Influence of acetylcholinesterase immobilization on the photoluminescence properties of mesoporous silicon surface

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Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

2014-01-01

Acetylcholinesterase immobilized p-type porous silicon surface was prepared by covalent attachment. The immobilization procedure was based on support surface chemical oxidation, silanization, surface activation with cyanuric chloride and finally covalent attachment of free enzyme on the cyanuric chloride activated porous silicon surface. Different pore diameter of porous silicon samples were prepared by electrochemical etching in HF based electrolyte solution and appropriate sample was selected suitable for enzyme immobilization with maximum trapping ability. The surface modification was studied through field emission scanning electron microscope, EDS, FT-IR analysis, and photoluminescence measurement by utilizing the fluctuation in the photoluminescence of virgin and enzyme immobilized porous silicon surface. Porous silicon showed strong photoluminescence with maximum emission at 643 nm and immobilization of acetylcholinesterase on porous silicon surface cause considerable increment on the photoluminescence of porous silicon material while acetylcholinesterase free counterpart did not exhibit any fluorescence in the range of 635–670 nm. The activities of the free and immobilized enzymes were evaluated by spectrophotometric method by using neostigmine methylsulfate as standard enzyme inhibitor. The immobilized enzyme exhibited considerable response toward neostigmine methylsulfate in a dose dependent manner comparable with that of its free counterpart alongside enhanced stability, easy separation from the reaction media and significant saving of enzyme. It was believed that immobilized enzyme can be exploited in organic and biomolecule synthesis possessing technical and economical prestige over free enzyme and prominence of easy separation from the reaction mixture.

Enzymatic and biochemical characterization of Bungarus sindanus snake venom acetylcholinesterase

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M Ahmed

2012-01-01

Full Text Available This study analyses venom from the elapid krait snake Bungarus sindanus, which contains a high level of acetylcholinesterase (AChE activity. The enzyme showed optimum activity at alkaline pH (8.5 and 45ºC. Krait venom AChE was inhibited by substrate. Inhibition was significantly reduced by using a high ionic strength buffer; low ionic strength buffer (10 mM PO4 pH 7.5 inhibited the enzyme by 1. 5mM AcSCh, while high ionic strength buffer (62 mM PO4 pH 7.5 inhibited it by 1 mM AcSCh. Venom acetylcholinesterase was also found to be thermally stable at 45ºC; it only lost 5% of its activity after incubation at 45ºC for 40 minutes. The Michaelis-Menten constant (Km for acetylthiocholine iodide hydrolysis was found to be 0.068 mM. Krait venom acetylcholinesterase was also inhibited by ZnCl2, CdCl2, and HgCl2 in a concentrationdependent manner. Due to the elevated levels of AChE with high catalytic activity and because it is more stable than any other sources, Bungarus sindanus venom is highly valuable for biochemical studies of this enzyme.

Methyl jasmonate enhances memory performance through inhibition of oxidative stress and acetylcholinesterase activity in mice.

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Eduviere, Anthony T; Umukoro, S; Aderibigbe, Adegbuyi O; Ajayi, Abayomi M; Adewole, Folashade A

2015-07-01

Current research effort focuses on the development of safer natural compounds with multipronged mechanisms of action that could be used to ameliorate memory deficits in patients with Alzheimer's disease, as cure for the disease still remains elusive. In this study, we evaluated the effect of methyl jasmonate (MJ), a naturally occurring bioactive compound on memory, acetylcholinesterase activity and biomarkers of oxidative stress in mice. Male Swiss mice were treated with intraperitoneal injection of MJ (10-40 mg/kg) alone or in combination with scopolamine (3mg/kg) once daily for 7 days. Thirty minutes after the last treatment, memory functions were assessed using Y-maze and object recognition tests. Thereafter, acetylcholinesterase activity and levels of biomarkers of oxidative stress were assessed in mice brains using standard biochemical procedures. MJ significantly enhanced memory performance and reversed scopolamine-induced cognitive impairment in mice. MJ demonstrated significant inhibition of acetylcholinesterase activity suggesting increased cholinergic neurotransmission. It further decreased malondialdehyde concentrations in mouse brain indicating antioxidant activity. Moreover, MJ significantly increased glutathione levels and activity of antioxidant enzymes (catalase and superoxide dismutase) in mice brains. The increased oxidative stress; evidenced by elevated levels of malondialdehyde and decreased antioxidant defense systems in scopolamine-treated mice was attenuated by MJ. The results of this study suggest that MJ may be useful in conditions associated with memory dysfunctions or age-related cognitive decline. The positive effect of MJ on memory may be related to inhibition of oxidative stress and enhancement of cholinergic neurotransmission through inhibition of acetylcholinesterase activity. Copyright © 2015 Elsevier Inc. All rights reserved.

The activity of detoxifying enzymes in the infective juveniles of Heterorhabditis bacteriophora strains: Purification and characterization of two acetylcholinesterases.

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Mohamed, Magda A; Mahdy, El-Sayed M E; Ghazy, Abd-El-Hady M; Ibrahim, Nihal M; El-Mezayen, Hatem A; Ghanem, Manal M E

2016-02-01

The infectivity and detoxifying enzyme activities including glutathione-S-transferase (GST), acetylcholinesterase (AChE) and carboxylesterase (CaE) are investigated in the infective juveniles (IJs) of six different strains of Heterorhabditis bacteriophora as a biocontrol agent against insect pests. The specific activities ranged from 10.8-29.8 and 50-220units/mg protein for GST and AChE, respectively; and from 24.7-129 and 22.6-77.3units/mg protein for CaE as estimated by P-nitrophenyl and α-naphthyl acetates, respectively. H. bacteriophora EM2 strain has the highest infectivity and the highest enzymatic activities as well. AChE is the predominant detoxifying enzyme that might imply its major role in the detoxification of insecticide(s). The isoenzyme pattern demonstrated two major slow-moving isoforms in all EPN strains examined. Purification of two AChE isoforms, AChEAII and AChEBI, from H. bacteriophora EM2 strain is performed by ammonium sulfate precipitation, gel filtration on Sephacryl S-200 and chromatography on DEAE-Sepharose. AChEAII and AChEBII have specific activities of 1207 and 1560unit/mg protein, native molecular weights of 180 and 68kDa, and are found in dimeric and monomeric forms, respectively. Both isoforms showed optimum activity at pH8.5 and 35°C. AChEBI exhibited higher thermal stability and higher activation energy than AChEAII. The enzymatic activities of purified AChEs are completely inhibited by Hg(+2) and Ni(+2) and greatly enhanced by Mn(+2). The substrate specificity, the relative efficiency of substrates hydrolysis, substrate inhibition and inhibition by BW284C51, but not by iso-OMPA, clearly indicated that they are true AChEs; their properties are compared with those recorded for insects as target hosts for H. bacteriophora EM2. Copyright © 2015 Elsevier Inc. All rights reserved.

Antioxidant Activity and Acetylcholinesterase Inhibition of Grape Skin Anthocyanin (GSA

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Mehnaz Pervin

2014-07-01

Full Text Available We aimed to investigate the antioxidant and acetylcholinesterase inhibitory activities of the anthocyanin rich extract of grape skin. Grape skin anthocyanin (GSA neutralized free radicals in different test systems, such as 2,-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS and 2,2-diphenyl-1-picrylhydrazyl (DPPH assays, to form complexes with Fe2+ preventing 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH-induced erythrocyte hemolysis and oxidative DNA damage. Moreover, GSA decreased reactive oxygen species (ROS generation in isolated mitochondria thus inhibiting 2',-7'-dichlorofluorescin (DCFH oxidation. In an in vivo study, female BALB/c mice were administered GSA, at 12.5, 25, and 50 mg per kg per day orally for 30 consecutive days. Herein, we demonstrate that GSA administration significantly elevated the level of antioxidant enzymes in mice sera, livers, and brains. Furthermore, GSA inhibited acetylcholinesterase (AChE in the in vitro assay with an IC50 value of 363.61 µg/mL. Therefore, GSA could be an excellent source of antioxidants and its inhibition of cholinesterase is of interest with regard to neurodegenerative disorders such as Alzheimer’s disease.

Identification of a trypsin-like site associated with acetylcholinesterase by affinity labelling with (/sup 3/H)diisopropyl fluorophosphate

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Small, D.H.; Chubb, I.W.

1988-07-01

In addition to its ability to hydrolyze acetylcholine, purified eel acetylcholinesterase possesses a trypsin-like endopeptidase activity. The tryptic activity is associated with a serine residue at a site that is distinct from the esteratic site. To label both the esteratic and tryptic sites, the enzyme was incubated with the serine hydrolase inhibitor (/sup 3/H)diisopropyl fluorophosphate. This compound labelled the protein in a biphasic manner, with both slow and rapid labelling kinetics. The time course of the rapid phase was similar to the time course of inactivation of the esteratic activity. The time course of the slow phase was similar to the time course of inactivation of the tryptic activity. Labelling of the nonesteratic site was inhibited by the trypsin inhibitor N alpha-p-tosyl-L-lysine chloromethyl ketone. The total number of sites labelled by (/sup 3/H)diisopropyl fluorophosphate on eel acetylcholinesterase was 2.6 mol/280,000 g protein, whereas the number of tryptic sites was less (0.52 mol/280,000 g). The results suggest that a subpopulation of acetylcholinesterase molecules may possess tryptic activity. Extensive chromatography of the purified enzyme by ion-exchange and gel filtration failed to separate the labelled tryptic component from acetylcholinesterase. On sodium dodecyl sulfate-polyacrylamide gels, the labelled tryptic component comigrated with a polypeptide of 50,000 molecular weight, which is a major proteolytic digestion product derived from the intact acetylcholinesterase monomer. Because of its localization in many noncholinergic peptide-containing cells, acetylcholinesterase could act as a neuropeptide processing enzyme in these cells.

Production and enzyme engineerinq of human acetylcholinesterase and its mutant derivatives. Midterm report, 15 January 1993-15 July 1994

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Shafferman, A.

1994-07-15

Specificity determinants of human acetylcholinesterase (HuAChE) towards ligands (substrate and some reversible and irreversible inhibitors) were identified by combination of site-directed mutagenesis, molecular modeling and kinetic studies with enzymes mutated in active center residues Trp86, Glu202, Trp286, Phe295, Phe297, Tyr337, Phe338 and Glu450. Thus, the anionic and hydrophobic subsites as well as the acyl pocket were identified. Enzymes with resistance to OP aging were engineered.The role of N-glycosylation in the function, biosynthesis and stability of HuAChE was examined by site-directed mutagenesis (Asn to GIn substitution) of the three potential N glycosylation sites, Asn265, Asn350 and Asn464. Large scale preparation of recombinant HuAChE was performed utilizing the microcarrier technology. Over 500 milligrams of enzyme was prepared for x-ray crystallography.

In situ monitoring of myenteric neuron activity using acetylcholinesterase-modified AlGaN/GaN solution-gate field-effect transistors.

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Müntze, Gesche Mareike; Pouokam, Ervice; Steidle, Julia; Schäfer, Wladimir; Sasse, Alexander; Röth, Kai; Diener, Martin; Eickhoff, Martin

2016-03-15

The response characteristics of acetylcholinesterase-modified AlGaN/GaN solution-gate field-effect transistors (AcFETs) are quantitatively analyzed by means of a kinetic model. The characterization shows that the covalent enzyme immobilization process yields reproducible AcFET characteristics with a Michaelis constant KM of (122 ± 4) μM for the immobilized enzyme layer. The increase of KM by a factor of 2.4 during the first four measurement cycles is attributed to partial denaturation of the enzyme. The AcFETs were used to record the release of acetylcholine (ACh) by neuronal tissue cultivated on the gate area upon stimulation by rising the extracellular K(+) concentration. The neuronal tissue constituted of isolated myenteric neurons from four to 12 days old Wistar rats, or sections from the muscularis propria containing the myenteric plexus from adult rats. For both cases the AcFET response was demonstrated to be related to the activity of the immobilized acetylcholinesterase using the reversible acetylcholinesterase blocker donepezil. A concentration response curve of this blocking agent revealed a half maximal inhibitory concentration of 40 nM which is comparable to values measured by complementary in vitro methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of fluorocarbons on acetylcholinesterase activity and some counter measures

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Young, W.; Parker, J. A.

1975-01-01

An isolated vagal sympathetic heart system has been successfully used for the study of the effect of fluorocarbons (FCs) on cardiac performance and in situ enzyme activity. Dichlorodifluoromethane sensitizes this preparation to sympathetic stimulation and to exogenous epinephrine challenge. Partial and complete A-V block and even cardiac arrest have been induced by epinephrine challenge in the FC sensitized heart. Potassium chloride alone restores the rhythmicity but not the normal contractility of the heart in such a situation. Addition of glucose will, however, completely restore the normal function of the heart which is sensitized by dichlorodifluoromethane. The ED 50 values of acetylcholinesterase activity which are used as a measure of relative effectiveness of fluorocarbons are compared with the maximum permissible concentration. Kinetic studies indicate that all the fluorocarbons tested so far are noncompetitive.

Novel coumarin derivatives bearing N-benzyl pyridinium moiety: potent and dual binding site acetylcholinesterase inhibitors.

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Alipour, Masoumeh; Khoobi, Mehdi; Foroumadi, Alireza; Nadri, Hamid; Moradi, Alireza; Sakhteman, Amirhossein; Ghandi, Mehdi; Shafiee, Abbas

2012-12-15

A novel series of coumarin derivatives linked to benzyl pyridinium group were synthesized and biologically evaluated as inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The enzyme inhibitory activity of synthesized compounds was measured using colorimetric Ellman's method. It was revealed that compounds 3e, 3h, 3l, 3r and 3s have shown higher activity compared with donepezil hydrochloride as standard drug. Most of the compounds in these series had nanomolar range IC(50) in which compound 3r (IC(50) = 0.11 nM) was the most active compound against acetylcholinesterase enzyme. Copyright © 2012 Elsevier Ltd. All rights reserved.

Inactivation of acetylcholinesterase by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride.

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Zang, Lun-Yi; Misra, Hara P

2003-12-01

The neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to reversibly inhibit the activity of acetylcholinesterase. The inactivation of the enzyme was detected by monitoring the accumulation of yellow color produced from the reaction between thiocholine and dithiobisnitrobenzoate ion. The kinetic parameter, Km for the substrate (acetylthiocholine), was found to be 0.216 mM and Ki for MPTP inactivation of acetylcholinesterase was found to be 2.14 mM. The inactivation of enzyme by MPTP was found to be dose-dependent. It was found that MPTP is neither a substrate of AChE nor the time-dependent inactivator. The studies of reaction kinetics indicate the inactivation of AChE to be a linear mixed-type inhibition. The dilution assays indicate that MPTP is a reversible inhibitor for AChE. These data suggest that once MPTP enters the basal ganglia of the brain, it can inactivate the acetylcholinesterase enzyme and thereby increase the acetylcholine level in the basal ganglia of brain, leading to potential cell dysfunction. It appears that the nigrostriatal toxicity by MPTP leading to Parkinson's disease-like syndrome may, in part, be mediated via the acetylcholinesterase inactivation.

A Rapid ELISA Method for 17, 20b-dihydroxy-4-pregenen-3-one (17,20bP Hormone Using Acetylcholinesterase Enzyme as Tracer

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M Ebrahimi

2004-06-01

Full Text Available Background: During the past 15 years Enzyme Linked ImmunoSorbent Assay (ELISA has been described as an alternative to radioimmunoassay for steroid detection. In addition to gonads, sperm itself is capable of producing reduced progesterone metabolites. In this study we introduced a method to extend the applicability of previous measures by describing a general preparation procedure for the enzyme label which is applicable to any steroid hormone. Methods: A simple and rapid Enzyme Linked Immunosorbant Assay (ELISA is described and validated for 17,20β- dihydroxy-4-pregnen-3-one (17,20βP. A general procedure for preparation of the acetylcholinesterase labelled steroid is described which is applicable to any steroid. Results: Use of acetylcholinesterase tracer increased the sensitivity of assay so that reliable measurements of each steroid could be achieved with only 10 µl of plasma. ELISA was applied to measure of 17,20βP steroid production by sperm of trout which has sufficient amount of potent and active 20βHSD enzyme to convert 17α-hydroxy-4-pregnen-3-one (17αP substrate to 17,20βP product. The results showed that a clear shift in 17,20βP production was found with increase in substrate concentration in all in vitro incubations. Conclusion: ELISA method presented in this study has greater sensitivity and accuracy compared to previously described method that uses radiolabelled substances. Keywords: Immunoassay, ELISA, Steroids, Hormone, Assay

Evaluating the antioxidant and acetylcholinesterase inhibitory activity of three Centaurea species

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H. Hajimehdipoor

2014-01-01

Full Text Available Factors such as oxidative stress and reduced acetylcholine level have been implicated in Alzheimer’s disease (AD pathology and recently there has been a trend towards natural product research to find potential sources of antioxidants and acetylcholinesterase inhibitors in the plants kingdom. Centaurea is a genus with about 500 species world wild, many of them have shown to possess biologic activity; Centaurea albonites, C. aucheri and C. pseudoscabiosa are three species which little investigation has been carried out about their biological properties. In the present study, the antioxidant and acetylcholinesterase inhibitory activity of the above mentioned species have been evaluated. The ability of the total extract and methanol fraction of the plants to scavenge free radicals has been assessed through DPPH radical scavenging assay, and the acetylcholinesterase inhibitory property has been evaluated by Ellman method. The total extract of all species exhibited moderate antioxidant activity whereas the extracts of C. pseudoscabiosa showed the strongest antioxidant property; its total extract also demonstrated the highest acetylcholinesterase inhibitory activity among the evaluated samples (19.2% inhibition. The results suggest the species as potential sources of natural antioxidants which could be focused in future studies of Alzheimer’s disease.

Changes in acetylcholinesterase activities in the developing and ...

