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Heliyon Jan 2021Kinetic and physicochemical properties of peroxidase purified using a novel and cost efficient protocol was investigated with a view to providing information on its...
Kinetic and physicochemical properties of peroxidase purified using a novel and cost efficient protocol was investigated with a view to providing information on its possible biotechnological potentials. peroxidase was purified to homogeneity in two steps, involving ATPS and size exclusion chromatography on Sephadex G-100 with a yield of 84.12 %. In-gel activity staining revealed the presence of one isoform of peroxidase. The purified peroxidase is monomeric with native and subunits molecular weight of 38.9 and 43.5 kDa respectively. Kinetic parameters - , , of the purified enzyme were 2.5 units/mg protein, 0.020 ± 0.04 mM and 1.37 ± 0.18 mM respectively. Its optimum pH and temperature were 5 and 30 °C respectively. The purified enzyme cross-linked BSA into an insoluble matrix with the aid of caffeic acid. The study concluded that the purification scheme adopted is rapid and efficient, the purified enzyme exhibited some physiochemical properties that make it suitable for various biotechnological applications.
PubMed: 33521366
DOI: 10.1016/j.heliyon.2021.e06032 -
Ecotoxicology and Environmental Safety Jan 2021The environmental effects of additives have attracted increasing attention. Sodium dehydroacetate (DHA-S), as an approved preservative, is widely added in processed...
The environmental effects of additives have attracted increasing attention. Sodium dehydroacetate (DHA-S), as an approved preservative, is widely added in processed foods, cosmetics and personal care products. However, DHA-S has been recently reported to induce hemorrhage and coagulation aberration in rats. Yet little is known about the ecotoxicological effect and underlying mechanisms of DHA-S. Here, we utilized the advantage of zebrafish model to evaluate such effects. DHA-S induced cerebral hemorrhage, mandibular dysplasia and pericardial edema in zebrafish after 24 h exposure (48-72 hpf) at 50 mg/L. We also observed the defective heart looping and apoptosis in DHA-S-treated zebrafish through o-dianisidine and acridine orange staining. Meanwhile, DHA-S induced the deficiency of Ca and vitamin D3 in zebrafish. We further demonstrated that DHA-S stimulated Ca influx resulting in Ca-dependent mitochondrial damage in cardiomyocytes. Additionally, DHA-S inhibited glucose uptake and repressed the biosynthesis of amino acids. Finally, we identified that sodium bicarbonate could rescue zebrafish from DHA-S induced cardiovascular toxicity. Altogether, our results suggest that DHA-S is a potential risk for cardiovascular system.
Topics: Animals; Apoptosis; Calcium; Cardiotoxicity; Cell Line; Cerebral Hemorrhage; Dose-Response Relationship, Drug; Edema, Cardiac; Embryo, Nonmammalian; Embryonic Development; Heart; Myocardium; Pericardium; Pyrones; Rats; Zebrafish
PubMed: 33396133
DOI: 10.1016/j.ecoenv.2020.111613 -
Polymers Dec 2020The pronouncedly low thermal conductivity of polymers in the range of 0.1-0.2 W m K is a limiting factor for their application as an insulating layer in microelectronics...
The pronouncedly low thermal conductivity of polymers in the range of 0.1-0.2 W m K is a limiting factor for their application as an insulating layer in microelectronics that exhibit continuously higher power-to-volume ratios. Two strategies can be applied to increase the thermal conductivity of polymers; that is, compounding with thermally conductive inorganic materials as well as blending with aromatic units arranged by the principle of π-π stacking. In this study, both strategies were investigated and compared on the example of epoxy-amine resins of bisphenol A diglycidyl ether (BADGE) and 1,2,7,8-diepoxyoctane (DEO), respectively. These two diepoxy compounds were cured with mixtures of the diamines isophorone diamine (IPDA) and -dianisidine (DAN). The epoxy-amine resins were cured without filler and with 5 wt.-% of SiO nanoparticles. Enhanced thermal conductivity in the range of 0.4 W·m·K was observed exclusively in DEO-based polymer networks that were cured with DAN (and do not contain SiO fillers). This observation is argued to originate from π-π stacking of the aromatic units of DAN enabled by the higher flexibility of the aliphatic carbon chain of DEO compared with that of BADGE. The enhanced thermal conductivity occurs only at temperatures above the glass-transition point and only if no inorganic fillers, which disrupt the π-π stacking of the aromatic groups, are present. In summary, it can be argued that the bisphenol-free epoxy-amine resin with an epoxy compound derivable from natural resources shows favorably higher thermal conductivity in comparison with the petrol-based bisphenol-based epoxy/amine resins.
PubMed: 33375238
DOI: 10.3390/polym13010065 -
Indoor Air Mar 2021With an increasing use of indoor disinfectants such as chlorine (Cl ) and hypochlorous acid, a convenient sampler for estimating exposure to oxidants, such as effective...
