Foods
·
2023
·Vol. 12
·期 6
·1289
·
IF 5.2
Xiao-Yan Liu,Wei Chen,Cheng-Tao Wang
Egg white (EW) is frequently used in bakery products because of its excellent foaming capabilities. However, egg yolk (EY) contamination often degrades the foaming characteristics of EW. The purpose of this study was to investigate the effect of different concentrations of phospholipase A1 (PLPA1) and lipase (LP) on EW. The changes in particle size distribution and potential before and after enzymatic digestion of EW with contaminated 0.5 wt% and 1.0%wt EY were tested. The foaming rate and foam stability were measured after the dispersions were digested with different concentrations of PLPA1 and LP. Additionally, the dispersion samples were used to prepare batter and angel cake, and the modulus, density, and microstructure of the batter were analyzed. Results showed that the potential absolute value increased when the EY was hydrolyzed by PLPA1. The distribution of yolk particle size showed a new aggregation and the average particle size decreased after LP hydrolysis. The dispersion samples hydrolyzed by PLPA1 and LP recovered all the properties of the samples at enzymatic concentrations of 500 U/g and 2500 U/g. This may be attributed to the changes in yolk particles resulting from the enzymatic digestion of EY and the production of amphiphilic lysophospholipids, fatty acids, and glycerol.Keywords:egg white;foaming properties;yolk-contaminated;lipase enzymolysis
研究领域:
食品科学
·
化学
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DOI
PubMed
高影响因子
ChemNanoMat
·
2023
·Vol. 9
·期 10
·e202300310
·
IF 3.8
Xin Cui,Jiachen Zhang,Yitong Liu,Wen Shao,Yawen Tang,Hanjun Sun
Graphical A Ru-ZIF-8 nanozyme with both esterase like and peroxidase like activities were prepared for acetylcholine (ACh) detection. On the basis of the Ru-ZIF-8 nanozyme, a portable nanozyme strip was developed as a novel biosensor for detecting ACh, which was conducive to promoting the development of multiple enzyme cascade assays. In the present study, the incorporation of Ru into the framework of ZIF-8 resulted in that a Ru-ZIF-8 nanozyme with both esterase-like activity and peroxidase-like activity. Owing to the dual nanozymatic activities of Ru-ZIF-8 nanozyme, the acetylcholine (ACh) detection process utilized only one natural enzyme (choline oxidase), which greatly simplified the detection procedure. In the detection process, nanozyme Ru-ZIF-8 showed esterase-like activity to catalyze the hydrolysis of ACh to choline. Then the generated choline was oxidized by choline oxidase to generate H 2 O 2 . Finally, Ru-ZIF-8 with peroxidase-like activity was used to catalyze H 2 O 2 to oxidize 2,2′-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid) ammonium salt with a color change. As a result, the linear range for ACh was from 0.01 μM-22 μM with the detection limit (DL) of 5.5 nM. In addition, Ru-ZIF-8 was utilized to fabricate a portable detection test strip. Our work provided a simple, portable, low-cost, highly sensitive and selective assay for the detection of ACh, which paved the way for the development of multi enzyme cascade assays.
研究领域:
生物化学
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纳米技术
·
分析化学
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生物传感器
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Bin Wu,Shiyu Wang,Yunjian Ma,Shuguang Yuan,Frank Hollmann,Yonghua Wang
Alcohol oxidases (AOxs) catalyze the aerobic oxidation of alcohols to the corresponding carbonyl products (aldehydes or ketones), producing only H2O2 as the byproduct. The majority of known AOxs, however, have a strong preference for small, primary alcohols, limiting their broad applicability, e.g., in the food industry. To broaden the product scope of AOxs, we performed structure-guided enzyme engineering of a methanol oxidase from Phanerochaete chrysosporium (PcAOx). The substrate preference was extended from methanol to a broad range of benzylic alcohols by modifying the substrate binding pocket. A mutant (PcAOx-EFMH) with four substitutions exhibited improved catalytic activity toward benzyl alcohols with increased conversion and kcat toward the benzyl alcohol from 11.3 to 88.9% and from 0.5 to 2.6 s–1, respectively. The molecular basis for the change of substrate selectivity was analyzed by molecular simulation.