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Changes in acetylcholinesterase activities in the developing and aging pig brain and hypophyses. ... International Journal of Agriculture and Rural Development. Journal Home · ABOUT ... Open Access DOWNLOAD FULL TEXT Subscription ...

Dual Binding Site and Selective Acetylcholinesterase Inhibitors Derived from Integrated Pharmacophore Models and Sequential Virtual Screening

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Shikhar Gupta

2014-01-01

Full Text Available In this study, we have employed in silico methodology combining double pharmacophore based screening, molecular docking, and ADME/T filtering to identify dual binding site acetylcholinesterase inhibitors that can preferentially inhibit acetylcholinesterase and simultaneously inhibit the butyrylcholinesterase also but in the lesser extent than acetylcholinesterase. 3D-pharmacophore models of AChE and BuChE enzyme inhibitors have been developed from xanthostigmine derivatives through HypoGen and validated using test set, Fischer’s randomization technique. The best acetylcholinesterase and butyrylcholinesterase inhibitors pharmacophore hypotheses Hypo1_A and Hypo1_B, with high correlation coefficient of 0.96 and 0.94, respectively, were used as 3D query for screening the Zinc database. The screened hits were then subjected to the ADME/T and molecular docking study to prioritise the compounds. Finally, 18 compounds were identified as potential leads against AChE enzyme, showing good predicted activities and promising ADME/T properties.

Antimicrobial activity and acetylcholinesterase inhibition by extracts from chromatin modulated fungi

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Matheus Thomaz Nogueira Silva Lima

Full Text Available ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine and/or a histone deacetylase inhibitor (suberohydroxamic acid. Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%, when compared to the control extract (39.62 ± 3.76%. Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.

Evaluation of acetylcholinesterase inhibitory activity of Brazilian red macroalgae organic extracts

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Levi P. Machado

Full Text Available Abstract Alzheimer's disease affects nearly 36.5 million people worldwide, and acetylcholinesterase inhibition is currently considered the main therapeutic strategy against it. Seaweed biodiversity in Brazil represents one of the most important sources of biologically active compounds for applications in phytotherapy. Accordingly, this study aimed to carry out a quantitative and qualitative assessment of Hypnea musciformis (Wulfen J.V. Lamouroux, Ochtodes secundiramea (Montagne M.A. Howe, and Pterocladiella capillacea (S.G. Gmelin Santelices & Hommersand (Rhodophyta in order to determine the AChE effects from their extracts. As a matter of fact, the O. secundiramea extract showed 48% acetylcholinesterase inhibition at 400 μg/ml. The chemical composition of the bioactive fraction was determined by gas chromatography–mass spectrometry (GC–MS; this fraction is solely composed of halogenated monoterpenes, therefore allowing assignment of acetylcholinesterase inhibition activity to them.

Shift in aggregation, ROS generation, antioxidative defense, lysozyme and acetylcholinesterase activities in the cells of an Indian freshwater sponge exposed to washing soda (sodium carbonate).

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Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

2016-09-01

Washing soda, chemically identified as anhydrous sodium carbonate, is a popular cleaning agent among the rural and urban populations of India which often contaminates the freshwater ponds and lakes, the natural habitat of sponge Eunapius carteri. Present investigation deals with estimation of cellular aggregation, generation of ROS and activities of antioxidant enzymes, lysozyme and acetylcholinesterase in the cells of E. carteri under the environmentally realistic concentrations of washing soda. Prolonged treatment of washing soda inhibited the degree of cellular aggregation. Experimental exposure of 8 and 16mg/l of sodium carbonate for 48h elevated the physiological level of reactive oxygen species (ROS) generation in the agranulocytes, semigranulocytes and granulocytes of E. carteri, whereas, treatment of 192h inhibited the ROS generation in three cellular morphotypes. Activities of superoxide dismutase, catalase and glutathione-S-transferase were recorded to be inhibited under prolonged exposure of washing soda. Washing soda mediated inhibition of ROS generation and depletion in the activities of antioxidant enzymes were indicative to an undesirable shift in cytotoxic status and antioxidative defense in E. carteri. Inhibition in the activity of lysozyme under the treatment of sodium carbonate was suggestive to a severe impairment of the innate immunological efficiency of E. carteri distributed in the washing soda contaminated habitat. Washing soda mediated inhibition in the activity of acetylcholinesterase indicated its neurotoxicity in E. carteri. Washing soda, a reported environmental contaminant, affected adversely the immunophysiological status of E. carteri with reference to cellular aggregation, oxidative stress, antioxidative defense, lysozyme and acetylcholinesterase activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Energetics of Ortho-7 (oxime drug translocation through the active-site gorge of tabun conjugated acetylcholinesterase.

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Vivek Sinha

Full Text Available Oxime drugs translocate through the 20 Å active-site gorge of acetylcholinesterase in order to liberate the enzyme from organophosphorus compounds' (such as tabun conjugation. Here we report bidirectional steered molecular dynamics simulations of oxime drug (Ortho-7 translocation through the gorge of tabun intoxicated enzyme, in which time dependent external forces accelerate the translocation event. The simulations reveal the participation of drug-enzyme hydrogen bonding, hydrophobic interactions and water bridges between them. Employing nonequilibrium theorems that recovers the free energy from irreversible work done, we reconstruct potential of mean force along the translocation pathway such that the desired quantity represents an unperturbed system. The potential locates the binding sites and barriers for the drug to translocate inside the gorge. Configurational entropic contribution of the protein-drug binding entity and the role of solvent translational mobility in the binding energetics is further assessed.

Effect of ions on the activity of brain acetylcholinesterase from tropical fish

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Caio Rodrigo Dias Assis

2015-07-01

Full Text Available Objective: To investigate the effect of ions on brain acetylcholinesterase (AChE; EC 3.1.1.7 activities from economic important fish [pirarucu, Arapaima gigas; tambaqui, Colossoma macropomum; cobia, Rachycentron canadum (R. canadum and Nile tilapia, Oreochromis niloticus (O. niloticus] comparing with a commercial enzyme from electric eel [Electrophorus electricus (E. electricus]. Methods: The in vitro exposure was performed at concentrations ranging from 0.001 to 10 mmol/L (except for ethylene diamine tetraacetic acid; up to 150 mmol/L. Inhibition kinetics on R. canadum and O. niloticus were also observed through four methods (Michaelis-Menten, Lineweaver-Burk, Dixon and Cornish-Bowden plots in order to investigate the type of inhibition produced by some ions. Results: Hg 2+ , As 3+ , Cu 2+ , Zn 2+ , Cd 2+ caused inhibition in all the species under study. Ca 2+ , Mg 2+ and Mn 2+ induced slight activation in R. canadum enzyme while Pb 2+ , Ba 2+ , Fe 2+ , Li + inhibited the AChE from some of the analyzed species. The lowest IC 50 and Ki values were estimated for E. electricus AChE in presence of Hg 2+ , Pb 2+ , Zn 2+ . Under our experimental conditions, the results for R. canadum and O. niloticus, As 3+ , Cu 2+ , Cd 2+ , Pb 2+ and Zn 2+ showed a non- competitive/mixed-type inhibition, while Hg 2+ inhibited the enzyme in a mixed/competitive- like manner. Conclusions: E. electricus AChE activity was affected by ten of fifteen ions under study showing that this enzyme could undergo interference by these ions when used as pesticide biosensor in environmental analysis. This hindrance would be less relevant for the crude extracts.

Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats

OpenAIRE

TEODORAK, BRENA P.; FERREIRA, GABRIELA K.; SCAINI, GISELLI; WESSLER, LETÍCIA B.; HEYLMANN, ALEXANDRA S.; DEROZA, PEDRO; VALVASSORI, SAMIRA S.; ZUGNO, ALEXANDRA I.; QUEVEDO, JOÃO; STRECK, EMILIO L.

2015-01-01

Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute...

Report: screening of selected medicinal plants for their enzyme inhibitory potential - a validation of their ethnopharmacological uses.

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Khuda, Fazli; Iqbal, Zafar; Khan, Ayub; Zakiullah; Shah, Yasar; Khan, Abad

2014-05-01

In present study four medicinal plants namely Valeriana wallichii, Xanthium strumarium, Achyranthes aspera and Duchesnea indica belonging to different families were collected in Khyber Pakhtunkhwa province and crude extract and subsequent fractions were analyzed for their inhibitory potential against acetylcholinesterase, butyrylcholinesterase and α-glucosidase enzymes. Valeriana wallichii, Xanthium strumarium and Achyranthes aspera were significantly active against cholinesterases. Chloroform and ethylacetate fractions of Valeriana wallichii exhibited significant activity against acetylcholinesterase (IC50: 61μg/ml) and butyrylcholinesterase enzymes (IC50: 58μg/ml), respectively. Similarly ethylacetate fraction of Achyranthes aspera showed significant activity against acetylcholinesterase (IC50: 61 μg/ml) and butyrylcholinesterase enzymes (IC50: 61 μg/ml), respectively. In case of α-glucosidase enzyme, the chloroform fraction of Xanthium strumarium exhibited significant inhibitory activity (IC50: 72 μg/ml) as compared to the standard compound acarbose (IC50: 483 μg/ml). Duchesnea indica showed no such activities.

Antioxidant and acetylcholinesterase inhibitory activities of ginger root (Zingiber officinale Roscoe) extract.

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Tung, Bui Thanh; Thu, Dang Kim; Thu, Nguyen Thi Kim; Hai, Nguyen Thanh

2017-05-04

Background Zingiber officinale Roscoe has been used in traditional medicine for the treatment of neurological disorder. This study aimed to investigate the phenolic contents, antioxidant, acetylcholinesterase enzyme (AChE) inhibitory activities of different fraction of Z. officinale root grown in Vietnam. Methods The roots of Z. officinale are extracted with ethanol 96 % and fractionated with n-hexane, ethyl acetate (EtOAc) and butanol (BuOH) solvents. These fractions evaluated the antioxidant activity by 1,1-Diphenyl -2-picrylhydrazyl (DPPH) assay and AChE inhibitory activity by Ellman's colorimetric method. Results Our data showed that the total phenolic content of EtOAc fraction was highest equivalents to 35.2±1.4 mg quercetin/g of fraction. Our data also demonstrated that EtOAc fraction had the strongest antioxidant activity with IC50 was 8.89±1.37 µg/mL and AChE inhibitory activity with an IC50 value of 22.85±2.37 μg/mL in a dose-dependent manner, followed by BuOH fraction and the n-hexane fraction is the weakest. Detailed kinetic analysis indicated that EtOAc fraction was mixed inhibition type with Ki (representing the affinity of the enzyme and inhibitor) was 30.61±1.43 µg/mL. Conclusions Our results suggest that the EtOAc fraction of Z. officinale may be a promising source of AChE inhibitors for Alzheimer's disease.

Simplified methods for in vivo measurement of acetylcholinesterase activity in rodent brain

International Nuclear Information System (INIS)

Kilbourn, Michael R.; Sherman, Phillip S.; Snyder, Scott E.

1999-01-01

Simplified methods for in vivo studies of acetylcholinesterase (AChE) activity in rodent brain were evaluated using N-[ 11 C]methylpiperidinyl propionate ([ 11 C]PMP) as an enzyme substrate. Regional mouse brain distributions were determined at 1 min (representing initial brain uptake) and 30 min (representing trapped product) after intravenous [ 11 C]PMP administration. Single time point tissue concentrations (percent injected dose/gram at 30 min), tissue concentration ratios (striatum/cerebellum and striatum/cortex ratios at 30 min), and regional tissue retention fractions (defined as percent injected dose 30 min/percent injected dose 1 min) were evaluated as measures of AChE enzymatic activity in mouse brain. Studies were carried out in control animals and after dosing with phenserine, a selective centrally active AChE inhibitor; neostigmine, a peripheral cholinesterase inhibitor; and a combination of the two drugs. In control and phenserine-treated animals, absolute tissue concentrations and regional retention fractions provide good measures of dose-dependent inhibition of brain AChE; tissue concentration ratios, however, provide erroneous conclusions. Peripheral inhibition of cholinesterases, which changes the blood pharmacokinetics of the radiotracer, diminishes the sensitivity of all measures to detect changes in central inhibition of the enzyme. We conclude that certain simple measures of AChE hydrolysis rates for [ 11 C]PMP are suitable for studies where alterations of the peripheral blood metabolism of the tracer are kept to a minimum

Hairy-root organ cultures for the production of human acetylcholinesterase

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Mor Tsafrir S

2008-12-01

Full Text Available Abstract Background Human cholinesterases can be used as a bioscavenger of organophosphate toxins used as pesticides and chemical warfare nerve agents. The practicality of this approach depends on the availability of the human enzymes, but because of inherent supply and regulatory constraints, a suitable production system is yet to be identified. Results As a promising alternative, we report the creation of "hairy root" organ cultures derived via Agrobacterium rhizogenes-mediated transformation from human acetylcholinesterase-expressing transgenic Nicotiana benthamiana plants. Acetylcholinesterase-expressing hairy root cultures had a slower growth rate, reached to the stationary phase faster and grew to lower maximal densities as compared to wild type control cultures. Acetylcholinesterase accumulated to levels of up to 3.3% of total soluble protein, ~3 fold higher than the expression level observed in the parental plant. The enzyme was purified to electrophoretic homogeneity. Enzymatic properties were nearly identical to those of the transgenic plant-derived enzyme as well as to those of mammalian cell culture derived enzyme. Pharmacokinetic properties of the hairy-root culture derived enzyme demonstrated a biphasic clearing profile. We demonstrate that master banking of plant material is possible by storage at 4°C for up to 5 months. Conclusion Our results support the feasibility of using plant organ cultures as a successful alternative to traditional transgenic plant and mammalian cell culture technologies.

Acetylcholinesterase inhibitory effects of some plants from Rosaceae

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S. Esmaeili

2015-10-01

Full Text Available Background and objectives: Alzheimer's disease (AD is an age dependent disorder. AD is associated with decrease of brain acetylcholine level. Nowadays, one of the methods for progression inhibition of AD is using acetylcholinesterase inhibitors. Rosaceae is a large plant family. Different biological effects of some species of this family have been reported. The aim of the present study was to assess the acetylcholinesterase inhibitory (AChEI activity of the selected plants belonging to Rosaceae family. Methods: AChEI activity of six species from Rosaceae including Cotoneaster nummularia, Cerasus microcarpa, Amygdalus scoparia, Agrimonia eupatoria, Rosa canina and Rosa damascena were evaluated based on Ellman’s method in concentration of 300 µg/mL using total extracts and methanol fractions which were obtained by maceration. Results: The results showed that the total extract and methanol fraction of the aerial parts of A. eupatoria demonstrated significant AChEI activity with 46.5% and 56.2% inhibition of the enzyme, respectively. Conclusion: According to the results of the AChEI activity of the methanol fraction of A. eupatoria, it seems that the polar components of the species such as flavonoids may be responsible for its effectiveness.

Fenugreek hydrogel–agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection

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Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang, E-mail: bhchiang@ntu.edu.tw

2015-07-30

A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel–agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10–20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel–agarose–acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. - Highlights: • Acetylcholinesterase (AChE) dip-strip biosensor fabricated to detect carbamates. • AChE entrapped in fenugreek hydrogel–agarose matrix with gold nanoparticles (GNPs). • High enzyme retention efficiency (92%) and shelf life (half-life, 55 days). • Detection limits of carbofuran, oxamyl and methomyl: 2, 21 and 113 nM. • The biosensor had good testing capabilities to detect carbamates in food samples.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some selected Nigerian medicinal plants

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Taiwo O. Elufioye

Full Text Available Plants have been found to be useful as memory enhansers as well as antiaging. Twenty two of such plants from sixteen families were investigated for their acetylcholinesterase (AChE and butyrylcholinesterase (BuChE inhibitory activities using the in vitro Ellman's spectrophotometric and in situ bioautographic methods with physostigmine as standard. At least three morphological parts were examined for each of the plants investigated and the test concentration was 42.5 µg/ mL. Some plants were active on both enzymes though with some morphological parts being more active than others. The root bark of Spondias mombin showed the highest activity to the two enzymes; 64.77% and 83.94% on AChE and BuChE respectively. Other plant parts of the selected plants exhibited some remarkable selectivity in their actions. Those selectively active against AChE were Alchornia laxiflora stem bark (41.12% and root bark, Callophyllum inophyllurn root bark (56.52%. The leaves of C. jagus (74.25%, Morinda lucida leaves (40.15%, Peltophorum pterocarpum leaves and stem bark (49.5% and 68.85%, respectively, physiostigmine gave 90.31% inhibition. Generally higher activities were found against BuChE. Bombax bromoposenze leaves, root bark and stem bark were particularly active. The inhibition was over 80%. Other selective plant parts are the leaves Antiaris africana, Cissampelos owarensis aerial parts (78.96%, Combretum molle leaves and stem bark (90.42% and 88.13%, respectively, Dioscorea dumentorum root bark and tuber (over 87%, G. kola leaves, Markhamia tomentosa root bark, Pycnanthus angolensis stem bark and Tetrapleura tetraptera leaves. Most of these plants are taken as food or are food ingredients in Nigeria and may account for the low incidence of Alzheimer's disease in the country and may play certain roles in the mediation of the disease.

Immobilization of Acetylcholinesterase on Screen-Printed Electrodes. Application to the Determination of Arsenic(III

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M. Julia Arcos-Martínez

2010-03-01

Full Text Available Enzymatic amperometric procedures for measuring arsenic, based on the inhibitive action of this metal on acetylcholinesterase enzyme activity, have been developed. Screen-printed carbon electrodes (SPCEs were used with acetylcholinesterase covalently bonded directly to its surface. The amperometric response of acetylcholinesterase was affected by the presence of arsenic ions, which caused a decrease in the current intensity. The experimental optimum working conditions of pH, substrate concentration and potential applied, were established. Under these conditions, repeatability and reproducibility of biosensors were determined, reaching values below 4% in terms of relative standard deviation. The detection limit obtained for arsenic was 1.1 × 10−8 M for Ach/SPCE biosensor. Analysis of the possible effect of the presence of foreign ions in the solution was performed. The method was applied to determine levels of arsenic in spiked tap water samples.

