Food Biophysics
·
2016
·Vol. 12
·期 1
·78-87
·
IF 1.605
Wu Zhibing,Shen Liangliang,Han Qingguo,Lu Jun,Tang Haifeng,Xu Xu,Xu Hong,Huang Fengwen,Xie Jiangfeng,He Zhendan,Zeng Zheling,Hu Zhangli
Ligupurpuroside A is a glycoside extracted from Ku-Ding tea. As extracts from Ku-Ding tea exhibit anti-inflammatory property, we hypothesize that Ligupurpuroside A may be an active compound which inhibits trypsin activity during the anti-inflammatory process. The mechanism and nature of inhibition of trypsin by Ligupurpuroside A have been studied by multi-spectroscopic method, enzyme-activity assay and molecular docking. Enzyme activity assay reveals that Ligupurpuroside A significantly inhibits the activity of trypsin through a competitive manner with an IC 50 value of 3.08 × 10 −3 mol L −1 . Fluorescence titration together with thermodynamic analysis indicate that a Ligupurpuroside A-trypsin complex is formed, and that hydrophobic force and hydrogen bonding are the main forces stabilizing the complex. UV-vis absorption, synchronous fluorescence and circular dichroism spectra show that the interaction between Ligupurpuroside A and trypsin induces conformational changes of trypsin with a decrease in the contents of α-helix and β-sheet. Finally, molecular docking further suggests that Ligupurpuroside A molecule binds within the active pocket of trypsin via hydrophobic force and hydrogen bond. Results from this study of the interaction of trypsin with its natural inhibitor should be useful to minimize the antinutritional effects and make full use of tea extracts in the food industry, and be also helpful to the design of the drugs for the diseases related to overexpression of trypsin.
研究领域:
生物化学
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药物设计
·
食品科学
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高影响因子
ANALYTICA CHIMICA ACTA
·
2026
·
IF 6.1
Leheng Wang,Jiyao Zhou,Zimeng Chen,Yi Lu,Guang Huang,Yechen Hu,Changgao Huang,Bangbang Wei,Yun Chen
Trypsin inhibitors (TIs) are common anti-nutritional factors in legumes and grains, necessitating reliable detection for food nutrition assessment and feed safety control. This study took advantage of immobilized enzymes and successfully constructed an efficient magnetic core-shell composite material, Fe 3 O 4 @SA/Trypsin@UiO-66. Within this structure, the sodium alginate (SA) hydrogel provides a mild microenvironment for trypsin immobilization, while the outer UiO-66 metal-organic framework (MOF) shell not only enhances the nanoreactor's stability but also improves substrate enrichment and catalytic efficiency through a nanoconfinement effect. The nanoreactor exhibits robust magnetic separability, well-retained catalytic activity, and long-term applicability. Systematic performance studies revealed that, compared to free enzyme, the nanoreactor exhibited enhanced stability under freeze-thaw cycles and across broad pH (2-11) and temperature (25-70 °C) ranges, maintaining over 70% of its initial activity after multiple uses. In practical sample detection, the established nanoreactor system, which uses the nanoreactor as the core material and benzoyl- l -arginine ethyl ester (BAEE) as the substrate, was successfully applied to analyze TI content in various grain flours and fish feeds. In addition, the results provide evidence supporting the role of thermal processing in reducing TI activity. This research provides a reliable approach for the efficient detection of anti-nutritional factors in complex matrices.
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FOOD HYDROCOLLOIDS
·
2019
·
IF 5.839
Jia-Nan Yan,Wen-Hui Shang,Jun Zhao,Jia-Run Han,Wen-Gang Jin,Hai-Tao Wang,Yi-Nan Du,Hai-Tao Wu,Srinivas Janaswamy,Youling L. Xiong,Bei-Wei Zhu
This article reported the gelation and microstructural properties of scallop male gonads hydrolysates (SMGHs) in the presence of κ-Carrageenan (κ-C) and treated or untreated with potassium chloride (KCl). The presence of κ-C significantly increased the elastic moduli (10.3–449.5 Pa) and melting temperature (32.7–46.7 °C) of SMGHs. The decrease in the relaxation time ( T 21 , T 23 ) signified the strong binding between SMGHs and κ-C. The blue shift in the amide I and II peals coupled with a new band of 1159 cm −1 in SMGHs/κ-C further demonstrated the electrostatic interactions between SMGHs and κ-C. κ-C rose the percentage of β-sheets from 28.10% to 35.93% but at the expense of α-helix and β-turn fractions and highly ebbed the intrinsic fluorescence of SMGHs. Such scenarios resulted in a more compact network formation and flocculation of κ-C chains. The salt-treatment to κ-C promoted helical formation, however, presence of SMGHs created larger interstitial spaces in the κ-C network due to aggregates of SMGHs and decreased the overall gel strength. The outcome promises novel opportunities in the design and development of functional hydrogels based on protein and polysaccharide complexes for food , pharmaceutical and biomedical applications.
