Electrochemical acetylcholinesterase biosensor for detection of cholinesterase inhibitors: study with eserine

Informacije MIDEM - Journal of Microelectronics Electronic Components and Materials ◽

10.33180/infmidem2018.406 ◽

2019 ◽

pp. 235-240

Keyword(s):

Gold Electrode ◽

Cholinesterase Inhibitors ◽

Electrochemical Biosensor ◽

Immobilized Enzyme ◽

Chemical Warfare Agents ◽

Chemical Warfare ◽

Initial Reduction ◽

Warfare Agents ◽

Ellman’S Method ◽

Acetylthiocholine Chloride

Cholinesterase inhibitors are widely used as pesticides, as chemical warfare agents and as drugs to treat symptoms of Alzheimer’s disease. Therefore, it is a high need to develop methods for their detection which are fast, sensitive, and reliable. This paper reports a preliminary work in the development of an electrochemical biosensor based on acetylcholinesterase (AChE) which is constructed by immobilization layers – cysteamine/glutaraldehyde/AChE on thin layer gold electrode for detection of cholinesterase inhibitors. Eserine (physostigmine) was used as a test inhibitor. The enzyme immobilization efficacy was evaluated by measuring activity of immobilized enzyme via Ellman’s method. The enzyme activity of the initial reduction of 33% in five days remained after that stable for at least one week. Chronoamperometric response to substrate acetylthiocholine chloride (ATCl) was assumed to follow Michaelis-Menten kinetics. After exposure biosensor to 25 mM eserine for 10 min, 70% inhibition of enzyme was detected. Reactivation factor of inhibited AChE was determined as 0.016 min-1.

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Some Possibilities to Study New Prophylactics against Nerve Agents

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557519666190301112530 ◽

2019 ◽

Vol 19 (12) ◽

pp. 970-979 ◽

Cited By ~ 1

Author(s):

J. Bajgar ◽

J. Kassa ◽

T. Kucera ◽

K. Musilek ◽

D. Jun ◽

...

Keyword(s):

Cholinesterase Inhibitors ◽

Chemical Warfare Agents ◽

Nerve Agents ◽

Chemical Warfare ◽

Huperzine A ◽

Acetylcholinesterase Inhibition ◽

Effective Prophylaxis ◽

Warfare Agents

Nerve agents belong to the most dangerous chemical warfare agents and can be/were misused by terrorists. Effective prophylaxis and treatment is necessary to diminish their effect. General principles of prophylaxis are summarized (protection against acetylcholinesterase inhibition, detoxification, treatment “in advance” and use of different drugs). They are based on the knowledge of mechanism of action of nerve agents. Among different examinations, it is necessary to test prophylactic effectivity in vivo and compare the results with protection in vitro. Chemical and biological approaches to the development of new prophylactics would be applied simultaneously during this research. Though the number of possible prophylactics is relatively high, the only four drugs were introduced into military medical practice. At present, pyridostigmine seems to be common prophylactic antidote; prophylactics panpal (tablets with pyridostigmine, trihexyphenidyl and benactyzine), transant (transdermal patch containing HI-6) are other means introduced into different armies as prophylactics. Scavenger commercionally available is Protexia®. Future development will be focused on scavengers, and on other drugs either reversible cholinesterase inhibitors (e.g., huperzine A, gallantamine, physostigmine, acridine derivatives) or other compounds.

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Mineralization of Paraoxon and Its Use as a Sole C and P Source by a Rationally Designed Catabolic Pathway in Pseudomonas putida

Applied and Environmental Microbiology ◽

10.1128/aem.00907-06 ◽

2006 ◽

Vol 72 (10) ◽

pp. 6699-6706 ◽

Cited By ~ 36

Author(s):

Matthew de la Peña Mattozzi ◽

Sundiep K. Tehara ◽

Thomas Hong ◽

Jay D. Keasling

Keyword(s):

Pseudomonas Putida ◽

Cholinesterase Inhibitors ◽

Chemical Warfare Agents ◽

Chemical Warfare ◽

Catabolic Pathway ◽

Warfare Agents ◽

Phosphorus Source ◽

High Concentrations ◽

Synthetic Operon ◽

Heterologous Pathway

ABSTRACT Organophosphate compounds, which are widely used as pesticides and chemical warfare agents, are cholinesterase inhibitors. These synthetic compounds are resistant to natural degradation and threaten the environment. We constructed a strain of Pseudomonas putida that can efficiently degrade a model organophosphate, paraoxon, and use it as a carbon, energy, and phosphorus source. This strain was engineered with the pnp operon from Pseudomonas sp. strain ENV2030, which encodes enzymes that transform p-nitrophenol into β-ketoadipate, and with a synthetic operon encoding an organophosphate hydrolase (encoded by opd) from Flavobacterium sp. strain ATCC 27551, a phosphodiesterase (encoded by pde) from Delftia acidovorans, and an alkaline phosphatase (encoded by phoA) from Pseudomonas aeruginosa HN854 under control of a constitutive promoter. The engineered strain can efficiently mineralize up to 1 mM (275 mg/liter) paraoxon within 48 h, using paraoxon as the sole carbon and phosphorus source and an inoculum optical density at 600 nm of 0.03. Because the organism can utilize paraoxon as a sole carbon, energy, and phosphorus source and because one of the intermediates in the pathway (p-nitrophenol) is toxic at high concentrations, there is no need for selection pressure to maintain the heterologous pathway.

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