LWT-FOOD SCIENCE AND TECHNOLOGY
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2024
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IF 6
Yun Zhang,Yibing Zhang,Ruihua Lun,Qingshan Fu,Yuqiao Chang,Jiansen Du,Yi Zhang,Junping Yu
Conventional methods for Staphylococcus aureus ( S. aureus ) detection using mammalian immunoglobulins could yield false positive results, owing to the presence of the protein G-producing Streptococcus . In this study, because canine IgM can bind to protein A but not to protein G, we firstly designed a colorimetric platform based on canine IgM to identify S. aureus . Magnetic beads (MBs) functionalized with canine IgM acted as captors to enrich S. aureus , relying on the binding interaction between the Fc region of canine IgM and protein A in the bacterial cell wall, while horseradish peroxidase (HRP)-labeled rabbit anti- S. aureus IgG served as a tracer in the sandwich-type immunoassay, catalyzing the colorimetric reaction. Under optimal conditions, the proposed strategy achieved a satisfactory analytical performance with a broad linear range from 1.6 × 10 3 CFU/mL to 1.0 × 10 5 CFU/mL, a colorimetric minimum resolution of as low as 1.4 × 10 2 CFU/mL in 100 μL phosphate-buffered saline (PBS), and good selectivity in differentiating target from protein G-producing Streptococcus . Moreover, the proposed approach successfully identified S. aureus in various application scenarios (except for samples containing IgG), can be completed in less than 90 min, and was not dependent on any specialized equipment.
研究领域:
微生物学
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免疫学
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分析化学
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产品关联
DOI
高影响因子
Journal of Analytical Methods in Chemistry
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2022
·Vol. 2022
·期 1
·5711384
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IF 2.594
Miao Yu,Ming Liu,Yuan Li
This work describes a label-free electrochemical immunosensor for the sensing of Epstein-Barr virus (EBV) with high sensitivity. First, a monolayer of 1,6-hexanedithiol (HDT) was fabricated on the screen-printed electrode surface by the interaction between sulfur atoms and SPE. AuNPs can be modified on the electrode by the Au-S bond formed between the HDT-free group and Au atom in AuNPs. Protein A is then adsorbed onto AuNPs. Several parameters were optimized. The optimum concentration of protein A is 0.6 mg/mL. The optimum immobilization time for protein A is 90 min. The optimum concentration of antibody is 80 μ g/mL. The optimum immobilization time for antibody is 90 min. Directional immobilization of EBV antibody is achieved by high affinity binding of protein A to the Fc segment of antibody. When antigen specifically binds to antibody, the formation of immune complexes blocks electron transfer of [Fe(CN)6] 4-/3- and is reflected in the detection of cyclic voltammetry/electrochemical impedance spectroscopy. The detection range is 1 pg/mL–l00 ng/mL with a LOD of 0.1 pg/mL. In addition, the proposed sensor exhibited an excellent antiinterference property.
研究领域:
医学检测
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生物传感
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DOI
高影响因子
PROTEIN EXPRESSION AND PURIFICATION
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2018
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IF 1.338
Hualong Xi,Jinfei Yu,Qing Sun,Jingcai Lu,Tiejun Gu,Xiaonan Guo,Bo Li,Xiaorui Chen,Kaixin Zhang,Wei Kong,Yongge Wu
Streptococcus pneumoniae is a major pathogen that causes life-threatening diseases, such as pneumonia, otitis media , bacteremia , and meningitis, worldwide and especially in young children and the elderly. Pneumococcal surface protein A (PspA) is a widely studied candidate protein vaccine that represents a promising replacement for current polysaccharide and polysaccharide-conjugate vaccines. In this study, we describe a simple method to produce PspA of clade 4 from an Escherichia coli expression system using hydroxylapatite and ion-exchange chromatography. Using this method, we successfully expressed soluble PspA4 in 10 L of autoinducing culture medium, with a wet-cell yield of 19 g/L and a final PspA4 concentration of 22.8 mg/L. Additionally, we improved PspA4 purity from 17% to 70% in a single step through the use of hydroxylapatite, resulting in acquisition of recombinant PspA4 (>95% purity) at a final yield of 43% from the starting cell-lysis solution. We subsequently verified the secondary structure molecular weight of recombinant PspA4 by circular dichroism and mass spectrometry , respectively. These results demonstrated a highly efficient method for mass producing PspA4 protein and that can also be applied for purification of PspA proteins from other clades.
