Foods
·
2023
·Vol. 12
·期 18
·3350
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IF 5.2
Yuhan Wang,Hongjuan Mo,Zhihong Hu,Bingjie Liu,Zhiqian Zhang,Yaowei Fang,Xiaoyue Hou,Shu Liu,Guang Yang
Chitooligosaccharides (COS), a high-value chitosan derivative, have many applications in food, pharmaceuticals, cosmetics and agriculture owing to their unique biological activities. Chitosanase, which catalyzes the hydrolysis of chitosan, can cleave β-1,4 linkages to produce COS. In this study, a chitosanase-producingBacillus paramycoidesBP-N07 was isolated from marine mud samples. The chitosanase enzyme (BpCSN) activity was 2648.66 ± 20.45 U/mL at 52 h and was able to effectively degrade chitosan. The molecular weight of purifiedBpCSN was approximately 37 kDa. The yield and enzyme activity ofBpCSN were 0.41 mg/mL and 8133.17 ± 47.83 U/mg, respectively. The optimum temperature and pH ofBpCSN were 50 °C and 6.0, respectively. The results of the high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) of chitosan treated withBpCSN for 3 h showed that it is an endo-chitosanase, and the main degradation products were chitobiose, chitotriose and chitotetraose.BpCSN was used for the preparation of oligosaccharides: 1.0 mg enzyme converted 10.0 g chitosan with 2% acetic acid into oligosaccharides in 3 h at 50 °C. In summary, this paper reports thatBpCSN has wide adaptability to temperature and pH and high activity for hydrolyzing chitosan substrates. Thus,BpCSN is a chitosan decomposer that can be used for producing chitooligosaccharides industrially.Keywords:Bacillus paramycoides;chitosanase;chitosan;chitosan oligosaccharides;enzymatic properties
研究领域:
微生物学
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生物技术
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生物化学
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PubMed
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2024
·
IF 4.1
Bingbing Xia,Zhiwei Li,Jinao Wei,Ganpeng Hu,Jingwen Yang,Hongbin Zhang,Xueqin Hu
Dextranases are hydrolases that exclusively catalyze the disruption of α−1,6 glycosidic bonds . A series of variant enzymes were obtained by comparing the sequences of dextranases from different sources and introducing sequence substitutions. A correlation was found between the number of amino acids in the 397–401 region and the hydrolytic process. When there were no more than 5 amino acids in the 397–401 region, the enzyme first hydrolyzed the dextran T70 to a low molecular weight dextran with a molecular weight of about 5000, then IMOs 1 appeared in the system if the degradation continued, showing a clear sequential relationship. And when there are more than 5 amino acids in the 397–401 region, IMOs were produced at the beginning of hydrolysis and continue to increase throughout the hydrolytic process. At the same time, we investigated the enzymatic properties of the variants and found that the hydrolytic rate of A-Ca was 11 times higher than that of the original enzyme. The proportion of IMOs produced by A-Ca was 80.68%, which was nearly10% higher than the original enzyme, providing a new enzyme for the industrial preparation of IMOs.
研究领域:
生物化学
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酶学
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分子生物学
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PubMed
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BIOSENSORS & BIOELECTRONICS
·
2025
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IF 10.5
Yuwei Zhang,Jiawen Han,Shuai Qin,Juan Wang,Zhihua Lv,Shaojun Dong,Daoqing Fan
Exploring novel versatile nanozymes for multi-signal biosensing and cellular application is one of the most promising directions to meet the diversified requirements in this field. Herein, by harnessing coordination-propelled self-assembly between Fe (II) and DNAs, we prepared Fe-DNA nanospheres (Fe-DNA NSs) via a cost-effective one-step hydrothermal method, and pioneered the application of its excellent POD-mimicking property to fluorescent substrates. Initially, we investigated its enzyme-like activity using TMB as canonical colorimetric substrate and screened its catalytic oxidation effects towards different fluorescent substrates, such as T-HCl, AR, OPD and Sc, respectively. Afterwards, by virtue of the contrary fluorescent changes of Sc (decreased FI 465 ) and OPD (increased FI 562 ) and the cooperative effects of FRET/IFE between them, we devised the first universal Fe-DNA nanospheres-based ratiometric fluorescent (RF) platform. Taking H 2 O 2 and glucose as model targets, two RF biosensors based on the alternative direct-nanozyme-catalysis and enzyme/nanozyme-tandem-catalysis were rationally fabricated, respectively. And we further exploited them to evaluate the quality of commercial contact lens care solution, and sensitively determine the blood glucose level of human. Moreover, corresponding cytotoxicity experiments adequately proved the superior biocompatibility of Fe-DNA NSs over most inorganic nanozymes. Furthermore, taking Cy5-labelled A20 strands as templates, we synthesized small-sized (∼60 nm) Fe-DNA fluorescent nanozyme and achieved efficient cellular delivery/imaging. This work not only offered a valid prototype for operating multi-signal-responsive nanozymatic biosensors, but also opened unique avenues for the bio-applications of nucleic acids-originated fluorescent nanozymes in cellular imaging and biotherapy.
