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期刊论文 62

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Preparation of hapten-specific monoclonal antibody for cadmium and its ELISA application to aqueous samples

Huan HE, Bo TANG, Cheng SUN, Shaogui YANG, Weijuan ZHENG, Zichun HUA

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 409-416 doi: 10.1007/s11783-011-0349-8

摘要: High-affinity and specific monoclonal antibodies against cadmium-ethylene diamine tetraacetic acid (EDTA) complex have been produced using the hybridoma technique. A hapten was synthesized and characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and UV-Vis. Competitive enzyme-linked immunosorbent assay (ELISA) for quantitative detection of cadmium in aqueous sample was developed. The monoclonal antibody with high level of binding affinity for Cd-IEDTA-BSA and high specificity for soluble Cd-EDTA complex showed less than 0.99% cross-reactivity with other 11 metals. The limit of detection was 0.10 μg·L , and the effective linear range was 10 –10 μg·L . The intra- and inter-assay coefficient variations were 1.5%–6.3% and 3.2%–7.4%, respectively. The spike recovery in different water samples were between 98.5% and 110.3%. The detection limit of this assay was well below the allowable concentration of cadmium (3 μg·L ), and the working range was wider than that of other methods which showed the range of 2.19–86.38 and 0–10 μg·L . The competitive ELISA established in this paper was sensitive and accurate in the screening of cadmium in aqueous samples. The results will lay a solid foundation for construction of an immunoassay kit for cadmium.

关键词: cadmium     hapten     monoclonal antibody     enzyme-linked immunosorbent assay (ELISA)    

Microcystin-LR detection based on indirect competitive enzyme-linked immunosorbent assay

SHENG Jianwu, HE Miao, YU Shaoqing, SHI Hanchang, QIAN Yi

《环境科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 329-333 doi: 10.1007/s11783-007-0056-7

摘要: Microcystins (MCs) are a group of closely related toxic cyclic heptapeptides produced by common cyanobacteria, which cause lots of accidents and threatens human health. In this paper, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established and used to detect microcystin-LR (MC-LR) in drinking and surface waters. The concentration of coating antigen was 5 ?g/mL, the dilution of monoclonal antibody MC10E7 was 1:3 000, the dilution of enzyme tracer (goat anti-mouse IgG-peroxidase) was 1:3 000, the standard concentration of MC-LR ranged from 0.001 μg/L to 30 μg/L, and o-phenylenediamine was used as substrate. The assay showed high relativity with high performance liquid chromatography (HPLC) with a correlation coefficient of more than 99%. The relative standard deviation was less than 10%, the detection limit was achieved down to 0.01 μg/L and up to 5.1 μg/L. The quantitative detection range was from 0.03 μg/L to 3 μg/L, and the antibody had high specificity for [4-arginine] microcystins. It performed well in spite of the influence of the real samples.

关键词: o-phenylenediamine     4-arginine     ic-ELISA     substrate     chromatography    

Detection of Escherichia coli in wastewater based on enzyme immunoassay

XI Haiyan, CAI Qiang, HE Miao, SHI Hanchang

《环境科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 381-384 doi: 10.1007/s11783-007-0065-6

摘要: This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay (ELISA) for in drainage of wastewater treatment plants. Optimized conditions such as the reaction format (sandwich or direct), the concentrations of diluted horse radish peroxidase (HRP)- conjugate, and anti-HPR antibody and pretreatment of were studied. Those results showed that the linear range of detection for was 10 cfu/mL– 6 × 10 cfu/mL. Compared with conventional methods, it is a convenient and sensitive detection method with low cost.

关键词: conventional     sandwich     pretreatment     enzyme-linked immunosorbent     detection    

广州市2 046例孕前育龄妇女TORCH检查状况分析

余志衡

《中国工程科学》 2014年 第16卷 第5期   页码 63-66

摘要:

采用酶联免疫吸附试验(ELISA) 对2013 年1 月—2013 年12 月进行孕前筛查和孕早期普查的2 046 例妇女进行

关键词: TORCH     感染率     酶联免疫吸附试验     出生缺陷     孕前检查    

Preparation, identification, and clinical application of anti-HBs monoclonal antibody that binds both wild-type and immune escape mutant HBsAgs

Fanghe LI BM , Chunyan ZHANG MS , Jinghua LIU MS , Xiaoyan ZHANG MS , Bing YAN , Bo ZHANG MS , Yongguo HUANG MS , Jingsong GONG BM , Yan CHEN BM ,