With an increasing use of indoor disinfectants such as chlorine (Cl ) and hypochlorous acid, a convenient sampler for estimating exposure to oxidants, such as effective chlorine, is necessary. Here, we developed a personal passive air sampler (PPAS) composed of a redox dye, o-dianisidine, in a polydimethylsiloxane (PDMS) sheet. o-Dianisidine readily reacts with gaseous oxidants generated by bleach usage, and its color changes as the reaction progresses; hence, personal exposure to effective chlorine could be easily detected by the naked eye, while cumulative exposure could be determined by measuring concentrations of o-dianisidine reacting with it. The PPAS was calibrated, and a sampling rate of 0.00253 m /h was obtained using a small test chamber. The PPAS was tested with the help of ten volunteers whose personal exposure to Cl -equivalent gas was estimated after bathrooms were cleaned using spray and liquid-type household disinfection products, and the accumulated exposure-gas concentrations ranged from 69 to 408 ppbv and 148 to 435 ppbv, respectively. These PPAS-derived exposure concentrations were approximately two orders lower than those estimated using ConsExpo, suggesting a significant overestimation by prevailing screening models, possibly due to the ignorance of transformation reactions.
Topics: Air Pollutants; Air Pollution, Indoor; Chlorine; Dimethylpolysiloxanes; Disinfectants; Disinfection; Environmental Monitoring; Humans; Hypochlorous Acid; Inhalation Exposure
PubMed: 32978992
DOI: 10.1111/ina.12747 -
Access Microbiology 2019Honey is a natural product with many beneficial properties including antimicrobial action. Production of hydrogen peroxide (HO) in diluted honey is central to this...
Honey is a natural product with many beneficial properties including antimicrobial action. Production of hydrogen peroxide (HO) in diluted honey is central to this action. Here, we describe an optimized method for measuring levels of HO in honey. This method is based on established methods, with the level of dilution, the time between dilution and reading the assay, and aeration of the samples during the assay identified as critical points for ensuring reliability and reproducibility. The method is cost-effective and easy to perform using common laboratory equipment. Using this method, we quantified the hydrogen peroxide content of five different, unprocessed polyfloral honeys collected in NC, USA. Our results show that HO production by these honeys varies greatly, with some samples producing negligible levels of HO. We assessed the effect of colour on the assay by measuring the recovery of spiked HO from light and dark honey and from serially diluted dark corn syrup, and found the amount of HO that could be detected was lower in dark corn syrup and darker honey samples.
PubMed: 32974499
DOI: 10.1099/acmi.0.000065 -
The Science of the Total Environment Nov 2020Surfactants are widely used in the industry of detergents, household products, and cosmetics. SAPDMA is a cationic surfactant that is used mostly in cosmetics,...
Surfactants are widely used in the industry of detergents, household products, and cosmetics. SAPDMA is a cationic surfactant that is used mostly in cosmetics, conditioning agents and has recently gained attention as a corrosion inhibitor in the sea pipelines industry. In this regard, literature concerning the ecotoxicological classification of SAPDMA on aquatic animals is lacking. This study aims to evaluate the potential ecotoxicity of SAPDMA using the aquatic zebrafish embryo model. The potential toxic effects of SAPDMA were assessed by different assays. This includes (i) mortality/survival assay to assess the median lethal concentration (LC); (ii) teratogenicity assay to assess the no observed effect concentration (NOEC); (iii) organ-specific toxicity assays including cardiotoxicity, neurotoxicity (using locomotion assay), hematopoietic toxicity (hemoglobin synthesis using o-dianisidine staining), hepatotoxicity (liver steatosis and yolk retention using Oil Red O (ORO) stain); (iv) cellular cytotoxicity (mitochondrial membrane potential) by measuring the accumulation of JC-1 dye into mitochondria. Exposure of embryos to SAPDMA caused mortality in a dose-dependent manner with a calculated LC of 2.3 mg/L. Thus, based on the LC value and according to the Fish and Wildlife Service (FWS) Acute Toxicity Rating Scale, SAPDMA is classified as "moderately toxic". The No Observed Effect Concentration (NOEC) concerning a set of parameters including scoliosis, changes in body length, yolk, and eye sizes was 0.1 mg/L. At the same NOEC concentration (0.1 mg/L), no organ-specific toxicity was detected in fish treated with SAPDMA, except hepatomegaly with no associated liver dysfunctions. However, higher SAPDMA concentrations (0.8 mg/L) have dramatic effects on zebrafish organ development (eye, heart, and liver development). Our data recommend a re-evaluation of the SAPDMA employment in the industry setting and its strictly monitoring by environmental and public health agencies.
Topics: Animals; Dimethylamines; Embryo, Nonmammalian; Lethal Dose 50; Surface-Active Agents; Water Pollutants, Chemical; Zebrafish
PubMed: 32886985
DOI: 10.1016/j.scitotenv.2020.140450 -
Methods and Protocols Feb 2020A simple method for the identification of brush-border membrane α-glucosidases is described. The proteins were first solubilized and separated in a gel under native,...