Antioxidant and anti-acetylcholinesterase activities of extracts from Rapistrum rugosum in Tunisia

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Omri Hichri Amel

2017-07-01

Full Text Available Objective: To investigate the antioxidant potential and anti-acetylcholinesterase activity of Rapistrum rugosum extracts. Methods: The crude, ethyl acetate, butanol and water extracts prepared from flowers, roots, stems and leaves of Rapistrum rugosum were tested at 1 mg/mL to determine their total polyphenol content, total flavonoid content and total condensed tannin content. Their antioxidant activity was assessed at different concentrations (0.0312, 0.0625, 0.1250, 0.25, 0.50 and 1.00 mg/ mL by using DPPH, ABTS, reducing power and β-carotene bleAChIng inhibition activity. Antiacetylcholinesterase activity was also determined. Results: The extract of leaves and stems had the highest total phenolic content [(110.45依0.03 mg gallic acid equivalent/g dry weight]. The ethyl acetate extract of flowers had the highest total flavonoid content [(24.62依0.13 mg quercetin equivalent/g dry weight]. The butanolic fraction of flowers had the highest total condensed tannin content [(317.85依0.01 mg catechin equivalent/g dry weight]. The crude extracts of flowers exhibited an interesting antioxidant activity for DPPH assay (93.00依0.01% at 1 mg/mL. The greatest acetylcholinesterase inhibitory activity (IC50=1.60 mg/mL was exhibited by the crude extracts from the flowers. Conclusions: The results demonstrated that Rapistrum rugosum contains active constituents which possess antioxidant and anti-acetylcholinesterase activities.

Simplified methods for in vivo measurement of acetylcholinesterase activity in rodent brain

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Kilbourn, Michael R. E-mail: mkilbour@umich.edu; Sherman, Phillip S.; Snyder, Scott E

1999-07-01

Simplified methods for in vivo studies of acetylcholinesterase (AChE) activity in rodent brain were evaluated using N-[{sup 11}C]methylpiperidinyl propionate ([{sup 11}C]PMP) as an enzyme substrate. Regional mouse brain distributions were determined at 1 min (representing initial brain uptake) and 30 min (representing trapped product) after intravenous [{sup 11}C]PMP administration. Single time point tissue concentrations (percent injected dose/gram at 30 min), tissue concentration ratios (striatum/cerebellum and striatum/cortex ratios at 30 min), and regional tissue retention fractions (defined as percent injected dose 30 min/percent injected dose 1 min) were evaluated as measures of AChE enzymatic activity in mouse brain. Studies were carried out in control animals and after dosing with phenserine, a selective centrally active AChE inhibitor; neostigmine, a peripheral cholinesterase inhibitor; and a combination of the two drugs. In control and phenserine-treated animals, absolute tissue concentrations and regional retention fractions provide good measures of dose-dependent inhibition of brain AChE; tissue concentration ratios, however, provide erroneous conclusions. Peripheral inhibition of cholinesterases, which changes the blood pharmacokinetics of the radiotracer, diminishes the sensitivity of all measures to detect changes in central inhibition of the enzyme. We conclude that certain simple measures of AChE hydrolysis rates for [{sup 11}C]PMP are suitable for studies where alterations of the peripheral blood metabolism of the tracer are kept to a minimum.

Inhibition of acetylcholinesterase activity by essential oil from Citrus paradisi.

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Miyazawa, M; Tougo, H; Ishihara, M

2001-01-01

Inhibition of acetylcholinesterase (AChE) activity by essential oils of Citrus paradisi (grapefruit pink in USA) was studied. Inhibition of AChE was measured by the colorimetric method. Nootkatone and auraptene were isolated from C. paradisi oil and showed 17-24% inhibition of AChE activity at the concentration of 1.62 microg/mL.

Anti-acetylcholinesterase and Antioxidant Activity of Essential Oils from Hedychium gardnerianum Sheppard ex Ker-Gawl

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Arruda, Miguel; Viana, Hugo; Rainha, Nuno; Neng, Nuno R.; Rosa, José Silvino; Nogueira, José M. F.; Barreto, Maria do Carmo

2012-01-01

Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC50 values of approximately 1 mg/mL, showing no statistical differences between collection sites. Three oils presented mixed inhibition, whilst one was almost truly competitive. This activity can be attributed to the presence of sesquiterpenes, which constituted more than 60% of the composi...

Chagas disease: modulation of the inflammatory response by acetylcholinesterase in hematological cells and brain tissue.

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Silva, Aniélen D; Bottari, Nathieli B; do Carmo, Guilherme M; Baldissera, Matheus D; Souza, Carine F; Machado, Vanessa S; Morsch, Vera M; Schetinger, Maria Rosa C; Mendes, Ricardo E; Monteiro, Silvia G; Da Silva, Aleksandro S

2018-01-01

Chagas disease is an acute or chronic illness that causes severe inflammatory response, and consequently, it may activate the inflammatory cholinergic pathway, which is regulated by cholinesterases, including the acetylcholinesterase. This enzyme is responsible for the regulation of acetylcholine levels, an anti-inflammatory molecule linked to the inflammatory response during parasitic diseases. Thus, the aim of this study was to investigate whether Trypanosoma cruzi infection can alter the activity of acetylcholinesterase and acetylcholine levels in mice, and whether these alterations are linked to the inflammatory cholinergic signaling pathway. Twenty-four mice were divided into two groups: uninfected (control group, n = 12) and infected by T. cruzi, Y strain (n = 12). The animals developed acute disease with a peak of parasitemia on day 7 post-infection (PI). Blood, lymphocytes, and brain were analyzed on days 6 and 12 post-infection. In the brain, acetylcholine and nitric oxide levels, myeloperoxidase activity, and histopathology were analyzed. In total blood and brain, acetylcholinesterase activity decreased at both times. On the other hand, acetylcholinesterase activity in lymphocytes increased on day 6 PI compared with the control group. Infection by T. cruzi increased acetylcholine and nitric oxide levels and histopathological damage in the brain of mice associated to increased myeloperoxidase activity. Therefore, an intense inflammatory response in mice with acute Chagas disease in the central nervous system caused an anti-inflammatory response by the activation of the cholinergic inflammatory pathway.

Brain acetylcholinesterase activity controls systemic cytokine levels through the cholinergic anti-inflammatory pathway

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Pavlov, Valentin A.; Parrish, William R.; Rosas-Ballina, Mauricio; Ochani, Mahendar; Puerta, Margot; Ochani, Kanta; Chavan, Sangeeta; Al-Abed, Yousef; Tracey, Kevin J.

2015-01-01

The excessive release of cytokines by the immune system contributes importantly to the pathogenesis of inflammatory diseases. Recent advances in understanding the biology of cytokine toxicity led to the discovery of the “cholinergic anti-inflammatory pathway,” defined as neural signals transmitted via the vagus nerve that inhibit cytokine release through a mechanism that requires the alpha7 subunit-containing nicotinic acetylcholine receptor (α7nAChR). Vagus nerve regulation of peripheral functions is controlled by brain nuclei and neural networks, but despite considerable importance, little is known about the molecular basis for central regulation of the vagus nerve-based cholinergic anti-inflammatory pathway. Here we report that brain acetylcholinesterase activity controls systemic and organ specific TNF production during endotoxemia. Peripheral administration of the acetylcholinesterase inhibitor galantamine significantly reduced serum TNF levels through vagus nerve signaling, and protected against lethality during murine endotoxemia. Administration of a centrally-acting muscarinic receptor antagonist abolished the suppression of TNF by galantamine, indicating that suppressing acetylcholinesterase activity, coupled with central muscarinic receptors, controls peripheral cytokine responses. Administration of galantamine to α7nAChR knockout mice failed to suppress TNF levels, indicating that the α7nAChR-mediated cholinergic anti-inflammatory pathway is required for the anti-inflammatory effect of galantamine. These findings show that inhibition of brain acetylcholinesterase suppresses systemic inflammation through a central muscarinic receptor-mediated and vagal- and α7nAChR-dependent mechanism. Our data also indicate that a clinically used centrally-acting acetylcholinesterase inhibitor can be utilized to suppress abnormal inflammation to therapeutic advantage. PMID:18639629

Biochemical effects of glyphosate based herbicide, Excel Mera 71 on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content on teleostean fishes.

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Samanta, Palas; Pal, Sandipan; Mukherjee, Aloke Kumar; Ghosh, Apurba Ratan

2014-09-01

Effects of glyphosate based herbicide, Excel Mera 71 at a dose of 17.20mg/l on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content were measured in different tissues of two Indian air-breathing teleosts, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch) during an exposure period of 30 days under laboratory condition. AChE activity was significantly increased in all the investigated tissues of both fish species and maximum elevation was observed in brain of H. fossilis, while spinal cord of A. testudineus showed minimum increment. Fishes showed significant increase LPO levels in all the tissues; highest was observed in gill of A. testudineus but lowest LPO level was observed in muscle of H. fossilis. CAT was also enhanced in both the fishes, while GST activity in liver diminished substantially and minimum was observed in liver of A. testudineus. Total protein content showed decreased value in all the tissues, maximum reduction was observed in liver and minimum in brain of A. testudineus and H. fossilis respectively. The results indicated that Excel Mera 71 caused serious alterations in the enzyme activities resulting into severe deterioration of fish health; so, AChE, LPO, CAT and GST can be used as suitable indicators of herbicidal toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Acetylcholinesterase inhibitors rapidly activate Trk neurotrophin receptors in the mouse hippocampus

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Autio, Henri; Mätlik, Kert; Rantamäki, Tomi; Lindemann, Lothar; Hoener, Marius C; Chao, Moses; Arumäe, Urmas; Castrén, Eero

2014-01-01

Acetylcholinesterase inhibitors are first-line therapies for Alzheimer's disease. These drugs increase cholinergic tone in the target areas of the cholinergic neurons of the basal forebrain. Basal forebrain cholinergic neurons are dependent upon trophic support by nerve growth factor (NGF) through its neurotrophin receptor, TrkA. In the present study, we investigated whether the acetylcholinesterase inhibitors donepezil and galantamine could influence neurotrophin receptor signaling in the brain. Acute administration of donepezil (3 mg/kg, i.p.) led to the rapid autophosphorylation of TrkA and TrkB neurotrophin receptors in the adult mouse hippocampus. Similarly, galantamine dose-dependently (3, 9 mg/kg, i.p.) increased TrkA and TrkB phosphorylation in the mouse hippocampus. Both treatments also increased the phosphorylation of transcription factor CREB and tended to increase the phosphorylation of AKT kinase but did not alter the activity of MAPK42/44. Chronic treatment with galantamine (3 mg/kg, i.p., 14 days), did not induce changes in hippocampal NGF and BDNF synthesis or protein levels. Our findings show that acetylcholinesterase inhibitors are capable of rapidly activating hippocampal neurotrophin signaling and thus suggest that therapies targeting Trk signaling may already be in clinical use in the treatment of AD. PMID:21820453

Synthesis and biological evaluation of phloroglucinol derivatives possessing α-glycosidase, acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase inhibitory activity.

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Burmaoglu, Serdar; Yilmaz, Ali O; Taslimi, Parham; Algul, Oztekin; Kilic, Deryanur; Gulcin, Ilhami

2018-02-01

A series of novel phloroglucinol derivatives were designed, synthesized, characterized spectroscopically and tested for their inhibitory activity against selected metabolic enzymes, including α-glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase I and II (hCA I and II). These compounds displayed nanomolar inhibition levels and showed K i values of 1.14-3.92 nM against AChE, 0.24-1.64 nM against BChE, 6.73-51.10 nM against α-glycosidase, 1.80-5.10 nM against hCA I, and 1.14-5.45 nM against hCA II. © 2018 Deutsche Pharmazeutische Gesellschaft.

Antioxidant activity, acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum extracts

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Elena Neagu

2018-03-01

Full Text Available In this study several investigations and tests were performed to determine the antioxidant activity and the acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum aqueous extracts (10% mass and ethanolic extracts (10% mass and 70% ethanol, respectively. Moreover, for each type of the prepared extracts of P. officinalis and of C. umbellatum the content in the biologically active compounds – polyphenols, flavones and proanthocyanidins was determined. The antioxidant activity was assessed using two methods, namely the 2,2-diphenyl-1-picrylhydrazyl (DPPH assay and reducing power assay. The analyzed plant extracts showed a high acetylcholinesterase and tyrosinase inhibitory activity in the range of 72.24–94.24% (at the highest used dose – 3 mg/mL, 66.96% and 94.03% (at 3 mg/mL, respectively correlated with a high DPPH radical inhibition – 70.29–84.9% (at 3 mg/mL. These medicinal plants could provide a potential natural source of bioactive compounds and could be beneficial to the human health, especially in the neurodegenerative disorders and as sources of natural antioxidants in food industry. Keywords: Acetylcholinesterase inhibitory activity, Tyrosinase inhibitory activity, Antioxidant activity, Pulmonaria officinalis and Centarium umbellatum

Interleukin 6 modulates acetylcholinesterase activity of brain neurons

International Nuclear Information System (INIS)

Clarencon, D.; Multon, E.; Galonnier, M.; Estrade, M.; Fournier, C.; Mathieu, J.; Mestries, J.C.; Testylier, G.; Fatome, M.

1995-01-01

Classically, radiation injuries results in a peripheral inflammatory process, and we have previously observed an early systemic interleukin 6 (IL-6) release following whole-body irradiation. Besides, we have demonstrated an early decrease of rat or primate brain acetylcholinesterase (AChE) activity a gamma exposure. The object of the present study is to find possible IL-6 systemic effects on the brain AChE activity. We show that, though intravenous (i.v.) or intra-cerebro-ventricular (ICV) injection of IL-6 can induce a drop in rat brain AChE activity, this cytokine induces only a slight decrease of the AChE release in cultured brain cells. (author)

Effects of hyper- and hypothyroidism on acetylcholinesterase, (Na(+), K (+))- and Mg ( 2+ )-ATPase activities of adult rat hypothalamus and cerebellum.

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Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Stolakis, Vasileios; Mourouzis, Iordanis; Cokkinos, Dennis; Tsakiris, Stylianos

2007-03-01

Thyroid hormones (THs) are recognized as key metabolic hormones, and the metabolic rate increases in hyperthyroidism, while it decreases in hypothyroidism. The aim of this work was to investigate how changes in metabolism induced by THs could affect the activities of acetylcholinesterase (AChE), (Na(+), K(+))- and Mg(2+)-ATPase in the hypothalamus and the cerebellum of adult rats. Hyperthyroidism was induced by subcutaneous administration of thyroxine (25 microg/100 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. All enzyme activities were evaluated spectrophotometrically in the homogenated brain regions of 10 three-animal pools. Neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE (-23%, p activities (-26%, p activities: AChE (-17%, p activity was found unaltered in both the hyper- and the hypothyroid brain regions. neither hyper-, nor hypothyroidism had any effect on the examined hypothalamic enzyme activities. In the cerebellum, hyperthyroidism provoked a significant decrease in both the AChE and the Na(+), K(+)-ATPase activities. The decreased (by the THs) Na(+), K(+)-ATPase activities may increase the synaptic acetylcholine release, and thus, could result in a decrease in the cerebellar AChE activity. Moreover, the above TH-induced changes may affect the monoamine neurotransmitter systems.

Myrtenal inhibits acetylcholinesterase, a known Alzheimer target.

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Kaufmann, Dorothea; Dogra, Anudeep Kaur; Wink, Michael

2011-10-01

Inhibition of acetylcholinesterase (AChE) is a common treatment for early stages of the most general form of dementia, Alzheimer's disease. In this study selected components of essential oils, which carry a variety of important functional groups, were tested for their in-vitro anti-acetylcholinesterase activity. In-vitro anti-acetylcholinesterase activity was measured by an adapted version of Ellman's colorimetric assay. 1,8-cineole, carvacrol, myrtenal and verbenone apparently inhibited AChE; the highest inhibitory activity was observed for myrtenal (IC50 = 0.17 mm). This is the first study showing the AChE inhibitory activity of myrtenal. Our investigations provided evidence for the efficacy of monoterpenes as inhibitors of AChE. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.

Inhibition of acetylcholinesterase and cytochrome oxidase activity in Fasciola gigantica cercaria by phytoconstituents.