研究领域:
生物化学
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纳米医学
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生物传感
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细胞生物学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
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IF 8.2
Ruyu Li,Yu Zhao,Tingting Zhang,Zejin Ju,Xianbing Ji,Yanshuai Cui,Longgang Wang,Haiyan Xiao
The development of nanozymes using noble metal nanoparticles to replace natural peroxidase in bio-related detection has been gain great interest. Noble metal nanoparticles with small size have large specific surface area. However, small noble metal nanoparticles tend to aggregate without stabilizer. In this paper, small Pd nanoparticles (3–6 nm) stabilized by bitter gourd polysaccharide (Pd n -BGP NPs) were prepared by using bitter gourd polysaccharide as reducing agent and stabilizing agent. Pd 25 -BGP NPs had peroxidase-like catalytic property. And the catalytic kinetics of Pd 25 -BGP NPs towards substrates conformed to the Michaelis-Menten equation. Furthermore, a method was established to detect H 2 O 2 using Pd 25 -BGP NPs. The linear range and detection limit of this method was 20–320 μM and 2.04 μM, respectively. Finally, Pd 25 -BGP NPs had good biocompatibility when the concentration was less than 80 μg/mL. The prepared Pd nanoparticles with high stability showed their good prospect in H 2 O 2 detection.
研究领域:
纳米技术
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生物化学
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分析化学
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材料科学
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PubMed
高影响因子
Journal of Oleo Science
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2020
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IF 1.304
Fenghuan Zhao,Xihong Zhao,Nanjing Zhong
In this study, lipase from Thermomyces lanuginosus (TLL) was immobilized onto the parent and organic groups modified SBA-15, and the enzymatic properties of the obtained immobilized TLL samples were investigated. 1) Activity of SBA-15-TLL at 2862.78 ± 293.24 U/g was obtained. 2) Most of the organic groups modification favored a great improvement in activity, and higher activity over 12000 U/g was observed for N-phenylaminomethyl and phenyl group modification. 3) Most of the supported TLL showed better thermostability in air while poor in phosphate buffer, with over 80% vers less than 20% of their initial activity retained after 4 h incubation at 70℃. 4) The n-dodecyl, phenyl and N-phenylaminomethyl group functionalization decreased the sensitivity of immobilized TLL in extreme pH values. 5) The n-octyl and 2-(propoxymethyl)oxirane group modification confered the supported TLL good reusability, and over 60% of their initial activity was retained after five successive cycles of reuse.
研究领域:
生物技术
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酶工程
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材料科学
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PubMed
高影响因子
Food Chemistry-X
·
2023
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IF 6.1
Yang Zhao,Luyue Zhang,Shiyu Zhang,Xing Zheng,Mingzhu Zheng,Jingsheng Liu
At presently, the catalytic activity of xylanase is sub-optimal, and the required reaction conditions are harsh. To improve its catalytic activity and stability, xylanase (XY) was chemically modified with maleic anhydride (MA). The enzymatic properties of this maleic anhydride-modified xylanase (MA-XY) were then evaluated and analyzed spectroscopically. The results showed that the thermal stability, use of organic solvents, storage stability and the pH range of 3.0 to 9.0 for MA-XY were better than that for XY alone. The kinetic parameters of the enzyme (K m values) decreased from 40.63 to 30.23 mg/mL. Spectroscopic analysis showed that XY had been modified by the acylation reaction to become a tertiary structure. An assay based on clarifying fruit juices showed that the clarification capacity and reducing sugar content using MA-XY increased compared with those using XY. Overall, this study provides a theoretical basis for improving the application of XY in the food industry.