研究领域:
食品科学
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生物化学
·
材料科学
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高影响因子
Journal of Chemistry
·
2023
·
IF 3
Tong Chen,Wanjing Cui,Ziwei Bi,Yafei Guo,Guoliang Zhu,Xiuyun Pan,Zhiqiang Cui,Zhen Yang,Tianlong Deng
The analysis of iodine content in kelp is mainly focused on determining total iodine content, which lacks a rapid and sensitive analytical method for iodine species corresponding to iodate, iodide, monoiodotyrosine (MIT), and diiodo-tyrosine (DIT). Based on exploring the pretreatment methods of enzymatic hydrolysis of kelp, a rapid determination method of high-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for different iodine species existed in kelp samples was established. The pretreatment method is trypsin hydrolysis of kelp samples treated at 50°C for 10 hours, then the extraction solution was obtained by centrifugation, and filtration was proved for the first time. A high-efficiency separation anion-exchange column (Dionex IonPac AS-14) for iodate, iodide, MIT, and DIT with 0.1 mol·L−1(NH4)2CO3 solution at pH = 9 as a mobile phase, a flow rate of 0.8 mL·min−1 for the first 1500 s, and 1.2 mL·min−1 for the last 1800 s was confirmed. The linear ranges of the standard calibrations on four iodine species are 1.0–150 μg·L−1, and the detection limits are 1.62, 1.02, 1.59, and 2.55 μg·L−1, respectively, while the RSD values of four iodine species are all less than 2%. Under the optimized conditions, the proposed method was successfully applied for the speciation analysis of iodine in kelp samples.
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JOURNAL OF CHROMATOGRAPHY A
·
2023
·
IF 4.1
Jincai Wang,Xiaoling Huang,Jie Mei,Xinwei Chen,Rong Ma,Guowei Li,Zhengjin Jiang,Jialiang Guo
In this study, an at-line nanofractionation (ANF) platform was successfully fabricated in parallel with mass spectrometry and trypsin inhibitory bioactivity assessment for rapid screening of trypsin inhibitors (TIs) from natural products for the first time. After systematic optimization, the ANF platform was applied to screen and identify TIs in the extract of a traditional Chinese herb, i.e., Cotinus coggygria Scop. The semi-preparative reverse-phase liquid chromatography was used subsequently to further simplify and enrich the insufficiently separated components. After comprehensive evaluation and validation, the ANF platform successfully identified 12 compounds as potential TIs, including 8 flavonoids and 2 organic acids . Additionally, a comparison study was conducted using two other ligand fishing approaches, i.e., capillary monolithic and magnetic beads-based trypsin-immobilized enzyme microreactors, which successfully identified 8 identical flavonoids as TIs. Importantly, the molecular docking study showed the molecular interactions between enzymes and inhibitors, thus strongly supporting the experimental results. Overall, this work has fully demonstrated the feasibility of the established ANF platform for screening TIs from Cotinus coggygria Scop., and proved its great prospects for screening bioactive components from natural products.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 413
·期 20
·5239-5249
·
IF 4.157
Yin Chenhui,Chen Ligang,Niu Na
A sensitive and effective strategy for the detection of cytochrome c (Cyt c) and trypsin was developed using biomass nitrogen-doped carbon quantum dots (N-CQDs) as the fluorescence probe. N-CQDs were synthesized through a one-pot hydrothermal method by utilizing cellulolytic enzyme lignin as the carbon source and ammonia as the solvent and nitrogen source. The obtained N-CQDs had good water solubility and stable optical properties. The introduction of nitrogen increased fluorescence quantum yield (QY) to 8.23%, which was almost four times as high as that before nitrogen doping. The N-CQDs were fabricated as a label-free biosensor to detect Cyt c and trypsin. The fluorescence of N-CQDs was quenched with positively charged Cyt c due to electrostatic induction aggregation and static quenching. However, Cyt c tended to be hydrolyzed into small peptides in the presence of trypsin, which caused fluorescence recovery of the N-CQDs/Cyt c complex. A wide linear response range was achieved for Cyt c within 1–50 μM and the developed N-CQDs/Cyt c complex displayed a linear response for trypsin within 0.09–5.4 U/mL. The detection limits were 0.29 μM for Cyt c and 0.013 U/mL for trypsin, respectively. Furthermore, this assay had been applied to Cyt c and trypsin detection in serum samples with the recoveries in the range of 94.6–98.5% and 95.5–102.0%, respectively. The established method was sensitive, selective, easy to operate, and low cost, which proved its potential application in clinical diagnosis. Graphical abstract