研究领域:
微生物学
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疫苗研究
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蛋白质工程
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DOI
PubMed
高影响因子
SENSORS
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2018
·Vol. 18
·期 11
·3757
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IF 2.475
Cuixia Guo,Xiaojie Yang,Zhiyuan Shen,Jian-Ping Wu,Suyi Zhong,Yonghong He,Tian Guan,Fangyi Chen
A phase-sensitive fluidic biosensor based on a spectral-domain low-coherence interferometer is presented in this paper. With a fiber optic probe employing the common-path interferometric configuration, subnanometric changes in thickness of the molecular layers can be detected through phase analysis of the acquired interference signal from the sensor surface. Advantages of this biosensor include its picometer-scale thickness sensitivity, 13.9-ms time response, and tolerance to the fluctuation in concentration of the target solution. The capabilities of this biosensor in monitoring specific molecular binding and recognizing specific molecular was successfully demonstrated by using the reactions between the molecules of protein A and IgG. The calculated minimum detectable concentration of IgG is 0.11 µg/mL.Keywords:phase-sensitive;low-coherence spectral-domain interferometer;fluidic;immunoassays
研究领域:
生物传感器
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光学干涉测量
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生物医学工程
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2015
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IF 2.729
Berlin Zang,Jun Ren,Li Xu,Lingyun Jia
Immobilization of affinity ligands on supporting matrices is a key step for the preparation of affinity chromatography resins, and an efficient coupling strategy can significantly improve the validity and cost of the affinity system, especially for systems that employ expensive recombinant proteins or antibodies as affinity ligands. This study described a simple method for obtaining site-specific immobilization of protein A (the ligand) via aldehyde-hydrazide conjugation and its application in antibody purification via protein A chromatography. An aldehyde group was generated at the N-terminus of protein A in vivo by co-expressing a formylglycine-generating enzyme (FGE) and recombinant protein A containing a FGE recognizing sequence (aldehyde tag) in Escherichia coli . The resulting aldehyde allowed direct immobilization of protein A onto the hydrazide-modified agarose matrices under mild condition. We found that 100 mM aniline was most effective for catalyzing the coupling reaction, and the recombinant protein A could be coupled with high selectivity, directly from a crude cell extract. The site-specific immobilized protein A showed good capacity for antibody purification. The specificity of the aldehyde-hydrazide reaction not only allowed site-specific immobilization of affinity ligands, but also improved the cost of the process by employing unpurified ligands, a method that might be of great use to industrial applications.
研究领域:
生物化学
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分子生物学
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蛋白质工程
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2025
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IF 7.3
Yuting Ren,Peng Ye,Limei Zhang,Huatai Zhu,Luying Wang,Jing Liu,Jiandu Lei
Inspiration by nature, we aimed to transfer the spatial distribution of flowers and grasses into the chromatographic column using raw green wood as a stationary phase for antibody purification. The column was made by modifying wood with dextran of varying chain lengths to emulate nature spatial distribution and coupling protein A. This retains a porous structure of wood and compensates for the drawback of its small specific surface area. The wood structure imparts the affinity wood monolithic column with high permeability. The jagged graft layer enhances the accessibility of the binding site by mitigating steric hindrance. The dextran-grafted affinity wood monolithic column exhibited static and dynamic adsorption capacities of 59.18 and 33.81 mg/g and achieved isolate IgG (purity >90%) in one step. This study identified the advantages and limitations of wood as a chromatographic matrix, providing insights for chromatography matrix improvement and suggesting new avenues for the fine utilization of wood.
研究领域:
生物工程
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材料科学
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DOI
高影响因子
MICROCHIMICA ACTA
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2020
·Vol. 187
·期 7
·1-9
·
IF 6.232
Wang Caixia,Li Mengsi,Wang Peijin,Liu Defang
An electrochemiluminescence (ECL) analytical platform is constructed based on boron nitride quantum dots (BNQDs) as a novel coreactant of luminol for quantitative assay of concanavalin A (Con A). Different from previous research that mainly focuses on its superior optical properties, BNQDs are used for the first time as a coreactant for boosting ECL intensity of luminol, which has a 10-fold enhancement compared with individual poly(luminol/aniline) nanorods loaded on reduced graphene oxide (PLA-rGO) using GCE. On the basis that BNQDs contain an abundance of active amino, a possible mechanism of amino oxidation facilitating ECL emission is proposed. Firstly, luminol as light spices are oxidized to luminol •− and BNQDs generate an abundance of BNQDs-NH +• via electrochemical oxidization, producing reductive intermediates BNQDs-N • in alkaline conditions. Finally, BNQDs-N • react with luminol •− to obtain the excited species AP 2−* , returning to ground state and emitting light. Due to the hindrance effect of Con A, the ECL intensity decreases gradually as various concentrations of Con A are modifying the electrode surface. Therefore, a sensitive ECL biosensor for detecting Con A is constructed exhibiting a wide linear range of 1.0 pg·mL −1 to 1.0 μg·mL −1 and a low detection limit of 0.15 pg·mL −1 .
