Food Chemistry-X
·
2024
·
IF 6.5
Maiquan Li,Yunxia Dong,Mangjun Kang,Tiantian Tao,Wenlan Li,Sheng Zhang,Wei Quan,Zhonghua Liu
Hyperglycemia can cause early damage to human bady and develop into diabates that will severely threaten human healthy. The effectively clinical treatment of hyperglycemiais is by inhibiting the activity of α-amylase. Black tea has been reported to show inhibitory effect on α-amylase and can be used for hyperglycemia treatment. However, the mechanism underlying is unclear. In this study, in vivo experiment showed that black tea theaflavins extract (BTE) effectively alleviated hyperglycemia. In vitro experiment showed that the effects may be caused by the interation between theaflavins and α-amylase. While TF1 and TF3 were mixed type inhibitors of α-amylase, TF2A and TF2B were competitive inhibitors of α-amylase. Molecular docking analysis showed that theaflavins monomers interacted with the hydrophobic region of α-amylase. Further study verified that monomer-α-amylase complex was spontaneously formed depending on hydrophobic interactions. Taken together, theaflavins showed potential anti-hyperglycemia effect via inhibiting α-amylase activity. Our results suggested that theaflavins might be utilized as a new type of α-amylase inhibitor to prevent and cure hyperglycemia.
研究领域:
营养学
·
药理学
·
分子生物学
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DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2015
·Vol. 81
·期 6
·
IF 3.668
Zhoukun Li,Jiale Wu,Biying Zhang,Fei Wang,Xianfeng Ye,Yan Huang,Qiang Huang,Zhongli Cui
A novel α-amylase, AmyM, was purified from the culture supernatant of Corallococcus sp. strain EGB. AmyM is a maltohexaose-forming exoamylase with an apparent molecular mass of 43 kDa. Based on the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry and peptide mass fingerprinting of AmyM and by comparison to the genome sequence of Corallococcus coralloides DSM 2259, the AmyM gene was identified and cloned into Escherichia coli. amyM encodes a secretory amylase with a predicted signal peptide of 23 amino acid residues, which showed no significant identity with known and functionally verified amylases. amyM was expressed in E. coli BL21(DE3) cells with a hexahistidine tag. The signal peptide efficiently induced the secretion of mature AmyM in E. coli. Recombinant AmyM (rAmyM) was purified by Ni-nitrilotriacetic acid (NTA) affinity chromatography, with a specific activity of up to 14,000 U/mg. rAmyM was optimally active at 50°C in Tris-HCl buffer (50 mM; pH 7.0) and stable at temperatures of <50°C. rAmyM was stable over a wide range of pH values (from pH 5.0 to 10.0) and highly tolerant to high concentrations of salts, detergents, and various organic solvents. Its activity toward starch was independent of calcium ions. The Km and V max of recombinant AmyM for soluble starch were 6.61 mg ml−1 and 44,301.5 μmol min−1 mg−1, respectively. End product analysis showed that maltohexaose accounted for 59.4% of the maltooligosaccharides produced. These characteristics indicate that AmyM has great potential in industrial applications.