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Sunita, Kumari; Habib, Maria; Kumar, P; Singh, Vinay Kumar; Husain, Syed Akhtar; Singh, D K

2016-02-01

Fasciolosis is an important cattle and human disease caused by Fasciola hepatica and Fasciola gigantica. One of the possible methods to control this problem is to interrupt the life cycle of Fasciola by killing its larva (redia and cercaria) in host snail. Molecular identification of cercaria larva of F. gigantica was done by comparing the nucleotide sequencing with adult F. gigantica. It was noted that nucleotide sequencing of cercaria larva and adult F. gigantica were 99% same. Every month during the year 2011-2012, in vivo treatment with 60% of 4 h LC50 of phyto cercaricides citral, ferulic acid, umbelliferone, azadirachtin and allicin caused significant inhibition of acetylcholinesterase (AChE) and cytochrome oxidase activity in the treated cercaria larva of F. gigantica. Whereas, activity of both enzymes were not significantly altered in the nervous tissues of vector snail Lymnaea acuminata exposed to same treatments. Maximum reduction in AChE (1.35% of control in month of June) and cytochrome oxidase (3.71% of control in the month of July) activity were noted in the cercaria exposed to 60% of 4 h LC50 of azadirachtin and allicin, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

An evaluation of the inhibition of human butyrylcholinesterase and acetylcholinesterase by the organophosphate chlorpyrifos oxon

International Nuclear Information System (INIS)

Shenouda, Josephine; Green, Paula; Sultatos, Lester

2009-01-01

Acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) are enzymes that belong to the superfamily of α/β-hydrolase fold proteins. While they share many characteristics, they also possess many important differences. For example, whereas they have about 54% amino acid sequence identity, the active site gorge of acetylcholinesterase is considerably smaller than that of butyrylcholinesterase. Moreover, both have been shown to display simple and complex kinetic mechanisms, depending on the particular substrate examined, the substrate concentration, and incubation conditions. In the current study, incubation of butyrylthiocholine in a concentration range of 0.005-3.0 mM, with 317 pM human butyrylcholinesterase in vitro, resulted in rates of production of thiocholine that were accurately described by simple Michaelis-Menten kinetics, with a K m of 0.10 mM. Similarly, the inhibition of butyrylcholinesterase in vitro by the organophosphate chlorpyrifos oxon was described by simple Michaelis-Menten kinetics, with a k i of 3048 nM -1 h -1 , and a K D of 2.02 nM. In contrast to inhibition of butyrylcholinesterase, inhibition of human acetylcholinesterase by chlorpyrifos oxon in vitro followed concentration-dependent inhibition kinetics, with the k i increasing as the inhibitor concentration decreased. Chlorpyrifos oxon concentrations of 10 and 0.3 nM gave k i s of 1.2 and 19.3 nM -1 h -1 , respectively. Although the mechanism of concentration-dependent inhibition kinetics is not known, the much smaller, more restrictive active site gorge of acetylcholinesterase almost certainly plays a role. Similarly, the much larger active site gorge of butyrylcholinesterase likely contributes to its much greater reactivity towards chlorpyrifos oxon, compared to acetylcholinesterase.

In vitro toxicity, antiplatelet and acetylcholinesterase inhibition of Buddleja thyrsoides Lam. leaves.

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Mahlke, Janaína Dorneles; Boligon, Aline Augusti; Machado, Michel Mansur; Athayde, Margareth Linde

2012-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder resulting in impaired memory and behaviour of remarkable socio-economic impact. A decrease in cholinergic activity is a key event in the biochemical of AD. Buddleja thyrsoides is a plant widely distributed in Southern parts of South America. In Brazilian traditional medicine, the infusion of its leaves and flowers is used for the treatment of bronchitis and cough. Crude ethanolic (70%) extract and fractions (dichloromethane, ethyl acetate and n-butanolic) were investigated regarding their toxicities in vitro and antiplatelet action. The enzyme acetylcholinesterase inhibition was evaluated to study the crude extract. The crude extract and fractions were evaluated by means of Brine Shrimp Lethality test and they showed low activities with LC(50) values 1698, 2818, 2187 and 3672 µg mL(-1) for dichloromethane, ethyl acetate, n-butanolic fractions and crude extract, respectively. Buddleja thyrsoides presented great antiplatelet action. The IC(50) values obtained for crude extract and dichloromethane, ethyl acetate and n-butanolic fractions were 361.29, 354.23, 368.75 and 344.30, respectively, while the IC(50) for the standard AAS was 257.01 µg mL(-1). The crude extract showed an inhibition of 22.8% of the acetylcholinesterase enzyme in 24 h.

Toxicity of azodrin on the morphology and acetylcholinesterase activity of the earthworm Eisenia foetida

International Nuclear Information System (INIS)

Rao, J.V.; Kavitha, P.

2004-01-01

The acute toxicity of azodrin (monocrotophos, an organophosphorus insecticide) was determined on a soil organism, Eisenia foetida. The median lethal concentrations (LC 50 ) were derived from a 48-h paper contact test and from artificial soil tests. The LC 50 of azodrin in the paper contact test was 0.46±0.1 μg cm -2 (23±6 mg L -1 ) and those in the 7- and 14-day artificial soil tests were 171±21 and 132±20 mg kg -1 , respectively. The neurotoxic potentiality of azodrin was assessed by using a marker enzyme, acetylcholinesterase (AChE; EC 3.1.1.7) in both in vitro and in vivo experiments. The progressive signs of morphological destruction are correlated with percentage inhibition of AChE in the in vivo experiments. The kinetics of AChE activity in the presence and absence of azodrin indicated that the toxicant is competitive in nature. This study demonstrated that azodrin causes concentration-dependent changes in the morphology and AChE activity of the earthworm E. foetida

High Efficiency Acetylcholinesterase Immobilization on DNA Aptamer Modified Surfaces

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Orada Chumphukam

2014-04-01

Full Text Available We report here the in vitro selection of DNA aptamers for electric eel acetylcholinesterase (AChE. One selected aptamer sequence (R15/19 has a high affinity towards the enzyme (Kd = 157 ± 42 pM. Characterization of the aptamer showed its binding is not affected by low ionic strength (~20 mM, however significant reduction in affinity occurred at high ionic strength (~1.2 M. In addition, this aptamer does not inhibit the catalytic activity of AChE that we exploit through immobilization of the DNA on a streptavidin-coated surface. Subsequent immobilization of AChE by the aptamer results in a 4-fold higher catalytic activity when compared to adsorption directly on to plastic.

Chemical composition and acetylcholinesterase inhibitory activity of Artemisia maderaspatana essential oil.

Science.gov (United States)

Jyotshna; Srivastava, Nidhi; Singh, Bhuwanendra; Chanda, Debabrata; Shanker, Karuna

2015-01-01

To date, there are no reports to validate the Indian traditional and folklore claims of Artemisia maderaspatana L. (syn. Grangea maderaspatana L.) (Asteraceae) for the treatment of Alzheimer's disease. The present study characterizes the volatile components (non-polar compounds) of A. maderaspatana and evaluates its acetylcholinesterase inhibition potential. The essential oils (yield 0.06% v/w) were obtained from fresh aerial part of A. maderaspatana. The characterization of volatile components (non-polar compounds) was performed by GC-MS data and with those of reference compounds compiled in the spectral library of in-house database. The in vitro acetylcholinesterase (AChE) inhibition of the volatile organic constituents (VOC's) of A. maderaspatana aerial part was evaluated in varying concentration ranges (0.70-44.75 µg/mL) with Ellman's method. The major components were α-humulene (46.3%), β-caryophyllene (9.3%), α-copaene (8.2%), β-myrcene (4.3%), Z(E)-α-farnesene (3.7%), and calarene (3.5%). Chemical variability among other Artemisia spp. from different climatic regions of India and countries namely Iran and France was observed. The experimental results showed that diverse volatile organic constituents of A. maderaspatana have significant acetylcholinesterase inhibitory activity (an IC50 value of 31.33 ± 1.03 µg/mL). This is the first report on the inhibition of acetylcholinesterase properties of essential oil of A. maderaspatana obtained from fresh aerial part. The present results indicate that essential oil of A. maderaspatana isolated from the northern region of India could inhibit AChE moderately. Therefore, the possibility of novel AChE inhibitors might exist in VOCs of this plant.

Acetylcholinesterase-Inhibiting Activity of Salicylanilide N-Alkylcarbamates and Their Molecular Docking

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Josef Jampilek

2012-08-01

Full Text Available A series of twenty-five novel salicylanilide N-alkylcarbamates were investigated as potential acetylcholinesterase inhibitors. The compounds were tested for their ability to inhibit acetylcholinesterase (AChE from electric eel (Electrophorus electricus L.. Experimental lipophilicity was determined, and the structure-activity relationships are discussed. The mode of binding in the active site of AChE was investigated by molecular docking. All the discussed compounds expressed significantly higher AChE inhibitory activity than rivastigmine and slightly lower than galanthamine. Disubstitution by chlorine in C'_(3,4 of the aniline ring and the optimal length of hexyl-undecyl alkyl chains in the carbamate moiety provided the most active AChE inhibitors. Monochlorination in C'₍₄ exhibited slightly more effective AChE inhibitors than in C'₍₃. Generally it can be stated that compounds with higher lipophilicity showed higher inhibition, and the activity of the compounds is strongly dependent on the length of the N-alkyl chain.

Acetylcholinesterase Inhibitory and Antioxidant Properties of Euphorbiacharacias Latex

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Francesca Pintus

2013-03-01

Full Text Available The aim of the present study was to evaluate the acetylcholinesterase inhibitory capacity and the antioxidant properties of extracts of Euphorbia characias latex, a Mediterranean shrub. We performed a new extraction method involving the use of the trichloroacetic acid. The extract showed high antioxidant activity, was rich in total polyphenolic and flavonoid content and exhibited substantial inhibition of acetylcholinesterase activity.

X-ray structure of a transition state analog complex reveals the molecular origins of the catalytic power and substrate specificity of acetylcholinesterase

Energy Technology Data Exchange (ETDEWEB)

Harel, M.; Silman, I. [Weizmann Inst. of Science, Rehovot (Israel); Quinn, D.M.; Nair, H.K. [Univ. of Iowa, Iowa City, IA (United States); Sussman, J.L. [Weizmann Inst. of Science, Rehovot (Israel)]|[Brookhaven National Lab., Upton, NY (United States)

1996-03-13

The structure of a complex of Torpedo californica acetylcholinesterase with the transition state analog inhibitor m-(N, N,N-trimethylammonio)-2,2,2-trifluoroacetophenone has been solved by X-ray crystallographic methods to 2.8 A resolution. Since the inhibitor binds to the enzyme about 10{sup 10}-fold more tightly than the substrate acetylcholine, this complex provides a visual accounting of the enzyme-ligand interactions that provide the molecular basis for the catalytic power of acetylcholinesterase. The acetyl ester hydrolytic specificity of the enzyme is revealed by the interaction of the CF{sub 3} function of the transition state analog with a concave binding site comprised of the residues G119, W233, F288, F290, and F331. The highly geometrically convergent array of enzyme-ligand interactions visualized in the complex described herein envelopes the acylation transition state and sequesters it from solvent, this being consistent with the location of the active site at the bottom of a deep and narrow gorge. 82 refs., 5 figs.

N-[11C]methylpiperidine esters as acetylcholinesterase substrates: an in vivo structure-reactivity study

International Nuclear Information System (INIS)

Kilbourn, Michael R.; Nguyen, Thinh B.; Snyder, Scott E.; Sherman, Phillip

1998-01-01

A series of simple esters incorporating the N-[ 11 C]methylpiperidine structure were examined as in vivo substrates for acetylcholinesterase in mouse brain. 4-N-[ 11 C]Methylpiperidinyl esters, including the acetate, propionate and isobutyrate esters, are good in vivo substrates for mammalian cholinesterases. Introduction of a methyl group at the 4-position of the 4-piperidinol esters, to form the ester of a teritary alcohol, effectively blocks enzymatic action. Methylation of 4- N-[ 11 C]methylpiperidinyl propionate at the 3-position gives a derivative with increased in vivo reactivity toward acetylcholinesterase. Esters of piperidinecarboxylic acids (nipecotic, isonipecotic and pipecolinic acid ethyl esters) are not hydrolyzed by acetylcholinesterase in vivo, nor do they act as in vivo inhibitors of the enzyme. This study has identified simple methods to both increase and decrease the in vivo reactivity of piperidinyl esters toward acetylcholinesterase

Changes in antioxidant status, protein concentration, acetylcholinesterase, (Na+,K+)-, and Mg2+ -ATPase activities in the brain of hyper- and hypothyroid adult rats.

Science.gov (United States)

Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Mourouzis, Iordanis; Varonos, Dennis; Cokkinos, Dennis; Tsakiris, Stylianos

2005-06-01

It is a common knowledge that metabolic reactions increase in hyperthyroidism and decrease in hypothyroidism. The aim of this work was to investigate how the metabolic reactions could affect the total antioxidant status (TAS), protein concentration (PC) and the activities of acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+ -ATPase in the brain of hyper- and hypothyroid adult male rats. Hyperthyroidism was induced in rats by subcutaneous administration of thyroxine (25 microg/l00 g body weight) once daily for 14 days, while hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. TAS, PC, and enzyme activities were evaluated spectrophotometrically in the homogenated brain of each animal. TAS, PC, and Mg2+ -ATPase activity were found unaffected in hyperthyroidism, while AChE and Na+,K+ -ATPase activities were reduced by 25% (p activities were found to be increased (approx. 23-30%, p activity and PC were shown to be inhibited (approx. 23-30%, p activities may reflect the different metabolic effects of hyper- and hypothyroidism. Such changes of the enzyme activities may differentially modulate the brain intracellular Mg2+, neural excitability, as well as the uptake and release of biogenic amines.

Repetitive obidoxime treatment induced increase of red blood cell acetylcholinesterase activity even in a late phase of a severe methamidophos poisoning: A case report.

Science.gov (United States)

Steinritz, Dirk; Eyer, Florian; Worek, Franz; Thiermann, Horst; John, Harald

2016-02-26

Accidental self-poisoning or deliberate use in suicidal intent of organophosphorus pesticides (OPP), which are widely used in agriculture, represent a health problem worldwide. Symptoms of poisoning are characterized by acute cholinergic crisis caused by inhibition of acetylcholinesterase. A 75-year-old male patient ingested 20ml of an OPP solution containing 10% methamidophos in suicidal intent. In the course of poisoning typical clinical symptoms of cholinergic crisis (miosis, bradycardia, hypotension, hypersalivation and impairment of neurologic status) were evident. Butyryl (plasma) cholinesterase (BChE) and red blood cell acetylcholinesterase (RBC-AChE) revealed decreased activities, thus specific treatment with the enzyme reactivator obidoxime was started. Inhibitory activity of the patient's plasma indicated significant amounts of persisting methamidophos in the circulation and was still found on day 4 after ingestion. Due to missing spontaneous breathing on day 6, obidoxime was administered again. Afterwards a significant increase of RBC-AChE activity was found. The patient was extubated on day 10 and a restitution ad integrum was achieved. In conclusion, obidoxime is a potent reactivator of OPP-inhibited AChE. A repetitive and prolonged administration of obidoxime should be considered in cases of severe methamidophos poisoning and should be tailored with an advanced analytical biomonitoring. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

EEG SPECTRA, BEHAVIORAL STATES AND MOTOR ACTIVITY IN RATS EXPOSED TO ACETYLCHOLINESTERASE INHIBITOR CHLORPYRIFOS.

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Exposure to organophosphate pesticides (OP) has been associated with sleep disorders: insomnia and ?excessive dreaming'. However neuronal mechanisms of these effects have not been analyzed. OP inhibit acetylcholinesterase activity leading to a hyperativity of the brain cholin...

Acetylcholinesterase inhibitory activity of lycopodane-type alkaloids from the Icelandic Lycopodium annotinum ssp. alpestre

DEFF Research Database (Denmark)

Halldórsdóttir, Elsa Steinunn; Jaroszewski, Jerzy W; Olafsdottir, Elin Soffia

2010-01-01

The aim of this study was to investigate structures and acetylcholinesterase inhibitory activities of lycopodane-type alkaloids isolated from an Icelandic collection of Lycopodium annotinum ssp. alpestre. Ten alkaloids were isolated, including annotinine, annotine, lycodoline, lycoposerramine M...

Polypyridylruthenium(II complexes exert in vitro and in vivo nematocidal activity and show significant inhibition of parasite acetylcholinesterases

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Madhu Sundaraneedi

2018-04-01

Full Text Available Over 4.5 billion people are at risk of infection with soil transmitted helminths and there are concerns about the development of resistance to the handful of frontline nematocides in endemic populations. We investigated the anti-nematode efficacy of a series of polypyridylruthenium(II complexes and showed they were active against L3 and adult stages of Trichuris muris, the rodent homologue of the causative agent of human trichuriasis, T. trichiura. One of the compounds, Rubb12-mono, which was among the most potent in its ability to kill L3 (IC50 = 3.1 ± 0.4 μM and adult (IC50 = 5.2 ± 0.3 μM stage worms was assessed for efficacy in a mouse model of trichuriasis by administering 3 consecutive daily oral doses of the drug 3 weeks post infection with the murine whipworm Trichuris muris. Mice treated with Rubb12-mono showed an average 66% reduction (P = 0.015 in faecal egg count over two independent trials. The drugs partially exerted their activity through inhibition of acetylcholinesterases, as worms treated in vitro and in vivo showed significant decreases in the activity of this class of enzymes. Our data show that ruthenium complexes are effective against T. muris, a model gastro-intestinal nematode and soil-transmitted helminth. Further, knowledge of the target of ruthenium drugs can facilitate modification of current compounds to identify analogues which are even more effective and selective against Trichuris and other helminths of human and veterinary importance. Keywords: Acetylcholinesterase, Trichuris muris, Ruthenium complex, Anthelmintic

Comparison of the oxime-induced reactivation of rhesus monkey, swine and guinea pig erythrocyte acetylcholinesterase following inhibition by sarin or paraoxon, using a perfusion model for the real-time determination of membrane-bound acetylcholinesterase activity.

Science.gov (United States)

Herkert, Nadja M; Lallement, Guy; Clarençon, Didier; Thiermann, Horst; Worek, Franz

2009-04-28

Recently, a dynamically working in vitro model with real-time determination of membrane-bound human acetylcholinesterase (AChE) activity was shown to be a versatile model to investigate oxime-induced reactivation kinetics of organophosphate- (OP) inhibited enzyme. In this assay, AChE was immobilized on particle filters which were perfused with acetylthiocholine, Ellman's reagent and phosphate buffer. Subsequently, AChE activity was continuously analyzed in a flow-through detector. Now, it was an intriguing question whether this model could be used with erythrocyte AChE from other species in order to investigate kinetic interactions in the absence of annoying side reactions. Rhesus monkey, swine and guinea pig erythrocytes were a stable and highly reproducible enzyme source. Then, the model was applied to the reactivation of sarin- and paraoxon-inhibited AChE by obidoxime or HI 6 and it could be shown that the derived reactivation rate constants were in good agreement to previous results obtained from experiments with a static model. Hence, this dynamic model offers the possibility to investigate highly reproducible interactions between AChE, OP and oximes with human and animal AChE.

