia Guo
Preparation of membranes with loose structure is often required for excellent small organic molecules desalination, but remains a grand challenge. In this work, a loose thin film composite (TFC) membrane was fabricated via interfacial polymerization of hydroxypropyl-β-cyclodextrin (HP-β-CD) and trimesoyl chloride. Besides, tannic acid was added in the aqueous phase to boost the rejection rate of the membrane by reducing the “outer space” distance among HP-β-CD. The resulting membrane exhibited an optimal permeability of 82.9 L m −2 h −1 bar −1 along with antibiotic desalination efficiency (94.8 % for tetracycline hydrochloride and 8.5% for NaCl). Moreover, experiment results demonstrate that the tannic acid incorporated HP-β-CD-based polyester (TIHP) membrane was also endowed with enhanced chlorine resistance and antifouling ability deriving from its rich hydroxyl and polyester structures, which makes the membrane promising for the purification of antibiotics in pharmaceutical fields.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
·
IF 8.2
Cuicui Ding,Mengdie Tian,Yue Wang,Kuan Cheng,Yifan Yi,Min Zhang
The effect of carbohydrates on collagen self-assembly behavior has been widely investigated because of their regulation on collagen fibrogenesis in vivo. In this paper, β-cyclodextrin (β-CD) was selected as an external disturbance to explore its intrinsic regulating mechanism on collagen self-assembly. The results of fibrogenesis kinetics indicated that β-CD had a bilateral regulation on collagen self-aggregation process, which was closely related to the content of β-CD: collagen protofibrils with low β-CD content were less aggregated compared to collagen protofibrils with high β-CD content. However, typical periodic stripes of ~67 nm on collagen fibrils were observed from transmission electron microscope (TEM), indicating that β-CD did not disturb the lateral arrangement of collagen molecules to form a 1/4 staggered structure. Correspondingly, the degree of aggregation of collagen self-assembled fibrils was closely correlated with the addition of β-CD content, as confirmed by field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). In addition, collagen/β-CD fibrillar hydrogel had good thermal stability and cytocompatibility. These results provide a better understanding of how to construct a structurally reliable collagen/β-CD fibrillar hydrogel as a biomedical material in a β-CD-regulated environment.
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JOURNAL OF BIOTECHNOLOGY
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2023
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IF 4.1
Zekang Wang,Haiyan Chen,Yuyue Qin,Tianqing Lan
In this study, the Fenton oxidized lignin was prepared to investigate the effect of Fenton oxidation modification on the activity of lignin immobilized β-glucosidase (β-GL). The results demonstrated that Fenton oxidation could significantly improve the activity and stability of immobilized β-GL. This is because the Fenton oxidation increased the electrostatic, hydrogen bonding, and hydrophobic forces between lignin and β-GL, resulting in increased lignin adsorption onto β-GL. The Fenton oxidation also changed the chemical structure of lignin, altering the lignin-β-GL binding site and reducing the negative effect of lignin on the β-GL catalytic domain . This research will improve understanding of the effect of Fenton lignin oxidation on immobilized β-GL activity and expand the use of lignin in enzyme immobilization .
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INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
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2018
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IF 1.333
Wei Wu,Jianjun Fang,Wenjuan Liu,Yunhui Zhao,Tianlong Huang,Yanmin Zhao,Xiaofei Li,Jiale Cui,Yun Yang,Zhihua Zhou
Biodegradable polymer/bioceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. A novel degradable scaffold material for bone tissue repairing was developed by combining 1,4-butanediamin-modified poly(lactide-co-glycolide) (BMPLGA) with nano-biaoactive glass and nano-β-tricalcium phosphate (NBAG-β-TCP) . The effects of the inorganic filler content on the morphology, water adsorption, and compressive strength of the nanocomposite scaffolds were investigated. The nanocomposite scaffolds showed an interconnected pore structure with the pore size ranging from 50 to 200 μm. The compressive strength and the water adsorption ability were enhanced with increasing content of the inorganic fillers. The cell proliferation of fibroblast was significantly improved after three and seven days of culture on BMPLGA/NBAG-β-TCP films in comparison with BMPLGA films. The BMPLGA/NBAG-β-TCP composites have a wide application as a potential biomaterial in medical field.