研究领域:
生物化学
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酶学
·
微生物学
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DOI
PubMed
高影响因子
Waste and Biomass Valorization
·
2024
·
IF 2.6
Chen Ziqian,Gao Xiaoyan,Zhu Yihui,Deng Yuefeng,Wang Jianjun,Yang Chengli,Hu Kaishun,He Guanya,Li Dali
Food waste cuttlebone has the potential as the raw material of carrier for enzyme immobilization. In this study, we presented a method for synthesizing CaCO 3 nanoparticles coated chitosan (nano-CaCO 3 @chitosan) using cuttlebone as the raw material in the deep eutectic solvent of betaine and urea. The yield of nano-CaCO 3 @chitosan was 89.9%. The nano-CaCO 3 @chitosan was used for immobilization of α-amylase. The yield of enzyme protein was 65.6%. The loading of α-amylase on these nanoparticles was 49.1 mg/g. The optimum reaction conditions of the immobilized α-amylase were 80 °C and pH 4.0. The residual activity of the immobilized α-amylase was 82.9% after reused for 10 cycles. The raw materials for preparing nano-CaCO 3 @chitosan were almost from cuttlebone. The nano-CaCO 3 @chitosan was regarded as reassembly of cuttlebone. Therefore, food waste cuttlebone was utilized as bioresource. Graphical
研究领域:
生物技术
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食品科学
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酶工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yajuan Qin,Xiaoai Chen,Fei Xu,Kexue Zhu,Ping Wang,Yutong Zhang,Yanjun Zhang
The human dietary system, which contains a variety of compounds such as polyphenols and polysaccharides, is very complex. Whether polysaccharides affect the inhibitory of polyphenol mixtures on α-amylase needs to be further investigated. The aim of this study was to analyze the effect and mechanism of pectin on the inhibition of α-amylase by a mixture of rutin and quercetin (R–Q). Results revealed that the inhibition and quenching affinity of R–Q for α-amylase was enhanced by pectin. The Stern-Volmer quenching constant of R–Q–α-amylase was increased by pectin from (6.08 ± 0.453) × 10 3 mL/mg to (9.80 ± 0.285) × 10 3 mL/mg. Pectin enhanced the ability of R–Q to inhibit α-amylase for two main reasons. On the one hand, it was owing to the binding of pectin to rutin, which increased the opportunity for quercetin to bind to the active center of α-amylase, thus enhancing the inhibitory effect of R–Q on α-amylase. On the other hand, pectin and quercetin simultaneously bound to different sites of α-amylase by noncovalent interactions to form the ternary complex of pectin–α-amylase–quercetin. The conformation of α-amylase and the hydrophobicity of amino acid residues were altered by the ternary complex, thereby enhancing the hydrogen bonding in the reaction system.
研究领域:
食品科学
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生物化学
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DOI
PubMed
高影响因子
Food & Function
·
2018
·Vol. 9
·期 5
·2644-2652
·
IF 3.289
Can Xu,Ningbo Qin,Chunyan Yan,Shumei Wang
The root of Pueraria lobata is considered to be a medicinal and edible herb for the treatment of diabetes, and it has a long history of application in China. To explore the constituents responsible for the anti-hyperglycemic activities of P. lobata, a water-soluble polysaccharide (PL70-1-1) was isolated and purified by using a DEAE-Cellulose 52 anion exchange column and a Sephacryl S-100 gel filtration column. Its molecular weight (2584 Da) was determined by high performance gel permeation chromatography (HPGPC). Its structure was deduced by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide composition analysis, gas chromatography coupled with mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). It was deduced that PL70-1-1 was a glucan, and its main chain consisted of (1→)-linked β-D-glucose, (1→4)-linked α-D-glucose, (1→4, 6)-linked β-D-glucose, and (1→3)-linked α-D-glucose, and the branch chain consisted of (1→)-linked β-D-glucose. The results of scanning electron microscopy showed that PL70-1-1 had a needle-like shape, and the surface had a scaly texture. The Congo red experiment showed that PL70-1-1 did not have a triple-helix structure. In addition, PL70 and PL70-1 displayed selective inhibitory effects on α-amylase and α-glucosidase in vitro. PL70 had remarkable α-glucosidase inhibitory activity. However, PL70-1-1 exhibited outstanding α-amylase inhibitory activity, with an IC50 of 3.945 μM in vitro. This indicated that its activity was 417 times higher than the positive control acarbose. PL70-1-1 may be beneficial as an α-amylase inhibitor, reducing the postprandial blood glucose level and treating type 2 diabetes.
研究领域:
药用植物学
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生物化学
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代谢疾病研究
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Jing Meng,Qingyue Li,Zengyuan Cao,Dongyu Gu,Yunxiao Wang,Yunci Zhang,Yi Wang,Yi Yang,Fei He
In the present study, an efficient method based on ligand fishing and high-speed counter-current chromatography (HSCCC) was established to screen, enrich and separate the active components with the α-amylase inhibitory activity from a traditional dish Toona sinensis . The active components were screened from T. sinensis by ligand fishing using the magnetic immobilized α-amylase prepared through solvothermal and crosslinking methods. HSCCC was used to separate the target compound according to the K value. As a result, a potential active compound 1,2,3,4,6-penta-O-galloyl-β- d -glucose and a non-target compound quercetin-3-O-α-L-rhamnopyranoside were separated and identified. In - vitro experiments indicated that 1,2,3,4,6-penta-O-galloyl-β- d -glucose had the activity against α-amylase and the IC 50 value was 93.49 ± 0.80 μg/mL which was higher than that of the non-target compound. The result further confirmed the molecular fishing effect of magnetic immobilized α-amylase. The present study can not only find and separate the hypoglycemic substances in T. sinensis quickly and effectively, but also can provide a new approach for the study of natural active components.