《医学前沿(英文)》 2009年 第3卷 第3期   页码 277-283 doi: 10.1007/s11684-009-0047-0

摘要: Using a standard cellular fusion technique and indirect enzyme-linked immunosorbent assay (ELISA), a hybridoma cell line strain secreting anti-HBs monoclonal antibody (mAb) (defined G6 mAb) was obtained. The cells grew and secreted mAb stably. Antibody titers in the culture supernatant and ascites were 2.048×10 and 4.096×10, respectively. By applying the anti-HBs G6 mAb and horseradish peroxidase (HRP)-labeled goat anti-HBs antibody, we developed a sandwich ELISA (defined G6m ELISA) for detecting both wild-type and immune escape mutant HBsAgs (IEM HBsAg). The assay was performed to detect 17 species of genome recombinant expression HBsAg, including two wild-type species and 15 IEM HBsAg species, which varied in the “a” determinant, in a group of patients infected with hepatitis B virus (HBV). The patients previously had a lower ELISA detection signal [(absorbance of patients/absorbance of normal people (P/N): 1.0―4.5)]. The results demonstrated that the sensitivity of this assay to wild-type HBsAg was no less than 0.125g/L; 12 of 15 IEM HBsAg species (P/N≥2.5) were positive for G6 mAb. Of the positive IEM HBsAg species, two had a low absorbance value at 450nm (), one had an intermediate value and nine had a high value, which was 7.55%(mean), 59.4% and 92.1%―109.4% of the wild-type value, respectively. The two species with low value and the three negative species mutated at the bases 120―124 in the first loop of the HBV “a” determinant. Using the G6 ELISA and two commercial ELISA kits (A and B), 177 patients were tested. The G6 ELISA had a significantly higher detection rate than either commercial ELISAs (19.21% 14.89% and 6.21%, respectively; <0.01, <0.05, respectively).

关键词: hepatitis B virus     gene variation     hepatitis B surface antigen     immune escape     enzyme-linked immunosorbent assay    

Cloning of human XAF1 gene promoter and assay of its transcription activity in a variety of cell lines

Qiong CHEN, Qing YU, Yuhu SONG, Peiyuan Li, Ying CHANG, Zhijun WANG, Lifeng LIU, Wei WU, Jusheng LIN

《医学前沿(英文)》 2009年 第3卷 第2期   页码 148-152 doi: 10.1007/s11684-009-0032-7

摘要: To investigate the regulation of tumor suppressor XAF1 gene expression in digestive system cancers, we studied XAF1 gene promoter transcription activity and mRNA level in digestive system cancer cell lines (human hepatoma cell line HepG2, human colon cancer cell line LoVo, and human gastric cancer cell line AGS) and nontumor cell lines (human embryonic liver cell line L02 (L02 cells) and human embryonic kidney 293 cells [HEK293 cells]) as controls. 1395-bp-promoter fragment of XAF1 gene was amplified by polymerase chain reaction (PCR) and cloned into pGL3-basic vector and pEGFP-1 vector to assay its promoter transcription activity. The plasmids were transfected into a variety of cell lines by lipofectamine 2000. The promoter transcription activity was determined by dual-luciferase report assay, and enhanced green fluorescent protein (EGFP)-positive cells were detected by fluorescence microscope. The expression of XAF1 mRNA in HEK293 and L02 were significantly higher than that in any of the three digestive system cancer cell lines. The dual-luciferase reporter assay showed that the promoter transcription activity in digestive system tumor cell lines transfected with pGL3-XAF1p promoter was apparently lower than that of both HEK293 and L02 cells. Expression of green fluorescent protein (GFP) under the control of XAF1 promoter in the three digestive system cancer cell lines was lower than that of both HEK293 and L02 cells. The activities of pGL3-XAF1p in the three digestive system cancer cell lines after treatment with heat stress were significantly lower than those in the unstressed cells. The results suggested that remarkably down-regulated XAF1 mRNA expression in digestive system cancer cell lines may be due to loss of transcription activity of XAF1 promoter.

关键词: gene     X-linked inhibitor of apoptosis protein associated factor-1 (XAF1)     promoter     transcription regulation    

Designer enzyme for green materials innovation: Lactate-polymerizing enzyme as a key catalyst

Seiichi Taguchi

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 139-142 doi: 10.1007/s11705-017-1636-0

摘要: Establishment of the regeneratable whole-cell catalyst platform for the?production of biobased polymeric materials is a?typical topic of synthetic biology. In this commentary, discovery story of a “lactate-polymerizing enzyme” (LPE)?and LPE-based?achievements for creating a new variety of polyesters with incorporated unnatural monomers are presented. Besides the importance of microbial platform itself is discussed referring to the “ballooning”- .

