ACS Omega
·
2020
·
IF 2.87
Feng Wang,Youhua Li,Lu Yu,Jinwen Zhu,Fuming Zhang,Robert J. Linhardt
Amphiphilic mPEG-modified peptide nanoparticles were developed from oligo-phenylalanine (OPhe) nanoparticles (NPs) synthesized via papain. Tyndall effects indicate that OPhe NPs are amphiphobic. Addition of protein perturbants, sodium dodecyl sulfate (SDS), and urea, in the dispersion solution of OPhe NPs can significantly reduce the Rh,m value of NPs, from approximately 749.2 nm to about 200 nm. Therefore, the hydrophobic interaction and hydrogen bonding play major roles in maintaining the aggregation of OPhe NPs. Using the “grafting to” method, the methoxypolyethylene-modified OPhe NPs (mPEG-g-OPhe NPs) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), 1H NMR, electrospray ionization mass spectrometry (ESI-MS), and dynamic light scattering (DLS). The attenuated total reflectance (ATR) spectrum of OPhe NPs and mPEG-g-OPhe NPs demonstrate that the secondary structures of these NPs are mainly β-type. mPEG-g-OPhe NPs can self-aggregate into spherical micelles both in water and cyclohexane. Increasing the chain length of the mPEG moiety, the critical micellar concentrations of mPEG-g-OPhe NPs increased in water but decreased in cyclohexane. The light stability, thermal stability, hydrolysis stability, and encapsulation stability of curcumin were significantly promoted by encapsulation in the micelles formed by mPEG-g-OPhe NPs. The protective effects regularly varied with the variations in the mPEG chain length of mPEG-g-OPhe NPs.
研究领域:
生物化学
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材料科学
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药物递送
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yue Guo,Shenglin Sun,Mingfei Gu,Liyue Zhang,Li Cheng,Zhaofeng Li,Caiming Li,Xiaofeng Ban,Yan Hong,Zhengbiao Gu
Linear α-glucan (LG), a linear polymer linked by α-1,4 bonds, has received increasing attention for its potential applications in synthetic polymer production. Notably, the functionality of LG is strongly influenced by its degree of polymerization (DP). In this study, SP and GP were successfully constructed and expressed. The reaction of enzymatic co -polymerization into LG was investigated. The preferred reaction was carried out at 37 °C and pH 7.4 for 72 h, with a maximum conversion rate of 25 %. Afterwards, two approaches were used to modulate the molecular structures of LGs. Firstly, LGs with distinct molecular weights ranging from 1062.33 ± 16.04 g/mol to 5679 ± 80.29 g/mol were obtained by adjusting the substrate/primer ratio during the LG synthesis process. Secondly, two distinct products could be produced by altering the enzyme addition method: short-chain LG with a DP < 10 (64.34 ± 0.54 %) or long-chain LG with a DP > 45 (45.57 ± 2.18 %). Additionally, theoretical synthesis model was constructed which subdivided the reaction into three stages to evaluate this dual-enzyme cooperative system. These findings have significant implications in promoting the application of LG in the fields of biomedicine and material science.
研究领域:
生物化学
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材料科学
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生物医药
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PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2022
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IF 10.723
Naixiang Xue,Yanli Wang,Xiaoxiao Li,Yuxiang Bai
Isomalto/malto-polysaccharides (IMMPs) with degree of polymerization (DP) 10–100 have novel potential applications, including enhanced solubility and anti-inflammatory. However, there are minimal synthetic methods for preparing IMMPs with a relatively higher DP, which is due to the lack of suitable molecular weight linear dextrins (I-LDs). The existing I-LDs preparation methods have disadvantages, such as low yield and uncontrollable molecular weight. Therefore, this study proposes a method for preparing soluble linear dextrins (S-LDs, M w = 2.1 kDa) by low-temperature retrogradation from debranched waxy corn starch (M w = 3.0 kDa). S-LDs reacted with 4,6-α-glucanotransferase GtfB-ΔN from Limosilactobacillus reuteri 121 to yield IMMPs with 12.3 kDa M w and 83.8% α1 → 6 linkages content. Process monitoring revealed the synthesis mechanism and a detailed reaction process. Finally, IMMPs were identified by enzyme fingerprinting as α1 → 6 chains with α1 → 4 fragments inlaid at the reducing, non-reducing end, and middle part. This study provides a new synthesis method and more structural information for IMMPs.