研究领域:
食品科学
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酶学
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化学修饰
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生物技术
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PubMed
高影响因子
ANALYST
·
2022
·Vol. 148
·期 1
·146-152
·
IF 5.227
Jie Wang,Chenglong Zhao,Feijin Zhou,Hui Lu,Zhenhong Huang,Cheng Yao,Chan Song
The development of novel nanozymes is of great importance for the efficient analysis of biomolecules such as H2O2, glucose, and antioxidants in the diagnosis of some diseases. Herein, novel nanozymes based on Fe nanoparticles (NPs) encapsulated in 2D carbon nanosheets (denoted as Fe@CNs) were constructed and employed in the field of biosensing. Notably, Fe@CNs have intrinsic dual mimic enzyme properties. The colorless colorimetric substrate 3,3′,5,5′-tetramethylbenzidine (TMB) can be oxidized by Fe@CNs as oxidase- and peroxidase-like nanozymes, respectively. The generation of the oxidation state TMB (oxTMB) resulted from the presence of reactive oxygen species (ROS) which were produced by the catalytic decomposition of the dissolved oxygen or H2O2. Thus, a simple colorimetric biosensor was proposed to detect glutathione (GSH), H2O2, and glucose. In addition, the Fe@CN-based nanozymes also have excellent reusability in enzymatic catalysis. After separating from the sensing systems, Fe@CNs can be reused in other catalytic processes. This colorimetric method could be used as a universal sensing platform for the detection of antioxidants and H2O2-related bioanalysis. This work broadens the application of novel nanozymes in biosensing.
研究领域:
生物化学
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纳米技术
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分析化学
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生物传感器
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PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2024
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IF 5.4
Xiaoli He,Xinran Sheng,Xinrui Yao,Yanyan Wang,Liping Zhang,Hongwei Wang,Lin Yuan
The continuous evolution of bacteria and the formation of biofilm have exacerbated resistance issues, highlighting the urgent need for new antibacterial materials. In this study, L-fucose was polymerized to synthesize thiolated poly(2-(L-fucose) ethyl methacrylate) (PFEMA-SH), which was subsequently co-modified with α-amylase onto gold nanorods (GNR) to prepare the antibacterial nanoparticle composite, GNR-Amy-PFEMA (G-A-P). These nanomaterials exhibit both photothermal and enzymatic properties, enabling G-A-P to effectively sterilize and disperse biofilm. Under near-infrared light irradiation, the temperature of G-A-P composite increases significantly, leading to bacterial cell damage and biofilm disruption. The G-A-P composite demonstrated nearly 100 % eradication of planktonic bacteria after 5 min of irradiation and achieved a 70.9 % reduction in mature biofilm biomass, with a 3.37-log decrease in the number of bacteria within the biofilm. These composites display strong antimicrobial activity and hold great potential for the removal of Pseudomonas aeruginosa biofilm. Furthermore, the ability of G-A-P to reduce biofilm formation without the use of traditional antibiotics suggests that it may offer an antibiotic-free alternative for managing biofilm-related infections.
