scholarly journals Shifting the Specificity of E. coli Biosensor from Inorganic Arsenic to Phenylarsine Oxide through Genetic Engineering

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3093
Author(s):  
Hyojin Kim ◽  
Yangwon Jeon ◽  
Woonwoo Lee ◽  
Geupil Jang ◽  
Youngdae Yoon
Keyword(s):  
Genetic Engineering ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Coli Cell ◽  
Biological Processes ◽  
Phenylarsine Oxide ◽  
Covalent Bonds ◽  
E Coli ◽  
Organic Arsenic ◽  
The Moment

It has recently been discovered that organic and inorganic arsenics could be detrimental to human health. Although organic arsenic is less toxic than inorganic arsenic, it could form inorganic arsenic through chemical and biological processes in environmental systems. In this regard, the availability of tools for detecting organic arsenic species would be beneficial. Because As-sensing biosensors employing arsenic responsive genetic systems are regulated by ArsR which detects arsenics, the target selectivity of biosensors could be obtained by modulating the selectivity of ArsR. In this study, we demonstrated a shift in the specificity of E. coli cell-based biosensors from the detection of inorganic arsenic to that of organic arsenic, specifically phenylarsine oxide (PAO), through the genetic engineering of ArsR. By modulating the number and location of cysteines forming coordinate covalent bonds with arsenic species, an E. coli cell-based biosensor that was specific to PAO was obtained. Despite its restriction to PAO at the moment, it offers invaluable evidence of the potential to generate new biosensors for sensing organic arsenic species through the genetic engineering of ArsR.

Contribution of organic arsenic species to total arsenic measurements using ferrihydrite-backed diffusive gradients in thin films (DGT)

2012 ◽  
Vol 9 (1) ◽  
pp. 55 ◽  
Author(s):  
Heléne Österlund ◽  
Mikko Faarinen ◽  
Johan Ingri ◽  
Douglas C. Baxter
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Speciation Analysis ◽  
Arsenic Species ◽  
Future Studies ◽  
Organic Arsenic ◽  
Arsenic Determination ◽  
Diffusive Gradients

Environmental contextBoth the mobility and toxicity of arsenic in natural waters are related to the aqueous species distribution. Passive sampling using ferrihydrite-backed diffusive gradients in thin films (DGT) devices has in previous studies been characterised to measure labile inorganic arsenic, and the possible contribution of organic species has been disregarded. This study shows that the two most prevalent organic arsenic species might be included in DGT measurements, which should be taken into consideration when evaluating DGT data in future studies. AbstractIn previous publications discussing arsenic determination using ferrihydrite-backed diffusive gradients in thin films (DGT) devices, organic arsenic forms have been disregarded, even though it is known that the two most prevalent in natural waters, dimethylarsinate (DMA) and monomethylarsonate (MMA), may adsorb to ferrihydrite and thereby be included in the measurement. In this work the accumulation of DMA and MMA, as well as inorganic arsenite and arsenate, to ferrihydrite-backed DGT devices was investigated. It could be demonstrated that MMA, and under acidic conditions also DMA, adsorbed to the binding layer and might therefore contribute to the total mass of measured arsenic. Diffusion coefficients were measured for all four species to enable quantification of DGT-labile concentrations of organic and inorganic arsenic. Elution of the analytes from the ferrihydrite binding layer was performed using 1 mL of 1 M NaOH to facilitate arsenic speciation analysis using chromatographic separation. Average recovery rates were between 87 and 108 %. This study shows that the contribution of DMA and MMA to the total accumulated mass must be taken into consideration when evaluating DGT data in future studies.

scholarly journals The Bioaccumulation and Tissue Distribution of Arsenic Species in Tilapia

2019 ◽  
Vol 16 (5) ◽  
pp. 757 ◽  
Author(s):  
Jia Pei ◽  
Jinxing Zuo ◽  
Xiaoyan Wang ◽  
Jingyu Yin ◽  
Liping Liu ◽  
...  
Keyword(s):  
Human Health ◽  
Time Course ◽  
Human Health Risk ◽  
Arsenic Concentration ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Total Arsenic ◽  
Organic Form ◽  
Exposure Pathway ◽  
Organic Arsenic

Arsenic is a public concern due to its widespread occurrence and carcinogenicity. Consumption of arsenic-contaminated fish is an important exposure pathway for human health. This study focused on understanding how exposure to arsenic-contaminated fish is informative to human health risk assessment. While the bioaccumulation and tissue distributions of total arsenic concentration in fish are commonly reported, there are limited studies related to the time-course of arsenic species in various tissues. Using the Tilapia as a case, this study aimed to investigate the bioaccumulation and tissue distributions (liver, gastrointestinal (GI), muscle, and gill) of arsenic species in freshwater fish via diet-borne inorganic arsenic exposure. In particular, the Tilapia were exposed to arsenic (III) and As(V) for 32 days. The accumulation of arsenic in all tissues linearly increased with time in the first 10 days’ exposure, while the arsenic levels remained stable in the following 20 days’ exposure. The accumulation of arsenic in tissue followed the sequence of intestine > liver > gill > muscle. Meanwhile, more than 90% of arsenic was converted into organic form in liver, gill, and muscle, while organic arsenic contributed about 30–80% to the total arsenic in the GI. The percentage of organic form in muscle is the highest, followed by gill, liver, and intestine, and arsenobetaine is the main form of organic arsenic. While the exposure profiles of As(III) and As(V) are quite similar, the absorption rate of As(V) is relatively higher than that of As(III). Information provided here can be instrumental for exposure assessment and risk management for arsenic in aquatic environment.

Daily intake of inorganic arsenic and some organic arsenic species of Japanese subjects

2012 ◽  
Vol 50 (8) ◽  
pp. 2663-2667 ◽  
Author(s):  
Tomoko Oguri ◽  
Jun Yoshinaga ◽  
Hiroaki Tao ◽  
Tetsuya Nakazato
Keyword(s):  
Daily Intake ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Organic Arsenic ◽  
Japanese Subjects

High-Level Expression of Human β-Defensin-2 Gene with Rare Codons in E. coli Cell-Free System

2006 ◽  
Vol 13 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Haiqin Chen ◽  
Zhinan Xu ◽  
Naizheng Xu ◽  
Peilin Cen
Keyword(s):  
Coli Cell ◽  
High Level Expression ◽  
Free System ◽  
Cell Free System ◽  
E Coli ◽  
Rare Codons ◽  
High Level

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

An economical method for producing stable-isotope labeled proteins by the E. coli cell-free system

2010 ◽  
Vol 48 (4) ◽  
pp. 193-201 ◽  
Author(s):  
Jun Yokoyama ◽  
Takayoshi Matsuda ◽  
Seizo Koshiba ◽  
Takanori Kigawa
Keyword(s):  
Stable Isotope ◽  
Coli Cell ◽  
Free System ◽  
Economical Method ◽  
Cell Free System ◽  
E Coli

Inhibition of polypeptide synthesis in E. Coli cell free system by influenza viral protein

FEBS Letters ◽  
1970 ◽  
Vol 7 (2) ◽  
pp. 201-204
Author(s):  
Kenji Sekikawa ◽  
Iwao Suzuka
Keyword(s):  
Viral Protein ◽  
Coli Cell ◽  
Free System ◽  
Cell Free System ◽  
E Coli ◽  
Polypeptide Synthesis

The E. coli cell surface: On the genetic organization of the tolP AB cluster

1973 ◽  
Vol 123 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Alan Bernstein
Keyword(s):  
Cell Surface ◽  
Coli Cell ◽  
E Coli ◽  
Genetic Organization
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