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Shiyu Tian, Ke Zeng, Aijun Yang, Qin Wang, Minghui Yang
We reported an enzyme-free ELISA to detect breast cancer biomarker human epidermal growth factor receptor 2 (HER2) in human serum samples. Instead of enzymes (such as horseradish peroxidase) used in traditional ELISA, CuO nanoparticles were utilized as the signal probe. Compared to traditional enzymes, CuO nanoparticles have the advantages of low cost and good stability. After dissolving CuO nanoparticles with acid, the Cu (II) ions generated catalyzed the reaction of o-phenylenediamine with ascorbic acid to produce fluorescent quinoxaline derivative molecules...
September 14, 2017: Journal of Immunological Methods
Xiaoting Li, Beibei Chen, Man He, Guangyang Xiao, Bin Hu
In this work, we developed an immunoassay based on tyramide signal amplification (TSA) and gold nanoparticles (Au NPs) labeling for highly sensitive detection of alpha fetoprotein (AFP) by inductively coupled plasma mass spectrometry (ICP-MS). AFP was captured by anti-AFP1 coating on the 96-well plate and labeled by anti-AFP2-horseradish peroxidase (HRP), in which the HRP can catalyze the deposition of biotinylated tyramine on the nearby protein. Then the streptavidin (SA)-Au NPs was labeled on the deposited biotinylated tyramine as the intensive signal probe for ICP-MS measurement...
January 1, 2018: Talanta
Jiaojiao Wang, Rui Zhang, Xiaxia Yang, Xiaoyan Liu, Haixia Zhang
The Cu(2+)-decorated functional mesoporous material was fabricated by thermally initiated free-radical polymerization of octavinyl polyhedral oligomeric silsesquioxane. It was used as adsorbent for highly specific separation of histidine (His)-rich proteins in blood and cell lysate based on immobilized metal affinity chromatography. The functional mesoporous material (named as PPOSS-IDA-Cu(2+)) was characterized in detail and its selectivity and binding capacity were evaluated using a His-rich protein (bovine hemoglobin, BHb) and other proteins (bovine serum albumin, myoglobin, lysozyme and horseradish peroxidase) containing fewer surface-exposed His residues as model proteins...
January 1, 2018: Talanta
Li Su, Xinai Yu, Yexi Cai, Puhua Kang, Wenjie Qin, Wenpei Dong, Guojiang Mao, Suling Feng
Nanomaterial-based peroxidase-mimetics are an emerging research field that promises to produce alternatives to horseradish peroxidase for a variety of applications. Generally, some peroxidase-mimetics substrates are used in acidic condition (pH ≤ 7). Then, it is necessary to screen some peroxidase-mimetics substrates suitable for basic condition because that some peroxidase-mimetics leached ions in acidic solution. In this paper, using Ni/Co layered double hydroxides (LDHs) as a nano-peroxidase mimic model, we evaluated three fluorogenic substrates suitable for basic condition though experimental conditions, reaction kinetic and glucose detection assay...
September 22, 2017: Analytica Chimica Acta
Chenguang Wang, Nan Cheng, Longjiao Zhu, Yuancong Xu, Kunlun Huang, Pengyu Zhu, Shuifang Zhu, Wei Fu, Wentao Xu
A colorimetric biosensor for DNA screening was designed based on the conformational changes of the horseradish peroxidase (HRP)-mimicking DNAzyme. The scheme of DNA biosensing was designed based on the base pairing of DNAzyme sequence to inhibit the formation of HRP-mimicking hemin/G-quadruplex structures in the process of amplification. DNA could be amplified via the universal primer multiplex polymerase chain reaction (UP-M-PCR) and innovatively detected as color disappear in the reaction visible to the naked eye...
September 22, 2017: Analytica Chimica Acta
Catherine E Taylor, Samya O Abdelhadi, Carlos G Dosoretz
A juxtaposition of regional cuisines and recent prospective studies of fish consumption in China and Japan points to fresh horseradish and/or radish (HRR) as possible contributors to delaying age-related dementia. The hypothesis is that the inverse association found sometimes between fish intake and cognitive decline is partially due to exposure of the oral cavity to active peroxidases from HRR served in conjunction with fish. This hypothesis can be tested by specifically looking at whether HRR is consumed with fish and whether such HRR is prepared in a way that preserves activity of HRR peroxidases...
September 2017: Medical Hypotheses
Muthukumar Gunasekaran, Thin Thin Maw, Rowena Delos Santos, Surendra Shenoy, Jason Wellen, T Mohanakumar
BACKGROUND: Immune responses to tissue-restricted self-antigens are thought to play a role in chronic rejection after solid organ transplantation. De novo development of antibodies (Abs) to vimentin have been reported to be associated with interstitial fibrosis/tubular atrophy after kidney transplant, and it has been suggested that immunoglobulin isotype switching of Abs to vimentin may occur during this process. We aimed to determine the correlation between immunoglobulin isotype switching of Abs to vimentin and development of transplant glomerulopathy (TG) after kidney transplant, and to determine whether citrullinated modification of vimentin is required for de novo anti-vimentin development...