研究领域:
生物化学
·
酶学
·
食品科学
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DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2022
·Vol. 2022
·期 20
·e202200202
·
IF 2.551
Zicong Tan,Ying Wang,Jie Zhang,Zhang Zhang,Samantha Sze Man Wong,Shiqing Zhang,Hongyan Sun,Ken Kin Lam Yung,Yung-Kang Peng
Graphical CeO 2 nanosphere enclosed by (100) and (111) surfaces has been reported to mimic phosphatase and peroxidase by catalyzing substrate dephosphorylation and oxidation (with H 2 O 2 ). We herein successfully boost the reaction specificity for this material by shape control. The acidic Ce species on octahedron (111) surface was found to selectively catalyze substrate dephosphorylation while its electron rich counterpart on cube (100) surface only promotes substrate oxidation. Among reported nanozymes, CeO 2 seems to be the only transition metal oxide that can mimic phosphatase and peroxidase by catalyzing substrate dephosphorylation and oxidation (with H 2 O 2 ). However, no consensus on the key Ce species was reached in the literature using spherical CeO 2 enclosed by (111) and (100) surfaces, not to mention the further control of its reaction specificity. In this study, octahedral and cubic CeO 2 preferentially terminated by (111) and (100) surfaces were found to exhibit high reaction specificity (and activity) towards each of the above reactions. Spectroscopic evidence suggests that this is closely associated with the Lewis acidity (or electron density) of surface Ce species. The acidic Ce species on (111) surface can catalyze substrate dephosphorylation at room temperature but do not for substrate oxidation with H 2 O 2 . This correlation was further evidenced by the electron-rich Ce species on (100) surface, hindering the first reaction while promoting the latter.
研究领域:
材料科学
·
生物化学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Xin Zhang,Xin Liu,Ziting Lin,Guangze Sun,Zihan Bian,Huan Liu,Aihua Liu
Nanozymes hold great promise in catalysis-based sensing, however, challenges remain due to their less specificity and unclear catalytic mechanisms, which limited their potential applications. Herein we report an ultrasensitive colorimetric/fluorescence dual-mode tartaric acid (TA) sensor based on hydroxy-iron oxide (FeOOH) nanorods (NRs)@carbon dots (CDs) nanocomposite incorporating with acid phosphatase (ACP). The peroxidase (POD)-like activity of FeOOH can catalyze H 2 O 2 to generate OH, which can further oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to produce blue oxTMB, while the fluorescence of CDs can be quenched by the assembled FeOOH NRs through internal filter effect. The FeOOH@CDs can effectively transfer electron enabling high catalytic activity, which is supported by Cytochrome c as an electron transporter. ACP can hydrolyze trisodium L-ascorbate-2-phosphate salt (AAP) to produce ascorbic acid (AA), which increases colorimetric signal generated by FeOOH@CDs. Interestingly, TA can inhibit ACP activity through strong complexation and reduce the generated AA, by which most ox-TMB could not be restored. Meanwhile, the generated AA could reduce FeOOH to collapse into Fe 2+ , enabling the assembled CDs dropping-off into solution and restored fluorescence. However, TA can inhibit the ACP activity, which prevents fluorescence recovery. A colorimetric/fluorescence dual-mode sensing was established by cascading ACP/POD mimics. The limits of detection are 0.83 μM and 22.8 μM (3σ/S) for the fluorescence mode and colorimetric mode, respectively. The as-proposed method was applied to detect TA in wine samples, consistent well with the results of HPLC. This work not only expands nanozyme’s potential applications in catalysis and sensing, but also provides a potential platform for rapid TA detection for food control.
研究领域:
生物化学
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传感技术
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食品科学
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产品关联
DOI
高影响因子
Processes
·
2023
·Vol. 11
·期 1
·255
·
IF 3.5
Ke Chen,Jingyun Zhang,Xing Liu,Peiyuan Zhang,Wenlong Yue,Zhiqiang Cai
Aspergillussp. D-23 was obtained by ultraviolet-diethyl sulfate (UV-DES) compound mutagenesis fromAspergillussp. C18 that the α-galactosidase was purified from. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and non-denaturing polyacrylamide gel electrophoresis (Native-PAGE), the purified enzyme demonstrated apparent homogeneity. The monomeric α-galactosidase’s native molecular weight was 125 kDa. The optimal temperature of α-galactosidase was 65 °C, and 75% of the initial enzyme activity could be maintained between 45 and 55 °C. Its optimal pH was 5.0 with good pH stability. After incubating for 2 h at pH 3.0–8.0, it could retain more than 80% of its original activity. Different concentrations of metal ions had different effects on the α-galactosidase activity. High concentrations of Cu2+could strongly inhibit enzyme activity and low concentrations of Fe2+could promote enzyme activity. Additionally, as shown by thin layer chromatography and high-performance liquid chromatography, the enzyme also had good hydrolysis ability, which could efficiently hydrolyze melibiose and raffinose by more than 95%. Therefore, these excellent characteristics could make α-galactosidase a good candidate for the food and feed industries.Keywords:α-galactosidase;enzymatic characterization;Aspergillussp.;enzymatic hydrolysis;higher molecular weight