Schematic representation of an electrochemiluminescence (ECL) biosensor based on boron nitride quantum dots (BNQDs) as an efficient coreactant of reduced graphene oxide functionalized poly(luminol/aniline) (PLA-rGO) for quantitative assay of concanavalin A (Con A).
研究领域:
分析化学
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纳米技术
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生物传感器
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产品关联
DOI
PubMed
高影响因子
Food Bioscience
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2025
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IF 5.9
Qing Zhang,Mengfan Ding,Zheng Huang,Shilong Jiang,Jianxin Zhao,Catherine Stanton,R. Paul Ross,Wei Chen,Bo Yang
The early life period is a critical phase for the colonization of initial gut microbes in infants, during which the immune system develops and matures. These processes have long-lasting implications that may extend into adolescence and even adulthood. Bifidobacterium longum subsp. infantis , recognized as an ideal probiotic during infancy, has the potential to modulate intestinal immunity and mitigate immune-mediated diseases. This research explored the potential of various B. longum subsp. infantis strains to modulate the balance between T helper (Th)1 and Th2 responses, immune cell populations, Immunoglobulin A (IgA), and the related genes expression in mice. Notably, B. longum subsp. infantis FHNFQ4M11 and CCFM1269 demonstrated more robust regulatory capabilities. These two strains, which exhibited higher ILA production, activated the aryl hydrocarbon receptor (AHR) signaling pathway, upregulated the levels of galectin-1 (Gal-1) and galectin-3 (Gal-3), and modulated Th1/Th2 differentiation markers in the colon. Additionally, these strains significantly elevated IgA concentrations in both serum and colon and modulated the gut microbiota composition. These findings underscored the potential of specific B. longum subsp. infantis strains as targeted probiotic interventions in early life, providing a promising strategy for promoting immune homeostasis and gut health in infants.
研究领域:
微生物学
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免疫学
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
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2025
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IF 2.3
Chang Guanglei,Yang Miaomiao,Xu Zhaobin,Wang Xinling,Li Wenyao,He Meixia,Zhang Jintao,Xu Yuanzhi,Wang Lulu,Zhang Liguo
The performance of chromatographic media affects the efficiency of purification. In this study, based on a T-type microfluidic droplet generation system, agarose microspheres with large pore size and high load were prepared by adjusting the viscosity of a 4% agarose solution to 70 mPa·s at high temperature. Optical microscopy revealed that the self-made agarose microspheres had a good spherical structure with an average particle size of 82.81 μm and a CV value of 0.0576. Subsequently, the stability and mechanical strength of the self-made agarose microspheres were improved by cross-linking and activation with epichlorohydrin. After the cross-linking and activation, the agarose microspheres were grafted with Protein A to make it have specific adsorption capacity for IgG. The adsorption capacity of the self-made agarose microspheres grafted with Protein A for IgG was 87 mg/g. In the complex serum environment, the agarose microspheres grafted with Protein A still maintained good IgG adsorption capacity and selectivity, demonstrating their potential in practical applications. This study demonstrates the great potential of microfluidic technology in the design and preparation of bio-separation media. By precisely controlling the particle size and pore size of the microspheres, the purification efficiency and selectivity can be significantly improved, providing a new solution for the efficient purification of bio-products. Graphical abstract
研究领域:
生物分离
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生物技术
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化学工程
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产品关联
DOI
高影响因子
Journal of Thoracic Disease
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2024
·Vol. 16
·期 9
·6024
·
IF 2.1
Guannan Chen,Jieqiong Song,Yue Zhou,Yuanyuan Wu,Chenghang Yang,Yingqin Wang,Ming Zhong