研究领域:
食品科学
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生物化学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Wei Gao,Ru Yang,Mengli Li,Ming Miao,Tao Zhang
The enzymatic synthesis of amylose is a sustainable solution for the valorisation of non-food cellulose. However, the limited thermostability and catalytic efficiency of existing α -glucan phosphorylases ( α GPs) hinders its potential for industrial scalability. In this study, we identified and characterised a novel α GP from Nicotiana attenuata ( Nicα GP) via genome mining. It exhibited superior catalytic performance, with a specific activity of 82.1 U/mg under optimised conditions (40 °C and pH 5.0), and notable temperature and pH stability. Supplementation of Mg 2+ further enhanced its activity by 5 %. Kinetic analysis revealed a catalytic efficiency ( k cat / K m ) of 27.46 mM −1 s −1 for maltotetraose (G4). Furthermore, a dual-enzyme cascade system integrating Nicα GP with Clostridium thermocellum cellobiose phosphorylase achieved up to 28.4 % cellulose conversion, synthesising amylose with tunable molecular weights (6602 ± 47.13–67,154 ± 47.28 g/mol) by modulating ratios of cellobiose/G4. Molecular docking identified the conserved residues (Gly196, Arg706, Lys711, and Lys821) critical for substrate binding and pyridoxal 5′-phosphate-mediated catalysis. Overall, this study provides a new enzyme component for the artificial synthesis of amylose from non-edible biomass, facilitating the widespread application of non-edible cellulosic resources for food conversion.
研究领域:
生物催化
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工业酶学
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生物质转化
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植物生物技术
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
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IF 4.192
Zijie Li,Fen Li,Li Cai,Zhou Chen,Ling Qin,Xiao-Dong Gao
A facile approach is introduced here for the synthesis of rare ketoses from glycerol and d-/l-glyceraldehyde (d-/l-GA). The reactions were carried out in a one-pot multienzyme fashion in which the only carbon source is glycerol. In the enzymatic cascade, glycerol is phosphorylated and then oxidized at C2 to afford dihydroxyacetone phosphate (DHAP), the key donor for enzymatic aldol reaction. Meanwhile, the primary alcohol of glycerol is also oxidized to give the acceptor molecule GA in situ (d- or l-isomer could be formed stereospecifically with either alditol oxidase or horse liver alcohol dehydrogenase). Different DHAP-dependent aldolases were used to generate the aldol adducts (rare ketohexose phosphates) with various stereoconfigurations and diastereomeric ratios. It is worth noting that the enzyme that catalyzes the phosphorylation reaction in the first step could also help recycle the phosphate in the last step to provide free rare sugar molecules. This study provides a useful method for rare ketose synthesis on a 100 mg to g scale, starting from relatively inexpensive materials which solved the problem of supplying both glycerol 3-phosphate and GA in our previous work. It also demonstrates an example of green synthesis due to highly efficient carbon usage and recycling of cofactors.
研究领域:
生物催化
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合成生物学
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绿色化学
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PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
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2021
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IF 5.537
Pengyu Zhao,Weidan Li,Chaoying Zhen,Ke Wang,Zhen Qin,Haiyan Gao
γ-Aminobutyric acid (GABA) has several physiological functions and broad application prospects. In this study, as a tool used for transcriptomics , RNA-seq sequencing was employed to determine the mechanism by which GABA slows browning and induces resistance against the growth of bacterial in fresh-cut apples. GABA altered the expression level of genes related to the synthesis of browning enzymes and phenolic substances in fresh-cut apples, which slowed the browning process during storage. Additionally, GABA promoted the gene expression of enzymes or proteins related to disease resistance, which resultantly induced disease resistance in fresh-cut apples. Notably, GABA maintained the integrity and stability of the cell wall composition and structure in apple tissues to reduce browning and induce disease resistance. Our findings revealed the mechanism by which GABA acts as a protective agent against browning and bacterial growth in for fresh-cut apples.