The synthesis and fluorescence mechanism of N-CQDs and the strategy for Cyt c and trypsin detection
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MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Shan Chen,Jinli Fu,Shu Zhou,Xiaodan Wu,Sisi Tang,Pengfei Zhao,Zhaohui Zhang
This report depicts an environment-friendly molecularly imprinted fluorescence sensor for rapid determination of trypsin based on new near infrared (NIR) fluorescence carbon dots and metal–organic frameworks. The novel NIR fluorescence carbon dots were facilely synthesized from green plants by one-step solvothermal treatment, and the imprinted sensor was prepared by sol–gel under mild condition. The imprinted NIR fluorescence sensor was characterized by Fourier-transform infrared spectrometry, energy disperse spectroscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The results showed the introduction of zeolite imidazolate framework-8 can improve the fluorescence response sensitivity and response speed. Under optimized conditions, the fluorescence quenching of the imprinted NIR fluorescence sensor was linear relationship with the increasing trypsin concentration in the range of 0.05–9.0 ng/L with a detection limit of 8.8 pg/L. The developed imprinted fluorescence sensor can selectively recognize trypsin in 1.5 min, which was applied to rapidly and sensitively detect trypsin in serum and urine samples successfully with the recoveries of 95.3–104.1% and 97.7–105.2%, respectively. The as-prepared imprinted fluorescence sensor provides a viable and eco-friendly method for rapidly sensitive detection of trace bio-macromolecule in complex samples.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·
IF 6.7
Bao-Rong Wang,Stella Zhu,Wen-Qi Liang,Zi-Ying Zhao,Ying-Hua Zhang,Zhi-Shen Mu
Cow’s milk-based infant formula aims to approximate human milk, but bovine αS1-casein remains an important allergen-related protein with a profile distinct from human milk caseins. This study controlled trypsin hydrolysis to preferentially reduce intact αS1-casein and generate candidate bioactive peptides. Under 38 °C, pH 8.0, and 5 h, the relative residual peak area of αS1-casein decreased markedly, while αS2-casein and β-casein remained detectable at 33.15% and 45.01%, respectively. Peptidomics identified 17 peptides, among which HQGLPQEVLNENLLR showed the strongest predicted binding affinity to α-amylase by molecular docking (−13.98 kcal/mol). The hydrolysate showed ABTS radical scavenging activity of 92.10% and α-amylase inhibition of 53.44%. Molecular dynamics further supported the stability of the peptide–enzyme complex. These findings provide a preliminary process window for reducing intact αS1-casein and prioritizing candidate functional peptides from casein hydrolysates.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Di Hu,Dakun Long,Tian Xia,Yunhao Wang,Shicheng Zhang,Jianjie Wang,Xiaowen Shi,Yanfeng Wang
Complex and stubborn bacterial biofilm infections significantly hinder diabetic wound healing and threaten public health. Therefore, a dressing material that effectively clears biofilms and promotes wound healing is urgently required. Herein, we introduce a novel strategy for simultaneously dispersing extracellular polymeric substances and eradicating drug-resistant bacteria. We prepared an ultrabroad-spectrum and injectable quaternized chitosan (QCS) hydrogel loaded with trypsin, which degrades biofilm extracellular proteins. Increased temperature initiated QCS gelation to form the hydrogel, enabling the sustained release of trypsin and effective adherence of the hydrogel to irregularly shaped wounds. To reproduce clinical scenarios, biofilms formed by a mixture of Staphylococcus aureus ( S. aureus ), Methicillin-resistant S. aureus , and Pseudomonas aeruginosa were administered to the wounds of rats with streptozotocin-induced diabetes. Under these severe infection conditions, the hydrogel efficiently suppressed inflammation, promoted angiogenesis, and enhanced collagen deposition, resulting in accelerated healing of diabetic wounds. Notably, the hydrogel demonstrates excellent biocompatibility without cytotoxicity. In summary, we present a trypsin-loaded QCS hydrogel with tremendous clinical applications potential for the treatment of chronic infected wounds.