A simple method for the identification of brush-border membrane α-glucosidases is described. The proteins were first solubilized and separated in a gel under native, non-denaturing, conditions. The gel was then incubated in substrate solutions (maltose or sucrose), and the product (glucose) exposed in situ by the oxidation of o-dianisidine, which yields a brown-orange color. Nano-liquid chromatography coupled to mass spectrometry analyses of proteins (nano LC-MS/MS) present in the colored bands excised from the gels, was used to confirm the presence of the enzymes. The stain is inexpensive and the procedure permits testing several substrates in the same gel. Once enzymes are identified, their abundance, relative to that of other proteins in the brush border, can be semi-quantified using nano LC-MS/MS.
PubMed: 32050538
DOI: 10.3390/mps3010015 -
Acta Crystallographica. Section E,... Mar 2018The title compound, (systematic name: ,'-dibenzyl-3,3'-dimeth-oxy-1,1'-biphenyl-4,4'-di-amine), CHNO, was synthesized by the reduction of a Schiff base prepared a...
The title compound, (systematic name: ,'-dibenzyl-3,3'-dimeth-oxy-1,1'-biphenyl-4,4'-di-amine), CHNO, was synthesized by the reduction of a Schiff base prepared a condensation reaction between -dianisidine and benzaldehyde under acidic conditions. The mol-ecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-mol-ecule. The biphenyl moiety compound is essentially planar. Two intra-molecular N-H⋯O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenyl-ene rings of a benzidine unit is 48.68 (6)°. The methyl-ene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779 (18):0.221 (18). In the crystal, mol-ecules are connected by hydrogen bonding between -dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.
PubMed: 29765704
DOI: 10.1107/S2056989018001688 -
Nanotoxicology Jun 2018Nowadays, nanotechnology environmental health and safety (nanoEHS) is gaining attention. We previously found that silica nanoparticles (SiNPs) could induce vascular...
Nowadays, nanotechnology environmental health and safety (nanoEHS) is gaining attention. We previously found that silica nanoparticles (SiNPs) could induce vascular endothelial damage. However, the subsequent toxicologic response to SiNPs-induced endothelial damage was still largely unknown. In this study, we explored the inflammation-coagulation response and thrombotic effects of SiNPs in endothelial cells and zebrafish embryos. For in vitro study, swollen mitochondria and autophagosome were observed in ultrastructural analysis. The cytoskeleton organization was disrupted by SiNPs in vascular endothelial cells. The release of proinflammatory and procoagulant cytokines including IL-6, IL-8, MCP-1, PECAM-1, TF and vWF, were markedly elevated in a dose-dependent manner. For in vivo study, based on the NOAEL for dosimetry selection, and using two transgenic zebrafish, Tg(mpo:GFP) and Tg(fli-1:EGFP), SiNPs-induced neutrophil-mediated inflammation and impaired vascular endothelial cells. With the dosage higher than NOAEL, SiNPs significantly decreased blood flow and velocity, exhibiting a blood hypercoagulable state in zebrafish embryos. The thrombotic effect was assessed by o-dianisidine staining, showed that an increasing of erythrocyte aggregation occurred in SiNPs-treated zebrafish. Microarray analysis was used to screen the possible genes for inflammation-coagulation response to SiNPs in zebrafish, and the JAK1/TF signaling pathway was further verified by qRT-PCR and Western blot assays. For in-deepth study, il6st was knocked down with specific morpholinos. The whole-mount in situ hybridization and qRT-PCR analysis showed that the expression jak1 and f3b were attenuated in il6st knockdown groups. In summary, our data demonstrated that SiNPs could induce inflammation-coagulation response and thrombotic effects via JAK1/TF signaling pathway.
Topics: Animals; Blood Coagulation; Cells, Cultured; Embryo, Nonmammalian; Endothelium, Vascular; Humans; Inflammation; Janus Kinase 1; Nanoparticles; Signal Transduction; Silicon Dioxide; Thrombosis; Zebrafish
PubMed: 29658397
DOI: 10.1080/17435390.2018.1461267 -
Analytical Sciences : the International... 2017A new kinetic and automated assay was developed to determine ceruloplasmin ferroxidase activity. Ferrous ions are turned into ferric ions via catalytic activity of the...
A new kinetic and automated assay was developed to determine ceruloplasmin ferroxidase activity. Ferrous ions are turned into ferric ions via catalytic activity of the ferroxidase enzyme. Acetohydroxamic acid, a chromogen, forms a colored complex with ferric ions. This reaction was measured kinetically. Significant and strong correlations were obtained between the new acetohydroxamic method and the p-phenylenediamine oxidase (r = 0.988, p <0.001), o-dianisidine oxidase (r = 0.981, p <0.001), norfloxacine oxidase (r = 0.989, p <0.001) and nephelometric methods (r = 0.861, p <0.001). This reliable, applicable, user-friendly, and low-priced method can be performed fully automatically or with manual spectrophotometry, and can be used to measure the ferroxidase activity of ceruloplasmin.
Topics: Automation; Ceruloplasmin; Copper; Enzyme Assays; Humans; Kinetics; Limit of Detection; Oxidation-Reduction; Spectrophotometry
PubMed: 29225221
DOI: 10.2116/analsci.33.1339