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MATERIALS SCIENCE FORUM
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2018
·
IF 0
Rui Min Zhao,Xian Ya Xue,You Fa Wang
Porous Hyaluronan/β-tricalcium phosphate composite scaffolds were synthesized through lyophilizing and subsequent heterogeneous crosslinking method. The morphology of the composite scaffolds were investigated by scanning electron microscopy (SEM). The swelling behavior, mechanical property, degradation behavior and cell adhesion ability of samples were also studied. The results revealed that hyaluronan mainly contributed to the polymer matrix and water adsorption, whereas β-TCP acted as a reinforcement to strengthen the porous structure, while too much β-TCP would make the structure collapse. The pose size of obtained scaffolds ranges from100μm to 200μm and the porosity decreased with the increase of β-TCP content. The degradation behavior and cell adhesion test indicated that increasing hyaluronan concentration can effectively improve the degradability of scaffolds and the incorporation of β-TCP improved the cell adhesion performance. Thus a simple way to prepare hyaluronan-based composite scaffolds was provided, which could be potentially used as an tissue engineering material.
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Applied Sciences-Basel
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2018
·Vol. 8
·期 9
·1481
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IF 1.689
Yao Ren,Haoyu Xie,Li Liu,Dongying Jia,Kai Yao,Yuanlong Chi
β-glucan extract (GE) was obtained from highland barley bran using alkaline–acid–alcohol extraction method. The stability, solubility, foaming ability, and prebiotics characteristics of GE were assessed consecutively. GE demonstrated excellent heat stability (hardly degraded at 220 °C) and pH stability, especially at neutral or alkaline condition, and its solubility was significantly influenced by temperature instead of pH or NaCl, achieving 0.91 g/100 g at 100 °C. Good foaming ability and foam stability of GE were observed during low temperatures (≤40 °C), neutral or alkaline condition. GE indicated a strong anti-digestibility capacity of resisting the hydrolysis of α-amylase and simulated human gastric acid. Interestingly, GE could effectively promote the growth ofLactobacillus bulgaricusandBifidobacterium adolescentis, which was close to fructooligosaccharide. The results of this study could offer valuable information for the application of β-glucan from highland barley as prebiotics in promoting human intestinal health metabolism.Keywords:β-glucan;highland barley;processing characteristics;prebiotics
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INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
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2018
·Vol. 42
·期 1
·61-70
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IF 2.784
Yuhuan Ma,Wenwei Zheng,Houhuang Chen,Xiang Shao,Pingdong Lin,Xianxiang Liu,Xihai Li,Hongzhi Ye
The present study investigated the mechanism underlying the effects of glucosamine (GlcN) on the proliferation of chondrocytes isolated from the knee cartilage of Sprague‑Dawley rats. Chondrocytes were treated with various concentrations of GlcN or without GlcN. The effects of GlcN on chondrocyte proliferation were determined using reverse transcription‑polymerase chain reaction, western blot analysis and immunohistochemistry. The results indicated that GlcN significantly improved chondrocyte viability, accelerated G1/S transition during progression of the cell cycle and promoted the expression of cell cycle regulatory proteins, including cyclin D1, cyclin‑dependent kinase (CDK)4 and CDK6, thus indicating that GlcN may promote chondrocyte proliferation. Furthermore, GlcN upregulated the expression levels of Wnt‑4, Frizzled‑2 and β‑catenin, and downregulated the expression of glycogen synthase kinase‑3. GlcN also promoted β‑catenin translocation; β‑catenin is able to activate numerous downstream target genes, including cyclin D1. To determine the role of the Wnt/β‑catenin signaling pathway in chondrocyte proliferation, the Wnt/β‑catenin signaling pathway was inhibited using Dickkopf‑1 (DKK‑1), after which chondrocytes were treated with GlcN. The results demonstrated that the expression levels of β‑catenin and cyclin D1 were decreased in chondrocytes treated with DKK‑1 and GlcN. These results suggested that GlcN may promote chondrocyte proliferation via the Wnt/β‑catenin signaling pathway.