研究领域:
植物化学
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药理学
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Liqin Liu,Xingye An,Hao Zhang,Zonghong Lu,Shuangxi Nie,Haibing Cao,Qingliang Xu,Hongbin Liu
Starch based bio-latex has been widely researched in the coating paper area for the purpose of partial replacement of petroleum-based binders. In this paper, a green and facile ball milling pretreatment was proposed to modify the starch granules before α-amylase hydrolysis by breaking up their crystalline structure, thus improving the accessibility and susceptibility of amylase into starch structure. It was found that the improved hydrolysis process after 8 h ball milling can generate suitable degree of polymerization of polysaccharides or oligosaccharides, which further facilitated the following H 2 O 2 oxidation and SHMP crosslinking processes. In addition, a mechanism was also demonstrated to illustrate the improvement induced by ball milling pretreatment. The prepared bio-latex with crosslinking-structure performed excellent adhesive properties when substituted 25 % of petroleum-based latex during paper coating application, which showed great potential in improving the economic, cost, and environment benefits of traditional production of coated paper.
研究领域:
材料科学
·
生物化学
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DOI
PubMed
高影响因子
ACS Agricultural Science & Technology
·
2024
·
IF 2.3
Leiyu Yang,Yifan Luo,Yapeng Chen,Sanyan Wang,Huashan Wang,Meiyi Wang
Fomesafen serves as a widely employed selective herbicide for addressing broadleaf weeds, but the short duration of efficacy limits utilization efficiency. There exists an exigent requirement to extend its efficacy through controlled release mechanisms. Fomesafen@SiO2-starch microspheres with α-amylase responsiveness were synthesized through the direct binding of drug-loaded silica microspheres and modified starch. This fabrication method capitalizes on the enzymatic degradation potential of the outer starch layer by amylase. In contrast with earlier analogous structures that exhibited inferior drug loading efficacy, the prepared fomesafen@SiO2-starch microspheres demonstrated a significantly enhanced drug loading capacity of up to 35.7%. Furthermore, in comparison to fomesafen technical, the prepared fomesafen@SiO2-starch microspheres exhibited a notable capacity to mitigate the photolysis of fomesafen through the utilization of the starch outer layer. Additionally, the fomesafen@SiO2-starch microspheres demonstrated favorable wettability and adhesive properties. At the recommended dosage, the herbicidal efficacy of fomesafen@SiO2-starch microspheres against Brassica napus L. and Portulaca oleracea L. over 14 days was observed to be comparable to that of the fomesafen technical, concurrently exhibiting a degree of sustained release. These findings underscore the potential of microspheres in regulating the release of fomesafen, thereby presenting a promising avenue for the development of sustainable drug delivery systems in agriculture.
研究领域:
农业科学
·
材料科学
·
植物保护学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Yi-Fan Tang,Wen-Xi Zhan,Mi-Zhuan Li,Lei Wang,Jie-Ying Wei,Jun-ling Deng,Zhong-Xiu Chen
Glutathione (GSH) is a natural antioxidant that helps fight free radicals. Whether it will affect the activity of amylase and starch digestion remains unknown. This research disclosed that GSH could interact with starch through hydrogen bonds, which accelerated the swelling of starch granules and promoted the formation of ordered double-helix crystalline, and therefore inhibited starch digestion. Moreover, pig pancreas α-amylase (PPA) which was incubated with GSH displayed a less stable conformation and decreased activity. However, in a crowded media constructed by sodium caseinate (NaCas), an antagonistic effect existed between GSH and NaCas. As the rate and extent of starch digestion have been linked with health aspects, this study suggests that GSH can be used in the formulation of diet foods. It also reminds us to consider the synergistic or antagonistic effects caused by the coexisted components in the complexed food matrix.