研究领域:
生物化学
·
食品科学
·
微生物学
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产品关联
DOI
高影响因子
NUCLEIC ACIDS RESEARCH
·
2024
·
IF 16.6
Liao Fumeng,Yu Guimei,Zhang Chendi,Liu Zhikun,Li Xuzichao,He Qiuqiu,Yin Hang,Liu Xiang,Li Zhuang,Zhang Heng
Recently, a novel two-gene bacterial defense system against phages, encoding a SIR2 NADase and a HerA ATPase/helicase, has been identified. However, the molecular mechanism of the bacterial SIR2–HerA immune system remains unclear. Here, we determine the cryo-EM structures of SIR2, HerA and their complex from Paenibacillus sp. 453MF in different functional states. The SIR2 proteins oligomerize into a dodecameric ring-shaped structure consisting of two layers of interlocked hexamers, in which each subunit exhibits an auto-inhibited conformation. Distinct from the canonical AAA+ proteins, HerA hexamer alone in this antiphage system adopts a split spiral arrangement, which is stabilized by a unique C-terminal extension. SIR2 and HerA proteins assemble into a ∼1.1 MDa torch-shaped complex to fight against phage infection. Importantly, disruption of the interactions between SIR2 and HerA largely abolishes the antiphage activity. Interestingly, binding alters the oligomer state of SIR2, switching from a dodecamer to a tetradecamer state. The formation of the SIR2–HerA binary complex activates NADase and nuclease activities in SIR2 and ATPase and helicase activities in HerA. Together, our study not only provides a structural basis for the functional communications between SIR2 and HerA proteins, but also unravels a novel concerted antiviral mechanism through NAD+ degradation, ATP hydrolysis, and DNA cleavage.
研究领域:
微生物学
·
结构生物学
·
分子生物学
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DOI
PubMed
高影响因子
Biomolecules
·
2024
·Vol. 14
·期 6
·712
·
IF 4.8
Gehad G. Ibrahim,Madhavi Perera,Saadiah A. Abdulmalek,Jinyong Yan,Yunjun Yan
Resveratrol, a phenylpropanoid compound, exhibits diverse pharmacological properties, making it a valuable candidate for health and disease management. However, the demand for resveratrol exceeds the capacity of plant extraction methods, necessitating alternative production strategies. Microbial synthesis offers several advantages over plant-based approaches and presents a promising alternative.Yarrowia lipolyticastands out among microbial hosts due to its safe nature, abundant acetyl-CoA and malonyl-CoA availability, and robust pentose phosphate pathway. This study aimed to engineerY. lipolyticafor resveratrol production. The resveratrol biosynthetic pathway was integrated intoY. lipolyticaby adding genes encoding tyrosine ammonia lyase fromRhodotorula glutinis, 4-coumarate CoA ligase fromNicotiana tabacum, and stilbene synthase fromVitis vinifera. This resulted in the production of 14.3 mg/L resveratrol. A combination of endogenous and exogenous malonyl-CoA biosynthetic modules was introduced to enhance malonyl-CoA availability. This included genes encoding acetyl-CoA carboxylase 2 fromArabidopsis thaliana, malonyl-CoA synthase, and a malonate transporter protein fromBradyrhizobium diazoefficiens. These strategies increased resveratrol production to 51.8 mg/L. The further optimization of fermentation conditions and the utilization of sucrose as an effective carbon source in YP media enhanced the resveratrol concentration to 141 mg/L in flask fermentation. By combining these strategies, we achieved a titer of 400 mg/L resveratrol in a controlled fed-batch bioreactor. These findings demonstrate the efficacy ofY. lipolyticaas a platform for the de novo production of resveratrol and highlight the importance of metabolic engineering, enhancing malonyl-CoA availability, and media optimization for improved resveratrol production.
研究领域:
生物技术
·
代谢工程
·
微生物学
·
药学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Research
·
2023
·
IF 11
Guangchun Song,Jia Xu,Hong Zhong,Qi Zhang,Xin Wang,Yitong Lin,Scott P. Beckman,Yunbo Luo,Xiaoyun He,Jin-Cheng Li,Kunlun Huang,Nan Cheng
The enzyme-mimicking catalytic activity of single-atom nanozymes has been widely used in tumor treatment. However, research on alleviating metabolic diseases, such as hyperglycemia, has not been reported. Herein, we found that the single-atom Ce-N4-C-(OH)2 (SACe-N4-C-(OH)2) nanozyme promoted glucose absorption in lysosomes, resulting in increased reactive oxygen species production in HepG2 cells. Furthermore, the SACe-N4-C-(OH)2 nanozyme initiated a cascade reaction involving superoxide dismutase-, oxidase-, catalase-, and peroxidase-like activity to overcome the limitations associated with the substrate and produce •OH, thus improving glucose intolerance and insulin resistance by increasing the phosphorylation of protein kinase B and glycogen synthase kinase 3β, and the expression of glycogen synthase, promoting glycogen synthesis to improve glucose intolerance and insulin resistance in high-fat diet-induced hyperglycemic mice. Altogether, these results demonstrated that the novel nanozyme SACe-N4-C-(OH)2 alleviated the effects of hyperglycemia without evident toxicity, demonstrating its excellent clinical application potential.