关键词: synthetic biology     enzyme evolutionary engineering     polyhydroxyalkanoate    

Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 89-94 doi: 10.1007/s11783-007-0017-1

摘要: The present work studied the influence of glucose feeding on the ligninolytic enzyme production of in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) stimulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L.

关键词: enzyme production     fed-batch culture     nitrogen-limited     inoculation     mmol/L    

Determination of growth kinetics of microorganisms linked with 1,4-dioxane degradation in a consortium

《环境科学与工程前沿(英文)》 2022年 第16卷 第5期 doi: 10.1007/s11783-022-1567-y

摘要:

● Evaluated three methods for determining the consortia’s growth kinetics.

关键词: Biodegradation     1     4-Dioxane     Kinetics     Microbial consortium     16S rRNA    

Biosensor-based assay of exosome biomarker for early diagnosis of cancer

《医学前沿(英文)》 2022年 第16卷 第2期   页码 157-175 doi: 10.1007/s11684-021-0884-z

摘要: Cancer imposes a severe threat to people’s health and lives, thus pressing a huge medical and economic burden on individuals and communities. Therefore, early diagnosis of cancer is indispensable in the timely prevention and effective treatment for patients. Exosome has recently become an attractive cancer biomarker in noninvasive early diagnosis because of the unique physiology and pathology functions, which reflects remarkable information regarding the cancer microenvironment, and plays an important role in the occurrence and evolution of cancer. Meanwhile, biosensors have gained great attention for the detection of exosomes due to their superior properties, such as convenient operation, real-time readout, high sensitivity, and remarkable specificity, suggesting promising biomedical applications in the early diagnosis of cancer. In this review, the latest advances of biosensors regarding the assay of exosomes were summarized, and the superiorities of exosomes as markers for the early diagnosis of cancer were evaluated. Moreover, the recent challenges and further opportunities of developing effective biosensors for the early diagnosis of cancer were discussed.

关键词: biosensor     exosome     cancer diagnosis    

Diffusion process in enzyme–metal hybrid catalysts

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 921-929 doi: 10.1007/s11705-022-2144-4

摘要: Enzyme–metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis, which is significant for expanding biocatalysis to a broader scope. Previous studies have demonstrated that the enzyme–metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions, compared with that of the combination of separated enzyme and metal catalysts. However, the precise mechanism of this phenomenon remains unclear. Here, we investigated the diffusion process in enzyme–metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase (Novozyme 435) and Pd/C as models. With reference to experimental data in previous studies, the Weisz–Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these catalysts. Thereafter, a kinetic model was developed and fitted to describe the proximity effect in hybrid catalysts. Results indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation, size effect of Pd clusters and proximity of the enzyme and metal active sites, which provides a theoretical foundation for the rational design of enzyme–metal hybrid catalysts.

关键词: enzyme–metal hybrid catalyst     internal diffusion     proximity effect     kinetic model    

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 784-794 doi: 10.1007/s11705-022-2278-4

摘要: In situ encapsulation is an effective way to synthesize enzyme@metal–organic framework biocatalysts; however, it is limited by the conditions of metal–organic framework synthesis and its acid-base stability. Herein, a biocatalytic platform with improved acid-base stability was constructed via a one-pot method using bismuth-ellagic acid as the carrier. Bismuth-ellagic acid is a green phenol-based metal–organic framework whose organic precursor is extracted from natural plants. After encapsulation, the stability, especially the acid-base stability, of amyloglucosidases@bismuth-ellagic acid was enhanced, which remained stable over a wide pH range (2–12) and achieved multiple recycling. By selecting a suitable buffer, bismuth-ellagic acid can encapsulate different types of enzymes and enable interactions between the encapsulated enzymes and cofactors, as well as between multiple enzymes. The green precursor, simple and convenient preparation process provided a versatile strategy for enzymes encapsulation.

关键词: bismuth-ellagic acid     in situ encapsulation     enzyme@MOF biocomposites    

Soil enzyme activities and their indication for fertility of urban forest soil

SHAN Qihua, YU Yuanchun, ZHANG Jinchi, YU Jian

《环境科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 218-223 doi: 10.1007/s11783-008-0037-5

摘要: To reveal the biological characteristics of urban forest soil and the effects of soil enzyme on soil fertility as well as the correlation between physicochemical properties and enzyme activities, 44 urban forest soil profiles in Nanjing were investigated. Basic soil physicochemical properties and enzyme activities were analyzed in the laboratory. Hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase were determined by potassium permanganate titration, TTC (CHN·Cl) colorimetry, phenyl phosphate dinatrium colorimetry, and anthrone colorimetry, respectively. The result showed that soil pH, organic carbon (C), and total nitrogen (N) had great effects on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 0–20 cm thick soil. However, pH only had great effect on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 20–40 cm thick soil. Hydrogen peroxidase, dehydrogenase, and alkaline phosphatase were important biological indicators for the fertility of urban forest soil. Both in 0–20 cm and 20–40 cm soil, soil enzyme system (hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase) had a close relationship with a combination of physicochemical indicators (pH, organic C, total N, available K, available P, cation exchange capacity (CEC), and microbial biomass carbon (C)). The more soil enzyme activities there were, the higher the fertility of urban forest soil.

Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for

《化学科学与工程前沿(英文)》 2023年 第17卷 第5期   页码 548-556 doi: 10.1007/s11705-022-2252-1

摘要: Covalent organic frameworks (COFs) have been increasingly used in capillary electrochromatography due to their excellent characteristics. In this work, hydrazine-linked TFPB-DHzDS (TFPB: 1,3,5-tris(4-formylphenyl)benzene; DHzDS: 2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide) was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material. The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature. After optimizing the coating concentration and experimental conditions of capillary electrochromatography, baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary. And the established method was used successfully to determine PAHs in natural water and soil samples. The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01% to 111.0%, indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples. Finally, molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.

关键词: hydrazine-linked TFPB-DHzDS     in-situ growth method     open-tubular capillary electrochromatography     molecular simulations    

Cofactor engineering in cyanobacteria to overcome imbalance between NADPH and NADH: A mini review

Jongmoon Park,Yunnam Choi

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 66-71 doi: 10.1007/s11705-016-1591-1

摘要: Cyanobacteria can produce useful renewable fuels and high-value chemicals using sunlight and atmospheric carbon dioxide by photosynthesis. Genetic manipulation has increased the variety of chemicals that cyanobacteria can produce. However, their uniquely abundant NADPH-pool, in other words insufficient supply of NADH, tends to limit their production yields in case of utilizing NADH-dependent enzyme, which is quite common in heterotrophic microbes. To overcome this cofactor imbalance and enhance cyanobacterial fuel and chemical production, various approaches for cofactor engineering have been employed. In this review, we focus on three approaches: (1) utilization of NADPH-dependent enzymes, (2) increasing NADH production, and (3) changing cofactor specificity of NADH-dependent enzymes from NADH to NADPH.

关键词: NADH-dependent enzyme     NADPH-dependent enzyme     transhydrogenase     site-directed mutagenesis     enzyme engineering    

标题 作者 时间 类型 操作

Preparation of hapten-specific monoclonal antibody for cadmium and its ELISA application to aqueous samples

Huan HE, Bo TANG, Cheng SUN, Shaogui YANG, Weijuan ZHENG, Zichun HUA

期刊论文

Microcystin-LR detection based on indirect competitive enzyme-linked immunosorbent assay

SHENG Jianwu, HE Miao, YU Shaoqing, SHI Hanchang, QIAN Yi

期刊论文

Detection of Escherichia coli in wastewater based on enzyme immunoassay

XI Haiyan, CAI Qiang, HE Miao, SHI Hanchang

期刊论文

广州市2 046例孕前育龄妇女TORCH检查状况分析

余志衡

期刊论文

Preparation, identification, and clinical application of anti-HBs monoclonal antibody that binds both wild-type and immune escape mutant HBsAgs

Fanghe LI BM , Chunyan ZHANG MS , Jinghua LIU MS , Xiaoyan ZHANG MS , Bing YAN , Bo ZHANG MS , Yongguo HUANG MS , Jingsong GONG BM , Yan CHEN BM ,

期刊论文

Cloning of human XAF1 gene promoter and assay of its transcription activity in a variety of cell lines

Qiong CHEN, Qing YU, Yuhu SONG, Peiyuan Li, Ying CHANG, Zhijun WANG, Lifeng LIU, Wei WU, Jusheng LIN

期刊论文

Designer enzyme for green materials innovation: Lactate-polymerizing enzyme as a key catalyst

Seiichi Taguchi

期刊论文

Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

期刊论文

Determination of growth kinetics of microorganisms linked with 1,4-dioxane degradation in a consortium

期刊论文

Biosensor-based assay of exosome biomarker for early diagnosis of cancer

期刊论文

Diffusion process in enzyme–metal hybrid catalysts

期刊论文

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

期刊论文

Soil enzyme activities and their indication for fertility of urban forest soil

SHAN Qihua, YU Yuanchun, ZHANG Jinchi, YU Jian

期刊论文

Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for

期刊论文

Cofactor engineering in cyanobacteria to overcome imbalance between NADPH and NADH: A mini review

Jongmoon Park,Yunnam Choi

期刊论文