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Zhanmin Liu, Chenhui Yao, Cuiyun Yang, Yanming Wang, Sibao Wan, Junyi Huang
Listeria monocytogenes is an important food-borne pathogen, and it can cause severe diseases. Rapid detection of L. monocytogenes is crucial to control this pathogen. A simple and robust strategy based on the cascade of PCR and G-quadruplex DNAzyme catalyzed reaction was used to detect L. monocytogenes. In the presence of hemin and the aptamer formed during PCR, the catalytic horseradish peroxidase-mimicking G-quadruplex DNAzymes allow the colorimetric responses of target DNA from L. monocytogenes. This assay can detect genomic DNA of L...
May 16, 2018: Analytical Biochemistry
Yilin Li, Chunhui Deng, Nianrong Sun
As one of the most important post-translational modifications (PTMs) of peptidome, glycopeptidome is closely related to serious disease, especially to cancer. In order to specifically discover and analyze glycopeptidome biomarkers for clinical diagnosis of cancer on early-stage, it is crucial to develop efficient technique to analyze low-abundance of endogenous glycopeptides in biological samples. In this report, a hydrophilic probe in mesoporous pore (denoted as Fe3 O4 @mSiO2 @G6P) was designed and prepared...
September 18, 2018: Analytica Chimica Acta
John Lowe, Eric Wakshull, Theresa Shek, Anan Chuntharapai, Rebecca Elliott, Jeriza Rusit, Mauricio Maia
Ranibizumab (Lucentis®), a humanized antigen-binding fragment (Fab) monoclonal antibody that blocks VEGF-A activity is currently approved for the treatment of several retinal degenerative diseases. The assessment of drug pharmacokinetics (PK) is essential for evaluating exposure as it relates to drug safety and efficacy. For drugs administered intravitreally, systemic drug levels during the course of clinical studies are typically 100 to 1000-fold lower than those of similar therapeutics dosed intravenously, posing a significant bioanalytical challenge for PK measurements...
May 14, 2018: Journal of Immunological Methods
Akif Zeb, Shafaq Sahar, Umair Yaqub Qazi, Atheer Hameid Odda, Naseeb Ullah, Ya-Nan Liu, Ishtiaq A Qazi, An-Wu Xu
Heteropolyacids (HPAs) are a class of polyoxometallates (POMs) with oxygen-rich surfaces. Herein, we have developed an Fe-containing heteropolyacid by cation-exchange and employed KFePW12O40 nanostructures for Fenton, photo-Fenton and enzyme-mimetic reactions. The as-prepared KFePW12O40 catalyst exhibits efficient degradation of Rhodamine B (RhB) via the photo-Fenton reaction. As an enzyme-mimetic, this material can effectively oxidize TMB and dopamine. The obtained nanomaterials were characterized via SEM, TEM, XPS, BET surface area, TGA, UV-Vis spectroscopy, FT-IR, and XRD techniques...
May 17, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Jie Pang, Yun Zhao, Hai-Ling Liu, Kang Wang
This paper reported a new method to observe the catalytic progress of the natural horseradish peroxidase (HRP) in-situ on single gold nanoparticles (GNPs) by the combination of dark field imaging and plasmonic resonance scattering spectra. The produced single HRP-GNP exhibited localized catalytic property toward H2 O2 -Diaminobenzidine (DAB), which could be used to detect the concentration of H2 O2 in micro/nanospace. The linear range for H2 O2 sensing was from 0.01 μM to 5 μM with a detection limit of 10 nM...
August 1, 2018: Talanta
Yadi Pan, Yufang Yang, Yanjiao Pang, Ying Shi, Yijuan Long, Huzhi Zheng
Ficin, a classical sulfhydryl protease, was found to possess intrinsic peroxidase-like activity. In this paper, we have put forward a novel strategy to improving the peroxidase-like activity of ficin through binding heme. Heme-ficin complexes were successfully obtained by simple one-step syntheticism. The results demonstrated that the catalytic activity and efficiency of heme-ficin complexes were about 1.7 times and 3 times higher than those of native ficin, respectively. Taking advantages of the high peroxidase-like activity, the heme-ficin complexes were used for colorimetric determination of uric acid with a low detection limit of 0...
August 1, 2018: Talanta
F Pires, M Julia Arcos-Martinez, A Cristina Dias-Cabral, Juan C Vidal, Juan R Castillo
Human cytomegalovirus (HCMV) is a herpes virus that can cause severe infections. Still, the available methods for its diagnostic have the main disadvantage of requiring long time to be performed. In this work, a simple magnetic particle-based enzyme immunoassay (mpEIA) for the quantification of glycoprotein B of Human cytomegalovirus (gB-HCMV) in urine samples is proposed. The immunosensor scheme is based on the analyte protein gB-HCMV sandwiched between a primary monoclonal antibody, (MBs-PrG-mAb1), and a secondary anti-gB-HCMV antibody labelled with Horseradish peroxidase (Ab2-HRP) to allow spectrophotometric detection...