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Food Science & Nutrition
·
2018
·Vol. 6
·期 4
·1053-1064
·
IF 1.521
Shuang Ma,Xu Yang,Changhui Zhao,Mingruo Guo
Effect of ultrasound treatment on the physicochemical properties and structure of β-lactoglobulin were investigated. β-Lactoglobulin was treated with ultrasound at different amplitudes, temperatures, and durations. The surface hydrophobicity and free sulfhydryl group of β-lactoglobulin were significantly increased after ultrasound treatment ( p < .05). The maximal surface hydrophobicity and free sulfhydryl group were 5,812.08 and 5.97 μmol/g, respectively. Ultrasound treatment changed the physicochemical properties of β-lactoglobulin including particle size (from 1.21 ± 0.05 nm to 1.66 ± 0.03 nm), absolute zeta potential (from 15.47 ± 1.60 mV to 27.63 ± 3.30 mV), and solubility (from 84.66% to 95.17%). Ultrasound treatment increased α-helix and β-sheet structures of β-lactoglobulin. Intrinsic fluorescence intensity of ultrasound-treated β-lactoglobulin was increased with shift of λ max from 334 to 329 nm. UV absorption of β-lactoglobulin was decreased with shift of λ max from 288 to 285 nm after ultrasound treatment. There were no significant changes in high-performance liquid chromatography and protein electrophoretic patterns. These findings indicated that ultrasound treatment had high potential in modifying the physiochemical and structural properties of β-lactoglobulin for industrial applications.
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Journal of the Taiwan Institute of Chemical Engineers
·
2017
·
IF 4.217
Junlei Zhang,Zhen Ma
Visible-light-driven photocatalysis for removing industrial dyes and antibiotics in waste water has attracted much interest. New catalysts with enhanced photocatalytic performance have been actively sought. Herein, via a simple sequential precipitation method, AgI nanoparticles were anchored onto micron-sized β-Ag 2 MoO 4 particles to form AgI/β-Ag 2 MoO 4 p–n heterojunctions. These heterojunctions exhibited remarkably upgraded activities in the visible-light-driven photocatalytic degradation of rhodamine B, methyl orange, and tetracycline hydrochloride compared with pristine AgI and β-Ag 2 MoO 4 . The enhanced photocatalytic activity can be mainly attributed to the tight heterojunction structure and well matched energy band that may facilitate the separation and transfer of photogenerated electron–hole pairs. Photogenerated holes (h + ) and superoxide radical anions (•O 2 − ) were found to be the main active species. A possible photocatalytic mechanism was proposed.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
·
IF 3.671
Ke-Lin Chen,Ling Gan,Zhen-Hua Wu,Jin-Fang Qin,Wen-Xia Liao,Huang Tang
A series of 4- substituted sampangine derivatives (4-aminoalkylaminosampangine Ar–NH(CH 2 ) n NR 1 R 2 ) has been designed, synthesized, and tested for their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and β-myloid (Aβ) aggregation. The synthetic compounds exhibited high AChE inhibitory activity and a significant in vitro inhibitory potency toward the self-induced Aβ aggregation. While, treatment of SH-SY5Y cells overexpressing the Swedish mutant form of human β-amyloid precursor protein (APPsw) with derivatives was associated with significant reduction of Aβ42 secretion levels. Moreover, most of the synthetic compounds were predicted to be able to cross the blood-brain barrier (BBB) to reach their targets in the central nervous system (CNS) according to a parallel artificial membrane permeation assay for BBB. The result encourages us to study this class of compounds thoroughly and systematically.
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