Background Ethyl palmitate (EP) is known to promote hepatic fetuin-A production and modulate inflammatory responses, but its potential role in lethal endotoxemia and sepsis remains unclear. This study investigates the plasma fetuin-A levels and further evaluates the impact of hepatic fetuin-A induced by EP on systemic inflammation and macrophage polarization in lethal endotoxemia and sepsis. Methods Blood samples from 55 sepsis patients and 18 non-septic controls with similar age and sex ratio were collected to perform proteomic analyses and identify significantly different proteins. Serum fetuin-A levels in lipopolysaccharide (LPS) induced endotoxemia mice were assayed by enzyme-linked immunosorbent assay (ELISA). The mouse hepatocyte cell (AML-12) was exposed to different concentrations of EP. In vivo experiments were conducted in which adult male C57BL/6J mice were given EP with or without intraperitoneal LPS. Fetuin-A was determined via western blot and immunohistochemical staining. Survival rates, lung and liver injury and levels of pro-inflammatory cytokines were also monitored and assessed using histology, real-time quantitative polymerase chain reaction (RT-qPCR) and ELISA. Additionally, the proportion of macrophages and M1/M2 subtypes in the lung and liver tissues were evaluated by flow cytometry. Results Our proteomic results revealed that the plasma fetuin-A levels were significantly decreased in sepsis patients compared with non-septic controls. Similarly, the serum fetuin-A levels were also reduced in endotoxemia mice compared with the control group. EP effectively promoted the production of fetuin-A in AML-12 cells and murine liver tissues. Subsequently, activation of fetuin-A by EP dramatically reduced LPS-induced murine mortality, alleviated lung and liver injury, down-regulated pro-inflammatory mediators and macrophage infiltration. Furthermore, EP regulated macrophage polarization from the M1 (CD45 + CD11b + F4/80 + CD86 + ) to the M2 (CD45 + CD11b + F4/80 + CD206 + ) subtype in murine liver tissue. Conclusions EP-induced production of fetuin-A prevents sepsis and endotoxemia progression by promoting M2 polarization of macrophages.
研究领域:
免疫学
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药理学
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病理学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2019
·
IF 9.518
Yun Zhang,Wenqing Tan,Yang Zhang,Huili Mao,Shuyou Shi,Liangwei Duan,Hui Wang,Junping Yu
To develop a specific method for the detection of S. aureus , chicken anti-protein A IgY was adopted for specifically capturing S. aureus , depending on the specific recognition of staphylococcal protein A (SPA) by chicken anti-protein A IgY, which can eliminate the interference from protein G-producing Streptococcus . HRP labeled IgG , Fc region of which has a high affinity towards SPA, was paired with IgY for the colorimeter analysis of the system. By optimizing the system, a super-low detection limit of 11 CFU of S. aureus in 100 μL PBS without enrichment, with a linear range from 5.0 × 10 2 CFU mL −1 to 5.0 × 10 4 CFU mL −1 was obtained. The entire assay was accomplished in less than 90 min and no cross-reactivity with the other tested bacterial species was observed. Moreover, the developed assay has been applied for the detection of S. aureus in three different types of real samples (sodium chloride injection, apple juice and human urine) with satisfactory results. To the best of our knowledge, it is the first time to report using chicken anti-protein A IgY and any IgG to detect S. aureus based on the dual-recognition mode of SPA. The novel method opened up a way for monitoring S. aureus in food samples with high sensitivity, specificity and simple operation.
研究领域:
微生物学
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分析化学
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食品安全
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产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Yu Fan,Xingrong Tan,Xin Ou,Qiyi Lu,Shihong Chen,Shaping Wei
In this work, a novel “on-off” electrochemiluminescence (ECL) biosensor was successfully constructed for ultrasensitive detection of concanavalin A (ConA). The “signal-on” state with strong initial ECL signal was obtained by Ag-doped graphitic carbon nitride nanosheet (Ag-g-C 3 N 4 ), which was modified onto the glassy carbon electrode (GCE) for immobilizing phenoxy dextran (DexP) through π-π interaction. Then, the target ConA was anchored onto the DexP/Ag-g-C 3 N 4 modified film via the specific carbohydrate-ConA interaction. Successively, polyaniline-3,4,9,10-perylenetetracarboxylic acid-DexP conjugate (denoted as PANI-PTCA-DexP), as the ECL signal quenching probe, was incubated onto the electrode through the carbohydrate-ConA interaction to achieve the “signal-off” state. Here, PTCA was used as a matrix for the high loading of PANI and DexP, PANI served as the quencher towards Ag-g-C 3 N 4 system, and DexP as the recognition element for bounding ConA. With the formation of the sandwiched structure of DexP, ConA and PANI-PTCA-DexP, a desirable quenching ECL signal was measured with S 2 O 8 2− as the co-reactant of Ag-g-C 3 N 4 . The quenching effect of PANI towards Ag-g-C 3 N 4 is positively correlated with the concentration of ConA. With such an “on-off” system, the detection of ConA was achieved with a wide linear range from 0.001 ng/mL to 50 ng/mL as well as a low detection limit down to 0.0003 ng/mL.
研究领域:
分析化学
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生物传感
·
材料科学
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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）