研究领域:
园艺学
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分子生物学
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食品科学
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DOI
高影响因子
MICROCHIMICA ACTA
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2020
·Vol. 187
·期 4
·1-7
·
IF 6.232
Huang Qingwei,Zhang Jinli,Li Wei,Fu Yan
Heparin was employed as the stabilizing agent in the synthesis of peroxidase-mimicking Pd nanoparticles. The heparin-capped Pd nanozyme can act as both the signal amplifier and the selective binder of protamine. The most efficient nanozyme with the mean size of 3.5 nm consists of 70.8% metallic Pd 0 and 29.2% Pd 2+ species. Enzyme kinetic studies show that the K m values are 0.036 mM for 3,3′,5,5′-tetramethylbenzidine and 78 mM for H 2 O 2 . Protamine shows strong affinity to the heparin-capped Pd nanozyme, and induces an apparent aggregation of the nanoparticles. This results in a significant inhibition of the peroxidase-mimicking activities. Hence, the oxidation of TMB by H 2 O 2 to a blue product with a maximum absorption at 652 nm is suppressed. Based on this finding, a photometric assay is developed for the determination of protamine. The linear response is in the concentration range 0.02 ~ 0.8 μg mL −1 , and the limit of detection is 0.014 μg mL −1 . This assay presents high selectivity toward other biological substances.
Highly active and selective Pd nanozyme was synthesized through adopting heparin as the capping agent for quantitative determination of protamine.
研究领域:
分析化学
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纳米技术
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生物化学
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PubMed
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ACS Applied Materials & Interfaces
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2021
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IF 9.229
Zhenfu Wang,Yang Liu,Xiaoyan Dong,Yan Sun
Chemoenzymatic catalysis combining the traits of chemical and enzymatic catalysis provides tremendous possibilities for the design of biosynthetic pathways utilizing inorganic catalysts and enzymes. However, the efficiency of chemoenzymatic catalysis is usually governed by the synergy and compatibility of the two catalysts. Here, we report for the first time the catalase-like activity of cobalt phosphate nanocrystals (CoPs). By a one-pot biomimetic mineralization with CoPs and l-amino acid oxidase (LAAO) under a mild condition, we have fabricated a hybrid nanobiocatalyst, LAAO@CoPs, for the chemoenzymatic synthesis of α-keto acid. The as-fabricated nanobiocatalyst with directly contacted catalytic sites of the enzyme and nanozyme maximizes the substrate channeling effects for in situ chemical decomposition of the oxidative intermediate, H2O2, during the enzymatic oxidation of l-tryptophan (l-Trp), thus minimizing the H2O2 accumulation and byproduct generation. Benefiting from the superiority of LAAO@CoPs, complete conversion (100.0%) of l-Trp to indole pyruvic acid is achieved, over two times higher than the yield of the free LAAO system (47.6%). Meanwhile, LAAO@CoPs show high stabilities against heat and proteolytic treatments. This work offers a new design approach for constructing a high-performance nanobiocatalyst for cascade reactions, especially for those systems with toxic or reactive intermediates.
研究领域:
纳米技术
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生物催化
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化学生物学
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酶学
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PubMed
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FOOD CHEMISTRY
·
2024
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IF 8.5
Jinhang Chen,Tieliang Liu,Yi Zhang,Lu Zheng,Kheng-Lim Goh,Vladimir Zivkovic,Mingming Zheng
Flavor esters are used in food and cosmetic industries, but sustainable production remains a big challenging. This study proposed the ultrasound-assisted biosynthesis of cinnamyl acetate using self-made immobilized lipase CSL@OMS-C 8 , with computational fluid dynamics (CFD) and molecular simulations revealing the hydrodynamic properties and lipase-catalytic mechanisms. The results demonstrate that ultrasonication-intensified enzymatic reaction facilitated 96.6 % conversion of cinnamic alcohol, due to the ultrasound-assisted catalytic efficiency of 13.7 mmol/g·min. Molecular docking analysis identifies the lowest binding energy of −3.7 kcal·mol −1 between lipase and vinyl acetate, contributing to the highest conversion rates compared to acetic acid, ethyl acetate. CFD simulation indicates that ultrasonic energy waves promote substrate diffusion and mixing with lower shear stress. The catalytic stability of CSL@OMS-C 8 was confirmed by 60.1 % of relative activity after 10-time reuse. This paper theoretically and experimentally studied the ultrasonic-assisted enzymatic synthesis of cinnamyl acetate, showcasing huge potential for sustainable production of flavor esters.
研究领域:
生物技术
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化学工程
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食品科学
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材料科学
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计算化学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）