研究领域:
材料科学
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纳米技术
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微生物学
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生物医学工程
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PubMed
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Molecular Catalysis
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2024
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IF 3.9
Kaixuan Ke,Ling Guo,Zhipeng Qi,Dou Dou,Han Ma,Xianying Fang,Linguo Zhao
Carotenoid cleavage dioxygenases (CCDs) play a pivotal role in the biosynthesis of volatile apocarotenoids, which have significant industrial applications due to their aromatic and bioactive properties. This study focuses on the molecular cloning and biochemical characterization of the LbCCD1 from Lycium barbarum . The LbCCD1 gene was successfully cloned and heterologously expressed in Escherichia coli and several carotenoids were using as substrates for investigate its specificity by in vitro and in vivo experiment. The LbCCD1 protein was able to cleave a variety of carotenoids including β-carotene, zeaxanthin, astaxanthin, and β-apo-8′-carotenal, at the 9, 10 (9′, 10′) double bond to produce β-ionone, 3‑hydroxy-4-oxo-β-ionone, and 3‑hydroxy-β-ionone, respectively in vitro. LbCCD1 could also cleave zeaxanthin and β-carotene at the 9, 10 (9′, 10′) double bond to produce β-ionone, respectively, in E. coli accumulating carotenoids. Interestingly, LbCCD1 did not exhibit cleavage activity on lycopene either in vivo or in vitro unlike other CCD1 family enzymes. In the previous experiment, it was confirmed that LbCCD1 exhibits cleavage activity towards β-apo-8′-carotenal in vitro, so we used β-apo-8′-carotenal as the substrate for characterizing the enzymatic properties. The expression of LbCCD1 was optimized at such conditions (temperature 24 °C, IPTG 0.1 mM, induction time 24 h). The biochemical characterization of LbCCD1 revealed the optimal activities were at pH 9 and 55 °C. The addition of 10 % ethanol could increase enzyme activity to above 15 %. However, the concentration of Fe 2+ has a minimal effect on enzyme activity. The V max for β-apo-8′-carotenal was 8.6 U/mg, while the K m was 0.27 mM. To preliminarily verify the potential of LbCCD1 as a biological component for β-ionone production. By introducing LbCCD1 into the β-carotene-high-producing chassis cell and optimizing the conditions (temperature 30 °C, IPTG 0.01 mM, Fe 2+ concentration 0.05 mM), the β-ionone yield reached 21.45 mg/L. This study focused on one of the CCDs derived from woody plants, which have been relatively underexplored. It lays the groundwork for expanding the CCD enzyme library, identifying suitable CCDs, and investigating the structure-function relationship of CCDs. Furthermore, it sets the stage for engineering novel CCD genes and developing advanced applications of CCDs as biocatalysts and platforms for synthetic biology. These advancements will enable the efficient production of volatile aroma compounds from carotenoids.
研究领域:
植物生物化学
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分子生物学
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生物技术
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合成生物学
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DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Jianwen Fei,Wei Yang,Yin Dai,Wei Xu,Huizhu Fan,Yani Zheng,Junli Hong,Jun Zhang,Wanying Zhu,Xuemin Zhou
The enzyme-like properties of nanozymes may be considerably affected by the structure and surface groups, which thus need to be optimized. Here, through a simple NaOH chemical corrosion method, the chemical structure similar to N-Methylpyrrolidone (NMP), which possessed intrinsic oxidase-like activity, was introduced into polypyrrole (PPy), and then this nanomaterial became oxygen-functionalized PPy ( o -PPy) with excellent oxidase-like activity from PPy without this property. Furthermore, after compounding magnetic Fe 3 O 4 , the obtained nanocomposites Fe 3 O 4 @o-PPy nanoparticles (Fe 3 O 4 @o-PPy NPs) showed superiorities in separation during synthesis and real-time control of enzyme catalysis . Studies have found that the enzymatic activity of Fe 3 O 4 @o-PPy NPs depended on the amount of functionalized oxygen and the conjugation extent of o -PPy. Fe 3 O 4 @o-PPy NPs had efficient oxidase-like activity under a wide range of pH and temperature. Based on the oxidase-like activity of Fe 3 O 4 @o-PPy NPs, a colorimetric sensor for glutathione (GSH), which presented rich color changes and satisfactory colorimetric resolution by adding the amaranth , was realized. We believe that the functional modification and structural regulation of PPy can not only realize its wider application but also promote the discovery of novel and efficient nanozymes .
研究领域:
材料科学
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纳米技术
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分析化学
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生物化学
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产品关联
DOI
PubMed
高影响因子
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