A novel biosensor method for surfactant determination based on acetylcholinesterase inhibition

International Nuclear Information System (INIS)

Kucherenko, I S; Soldatkin, O O; Arkhypova, V M; Dzyadevych, S V; Soldatkin, A P

2012-01-01

A novel enzyme biosensor based on acetylcholinesterase inhibition for the determination of surfactants in aqueous solutions is described. Acetylcholinesterase-based bioselective element was deposited via glutaraldehyde on the surface of conductometric transducers. Different variants of inhibitory analysis of surfactants were tested, and finally surfactant's concentration was evaluated by measuring initial rate of acetylcholinesterase inhibition. Besides, we studied the effect of solution characteristics on working parameters of the biosensor for direct measurement of acetylcholine and for inhibitory determination of surfactants. The biosensor's sensitivity to anionic and cationic surfactants (0.35 mg l −1 ) was tested. The high operational stability of the biosensor during determination of acetylcholine (RSD 2%) and surfactants (RSD 11%) was shown. Finally, we discussed the selectivity of the biosensor toward surfactants and other AChE inhibitors. The proposed biosensor can be used as a component of the multibiosensor for ecological monitoring of toxicants. (paper)

Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

Institute of Scientific and Technical Information of China (English)

Jihene Ghedira; Jamel Jebali; Zied Bouraoui; Mohamed Banni; Lassaad Chouba; Hamadi Boussetta

2009-01-01

The acute effects of commercial formulation of chlorpyrifos-ethyl (Dursban(r)) and the secondary treated industrial/urban effluent (STIUE) exposure on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μg/L, whereas the BuChE was inhibited only at higher concentration 7.82 μg/L of commercial preparation Dursban(r). The exposure of crabs to Dursban(r) (3.12 μg/L) showed a significant decrement of AChE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. meanas would be useful biomarker of organophosphorous (OP) and of neurotoxic effects of STIUE in Tunisia.

Anti-acetylcholinesterase and Antioxidant Activity of Essential Oils from Hedychium gardnerianum Sheppard ex Ker-Gawl

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José Silvino Rosa

2012-03-01

Full Text Available Acetylcholinesterase inhibition, antioxidant and cytotoxic activities of Hedychium gardnerianum leaf essential oils from S. Miguel Island were determined. All the oils inhibited acetylcholinesterase, with IC50 values of approximately 1 mg/mL, showing no statistical differences between collection sites. Three oils presented mixed inhibition, whilst one was almost truly competitive. This activity can be attributed to the presence of sesquiterpenes, which constituted more than 60% of the composition of the oils. Regarding the antioxidant activity as measured by the DPPH method, all the oils presented activities similar to reference compounds, although with statistical differences between collection sites. Cytotoxicity measured using Artemia salina classified these oils as moderately toxic, with LC50 values ranging from 300 to 500 µg/mL. These results indicate a possible application of these oils in aromatherapy as coadjuvants in the treatment of cognitive diseases such as Alzheimer, since they may contribute to increase acetylcholine in cholinergic neurons and simultaneously fight deleterious oxidations responsible by neurological degeneration.

Rapid eye movement (REM sleep deprivation reduces rat frontal cortex acetylcholinesterase (EC 3.1.1.7 activity

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Camarini R.

1997-01-01

Full Text Available Rapid eye movement (REM sleep deprivation induces several behavioral changes. Among these, a decrease in yawning behavior produced by low doses of cholinergic agonists is observed which indicates a change in brain cholinergic neurotransmission after REM sleep deprivation. Acetylcholinesterase (Achase controls acetylcholine (Ach availability in the synaptic cleft. Therefore, altered Achase activity may lead to a change in Ach availability at the receptor level which, in turn, may result in modification of cholinergic neurotransmission. To determine if REM sleep deprivation would change the activity of Achase, male Wistar rats, 3 months old, weighing 250-300 g, were deprived of REM sleep for 96 h by the flower-pot technique (N = 12. Two additional groups, a home-cage control (N = 6 and a large platform control (N = 6, were also used. Achase was measured in the frontal cortex using two different methods to obtain the enzyme activity. One method consisted of the obtention of total (900 g supernatant, membrane-bound (100,000 g pellet and soluble (100,000 g supernatant Achase, and the other method consisted of the obtention of a fraction (40,000 g pellet enriched in synaptic membrane-bound enzyme. In both preparations, REM sleep deprivation induced a significant decrease in rat frontal cortex Achase activity when compared to both home-cage and large platform controls. REM sleep deprivation induced a significant decrease of 16% in the membrane-bound Achase activity (nmol thiocholine formed min-1 mg protein-1 in the 100,000 g pellet enzyme preparation (home-cage group 152.1 ± 5.7, large platform group 152.7 ± 24.9 and REM sleep-deprived group 127.9 ± 13.8. There was no difference in the soluble enzyme activity. REM sleep deprivation also induced a significant decrease of 20% in the enriched synaptic membrane-bound Achase activity (home-cage group 126.4 ± 21.5, large platform group 127.8 ± 20.4, REM sleep-deprived group 102.8 ± 14.2. Our results

Blocked Enzymatic Etching of Gold Nanorods: Application to Colorimetric Detection of Acetylcholinesterase Activity and Its Inhibitors.

Science.gov (United States)

Saa, Laura; Grinyte, Ruta; Sánchez-Iglesias, Ana; Liz-Marzán, Luis M; Pavlov, Valeri

2016-05-04

The anisotropic morphology of gold nanorods (AuNRs) has been shown to lead to nonuniform ligand distribution and preferential etching through their tips. We have recently demonstrated that this effect can be achieved by biocatalytic oxidation with hydrogen peroxide, catalyzed by the enzyme horseradish peroxidase (HRP). We report here that modification of AuNRs with thiol-containing organic molecules such as glutathione and thiocholine hinders enzymatic AuNR etching. Higher concentrations of thiol-containing molecules in the reaction mixture gradually decrease the rate of enzymatic etching, which can be monitored by UV-vis spectroscopy through changes in the AuNR longitudinal plasmon band. This effect can be applied to develop novel optical assays for acetylcholinesterase (AChE) activity. The biocatalytic hydrolysis of acetylthiocholine by AChE yields thiocholine, which prevents enzymatic AuNR etching in the presence of HRP. Additionally, the same bioassay can be used for the detection of nanomolar concentrations of AChE inhibitors such as paraoxon and galanthamine.

Virtual Screening of Acetylcholinesterase Inhibitors Using the Lipinski’s Rule of Five and ZINC Databank

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Pablo Andrei Nogara

2015-01-01

Full Text Available Alzheimer’s disease (AD is a progressive and neurodegenerative pathology that can affect people over 65 years of age. It causes several complications, such as behavioral changes, language deficits, depression, and memory impairments. One of the methods used to treat AD is the increase of acetylcholine (ACh in the brain by using acetylcholinesterase inhibitors (AChEIs. In this study, we used the ZINC databank and the Lipinski’s rule of five to perform a virtual screening and a molecular docking (using Auto Dock Vina 1.1.1 aiming to select possible compounds that have quaternary ammonium atom able to inhibit acetylcholinesterase (AChE activity. The molecules were obtained by screening and further in vitro assays were performed to analyze the most potent inhibitors through the IC50 value and also to describe the interaction models between inhibitors and enzyme by molecular docking. The results showed that compound D inhibited AChE activity from different vertebrate sources and butyrylcholinesterase (BChE from Equus ferus (EfBChE, with IC50 ranging from 1.69 ± 0.46 to 5.64 ± 2.47 µM. Compound D interacted with the peripheral anionic subsite in both enzymes, blocking substrate entrance to the active site. In contrast, compound C had higher specificity as inhibitor of EfBChE. In conclusion, the screening was effective in finding inhibitors of AChE and BuChE from different organisms.

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

Science.gov (United States)

Bond, Cherie E.; Zimmermann, Martina; Greenfield, Susan A.

2009-01-01

Background The alpha-7 nicotinic acetylcholine receptor (α7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the α7-nAChR, or peptide modulation of receptor expression. Methodology/Principal Findings This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the α7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of α7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. Conclusions/Significance The results reported here demonstrate a hitherto unknown relationship between the α7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration. PMID:19287501

Delayed effects of radiation on enzymes in erythrocytes

International Nuclear Information System (INIS)

Li Jinying; Zhang Weiping; Liu Benti

1998-01-01

Objective: To study the delayed effects of radiation on the enzymes in erythrocytes. Methods: The activity of 8 enzymes, related glycolysis, hexose monophosphate shunt, nucleotide metabolism, redox reaction and esterase in erythrocytes of five patients with bone marrow form of acute radiation sickness (ARS) were assayed at 1,2,3 and 6 years after exposure to 60 Co radiation. Results: The decreased activities of glucose-6-phosphate dehydrogenase (G6PD), pyruvate kinase (PK), NADH-methemoglobin reductase (MR) during the stage of crisis and of acetylcholinesterase (ACE) during the stage of convalescence were recovered to varying extent, whereas the lowered activities of the first three enzymes in some cases remained unchanged. There was no correlation between the enzyme activity and the radiation dose as well as the age of the patients. Conclusion: It is demonstrated that the delayed effects of radiation damage to erythrocyte enzymes are most significant in PK of glycolysis, G6PD of hexose monophosphate shunt and MR of redox reaction. It is suggested that the genes related to the synthesis of erythrocyte enzymes may be damaged by radiation

Hyperglycemia induces memory impairment linked to increased acetylcholinesterase activity in zebrafish (Danio rerio).

Science.gov (United States)

Capiotti, Katiucia Marques; De Moraes, Daiani Almeida; Menezes, Fabiano Peres; Kist, Luiza Wilges; Bogo, Maurício Reis; Da Silva, Rosane Souza

2014-11-01

Diabetes mellitus, which causes hyperglycemia, affects the central nervous system and can impairs cognitive functions, such as memory. The aim of this study was to investigate the effects of hyperglycemia on memory as well as on the activity of acethylcholinesterase. Hyperglycemia was induced in adult zebrafish by immersion in glucose 111mM by 14 days. The animals were divided in 4 groups: control, glucose-treated, glucose-washout 7-days and glucose-washout 14-days. We evaluated the performance in inhibitory avoidance task and locomotor activity. We also determined acethylcholinesterase activity and gene expression from whole brain. In order to counteract the effect of hyperglycemia underlined by effects on acethylcholinesterase activity, we treated the animals with galantamine (0.05ng/g), an inhibitor of this enzyme. Also we evaluated the gene expression of insulin receptor and glucose transporter from zebrafish brain. The hyperglycemia promoted memory deficit in adult zebrafish, which can be explained by increased AChE activity. The ache mRNA levels from zebrafish brain were decrease in 111mM glucose group and returned to normal levels after 7 days of glucose withdrawal. Insulin receptors (insra-1, insra-2, insrb-1 and insrb-2) and glut-3 mRNA levels were not significantly changed. Our results also demonstrated that galantamine was able to reverse the memory deficit caused by hyperglycemia, demonstrating that these effects involve modulation of AChE activity. These data suggest that the memory impairment induced by hyperglycemia is underlined by the cholinergic dysfunction caused by the mechanisms involving the control of acetylcholinesterase function and gene expression. Copyright © 2014 Elsevier B.V. All rights reserved.

Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

Science.gov (United States)

Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

2013-01-01

The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on the ligand fishing experiments and zonal chromatography. For that, the magnetic beads were used for the ligand fishing experiments and capillary bioreactors for the activity assays. The latter was employed also under non-linear conditions to determine the affinity constants of known ligands, for the first time, as well as for the active fished ligand. PMID:24148457

Surface modification of chitosan/PEO nanofibers by air dielectric barrier discharge plasma for acetylcholinesterase immobilization

Energy Technology Data Exchange (ETDEWEB)

Dorraki, Naghme, E-mail: n.dorraki@web.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Safa, Nasrin Navab [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Jahanfar, Mehdi [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of)

2015-09-15

Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH{sub 3}{sup +} group was generated on the 6 min plasma modified membrane. • We immobilized acetylcholinesterase on the plasma modified and unmodified membranes. • More enzyme activity was detected on the modified membrane by plasma. - Abstract: There are different methods to modify polymer surfaces for biological applications. In this work we have introduced air-dielectric barrier discharge (DBD) plasma at atmospheric pressure as an economical and safe method for modifying the surface of electrospun chitosan/PEO (90/10) nanofibers for acetylcholinesterase (AChE) immobilization. According to the contact angle measurement results, the nanofibers become highly hydrophilic when they are exposed to the DBD plasma for 6 min in compared to unmodified membrane. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results reveal hydroxyl, C=O and NH{sub 3}{sup +} polar groups increment after 6 min plasma treatment. Contact angle measurements and ATR-FTIR results are confirmed by X-ray photoelectron spectroscopy (XPS). AChE at pH 7.4 carries a negative charge and after immobilization on the surface of plasma-treated nanofibrous membrane attracts the NH{sub 3}{sup +} group and more enzyme activity is detected on the plasma-modified nanofibers for 6 min in compared to unmodified nanofibers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used for the surface topography and morphology characterization. The results have proved that air-DBD plasma is a suitable method for chitosan/PEO nanofibrous membrane modification as a biodegradable and functionalized substrate for enzyme immobilization.

Interleukin 6 modulates acetylcholinesterase activity of brain neurons; Effet de l`interleukine 6 sur l`activite de l`acetylcholinesterase des neurones centraux

Energy Technology Data Exchange (ETDEWEB)

Clarencon, D.; Multon, E.; Galonnier, M.; Estrade, M.; Fournier, C.; Mathieu, J.; Mestries, J.C.; Testylier, G.; Fatome, M.

1995-12-31

Classically, radiation injuries results in a peripheral inflammatory process, and we have previously observed an early systemic interleukin 6 (IL-6) release following whole-body irradiation. Besides, we have demonstrated an early decrease of rat or primate brain acetylcholinesterase (AChE) activity a gamma exposure. The object of the present study is to find possible IL-6 systemic effects on the brain AChE activity. We show that, though intravenous (i.v.) or intra-cerebro-ventricular (ICV) injection of IL-6 can induce a drop in rat brain AChE activity, this cytokine induces only a slight decrease of the AChE release in cultured brain cells. (author). 3 refs.

Rapid eye movement sleep deprivation induces an increase in acetylcholinesterase activity in discrete rat brain regions

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Benedito M.A.C.

2001-01-01

Full Text Available Some upper brainstem cholinergic neurons (pedunculopontine and laterodorsal tegmental nuclei are involved in the generation of rapid eye movement (REM sleep and project rostrally to the thalamus and caudally to the medulla oblongata. A previous report showed that 96 h of REM sleep deprivation in rats induced an increase in the activity of brainstem acetylcholinesterase (Achase, the enzyme which inactivates acetylcholine (Ach in the synaptic cleft. There was no change in the enzyme's activity in the whole brain and cerebrum. The components of the cholinergic synaptic endings (for example, Achase are not uniformly distributed throughout the discrete regions of the brain. In order to detect possible regional changes we measured Achase activity in several discrete rat brain regions (medulla oblongata, pons, thalamus, striatum, hippocampus and cerebral cortex after 96 h of REM sleep deprivation. Naive adult male Wistar rats were deprived of REM sleep using the flower-pot technique, while control rats were left in their home cages. Total, membrane-bound and soluble Achase activities (nmol of thiocholine formed min-1 mg protein-1 were assayed photometrically. The results (mean ± SD obtained showed a statistically significant (Student t-test increase in total Achase activity in the pons (control: 147.8 ± 12.8, REM sleep-deprived: 169.3 ± 17.4, N = 6 for both groups, P<0.025 and thalamus (control: 167.4 ± 29.0, REM sleep-deprived: 191.9 ± 15.4, N = 6 for both groups, P<0.05. Increases in membrane-bound Achase activity in the pons (control: 171.0 ± 14.7, REM sleep-deprived: 189.5 ± 19.5, N = 6 for both groups, P<0.05 and soluble enzyme activity in the medulla oblongata (control: 147.6 ± 16.3, REM sleep-deprived: 163.8 ± 8.3, N = 6 for both groups, P<0.05 were also observed. There were no statistically significant differences in the enzyme's activity in the other brain regions assayed. The present findings show that the increase in Achase activity

Analysis of structure and specific functional groups involved in acetylcholinesterase catalysis and inhibition. Final report, 14 June 1991-13 September 1994

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Taylor, P.

1994-10-01

The interactions of substrates, inhibitors and antibodies with Torpedo and mammalian acetylcholinesterases and butyrylcholinesterases have been studied by enzyme kinetic analyses, site-specific mutagenesis, molecular modeling, and peptide and antibody titrations. The high yield expression systems we developed have enabled us to obtain sufficient wild-type and mutant enzymes for the kinetic and physical studies. These studies have benefited from the availability of a three-dimensional X-ray-derived structure of acetylcholinesterase which allows for interpretations at an atomic level of resolution. Three distinct regions in the enzyme appear responsible for conferring selectivity: the acyl pocket defined primarily by phenylalanines 295 and 297, the choline subsite primarily defined by tryptophan 86, tyrosine 337 and glutamate 202 and the peripheral anionic site defined by tryptophan 286, tyrosine 72, tyrosine 124 and aspartate 74. Through site-specific mutagenesis we have been able to modify acyl pocket specificity, selectivity toward neutral and charged substrates, substrate inhibition, organophosphate reactivity, organophosphate aging and oxime reactivation. These studies have important implications in developing superior antidotes for organophosphate poisoning and in using recombinant acetylcholinesterase as an antidote.

Curcumin administration suppress acetylcholinesterase gene expression in cadmium treated rats.