研究领域:
材料科学
·
生物医学工程
·
药学
·
伤口愈合
·
细菌感染
·
糖尿病
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JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xiangxiang Li,Yanzhe Wang,Shaoyang Hu,Wansong Zong,Rutao Liu
Nanoplastics (NPs) are emerging global contaminants that can exacerbate the animal toxicity and cytotoxicity of cadmium (Cd). However, the mechanisms by which NPs influence the toxic effects of Cd on key functional proteins within the body remain unknown. In this study, trypsin, a protein that is prone to coexist with NPs in the digestive tract, was selected as the target protein. The effects and mechanisms of NPs on Cd 2+ -induced structural damage at multiple levels and alterations in the biological function of trypsin were investigated using multi-spectroscopy techniques, enzyme activity assays, and computational modeling. Results indicated that the Cd 2+ -induced decrease and red shift of the trypsin backbone peak were exacerbated by the presence of NPs, leading to more serve backbone loosening. Furthermore, compared to Cd 2+ , NPs@Cd 2+ caused a more pronounced reduction in the α -helix content of trypsin. These structural changes led to the opening of the trypsin pocket and the overactivation of the enzyme (NPs@Cd 2+ : 227.22%; Cd 2+ : 53.35%). Ultimately, the formation of a “protein corona” around NPs@Cd 2+ and the metal contact of Cd 2+ to the trypsin surface were identified as the mechanisms by which NPs enhanced the protein toxicity of Cd 2+ . This study elucidates, for the first time, the effects and underlying mechanisms of NPs on the toxicity of key functional proteins of Cd 2+ . These findings offer novel mechanistic insights and critical evidence essential for evaluating the risks associated with NPs.
研究领域:
环境科学
·
毒理学
·
蛋白质化学
·
计算生物学
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SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Fanping Shi,Lei Wang,Yan Li,Yu Zhang,Xingguang Su
In this work, we designed a simple, convenient and high sensitive “turn-on” fluorescence platform for trypsin assay based on N -acetyl- l -cysteine capped CdTe Quantum Dots (NAC-CdTe QDs). A series of NAC-CdTe QDs with different sizes were synthesized in aqueous via refluxing routes. The fluorescence of NAC-CdTe QDs could be effectively quenched by hemoglobin (Hb) via the electron transfer interactions from NAC-CdTe QDs to hemoglobin due to the electrostatic attraction of QDs/Hb complex. In the presence of trypsin, hemoglobin would be hydrolyzed to small peptides, releasing inactive hemin molecules.Hemin has slight effect on the fluorescent intensity of NAC-CdTe QDs, so the combination of hemoglobin and NAC-CdTe QDs would be dissociated, leading to the fluorescence recovery of NAC-CdTe QDs. Therefore, we could monitor the trypsin activity by utilizing the different fluoresence responses of NAC-CdTe QDs to hemoglobin and hemin. The recovered fluorescence intensity of NAC-CdTe QDs was proportional to the logarithm of trypsin concentration in the range of 0.05–10 mU mL −1 and the detection limit for trypsin was 0.036 mU mL −1 . A model for trypsin inhibition was further established to verify the feasibility of the system. The IC 50 value is 3.06 μg mL −1 for the inhibitor from soybean. Thus, a label free real time fluorometric assay for trypsin and inhibitor screening has been developed. The established method showed a high selectivity and sensitivity for trypsin over other biological relevant enzyme, and it was applied to the determination of trypsin in human urine sample with satisfactory results.
研究领域:
生物化学
·
医学诊断
·
纳米技术
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 8
·1-9
·
IF 5.479
Kong Weisu,Li Qin,Xia Lian,Li Xiaomeng,Sun Han,Kong Rong-Mei,Qu Fengli
A photoelectrochemical (PEC) method has been developed for sensitive detection of trypsin. It is based on the use of a composite consisting of MoS 2 nanosheets and TiO 2 nanorods (MoS 2 -TiO 2 ). The material has a high specific surface area, superior electrical conductivity, excellent biocompatibility and good band gap matching. The composite was synthesized by a one-pot method using TiO 2 as a template. This results in a uniform distribution of the MoS 2 nanosheets (<5 layers) in the composite. If the composite, placed on an indium tin oxide (ITO) electrode, is coupled to apoferritin, the photocurrent response decreases due to the insulating effect of the protein. Trypsin, in acting as an alkaline protease, decomposes the apoferritin. This results in the recovery of the PEC signal. Attractive features of this PEC method include (a) a superior PEC signal, (b) sensor stability, (c) simple operation, and (d) the lack of any additional modifications of the biosensor. This warrants high sensitivity, reproducibility, repeatability and practicality. The ITO sensor has a linear response in the 1 to 1000 ng·mL −1 trypsin concentration range and a 0.82 ng·mL −1 detection limit. The assay was applied to the determination of trypsin in spiked serum samples and gave satisfactory results.
Schematic presentation of an indium tin oxide (ITO)/MoS 2 -TiO 2 sensor for detecting trypsin. The PEC signal was decreased after immobilization of apoferritin (APO) on the modified ITO. Trypsin catalytically hydrolyzes APO specifically and induces the PEC signal to recover.
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高影响因子
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