April 17, 2018: Journal of Pharmaceutical and Biomedical Analysis
Hanrui Su, Chunyang Yu, Yongfeng Zhou, Lidong Gong, Qilin Li, Pedro J J Alvarez, Mingce Long
Tetra-amido macrocyclic ligand (TAML) activator is a functional analog of peroxidase enzymes, which activates hydrogen peroxide (H2 O2 ) to form high valence iron-oxo complexes that selectively degrade persistent aromatic organic contaminants (ACs) in water. Here, we develop quantitative structure-activity relationship (QSAR) models based on measured pseudo first-order kinetic rate coefficients (kobs ) of 29 ACs (e.g., phenols and pharmaceuticals) oxidized by TAML/H2 O2 at neutral and basic pH values to gain mechanistic insight on the selectivity and pH dependence of TAML/H2 O2 systems...
May 2, 2018: Water Research
Lizhen Chen, Ying Fu, Naixiang Wang, Anneng Yang, Yuanzhe Li, Jie Wu, Huangxian Ju, Feng Yan
Cell surface glycans play critical roles in diverse biological processes, such as cell-cell communication, immunity, infection, development and differentiation. Their expressions are closely related to cancer growth and metastasis. This work demonstrates an organic electrochemical transistor (OECT) -based biosensor for the detection of glycan expression on living cancer cells. Using mannose on human breast cancer cells (MCF-7) as a target model, the gate electrode of the OECT is modified with concanavalin A that can specifically bind cell surface mannose and capture the cancer cells...
May 11, 2018: ACS Applied Materials & Interfaces
Fabio Bachmann, Urs Duthaler, Deborah Rudin, Stephan Krähenbühl, Manuel Haschke
Metamizole is an old analgesic used frequently in some countries. Active metabolites of metamizole are the non-enzymatically generated N-methyl-4-aminoantipyrine (4-MAA) and its demethylation product 4-aminoantipyrine (4-AA). Previous studies suggested that 4-MAA demethylation can be performed by hepatic cytochrome P450 (CYP) 3A4, but the possible contribution of other CYPs remains unclear. Using human liver microsomes (HLM), liver homogenate and HepaRG cells, we could confirm 4-MAA demethylation by CYPs. Based on CYP induction (HepaRG cells) and CYP inhibition (HLM) we could identify CYP2B6, 2C8, 2C9 and 3A4 as major contributors to 4-MAA demethylation...
May 8, 2018: European Journal of Pharmaceutical Sciences
Diego Alberto Morales Urrea, Patricia Mónica Haure, Fernando Sebastián García Einschlag, Edgardo Martín Contreras
Enzymatic decolourization of azo-dyes could be a cost-competitive alternative compared to physicochemical or microbiological methods. Stoichiometric and kinetic features of peroxidase-mediated decolourization of azo-dyes by hydrogen peroxide (P) are central for designing purposes. In this work, a modified version of the Dunford mechanism of peroxidases was developed. The proposed model takes into account the inhibition of peroxidases by high concentrations of P, the substrate-dependant catalatic activity of peroxidases (e...
May 9, 2018: Environmental Science and Pollution Research International
Zsolt Szűcs, Tamás Plaszkó, Zoltán Cziáky, Attila Kiss-Szikszai, Tamás Emri, Regina Bertóti, László Tamás Sinka, Gábor Vasas, Sándor Gonda
BACKGROUND: The health of plants is heavily influenced by the intensively researched plant microbiome. The microbiome has to cope with the plant's defensive secondary metabolites to survive and develop, but studies that describe this interaction are rare. In the current study, we describe interactions of endophytic fungi with a widely researched chemical defense system, the glucosinolate - myrosinase - isothiocyanate system. The antifungal isothiocyanates are also of special interest because of their beneficial effects on human consumers...
May 9, 2018: BMC Plant Biology
Marwa N El-Nahass, Mai M El-Keiy, Ehab M M Ali
Mesoporous silicate, SBA-16 is one of the most promising supports for horseradish peroxidase. In this study, SBA-16 was synthesized, and anchored to HRP enzyme in the organized porous networks, SBA-16. The mesoporous structures and morphologies of SBA-16 and the anchored HRP enzyme were characterized by Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption isotherms, low-angle X-ray diffraction and thermogravimetric analysis. The percentage of immobilized HRP was 57%...
May 5, 2018: International Journal of Biological Macromolecules
Oya Sena Aydos, Yunus Yukselten, Sinan Ozkavukcu, Asuman Sunguroglu, Kaan Aydos
In this study, our aim was to detect protein levels of A Disintegrin and Metalloproteinase with Thrombospondin Motifs 1 and 5 (ADAMTS1 and ADAMTS5) proteases and to examine the effect of in vitro FSH supplementation on protease production in cultured Sertoli cells. The expression of metalloproteases, ADAMTS1, and ADAMTS5 were investigated in Sertoli cell cultures as well as in ejaculate of azoospermic men which then were compared with ejaculates of the fertile control group. A total of 15 azoospermic men, diagnosed as obstructive (OA, n = 5) and nonobstructive (NOA, n = 10) azoospermia were included in the study...