September 11, 2017: Transplant Immunology
Mostafa Kamal Masud, Sharda Yadav, Md Nazmul Islam, Nam-Trung Nguyen, Carlos Salomon, Richard Kline, Hatem R Alamri, Zeid Abdullah Alothman, Yusuke Yamauchi, Md Shahriar A Hossain, Muhammad J A Shiddiky
Enzyme-mimicking activity of iron oxide based nanostructures have provided a significant advantage in developing advanced molecular sensors for biomedical and environmental applications. Herein, we introduce the horseradish peroxidase (HRP)-like activity of gold loaded nanoporous ferric oxide nanocubes (Au-NPFe2O3NC) for the development of a molecular sensor with enhanced electrocatalytic and colorimetric (naked-eye) detection of autoantibodies. The results showed that Au-NPFe2O3NC exhibits enhanced peroxidase-like activity towards the catalytic oxidation of 3,3',5,5'-tertamethylbenzidine (TMB) in the presence of H2O2 at room temperature (25°C) and follows the typical Michaelis-Menten kinetics...
September 11, 2017: Analytical Chemistry
Seth Villarreal, Sung Hoon Lee, Ling-Gang Wu
During endocytosis, fused synaptic vesicles are retrieved at nerve terminals, allowing for vesicle recycling and thus the maintenance of synaptic transmission during repetitive nerve firing. Impaired endocytosis in pathological conditions leads to decreases in synaptic strength and brain functions. Here, we describe methods used to measure synaptic vesicle endocytosis at the mammalian hippocampal synapse in neuronal culture. We monitored synaptic vesicle protein endocytosis by fusing a synaptic vesicular membrane protein, including synaptophysin and VAMP2/synaptobrevin, at the vesicular lumenal side, with pHluorin, a pH-sensitive green fluorescent protein that increases its fluorescence intensity as the pH increases...
September 4, 2017: Journal of Visualized Experiments: JoVE
Yuki Sakaguchi, Tomoka Minamikawa, Mayuko Yamamuro, Tadayuki Tsujita, Toshihisa Ueda, Kai Kamada, Nobuaki Soh
Luminescent europium-doped layered titanates (Eu-TiOx) were synthesized and complexed with horseradish peroxidase (HRP) and glucose oxidase (GOx). The emission of a resultant Eu-TiOx/HRP/GOx complex decreased upon the addition of glucose in the presence of guaiacol. The emission decrease was dependent on the concentrations of glucose, and the detection limit for glucose was 3.1 μM. The proposed system would be promising as a new detection method for glucose.
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Buguang Zhou, Min He, Ping Wang, Haitian Fu, Yuanyuan Yu, Qiang Wang, Xuerong Fan
Silk fibroin (SF) as a bioactive protein can offer growth substrates for hydroxyapatite (HAp) deposition. In the current work, graft copolymerization of acrylic acid (AA) onto fibroin chains was carried out using hydrogen peroxide-horseradish peroxidase (H2O2-HRP) catalytic system, SF-g-polyacrylic acid (PAA) membranes was prepared subsequently, followed by in situ biomimetic mineralization in the Ca/P solutions, aiming at promoting the deposition of HAp and endowing the fibroin-based biocomposite with enhanced bioactivity...
December 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Laurène Leclair-Visonneau, Thomas Clairembault, Emmanuel Coron, Séverine Le Dily, Fabienne Vavasseur, Marie Dalichampt, Yann Péréon, Michel Neunlist, Pascal Derkinderen
OBJECTIVE: To determine whether REM sleep behavior disorder (RBD) in Parkinson disease (PD) is associated with lesions and dysfunctions of the autonomic nervous system by evaluating enteric phosphorylated α-synuclein histopathology (PASH) and permeability. METHODS: A total of 45 patients with PD were included in this cross-sectional study. RBD was diagnosed on the basis of a standardized clinical interview and confirmed by polysomnography. For each patient, 5 biopsies were taken at the junction between the sigmoid and descending colon during the course of a rectosigmoidoscopy...
September 8, 2017: Neurology
Zesheng An, Zhifen Liu, Yue Lv
Synthesis of well-defined multiblock and ultrahigh-molecular-weight (UHMW) polymers has been a perceived challenge for reversible-deactivation radical polymerization (RDRP). An even more formidable task is to synthesize these extreme polymers in the presence of oxygen. A novel methodology involving enzymatic cascade catalysis is developed for the unprecedented synthesis of multiblock polymers in open vessels with direct exposure to air and UHMW polymers in closed vessels without prior degassing. The success of this methodology relies on the extraordinary deoxygenation capability of pyranose oxidase (P2Ox) and the mild yet efficient radical generation by horseradish peroxidase (HRP)...