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Akinyemi, Ayodele Jacob; Oboh, Ganiyu; Fadaka, Adewale Oluwaseun; Olatunji, Babawale Peter; Akomolafe, Seun

2017-09-01

Curcumin, the main polyphenolic component of turmeric (Curcuma longa) rhizomes have been reported to exert anticholinesterase potential with limited information on how they regulate acetylcholinesterase (AChE) gene expression. Hence, this study sought to evaluate the effect of curcumin on cerebral cortex acetylcholinesterase (AChE) activity and their mRNA gene expression level in cadmium (Cd)-treated rats. Furthermore, in vitro effect of different concentrations of curcumin (1-5μg/mL) on rat cerebral cortex AChE activity was assessed. Animals were divided into six groups (n=6): group 1 serve as control (without Cd) and receive saline/vehicle, group 2 receive saline plus curcumin at 25mg/kg, group 3 receive saline plus curcumin 50mg/kg, group 4 receive Cd plus vehicle, group 5 receive Cd plus curcumin at 25mg/kg and group 6 receive Cd plus curcumin at 50mg/kg. Rats received Cd (2.5mg/kg) and curcumin (25 and 50mg/kg, respectively) by oral gavage for 7days. Acetylcholinesterase activity was measured by Ellman's method and AChE expression was carried out by a quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) assay. We observed that acute administration of Cd increased acetylcholinesterase activity and in addition caused a significant (Pcurcumin inhibited AChE activity and alters AChE mRNA levels when compared to Cd-treated group. In addition, curcumin inhibits rat cerebral cortex AChE activity in vitro. In conclusion, curcumin exhibit anti-acetylcholinesterase activity and suppressed AChE mRNA gene expression level in Cd exposed rats, thus providing some biochemical and molecular evidence on the therapeutic effect of this turmeric-derived compound in treating neurological disorders including Alzheimer's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Diallyl tetrasulfide improves cadmium induced alterations of acetylcholinesterase, ATPases and oxidative stress in brain of rats

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Pari, Leelavinothan; Murugavel, Ponnusamy

2007-01-01

Cadmium (Cd) is a neurotoxic metal, which induces oxidative stress and membrane disturbances in nerve system. The garlic compound diallyl tetrasulfide (DTS) has the cytoprotective and antioxidant activity against Cd induced toxicity. The present study was carried out to investigate the efficacy of DTS in protecting the Cd induced changes in the activity of acetylcholinesterase (AChE), membrane bound enzymes, lipid peroxidation (LPO) and antioxidant status in the brain of rats. In rats exposed to Cd (3 mg/kg/day subcutaneously) for 3 weeks, a significant (P + K + -ATPase, Mg 2+ -ATPase and Ca 2+ -ATPase) were observed in brain tissue. Oral administration of DTS (40 mg/kg/day) with Cd significantly (P < 0.05) diminished the levels of LPO and protein carbonyls and significantly (P < 0.05) increased the activities of ATPases, antioxidant enzymes, GSH and TSH in brain. These results indicate that DTS attenuate the LPO and alteration of antioxidant and membrane bound enzymes in Cd exposed rats, which suggest that DTS protects the brain function from toxic effects of Cd

Two Bombyx mori acetylcholinesterase genes influence motor control and development in different ways

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Among its other biological roles, acetylcholinesterase (AChE, EC 3.1.1.7), encoded by two ace genes in most insects, catalyses the breakdown of acetylcholine, thereby terminating synaptic transmission. ace1 encodes the synaptic enzyme and ace2 has other essential actions in many insect species, such...

Screening of plants used in the European traditional medicine to treat memory disorders for acetylcholinesterase inhibitory activity and anti amyloidogenic activity

DEFF Research Database (Denmark)

Lobbens, Eva S B; Vissing, Karina J.; Jorgensen, Lene

2017-01-01

and the ability to inhibit the enzymatic activity of acetylcholinesterase was evaluated monitoring the hydrolysis of acetylthiocholine Results Under the experimental conditions investigated, extracts of two plants, Carum carvi and Olea sylvestris, inhibited amyloid beta fibrillation considerably, eight plant...

Effect of allyl isothiocyanate on ultra-structure and the activities of four enzymes in adult Sitophilus zeamais.

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Wu, Hua; Liu, Xue-ru; Yu, Dong-dong; Zhang, Xing; Feng, Jun-tao

2014-02-01

Rarefaction and vacuolization of the mitochondrial matrix of AITC-treated (allyl isothiocyanate-treated) adult Sitophilus zeamais were evident according to the ultra-structural by TEM. Four important enzymes in adult S. zeamais were further studied after fumigation treatment with allyl isothiocyanate (AITC) extracted from Armoracia rusticana roots and shoots. The enzymes were glutathione S-transferase (GST), catalase (CAT), cytochrome c oxidase, and acetylcholinesterase (AChE). The results indicated that the activities of the four enzymes were strongly time and dose depended. With prolonged exposure time, treatment with 0.74μg/mL AITC inhibited the activities of cytochrome c oxidase, AChE, and CAT, but induced the activity of GST. The activities of cytochrome c oxidase, AChE, and CAT were remarkably induced at a low AITC dosage (0.25μg/mL), but were restrained with increased AITC dosage. The activity of GST was inhibited at a low AITC dosage (0.5μg/mL), but was induced at a high AITC dosage (1.5μg/mL). According to the results of TEM, toxic symptoms and enzymes activities, it suggested that mitochondrial maybe the one site of action of AITC against the adult S. zeamais and it also suggested that cytochrome c oxidase maybe one target protein of AITC against the adult S. zeamais, which need to further confirmed by protein function tested. Copyright © 2014 Elsevier Inc. All rights reserved.

Phytochemical screening and in vitro acetylcholinesterase inhibitory ...

African Journals Online (AJOL)

Phytochemical screening and in vitro acetylcholinesterase inhibitory activity of seven plant extracts. Titilayo Johnson, Oduje A. Akinsanmi, Enoch J. Banbilbwa, Tijani A. Yahaya, Karima Abdulaziz, Kolade Omole ...

Inhibitory effect of ebselen on cerebral acetylcholinesterase activity in vitro: kinetics and reversibility of inhibition.

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Martini, Franciele; Bruning, César Augusto; Soares, Suelen Mendonca; Nogueira, Cristina Wayne; Zeni, Gilson

2015-01-01

Ebselen is a synthetic organoselenium compound that has been considered a potential pharmacological agent with low toxicity, showing antioxidant, anti-inflammatory and neuroprotective effects. It is bioavailable, blood-brain barrier permeant and safe based on cellular toxicity and Phase I-III clinical trials. There is evidence that ebselen inhibits acetylcholinesterase (AChE) activity, an enzyme that plays a key role in the cholinergic system by hydrolyzing acetylcholine (ACh), in vitro and ex vivo. This system has a well-known relationship with cognitive process, and AChE inhibitors, such as donepezil and galantamine, have been used to treat cognitive deficits, mainly in the Alzheimer's Disease (AD). However, these drugs have poor bioavailability and a number of side effects, including gastrointestinal upsets and hepatotoxicity. In this way, this study aimed to evaluate the effect of ebselen on cerebral AChE activity in vitro and to determine the kinetic profile and the reversibility of inhibition by dialysis. Ebselen inhibited the cerebral AChE activity with an IC50 of 29 µM, similar to IC50 found with pure AChE from electric eel, demonstrating a mixed and reversible inhibition of AChE, since it increased Km and decreased Vmax. The AChE activity was recovered within 60 min of dialysis. Therefore, the use of ebselen as a therapeutic agent for treatment of AD should be considered, although memory behavior tasks are needed to support such hypothesis.

The Effect of Parathion on Red Blood Cell Acetylcholinesterase in the Wistar Rat

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Naofumi Bunya

2016-01-01

Full Text Available Organophosphorus (OP pesticide poisoning is a significant problem worldwide. Research into new antidotes for these acetylcholinesterase inhibitors, and even optimal doses for current therapies, is hindered by a lack of standardized animal models. In this study, we sought to characterize the effects of the OP pesticide parathion on acetylcholinesterase in a Wistar rat model that included comprehensive medical care. Methods. Male Wistar rats were intubated and mechanically ventilated and then poisoned with between 20 mg/kg and 60 mg/kg of intravenous parathion. Upon developing signs of poisoning, the rats were treated with standard critical care, including atropine, pralidoxime chloride, and midazolam, for up to 48 hours. Acetylcholinesterase activity was determined serially for up to 8 days after poisoning. Results. At all doses of parathion, maximal depression of acetylcholinesterase occurred at 3 hours after poisoning. Acetylcholinesterase recovered to nearly 50% of baseline activity by day 4 in the 20 mg/kg cohort and by day 5 in the 40 and 60 mg/kg cohorts. At day 8, most rats’ acetylcholinesterase had recovered to roughly 70% of baseline. These data should be useful in developing rodent models of acute OP pesticide poisoning.

Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.

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Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Carvalho, Elba Veronica Matoso Maciel; Bezerra, Ranilson Souza; de Carvalho, Luiz Bezerra

2012-12-15

Monitoring of pesticides based on acetylcholinesterase (AChE; EC 3.1.1.7) inhibition in vitro avoids interference of detoxification defenses and bioactivation of some of those compounds in non-target tissues. Moreover, environmental temperature, age and stress are able to affect specific enzyme activities when performing in vivo studies. Few comparative studies have investigated the inter-specific differences in AChE activity in fish. Screening studies allow choosing the suitable species as source of AChE to detect pesticides in a given situation. Brain AChE from the tropical fish: pirarucu (Arapaima gigas), cobia (Rachycentron canadum) and Nile tilapia (Oreochromis niloticus) were characterized and their activities were assayed in the presence of pesticides (the organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate- TEPP and the carbamates: carbaryl and carbofuran). Inhibition parameters (IC₅₀ and Ki) for each species were found and compared with commercial AChE from electric eel (Electrophorus electricus). Optimal pH and temperature were found to be 8.0 and 35-45 °C, respectively. A. gigas AChE retained 81% of the activity after incubation at 50 °C for 30 min. The electric eel enzyme was more sensitive to the compounds (mainly carbofuran, IC₅₀ of 5 nM), excepting the one from A. gigas (IC₅₀ of 9 nM) under TEPP inhibition. These results show comparable sensitivity between purified and non-purified enzymes suggesting them as biomarkers for organophosphorus and carbamate detection in routine environmental and food monitoring programs for pesticides. Copyright © 2012 Elsevier B.V. All rights reserved.

Global loss of acetylcholinesterase activity with mitochondrial complexes inhibition and inflammation in brain of hypercholesterolemic mice.

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Paul, Rajib; Borah, Anupom

2017-12-20

There exists an intricate relationship between hypercholesterolemia (elevated plasma cholesterol) and brain functions. The present study aims to understand the impact of hypercholesterolemia on pathological consequences in mouse brain. A chronic mouse model of hypercholesterolemia was induced by giving high-cholesterol diet for 12 weeks. The hypercholesterolemic mice developed cognitive impairment as evident from object recognition memory test. Cholesterol accumulation was observed in four discrete brain regions, such as cortex, striatum, hippocampus and substantia nigra along with significantly damaged blood-brain barrier by hypercholesterolemia. The crucial finding is the loss of acetylcholinesterase activity with mitochondrial dysfunction globally in the brain of hypercholesterolemic mice, which is related to the levels of cholesterol. Moreover, the levels of hydroxyl radical were elevated in the regions of brain where the activity of mitochondrial complexes was found to be reduced. Intriguingly, elevations of inflammatory stress markers in the cholesterol-rich brain regions were observed. As cognitive impairment, diminished brain acetylcholinesterase activity, mitochondrial dysfunctions, and inflammation are the prima facie pathologies of neurodegenerative diseases, the findings impose hypercholesterolemia as potential risk factor towards brain dysfunction.

Evaluation of enzymes inhibition activities of medicinal plant from Burkina Faso.

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Bangou, Mindiédiba Jean; Kiendrebeogo, Martin; Meda, Nâg-Tiero Roland; Coulibaly, Ahmed Yacouba; Compaoré, Moussa; Zeba, Boukaré; Millogo-Rasolodimby, Jeanne; Nacoulma, Odile Germaine

2011-01-15

The aim of the present study was to evaluate some enzymes inhibitory effects of 11 plant species belonging to 9 families from Burkina Faso. Methanolic extracts were used for their Glutathione-s-transferase (GST), Acetylcholinesterase (AChE), Carboxylesterase (CES) and Xanthine Oxidase (XO) inhibitory activities at final concentration of 100 microg mL(-1). The total phenolics, flavonoids and tannins were also determined spectrophotometrically using Folin-Ciocalteu, AlCl3 and ammonium citrate iron reagents, respectively. Among the 11 species tested, the best inhibitory percentages were found with Euphorbia hirta, Sclerocarya birrea and Scoparia dulcis (inhibition > 40%) followed by Annona senegalensis, Annona squamosa, Polygala arenaria and Ceratotheca sesamoides (inhibition > 25%). The best total phenolic and tannin contents were found with S. birrea with 56.10 mg GAE/100 mg extract and 47.75 mg TAE/100 mg extract, respectively. E hirta presented the higher total flavonoids (9.96 mg QE/100 mg extract). It's was found that Sclerocarya birrea has inhibited all enzymes at more than 30% and this activity is correlated to total tannins contents. Contrary to S. birrea, the enzymatic activities of E. hirta and S. dulcis are correlated to total flavonoids contents. Present findings suggest that the methanolic extracts of those plant species are potential inhibitors of GST, AChE, CES and XO and confirm their traditional uses in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.

Evaluation, partial characterization and purification of acetylcholine esterase enzyme and antiangiogenic activity from marine sponges

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Maushmi Shailesh Kumar

2014-11-01

Full Text Available Objective: To test three marine sponges Halichondria glabrata Keller, 1891; Spirastrella pachyspira (S. pachyspira Levi, 1958 and Cliona lobata Hancock, 1849 for the presence of the acetylcholinesterase (AChE in both young and developed samples from western coastal area of India. S. pachyspira methanolic extract was selected for anti/pro angiogenic activity. Methods: They were evaluated for AChE activity using Ellman’s assay based on production of yellow colored 5-thio-2-nitrobenzoate. Purification of the enzyme was planned using ammonium sulphate precipitation and characterization by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Chorioallantoic membrane (ChAM assay model was used for angiogenic/ antiangiogenic testing. Results: All the three sponges showed good specific enzyme activity and S. pachyspira contained maximum specific enzyme activity. Sixty percent of ammonium sulphate precipitation of crude protein sample gave single band at 66 kDa corresponding to the true AChE. ChAM assay was performed at 62.5, 125.0 and 250.0 µg/mL. Dosage beyond 250 µg/mL extract showed toxic response with anti angiogenic activity at all the concentrations. Conclusions: AChE activity was detected in all samples. Extract showed good anti-angiogenic response at 62.5 µg/mL. Extract was highly toxic affecting microvasculature of ChAM as well as normal growth and development of the embryo at 500 µg/mL. With further characterization of bioactive compounds from the extract of S. pachyspira, the compounds can be developed for anti tumor activity.

Flavonoids, Antioxidant Potential, and Acetylcholinesterase Inhibition Activity of the Extracts from the Gametophyte and Archegoniophore of Marchantia polymorpha L.

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Xin Wang

2016-03-01

Full Text Available Marchantia polymorpha L. is a representative bryophyte used as a traditional Chinese medicinal herb for scald and pneumonia. The phytochemicals in M. polymorpha L. are terpenoids and flavonoids, among which especially the flavonoids show significant human health benefits. Many researches on the gametophyte of M. polymorpha L. have been reported. However, as the reproductive organ of M. polymorpha L., the bioactivity and flavonoids profile of the archegoniophore have not been reported, so in this work the flavonoid profiles, antioxidant and acetylcholinesterase inhibition activities of the extracts from the archegoniophore and gametophyte of M. polymorpha L. were compared by radical scavenging assay methods (DPPH, ABTS, O2−, reducing power assay, acetylcholinesterase inhibition assay and LC-MS analysis. The results showed that the total flavonoids content in the archegoniophore was about 10-time higher than that of the gametophyte. Differences between the archegoniophore and gametophyte of M. polymorpha L. were observed by LC-MS analysis. The archegoniophore extracts showed stronger bio-activities than those of the gametophyte. The archegoniophore extract showed a significant acetylcholinesterase inhibition, while the gametophyte extract hardly inhibited it.

Proline-induced changes in acetylcholinesterase activity and gene expression in zebrafish brain: reversal by antipsychotic drugs.

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Savio, L E B; Vuaden, F C; Kist, L W; Pereira, T C; Rosemberg, D B; Bogo, M R; Bonan, C D; Wyse, A T S

2013-10-10

Hyperprolinemia is an inherited disorder of proline metabolism and hyperprolinemic patients can present neurological manifestations, such as seizures, cognitive dysfunctions, and schizoaffective disorders. However, the mechanisms related to these symptoms are still unclear. In the present study, we evaluated the in vivo and in vitro effects of proline on acetylcholinesterase (AChE) activity and gene expression in the zebrafish brain. For the in vivo studies, animals were exposed at two proline concentrations (1.5 and 3.0mM) during 1h or 7 days (short- or long-term treatments, respectively). For the in vitro assays, different proline concentrations (ranging from 3.0 to 1000 μM) were tested. Long-term proline exposures significantly increased AChE activity for both treated groups when compared to the control (34% and 39%). Moreover, the proline-induced increase on AChE activity was completely reverted by acute administration of antipsychotic drugs (haloperidol and sulpiride), as well as the changes induced in ache expression. When assessed in vitro, proline did not promote significant changes in AChE activity. Altogether, these data indicate that the enzyme responsible for the control of acetylcholine levels might be altered after proline exposure in the adult zebrafish. These findings contribute for better understanding of the pathophysiology of hyperprolinemia and might reinforce the use of the zebrafish as a complementary vertebrate model for studying inborn errors of amino acid metabolism. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of endosulfan on brain acetylcholinesterase activity in juvenile bluegill sunfish

International Nuclear Information System (INIS)

Dutta, Hiran M.; Arends, Dane A.