研究领域:
纳米技术
·
生物化学
·
代谢疾病
·
药理学
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DOI
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Hao Cao,Lichao Sun,Ying Huang,Xin Liu,Dong Yang,Tengfei Liu,Xiaojing Jia,Boting Wen,Tianyi Gu,Fengzhong Wang,Fengjiao Xin
Enzymes are usually characterized by their evolutionarily conserved catalytic domains; however, this work presents the incidental gain-of-function of an enzyme in a loop region by natural evolution of its amino acids. A bifunctional acetyl ester–xyloside hydrolase (CLH10) was heterologously expressed, purified, and characterized. The primary sequence of CLH10 contains the fragments of the conserved sequence of esterase and glycosidase, which distribute in a mixed type. The crystal structure revealed that the primary sequence folded into two independent structural regions to undertake both acetyl esterase and β-1,4-xylanase hydrolase functions. CLH10 is capable of cleaving both the β-1,4-xylosidic bond-linked main chain and the ester bond-linked acetylated side chain of xylan, which renders it valuable because it can degrade acetylated xylan within one enzyme. Significantly, the β-1,4-xylanase activity of CLH10 appears to have been fortuitously obtained because of the variable Asp10 and Glu139 located in its loop region, which suggested that the exposed loop region might act as a potential hot-spot for the design and generation of promising enzyme function in both directed evolution and rational protein design.
研究领域:
生物化学
·
酶学
·
结构生物学
·
分子进化
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Hong Guo,Shaolan Zou,Boshi Liu,Rongxin Su,Renliang Huang,Wei Qi,Minhua Zhang,Zhimin He
Enzyme recycling by re-adsorption is one of the primary methods for reducing enzyme usage in lignocellulose conversion. This work proposes the combination of an engineered yeast strain that expresses β-glucosidase with enzyme recycling to reduce the amount of supplemented β-glucosidase in enzyme recycling experiments. Using the engineered strain, a slight increase in ethanol concentration was obtained after a 96-h fermentation of pretreated corncobs. Ethanol concentrations increased by 34.7% and 62.7% in the following two recycle rounds using the engineered strain compared with those using its parental strain without β-glucosidase addition. Furthermore, with the addition of β-glucosidase at 30 CBU/g cellulose, the ethanol concentration after two recycle rounds exceeded 90% of that observed in the first SSF round with the engineered strain at a high initial cellulase loading of 45 FPU/g cellulose.
研究领域:
生物技术
·
酶工程
·
发酵工程
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DOI
PubMed
高影响因子
APPLIED SPECTROSCOPY
·
2024
·
IF 2.2
Yongmei Zhang,Haibo Liang,Xinru Wang,Ying Yu,Yujuan Cao,Manli Guo,Bixia Lin
The precise regulation of nanoenzyme activity is of great significance for application to biosensing analysis. Herein, the peroxidase-like activity of carbon dots was effectively modulated by doping phosphorus, which was successfully employed for sensitive, selective detection of acid phosphatase (ACP). Phosphorus-doped carbon dots (P-CDs) with excellent peroxidase-like activity were synthesized by a one-pot hydrothermal method, and the catalytic activity could be easily modulated by controlling the additional amount of precursor phytic acid. P-CDs could effectively catalyze the oxidation of colorless 3,3’,5,5'-tetramethylbenzidine (TMB) to blue TMB oxidation products in the presence of hydrogen peroxide. While ACP was able to catalyze the hydrolysis of L-ascorbyl-2-phosphate trisodium salt (AAP) to produce ascorbic acid (AA), which inhibited the peroxidase-like activity of P-CDs, by combining P-CDs nanoenzymes and ACP-catalyzed hydrolysis the colorimetric method was established for ACP detection. The absorbance variation showed a good linear relationship with ACP concentration in the range of 0.4–4.0 mU/mL with a limit of detection at 0.12 mU/mL. In addition, the method was successfully applied to detect ACP in human serum samples with recoveries in the range of 98.7–101.6%. The work provides an effective strategy for regulating nanoenzymes activity and a low-cost detection technique for ACP.
研究领域:
生物化学
·
医学诊断
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）