September 8, 2017: Angewandte Chemie
Kun Lu, Jinyuan Hu, Shixiang Gao, Liang Mao
In this study, we systematically investigated the effect of multiwall carbon nanotubes (MWCNTs) on the removal of tetrabromobisphenol A (TBBPA) mediated by horseradish peroxidase (HRP) at varying important conditions. The results suggested that the presence of MWCNTs significantly enhanced the removal of TBBPA mediated by HRP and the reaction rate constant was linear with the MWCNTs dosage. The enhancement of MWCNTs on the HRP-mediated reaction was attributed to two facts, one is that MWCNTs protected HRP from inactivation, the other is that the presence of MWCNTs made the homogeneous reaction of TBBPA be heterogeneous reaction by adsorbing TBBPA on its surface...
September 4, 2017: Environmental Pollution
Kaili Yang, Min Huo, Yuehua Guo, Yizhuo Yang, Jie Wu, Lin Ding, Huangxian Ju
A target-induced cyclic strategy for DNAzyme formation was proposed to achieve simple, sensitive and universal detection of protein biomarkers with convenient colorimetric or chemiluminescence imaging readout. In the assay, the target protein was recognized by a pair of DNA-labeled antibodies (Ab1-DNA1 and Ab2-DNA2) to form a proximate complex, which could hybridize with the conjugate DNA3/DNA4 to release the guanine-rich DNA4 and thus formed G-quadruplex/hemin horseradish peroxidase-mimicking DNAzyme. The process could be further recycled with Exonuclease III by cleaving DNA3 to free the proximate complex, resulting in the cyclic formation of DNAzyme...
September 7, 2017: Analyst
Hussein Kanso, Nicolas Inguimbert, Georges Istamboulie, Lise Barthelmebs, Carole Calas-Blanchard, Thierry Noguer
New chemiluminescence-based immunoassays for sensitive detection of 17-β estradiol (E2) and ethinylestradiol (EE2) are described on the basis of the use of biotinylated estrogen derivatives. Estrogen derivatives bearing a carboxylic group (E2-COOH and EE2-COOH) on C-3 position were synthesized, covalently bound to aminated biotin and subsequently immobilized on avidin-coated microtiter plates. The assay principle was based on competition between free and immobilized estrogens for their binding to primary antibodies, with subsequent revelation using horseradish peroxidase (HRP)-labeled secondary antibodies...
September 7, 2017: Analytical Biochemistry
N Kuru, K Cinar, E Demirbag, R Ilgun
We investigated carbohydrate residues on the epithelial surface, in the epithelial cells and in gland cells of the tongue of the mole rat using histochemical methods. We used horseradish peroxidase-conjugated lectins from Helix pomatia (HPA), Arachishypogaea (PNA), Ulexeuropaeus (UEA I), Canavaliaensiformis (Con A). The most intense reactivity was observed in the keratin layer with HPA, UEA I and Con A, and in the epithelial cells with UEA I and Con A. In the glands, we found strong reactivity in serous cells with HPA and Con A, and in mucous cells with HPA and UEA I...
September 1, 2017: Biotechnic & Histochemistry: Official Publication of the Biological Stain Commission
Monireh Besharati Vineh, Ali A Saboury, Amir A Poostchi, Ali M Rashid, Kazem Parivar
The covalent bonding process was applied to immobilize horseradish peroxidase (HRP) onto a functionalized reduced graphene oxide with size of 60nm through glutaraldehyde as a cross-linker. The catalytic constant, kcat, and the catalytic efficiency, kcat/Km, increased 6.5 and 8.5 times, respectively, after immobilization. The circular dichroism analysis revealed that the α-helical content decreased from 18% to 10% after immobilization. The reusability of HRP was improved by immobilization and 70% of initial activity retained after 10 cycles...
August 26, 2017: International Journal of Biological Macromolecules
Pichayanut Poolperm, Thanya Varinrak, Yasushi Kataoka, Khajornsak Tragoolpua, Takuo Sawada, Nattawooti Sthitmatee
Serological tests, such as agglutination and indirect hemagglutination assay (IHA), have been used to identify antibodies against Pasteurella multocida in poultry sera, but none are highly sensitive. An enzyme-linked immunosorbent assays (ELISA) has been used with varying degrees of success in attempts to monitor seroconversion in vaccinated poultry, but are not suitable for diagnosis. Commercial ELISA kits are available for chickens and turkeys, but not for ducks. The present study reports development and standardization of an in-house indirect ELISA for detection of duck antibody to fowl cholera...
August 24, 2017: Journal of Microbiological Methods
Reguia Mahfoudi, Amar Djeridane, Khedidja Benarous, Emile M Gaydou, Mohamed Yousfi
For the first time, the structure-activity relationships of thirteen synthesized flavonoids have been investigated by evaluating their ability to modulate horseradish peroxidase (HRP) catalytic activity. Indeed, a modified spectrophotometrically method was carried out and optimized using 4-methylcatechol (4-MC) as peroxidase co-substrate. The results show that these flavonoids exhibit a great capacity to inhibit peroxidase with Ki values ranged from 0.14±0.01 to 65±0.04mM. Molecular docking has been achieved using Auto Dock Vina program to discuss the nature of interactions and the mechanism of inhibition...
August 10, 2017: Bioorganic Chemistry
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