2003-01-01

The effects of endosulfan upon brain acetylcholinesterase (AChE) activity were measured in juvenile blue gill sunfish (Lepomis macrochirus). Based on exposure durations of 0, 24, 48, 72, and 96 h and 1 week at 1.0 μg/L (just below the LC50 of 1.2 μg/L for this species), step-wise decreases in AChE activity were noted, corresponding to 0%, 3.57%, 12.65%, 14.23%, 16.31%, and 3.11% inhibition, respectively. Total brain protein concentrations were measured to test the accuracy of the Ache data with no significant anomalies. The duration of exposure was related to the reduction in the AChE activities which reflected the biotoxicity of endosulfan. The changes in the AChE activities will certainly affect the normal behavior of the juvenile blue gill which is detrimental to their very existence in the natural habitat

Unmasking tandem site interaction in human acetylcholinesterase. Substrate activation with a cationic acetanilide substrate.

Science.gov (United States)

Johnson, Joseph L; Cusack, Bernadette; Davies, Matthew P; Fauq, Abdul; Rosenberry, Terrone L

2003-05-13

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge, and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. A conformational interaction between the A- and P-sites has recently been found to modulate ligand affinities. We now demonstrate that this interaction is of functional importance by showing that the acetylation rate constant of a substrate bound to the A-site is increased by a factor a when a second molecule of substrate binds to the P-site. This demonstration became feasible through the introduction of a new acetanilide substrate analogue of acetylcholine, 3-(acetamido)-N,N,N-trimethylanilinium (ATMA), for which a = 4. This substrate has a low acetylation rate constant and equilibrates with the catalytic site, allowing a tractable algebraic solution to the rate equation for substrate hydrolysis. ATMA affinities for the A- and P-sites deduced from the kinetic analysis were confirmed by fluorescence titration with thioflavin T as a reporter ligand. Values of a >1 give rise to a hydrolysis profile called substrate activation, and the AChE site-specific mutant W86F, and to a lesser extent wild-type human AChE itself, showed substrate activation with acetylthiocholine as the substrate. Substrate activation was incorporated into a previous catalytic scheme for AChE in which a bound P-site ligand can also block product dissociation from the A-site, and two additional features of the AChE catalytic pathway were revealed. First, the ability of a bound P-site ligand to increase the substrate acetylation rate constant varied with the structure of the ligand: thioflavin T accelerated ATMA acetylation by a factor a(2) of 1.3, while propidium failed to accelerate. Second, catalytic rate

Synthesis and discovery of potent carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase, and α-glycosidase enzymes inhibitors: The novel N,N'-bis-cyanomethylamine and alkoxymethylamine derivatives.

Science.gov (United States)

Taslimi, Parham; Caglayan, Cuneyt; Farzaliyev, Vagif; Nabiyev, Oruj; Sujayev, Afsun; Turkan, Fikret; Kaya, Ruya; Gulçin, İlhami

2018-04-01

During this investigation, N,N'-bis-azidomethylamines, N,N'-bis-cyanomethylamine, new alkoxymethylamine and chiral derivatives, which are considered to be a new generation of multifunctional compounds, were synthesized, functional properties were investigated, and anticholinergic and antidiabetic properties of those compounds were studied through the laboratory tests, and it was approved that they contain physiologically active compounds rather than analogues. Novel N-bis-cyanomethylamine and alkoxymethylamine derivatives were effective inhibitors of the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms, butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) with K i values in the range of 0.15-13.31 nM for α-glycosidase, 2.77-15.30 nM for human carbonic anhydrase isoenzymes I (hCA I), 3.12-21.90 nM for human carbonic anhydrase isoenzymes II (hCA II), 23.33-73.23 nM for AChE, and 3.84-48.41 nM for BChE, respectively. Indeed, the inhibition of these metabolic enzymes has been considered as a promising factor for pharmacologic intervention in a diversity of disturbances. © 2018 Wiley Periodicals, Inc.

Detection of Carbofuran with Immobilized Acetylcholinesterase Based on Carbon Nano tubes-Chitosan Modified Electrode

International Nuclear Information System (INIS)

Zhang, Sh.; Li, Sh.; Ma, J.; Xiong, F.; Qu, S.; Zhang, Sh.; Li, Sh.

2013-01-01

A sensitive and stable enzyme biosensor based on efficient immobilization of acetylcholinesterase (AChE) to MWNTs-modified glassy carbon electrode (GCE) with chitosan (CS) by layer-by-layer (LBL) technique for rapid determination of carbofuran has been devised. According to the inhibitory effect of carbamate pesticide on the enzymatic activity of AChE, we use carbofuran as a model pesticide. The inhibitory effect of carbofuran on the biosensor was proportional to concentration of carbofuran in the range from 10 -10  g/L to 10 -3  g/L with a detection limit of 10 -12  g/L. This biosensor is a promising new method for pesticide analysis

Polypyridylruthenium(II complexes exert anti-schistosome activity and inhibit parasite acetylcholinesterases.

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Madhu K Sundaraneedi

2017-12-01

Full Text Available Schistosomiasis affects over 200 million people and there are concerns whether the current chemotherapeutic control strategy (periodic mass drug administration with praziquantel (PZQ-the only licenced anti-schistosome compound is sustainable, necessitating the development of new drugs.We investigated the anti-schistosome efficacy of polypyridylruthenium(II complexes and showed they were active against all intra-mammalian stages of S. mansoni. Two compounds, Rubb12-tri and Rubb7-tnl, which were among the most potent in their ability to kill schistosomula and adult worms and inhibit egg hatching in vitro, were assessed for their efficacy in a mouse model of schistosomiasis using 5 consecutive daily i.v. doses of 2 mg/kg (Rubb12-tri and 10 mg/kg (Rubb7-tnl. Mice treated with Rubb12-tri showed an average 42% reduction (P = 0.009, over two independent trials, in adult worm burden. Liver egg burdens were not significantly decreased in either drug-treated group but ova from both of these groups showed significant decreases in hatching ability (Rubb12-tri-68%, Rubb7-tnl-56% and were significantly morphologically altered (Rubb12-tri-62% abnormal, Rubb7-tnl-35% abnormal. We hypothesize that the drugs exerted their activity, at least partially, through inhibition of both neuronal and tegumental acetylcholinesterases (AChEs, as worms treated in vitro showed significant decreases in activity of these enzymes. Further, treated parasites exhibited a significantly decreased ability to uptake glucose, significantly depleted glycogen stores and withered tubercules (a site of glycogen storage, implying drug-mediated interference in this nutrient acquisition pathway.Our data provide compelling evidence that ruthenium complexes are effective against all intra-mammalian stages of schistosomes, including schistosomula (refractory to PZQ and eggs (agents of disease transmissibility. Further, the results of this study suggest that schistosome AChE is a target of

Research Advances and Detection Methodologies for Microbe-Derived Acetylcholinesterase Inhibitors: A Systemic Review

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Jingqian Su

2017-01-01

Full Text Available Acetylcholinesterase inhibitors (AChEIs are an attractive research subject owing to their potential applications in the treatment of neurodegenerative diseases. Fungi and bacteria are major producers of AChEIs. Their active ingredients of fermentation products include alkaloids, terpenoids, phenylpropanoids, and steroids. A variety of in vitro acetylcholinesterase inhibitor assays have been developed and used to measure the activity of acetylcholinesterases, including modified Ellman’s method, thin layer chromatography bioautography, and the combined liquid chromatography-mass spectrometry/modified Ellman’s method. In this review, we provide an overview of the different detection methodologies, the microbe-derived AChEIs, and their producing strains.

Acetylcholinesterase inhibition and antibacterial activity of Mondia whitei adventitious roots and ex vitro-grown somatic embryogenic-biomass

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Ponnusamy Baskaran

2016-10-01

Full Text Available Mondia whitei (Hook.f. Skeels is an important endangered medicinal and commercial plant in South Africa. In vitro propagation systems are required for biomass production and bioactivity analysis to supplement wild resources/stocks. Adventitious roots from somatic embryogenic explants using suspension culture and ex vitro-grown plants produced via somatic embryogenesis were established using different plant growth regulator treatments. The adventitious root biomass and different parts of ex vitro-grown and mother plants were used to investigate the potential for acetylcholinesterase (AChE and antibacterial activities. Adventitious roots derived from 2.5 µM indole-3-acetic acid (IAA treatments and ex vitro-grown plants derived from meta-topolin riboside (mTR and IAA treatments gave the best AChE and antibacterial activities. The in vitro-established M. whitei and ex vitro biomass have comparable ability to function as inhibitors of acetylcholinesterase and antibacterial agents, and can be used as potent bioresources in traditional medicine

Acetylcholinesterase Reactivators (HI-6, Obidoxime, Trimedoxime, K027, K075, K127, K203, K282: Structural Evaluation of Human Serum Albumin Binding and Absorption Kinetics

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Filip Zemek

2013-08-01

Full Text Available Acetylcholinesterase (AChE reactivators (oximes are compounds predominantly targeting the active site of the enzyme. Toxic effects of organophosphates nerve agents (OPNAs are primarily related to their covalent binding to AChE and butyrylcholinesterase (BChE, critical detoxification enzymes in the blood and in the central nervous system (CNS. After exposure to OPNAs, accumulation of acetylcholine (ACh overstimulates receptors and blocks neuromuscular junction transmission resulting in CNS toxicity. Current efforts at treatments for OPNA exposure are focused on non-quaternary reactivators, monoisonitrosoacetone oximes (MINA, and diacylmonoxime reactivators (DAM. However, so far only quaternary oximes have been approved for use in cases of OPNA intoxication. Five acetylcholinesterase reactivator candidates (K027, K075, K127, K203, K282 are presented here, together with pharmacokinetic data (plasma concentration, human serum albumin binding potency. Pharmacokinetic curves based on intramuscular application of the tested compounds are given, with binding information and an evaluation of structural relationships. Human Serum Albumin (HSA binding studies have not yet been performed on any acetylcholinesterase reactivators, and correlations between structure, concentration curves and binding are vital for further development. HSA bindings of the tested compounds were 1% (HI-6, 7% (obidoxime, 6% (trimedoxime, and 5%, 10%, 4%, 15%, and 12% for K027, K075, K127, K203, and K282, respectively.

Formulation and characterization of novel functional beverages with antioxidant and anti-acetylcholinesterase activities

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Suree Nanasombat

2015-01-01

beverages B1, B2, B3, B4 and B5 in the ratio of 60:40 to prepare alcoholic beverages W1, W2, W3, W4 and W5, respectively. Two different fermentation conditions (fermentation with or without pieces of sliced medicinal plant residue, PMPR were compared. After fermenting, racking and aging, all alcoholic beverages, as well as all non-alcoholic beverages,were analyzed for some phytochemical properties. Results: Grape fermented with PMPR had higher anti-acetylcholinesterase and antioxidant activities, and total phenolics, flavonoids and tannins, compared to the others. Among all nonalcoholic beverages, the beverage B3 contained the highest anti-acetylcholinesterase (22.78% inhibition at 1:10,000 dilution and antioxidant activities (reducing capacity, 4.22 mmol Fe(II/100 mL, total phenolics, flavonoids, and tannins (494.44 mg gallic acid equivalents (GAE, 383.22 mg catechin equivalents (CE and 338.29 mg tannic acid equivalents ((TAE/100 mL, respectively. Among all alcoholic beverages, the beverage W3 (fermented with PMPR exhibited the highest antioxidant activity (DPPH radical inhibition, 95.99 mg trolox equivalents and reducing capacity, 3.57 mmol Fe(II /100 mL, total phenolics, flavonoids and tannins (239.71 mg GAE, 372.67 mg CE and 157.67 mg TAE/100 mL, respectively. The beverage W2 (fermented with PMPR had the highest anti-acetylcholinesterase activity (21.35% inhibition at 1:10,000 dilution. Conclusion: The beverages B3, W2 and W3 contained valuable sources of natural antioxidants and acetylcholinesterase inhibitors, and may provide health benefits when consumed.

Differential effects of developmental hypo- and hyperthyroidism on acetylcholinesterase and butyrylcholinesterase activity in the spinal cord of developing postnatal rat pups.

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Koohestani, Faezeh; Brown, Chester M; Meisami, Esmail

2012-11-01

The plasticity and vulnerability of the rat spinal cord (SC) during postnatal development has been less investigated compared to other CNS structures. In this study, we determined the effects of thyroid hormonal (TH) deficiency and excess on postnatal growth and neurochemical development of the rat SC. The growth as well as the specific and total activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes of the SC were determined in hypo- and hyperthyroid rat pups at postnatal (P) days P1, P5, P10 and P21 (weaning), and were compared to age-matched untreated normal controls. AChE is a cholinergic synaptic enzyme while BuChE is a metabolic enzyme mainly found in glial cells and neurovascular cells. The SC is rich in somatic motor, autonomic cholinergic neurons and associated interneurons. Daily subcutaneous injection of pups with thyroxine (T4) and administration of antithyroid goitrogen propylthiouracil (PTU) in the litter's drinking water were used to induce hyper- and hypothyroidism, respectively. Enzyme assays were carried out spectrophotometrically at the above-mentioned ages, using SC homogenates with acetylthiocholine-chloride as the substrate, together with specific cholinesterase inhibitors, which specifically target AChE and BuChE. SC weights were significantly lower at P10 and P21 in hypothyroid pups but unchanged in the hyperthyroid ones. Hypothyroidism significantly reduced both specific and total AChE activity in SC of P10 and P21 rat pups, while having no effects on the BuChE activity, although total BuChE activity was decreased due to reduced total tissue weight. In contrast both specific and total AChE activities were markedly and significantly increased (>100%) in the P10 and P21 hyperthyroid pups. However, BuChE specific activity was unaffected by this treatment. The results indicate that hypothyroid condition significantly reduces, while hyperthyroidism increases, the postnatal development of cholinergic synapses, thereby

Acetylcholinesterase and Nissl staining in the same histological section.

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Shipley, M T; Ennis, M; Behbehani, M M

1989-12-18

Acetylcholinesterase (AChE) enzyme histochemistry and Nissl staining are commonly utilized in neural architectonic studies. However, the opaque reaction deposit produced by the most commonly used AChE histochemical methods is not compatible with satisfactory Nissl staining. As a result, precise correlation of AChE and Nissl staining necessitates time-consuming comparisons of adjacent sections which may have differential shrinkage. Here, we have modified the Koelle-Friedenwald histochemical reaction for AChE by omitting the final intensification steps. The modified reaction yields a non-opaque reaction product that is selectively visualized by darkfield illumination. This non-intensified darkfield AChE (NIDA) reaction allows clear visualization of Nissl staining in the same histological section. This combined AChE-Nissl method greatly facilitates detailed correlation of enzyme and cytoarchitectonic organization.

Synthesis and study of thiocarbonate derivatives of choline as potential inhibitors of acetylcholinesterase.

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Boyle, N A; Talesa, V; Giovannini, E; Rosi, G; Norton, S J

1997-09-12

Fourteen alkyl and aryl thiocarbonate derivatives of choline were synthesized and studied as potential inhibitors of acetylcholinesterase (AChE). Twelve of the compounds inhibited AChEs derived from calf forebrain, human red blood cells, and octopus brain ranging from low to moderately high inhibition potency. The concentration of each inhibitory compound giving 50% inhibition of enzyme activity (IC50 values, which ranged from 1 x 10(-2) to 8 x 10(-7) M) was determined and is reported; inhibitor constants (Ki values) for the most inhibitory compounds, (1-pentylthiocarbonyl)choline chloride and (1-heptylthiocarbonyl)choline chloride, were calculated from kinetic data and are also reported. The inhibitors are competitive with substrate, and they are not hydrolyzed by the AChE activities. Certain of these new compounds may provide direction for the development of new drugs that have anticholinesterase activity and may be used for the treatment of Alzheimer's disease.

Investigating the Antioxidant and Acetylcholinesterase Inhibition Activities of Gossypium herbaceam

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Haji Akber Aisa

2013-01-01

Full Text Available Our previous research showed that standardized extract from the flowers of the Gossypium herbaceam labeled GHE had been used in clinical trials for its beneficial effects on brain functions, particularly in connection with age-related dementia and Alzheimer’s disease (AD. The aim of this work was to determine the components of this herb and the individual constituents of GHE. In order to better understand this herb for AD treatment, we investigated the acetylcholinesterase (AChE inhibition and antioxidant activity of GHE as well as the protective effects to PC12 cells against cytotoxicity induced by tertiary butyl hydroperoxide (tBHP using in vitro assays. The antioxidant activities were assessed by measuring their capabilities for scavenging 1,1-diphenyl-2-picylhydrazyl (DPPH and 2-2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS free radical as well as in inhibiting lipid peroxidation. Our data showed that GHE exhibited certain activities against AChE and also is an efficient free radical scavenger, which may be helpful in preventing or alleviating patients suffering from AD.

Effect of single and binary combinations of plant-derived molluscicides on different enzyme activities in the nervous tissue of Achatina fulica.

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Rao, I G; Singh, Amrita; Singh, V K; Singh, D K

2003-01-01

Effect of single and binary treatments of plant-derived molluscicides on different enzymes--acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and acid/alkaline phosphatase (ACP/ALP)--in the nervous tissue of the harmful terrestrial snail Achatina fulica were studied. Sublethal in vivo 24-h exposure to 40% and 80% LC(50) of Azadirachta indica oil, Cedrus deodara oil, Allium sativum bulb powder, Nerium indicum bark powder and binary combinations of A. sativum (AS) + C. deodara (CD) and CD + A. indica (AI) oils significantly altered the activity of these enzymes in the nervous tissue of Achatina fulica. The binary treatment of AS + CD was more effective against AChE, LDH, and ALP than the single ones. However, binary treatment of AI + CD was more effective against ALP. Copyright 2003 John Wiley & Sons, Ltd.

Binding free energy calculations to rationalize the interactions of huprines with acetylcholinesterase.