研究领域:
食品科学
·
生物化学
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DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 2.579
Zhongjie Wu,Wei Qi,Mengfan Wang,Yuefei Wang,Rongxin Su,Zhimin He
The ceramic powder with high metal content (MCP) was prepared as a new kind of immobilization carrier. Cu-MCP showed the best affinity to α-amylase and exhibited maximal activity. The effects of metal content, chelation time and amylase concentration on Cu-MCP-amylase activity were investigated. Under the optimal preparation conditions (the ratio of metal hydroxide precipitation to matrix (P/M): 0.23, chelation time: 8 h and amylase solution: 2.2 g/L), the activity of Cu-MCP-amylase could reach 31.5 U/g (54.5% of activity yield). Then, both Cu-MCP and Cu-MCP-amylase were characterized by XRD, SEM, BET-N 2 and FTIR. These characterizations confirmed that the Cu-MCP was a superior carrier with significant mechanical strength, considerable surface area, stable environment, homogeneous surface and low cost. Meanwhile, it also indicated that amylase had been efficiently immobilized on the external surface of Cu-MCP. Next, the properties of Cu-MCP-amylase were determined. It had optimal pH 7.0 and optimal temperature 70 °C with improved thermal stability. Finally, Cu-MCP-amylase showed significant catalytic capacity and stability in a column reactor, which could retain 80% of initial catalytic capacity after 40 recycle times.
研究领域:
生物化学
·
酶工程
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产品关联
DOI
高影响因子
JOURNAL OF INSECT SCIENCE
·
2014
·
IF 0.921
Wenping Xu,Qingchun Huang,Xiwei Wu,Xiaoqin Yu,Xuexiao Wang,Liming Tao
Midgut α-amylase is an important digestive enzyme involved in larval energy metabolism and carbohydrate assimilation. In this article, the properties of midgut α-amylase from the Oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae), larvae were characterized, and its in vitro responses to chemical inhibitors were also determined. The kinetic parameters Km and Vmax of midgut α-amylase were 0.064 M, 4.81 U mg pro(-1) in phosphate buffer, and 0.128 M, 1.96 U mg pro(-1) in barbiturate-acetate buffer; α-amylase activity linearly increased as starch concentration increased. α-Amylase activity was not influenced by amino acids such as Pro, Met, Try, His, Ala, and Phe but was strongly activated by antioxidants. Reduced glutathione, 1,4-dithiothreitol, β-mercaptoethanol, and ascorbic acid improved the activity of α-amylase about 2.06, 3.46, 3.37, and 6.38 times, respectively, relative to the control. Ethylenediaminetetraacetic acid, sodium dodecyl sulfonate, and N-bromosuccinimide (NBS) strongly inhibited α-amylase. α-, β-, and γ-cyclodextrin were not the preferred substrates for α-amylase. Kinetic analysis showed that IC50 value of NBS against α-amylase was 1.52 (±0.26) µM, and the mode of action of NBS with Ki as 2.53 (0.35) µM was a mixed-type inhibition that indicated a combination of partial competitive and pure noncompetitive inhibition. The midgut α-amylase of armyworm larvae may be a potential target for novel insecticide development and pest control.
研究领域:
昆虫生理学
·
酶学
·
害虫控制
·
生物化学
·
分子生物学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2013
·
IF 3.548
Ling Jiang,Liying Zhu,Xian Xu,Ming Lin,Yanping Li,Xiaotong Li,Huaiyan Cui,He Huang
Laboratory mutagenesis of microorganisms offers the possibility of relating acquired mutations to improve the quality of microbial cultures. In the present study, a mutant strain, Clostridium tyrobutyricum ATCC 25755 DG-8, with significantly elevated α-amylase activity as well as resistant to the non-metabolizable and toxic glucose analog 2-deoxyglucose (2-DG) was obtained by implanting the low-energy nitrogen ion beam. DG-8 was further developed to produce hydrogen by simultaneous saccharification and fermentation (SSF) directly form cassava starch in batch fermentation mode, which to our knowledge is at the first attempt in genus Clostridium . Our results demonstrated that the increased activity of α-amylase would be attributed to the hydrogen over-producing. Higher hydrogen yield (3.2 mol/mol glucose) was achieved with the volumetric productivity of 0.41 L/h/L when the initial total sugar concentration of cassava starch rise up to 100 g/L. The present work will help to decrease the cost of hydrogen fermentation process and stimulate its industrial application in the near future.
研究领域:
微生物学
·
生物工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）