May 8, 2018: Systems Biology in Reproductive Medicine
Yuta Yamamoto, Tetsuya Saita, Yutaro Yamamoto, Masashi Shin
A selective and sensitive competitive enzyme-linked immunosorbent assay (ELISA) method was developed and validated for the quantification of erlotinib in 50 µL of samples of human serum. Anti-erlotinib serum was obtained by immunizing mice with an antigen conjugated with bovine serum albumin and 3,4-bis(2-methoxyethoxy)benzoic acid using the N -succinimidyl ester method. Enzyme labeling of erlotinib with horseradish peroxidase was similarly performed using 3,4-bis(2-methoxyethoxy)benzoic acid. A simple competitive ELISA for erlotinib was developed using the principle of direct competition between erlotinib and the enzyme marker for anti-erlotinib antibody, which had been immobilized on the plastic surface of a microtiter plate...
April 2018: Journal of Pharmaceutical Analysis
Jian Yuan, Sheng Xu, Hong-Yan Zeng, Xi Cao, A Dan Pan, Gao-Fei Xiao, Peng-Xuan Ding
The composites (LDH-CMC) composed of carboxymethyl chitosan (CMC) and 2D ZnAl layered double hydroxide (LDH) were successfully prepared using the one-step urea method; these composites were characterized by XRD, FT-IR, UV-vis DRS, SEM, BJH/BET, TG-DTG and pHzpc analyses, cyclic voltammetry, and electrochemical impedance spectroscopy. The use of CMC could impact the textural and surface chemical properties of the LDH-CMC composites, where the composites still maintained the 2D layered structure. Incorporating a moderate amount of CMC could increase both the surface area and the permanent charge density of the composites, leading to improved electrochemical performances...
April 23, 2018: Bioelectrochemistry
Gang Peng, Xiaoyan Li, Feng Cui, Qianying Qiu, Xiaojun Chen, He Huang
In the food safety evaluation, aflatoxin B1 (AFB1) is an important indicator. In this work, we developed an AFB1 electrochemical aptasensor based on tetrahedral DNA nanostructures (TDNs) immobilized three dimensionally ordered macroporous MoS2-AuNPs hybrid (3DOM MoS2-AuNPs) recognition interface and horseradish peroxidase (HRP) functionalized magnetic signal amplifier. To greatly enhance the recognition efficiency, sensitivity and stability of the aptasensor, the AFB1 aptamer-incorporated TDNs were ingeniously combined with the 3DOM MoS2-AuNPs film for the construction of the sensing interface...
May 7, 2018: ACS Applied Materials & Interfaces
Akihiko Kameyama, Santha Kumara Dissanayake, Wai Wai Thet Tin
Glycan analysis may result in exploitation of glycan biomarkers and evaluation of heterogeneity of glycosylation of biopharmaceuticals. For N-linked glycan analysis, we investigated alkaline hydrolysis of the asparagine glycosyl carboxamide of glycoproteins as a deglycosylation reaction. By adding hydroxylamine into alkaline de-N-glycosylation, we suppressed the degradation of released glycans and obtained a mixture of oximes, free glycans, and glycosylamines. The reaction was completed within 1 h, and the mixture containing oximes was easily tagged with 2-aminobenzamide by reductive amination...
2018: PloS One
Yunki Lee, Joo Young Son, Jeon Il Kang, Kyung Min Park, Ki Dong Park
Reactive oxygen species (ROS) have been implicated as a critical modulator for various therapeutic applications such as treatment of vascular disorders, wound healing, and cancer treatment. Specifically, growing evidence has recently demonstrated that transient or low levels of hydrogen peroxide (H2 O2 ) facilitate tissue regeneration and wound repair through acute oxidative stress that can evaluate intracellular ROS levels in cells or tissues. Herein, we report a gelatin-based H2O2-releasing hydrogel formed by dual enzyme-mediated reaction using horseradish peroxidase (HRP) and glucose oxidase (GOx)...
May 3, 2018: ACS Applied Materials & Interfaces
Nannan Liu, Huan Yi, Yanyu Lin, Hongli Zheng, Xiangqing Zheng, Danmei Lin, Hong Dai
A dual-responsive sandwich-type immunosensor is described for the detection of interleukin 6 (IL-6) by combining electrochemiluminescent (ECL) and electrochemical (EC) detection based on the use of two kinds of TiO2 mesocrystal nanoarchitectures. A composite was prepared from TiO2 (anatase) mesocages (AMCs) and a carboxy-terminated ionic liquid (CTIL) and then placed on a glassy carbon electrode (GCE). In the next step, the ECL probe Ru(bpy)3 (II) and antibody against IL-6 (Ab1 ) were immobilized on the GCE...
May 2, 2018: Mikrochimica Acta
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