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Nascimento, Érica C M; Oliva, Mónica; Andrés, Juan

2018-05-01

In the present study, the binding free energy of a family of huprines with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation method, based on hybrid quantum mechanics and molecular mechanics potentials. Binding free energy calculations and the analysis of the geometrical parameters highlight the importance of the stereochemistry of huprines in AChE inhibition. Binding isotope effects are calculated to unravel the interactions between ligands and the gorge of AChE. New chemical insights are provided to explain and rationalize the experimental results. A good correlation with the experimental data is found for a family of inhibitors with moderate differences in the enzyme affinity. The analysis of the geometrical parameters and interaction energy per residue reveals that Asp72, Glu199, and His440 contribute significantly to the network of interactions between active site residues, which stabilize the inhibitors in the gorge. It seems that a cooperative effect of the residues of the gorge determines the affinity of the enzyme for these inhibitors, where Asp72, Glu199, and His440 make a prominent contribution.

Binding free energy calculations to rationalize the interactions of huprines with acetylcholinesterase

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Nascimento, Érica C. M.; Oliva, Mónica; Andrés, Juan

2018-05-01

In the present study, the binding free energy of a family of huprines with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation method, based on hybrid quantum mechanics and molecular mechanics potentials. Binding free energy calculations and the analysis of the geometrical parameters highlight the importance of the stereochemistry of huprines in AChE inhibition. Binding isotope effects are calculated to unravel the interactions between ligands and the gorge of AChE. New chemical insights are provided to explain and rationalize the experimental results. A good correlation with the experimental data is found for a family of inhibitors with moderate differences in the enzyme affinity. The analysis of the geometrical parameters and interaction energy per residue reveals that Asp72, Glu199, and His440 contribute significantly to the network of interactions between active site residues, which stabilize the inhibitors in the gorge. It seems that a cooperative effect of the residues of the gorge determines the affinity of the enzyme for these inhibitors, where Asp72, Glu199, and His440 make a prominent contribution.

Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

OpenAIRE

Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

2013-01-01

The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on t...

A fluorescence assay for measuring acetylcholinesterase activity in rat blood and a human neuroblastoma cell line (SH-SY5Y).

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Santillo, Michael F; Liu, Yitong

2015-01-01

Acetylcholinesterase (AChE) is an enzyme responsible for metabolism of the neurotransmitter acetylcholine, and inhibition of AChE can have therapeutic applications (e.g., drugs for Alzheimer's disease) or neurotoxic consequences (e.g., pesticides). A common absorbance-based AChE activity assay that uses 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) can have limited sensitivity and be prone to interference. Therefore, an alternative assay was developed, in which AChE activity was determined by measuring fluorescence of resorufin produced from coupled enzyme reactions involving acetylcholine and Amplex Red (10-acetyl-3,7-dihydroxyphenoxazine). The Amplex Red assay was used for two separate applications. First, AChE activity was measured in rat whole blood, which is a biomarker for exposure to AChE inhibitor pesticides. Activity was quantified from a 10(5)-fold dilution of whole blood, and there was a linear correlation between Amplex Red and DTNB assays. For the second application, Amplex Red assay was used to measure AChE inhibition potency in a human neuroblastoma cell line (SH-SY5Y), which is important for assessing pharmacological and toxicological potential of AChE inhibitors including drugs, phytochemicals, and pesticides. Five known reversible inhibitors were evaluated (IC50, 7-225 nM), along with irreversible inhibitors chlorpyrifos-oxon (ki=1.01 nM(-1)h(-1)) and paraoxon (ki=0.16 nM(-1)h(-1)). Lastly, in addition to inhibition, AChE reactivation was measured in SH-SY5Y cells incubated with pralidoxime chloride (2-PAM). The Amplex Red assay is a sensitive, specific, and reliable fluorescence method for measuring AChE activity in both rat whole blood and cultured SH-SY5Y cells. Published by Elsevier Inc.

Measuring the Enzyme Activity of Arabidopsis Deubiquitylating Enzymes.

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Kalinowska, Kamila; Nagel, Marie-Kristin; Isono, Erika

2016-01-01

Deubiquitylating enzymes, or DUBs, are important regulators of ubiquitin homeostasis and substrate stability, though the molecular mechanisms of most of the DUBs in plants are not yet understood. As different ubiquitin chain types are implicated in different biological pathways, it is important to analyze the enzyme characteristic for studying a DUB. Quantitative analysis of DUB activity is also important to determine enzyme kinetics and the influence of DUB binding proteins on the enzyme activity. Here, we show methods to analyze DUB activity using immunodetection, Coomassie Brilliant Blue staining, and fluorescence measurement that can be useful for understanding the basic characteristic of DUBs.

Evaluation of antioxidant potential, enzyme inhibition activity and phenolic profile of Lathyrus cicera and Lathyrus digitatus: Potential sources of bioactive compounds for the food industry.

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Llorent-Martínez, E J; Ortega-Barrales, P; Zengin, G; Mocan, A; Simirgiotis, M J; Ceylan, R; Uysal, S; Aktumsek, A

2017-09-01

The genus Lathyrus has great importance in terms of food and agricultural areas. In this study, the in vitro antioxidant activity (phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC and metal chelating) and enzyme inhibitory activity evaluation (acetylcholinesterase, butyrylcholinesterase, α-amylase and α-glucosidase) of L. cicera and L. digitatus were investigated, as well as their phytochemical profiles. The screening of the main phytochemical compounds in aerial parts of L. cicera and L. digitatus was carried out by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MS n ), observing that flavonoids represent the highest percentage of identified compounds, with abundance of tri- and tetra-glycosilated flavonoids, including acylated ones, especially in L. cicera. Generally, L. digitatus exhibited stronger antioxidant and enzyme inhibitory activities in correlation with its higher level of phenolics. The high number of phenolic compounds and the results of the antioxidant and enzyme assays suggest that these plants may be further used as sources of bioactive compounds, and for the preparation of new nutraceuticals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Endosulfan induces changes in spontaneous swimming activity and acetylcholinesterase activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

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Ballesteros, M.L.; Durando, P.E.; Nores, M.L.; Diaz, M.P.; Bistoni, M.A.; Wunderlin, D.A.

2009-01-01

We assessed changes in spontaneous swimming activity and acetylcholinesterase (AchE) activity of Jenynsia multidentata exposed to Endosulfan (EDS). Females of J. multidentata were exposed to 0.072 and 1.4 μg L -1 EDS. Average speed and movement percentage were recorded during 48 h. We also exposed females to EDS at five concentrations between 0.072 and 1.4 μg L -1 during 24 h, and measured the AchE activity in brain and muscle. At 0.072 μg L -1 EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 μg L -1 EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 μg L -1 , while no significant changes were observed in brain. Thus, changes in swimming activity and AchE activity in muscle are good biomarkers of exposure to EDS in J. multidentata. - This work reports changes observed in spontaneous swimming activity and AchE activity of Jenynsia multidentata exposed to sublethal concentrations of Endosulfan.

Endosulfan induces changes in spontaneous swimming activity and acetylcholinesterase activity of Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

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Ballesteros, M.L. [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Durando, P.E. [Facultad de Ciencias Exactas, Fisicas y Naturales, Departamento de Biologia, Catedra de Fisiologia Animal, Universidad Nacional de San Juan, Complejo ' Islas Malvinas' , Av. Jose I. de la Roza y Meglioli, Rivadavia, San Juan (Argentina); Nores, M.L. [Facultad de Ciencias Medicas, Universidad Nacional de Cordoba-CONICET, Ciudad Universitaria, Cordoba (Argentina); Diaz, M.P. [Facultad de Ciencias Medicas, Catedra de Estadistica y Bioestadistica, Escuela de Nutricion, Universidad Nacional de Cordoba, Pabellon Chile, Ciudad Universitaria, 5000 Cordoba (Argentina); Bistoni, M.A., E-mail: mbistoni@com.uncor.ed [Facultad de Ciencias Exactas, Fisicas y Naturales, Catedra Diversidad Animal II, Universidad Nacional de Cordoba, Av. Velez Sarsfield 299, 5000 Cordoba (Argentina); Wunderlin, D.A. [Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica-CIBICI, Universidad Nacional de Cordoba-CONICET, Haya de la Torre esq. Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

2009-05-15

We assessed changes in spontaneous swimming activity and acetylcholinesterase (AchE) activity of Jenynsia multidentata exposed to Endosulfan (EDS). Females of J. multidentata were exposed to 0.072 and 1.4 mug L{sup -1} EDS. Average speed and movement percentage were recorded during 48 h. We also exposed females to EDS at five concentrations between 0.072 and 1.4 mug L{sup -1} during 24 h, and measured the AchE activity in brain and muscle. At 0.072 mug L{sup -1} EDS swimming motility decreased relative to the control group after 45 h, while at 1.4 mug L{sup -1} EDS swimming motility decreased after 24 h. AchE activity significantly decreased in muscle when J. multidentata were exposed to EDS above 0.072 mug L{sup -1}, while no significant changes were observed in brain. Thus, changes in swimming activity and AchE activity in muscle are good biomarkers of exposure to EDS in J. multidentata. - This work reports changes observed in spontaneous swimming activity and AchE activity of Jenynsia multidentata exposed to sublethal concentrations of Endosulfan.

Phytochemical Quantification and the In Vitro Acetylcholinesterase Inhibitory Activity of Phellodendron chinense and Its Components.

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Kim, Yu Jin; Lim, Hye-Sun; Kim, Yoonju; Lee, Jun; Kim, Bu-Yeo; Jeong, Soo-Jin

2017-06-02

The dried bark of Phellodendron chinense has been used as a traditional herbal medicine to remove damp heat, relieve consumptive fever, and cure dysentery and diarrhea. In the present study, we performed quantitative analyses of the two components of P. chinense , phellodendrine and berberine, using high-performance liquid chromatography. A 70% ethanol extract of P. chinense was prepared and the two components were separated on a C-18 analytical column using a gradient solvent system of acetonitrile and 0.1% ( v / v ) aqueous trifluoroacetic acid. The ultraviolet wavelength used for detection was 200 nm for phellodendrine and 226 nm for berberine. The analytical method established here showed high linearity (correlation coefficient, ≥0.9991). The amount of phellodendrine and berberine used was 22.255 ± 0.123 mg/g and 269.651 ± 1.257 mg/g, respectively. Moreover, we performed an in vitro acetylcholinesterase (AChE) activity assay and an amyloid-β aggregation test to examine the biological properties of phellodendrine and berberine as therapeutic drugs for Alzheimer's disease. Phellodendrine and berberine inhibited AChE activity in a dose-dependent manner (IC 50 = 36.51 and 0.44 μM, respectively). In contrast, neither phellodendrine nor berberine had an effect on amyloid-β aggregation. The P. chinense extract and phellodendrine, but not berberine, exhibited antioxidant activity by increasing radical scavenging activity. Moreover, P. chinense demonstrated a neuroprotective effect in hydrogen peroxide-treated HT22 hippocampal cells. Overall, our findings suggest that P. chinense has potential as an anti-Alzheimer's agent via the suppression of the enzymatic activity of acetylcholinesterase and the stimulation of antioxidant activity.

Activity changes of antioxidant and detoxifying enzymes in Tenebrio molitor (Coleoptera: Tenebrionidae) larvae infected by the entomopathogenic nematode Heterorhabditis beicherriana (Rhabditida: Heterorhabditidae).

Science.gov (United States)

Li, Xingyue; Liu, Qizhi; Lewis, Edwin E; Tarasco, Eustachio

2016-12-01

Entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis are lethal parasites of many insect species. To investigate defensive mechanisms towards EPNs in relation to antioxidative and detoxifying enzymes, we chose Tenebrio molitor (Coleoptera: Tenebrionidae) as experimental insect. We studied the activity changes of superoxide dismutases (SODs), peroxidases (PODs), and catalases (CATs), as well as tyrosinase (TYR), acetylcholinesterase (AChE), carboxylesterase (CarE), and glutathione S-transferase (GSTs) for 40 h in T. molitor larvae infected with Heterorhabditis beicherriana infective juveniles (IJs) at 5 rates (0, 20, 40, 80, and 160 IJs/larva). We found that when T. molitor larvae infected with H. beicherriana at higher rates (80 and 160 IJs/larva), SOD activity quickly increased to more than 70 % higher than that control levels. The activities of POD and CAT increased after 24 h. TYR activity increased slowly at lower rates of infection for 16 h, followed by a slight decrease, and then increasing from 32 to 40 h. The other detoxifying enzymes (GST, CarE, and AChE) were enhanced at lower infection rates, but were inhibited at higher rates. Our results suggested that host antioxidative response and detoxification reactions played a central role in the defensive reaction to EPNs, and that this stress which was reflected by the higher level enzymes activity contributed to the death of hosts. Further study should explore the exact function of these enzymes using different species of EPNs and investigate the links between enzyme activity and host susceptibility to EPNs.

Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry.

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Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

2018-01-01

At present, approximately 17-25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro . The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF-LC-ESI-MS/MS): ultrafiltration-liquid chromatography-electrospray ionization tandem mass spectrometry; (ACh

Rapid Screening and Characterization of Acetylcholinesterase Inhibitors from Yinhuang Oral Liquid Using Ultrafiltration-liquid Chromatography-electrospray Ionization Tandem Mass Spectrometry

Science.gov (United States)

Zhang, Haomin; Guo, Yinan; Meng, Lingwen; Sun, Hui; Yang, Yinping; Gao, Ying; Sun, Jiaming

2018-01-01

Background: At present, approximately 17–25 million people in the world suffer from Alzheimer's disease (AD). The most efficacious and acceptable therapeutic drug clinically are the acetylcholinesterase inhibitors (AChEIs). Yinhuang oral liquid is a Chinese medicine preparation which contains AChEIs according to the literatures. However, no strategy has been presented for rapid screening and identification of AChEIs from Yinhuang oral liquid. Objective: To develop a method for rapid screening and identification of AChEIs from Yinhuang oral liquid using ultrafiltration–liquid chromatography–electrospray ionization tandem mass spectrometry (UF-LC-ESI-MS/MS). Materials and Methods: In this study, UF incubation conditions such as enzyme concentration, incubation time, and incubation temperature were optimized so as to get better screening results. The AChEIs from Yinhuang oral liquid were identified by high-performance liquid chromatography-ESI-MS and the improved Ellman method was used for the AChE inhibitory activity test in vitro. Results: The results showed that Yinhuang oral liquid can inhibit the activity of AChE. We screened and identified seven compounds with potential AChE inhibitory activity from Yinhuang oral liquid, which provided experimental basis for the treatment and prevention of AD. Conclusion: The current technique was used to directly screen the active ingredients with acetylcholinesterase inhibition from complex traditional Chinese medicine, which was simple, rapid, accurate, and suitable for high-throughput screening of AChEI from complex systems. SUMMARY A UF-LC-ESI-MS/MS method for rapid screening and identification of AChEIs from Yinhuang oral liquid was developedSeven compounds were screened and identified with potential AChE inhibitory activity from Yinhuang oral liquidIt provided experimental basis of Yinhuang oral liquid for the treating and preventing AD. Abbreviations used: (AD): Alzheimer's disease; (UF

Acetylcholinesterase inhibition by somes promising Brazilian medicinal plants.

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Feitosa, C M; Freitas, R M; Luz, N N N; Bezerra, M Z B; Trevisan, M T S

2011-08-01

A microplate assay and a thin-layer chromatography (TLC) "in situ" assay based on the Ellman assay was used to screen for acetylcholinesterase inhibitors from ethyl acetate and methanol extracts of Brazilian medicinal plants of families that, according to the literature, have traditional uses that might be connected with acetylcholinesterase inhibition. Eighteen species belonging to Convolvulaceae, Crassulaceae, Euphorbiaceae, Leguminosae, Malvaceae, Moraceae, Nyctaginaceae and Rutaceae families were tested. The most active plants were Ipomoea asarifolia (IC50 = 0.12 mg/mL), Jatropha curcas (IC50 = 0.25 mg/mL), Jatropha gossypiifolia (IC50 = 0.05 mg/mL), Kalanchoe brasiliensis (IC50 = 0.16 mg/mL) and Senna alata (IC50 = 0.08 mg/mL). The most promising extracts were the Jatropha gossypiifolia and Senna alata species assuming there were compounds with a similar activity to galanthamine, which should contain about 1% of an active compound, or if present at lower levels even more active compounds than galanthamine (IC50 = 0.37 x 10-3 mg/mL) should be present.

Acetylcholinesterase inhibition by somes promising Brazilian medicinal plants

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CM. Feitosa

Full Text Available A microplate assay and a thin-layer chromatography (TLC "in situ" assay based on the Ellman assay was used to screen for acetylcholinesterase inhibitors from ethyl acetate and methanol extracts of Brazilian medicinal plants of families that, according to the literature, have traditional uses that might be connected with acetylcholinesterase inhibition. Eighteen species belonging to Convolvulaceae, Crassulaceae, Euphorbiaceae, Leguminosae, Malvaceae, Moraceae, Nyctaginaceae and Rutaceae families were tested. The most active plants were Ipomoea asarifolia (IC50 = 0.12 mg/mL, Jatropha curcas (IC50 = 0.25 mg/mL, Jatropha gossypiifolia (IC50 = 0.05 mg/mL, Kalanchoe brasiliensis (IC50 = 0.16 mg/mL and Senna alata (IC50 = 0.08 mg/mL. The most promising extracts were the Jatropha gossypiifolia and Senna alata species assuming there were compounds with a similar activity to galanthamine, which should contain about 1% of an active compound, or if present at lower levels even more active compounds than galanthamine (IC50 = 0.37 x 10-3 mg/mL should be present.

Bioactive properties of commercialised pomegranate (Punica granatum) juice: antioxidant, antiproliferative and enzyme inhibiting activities.

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Les, Francisco; Prieto, Jose M; Arbonés-Mainar, Jose Miguel; Valero, Marta Sofía; López, Víctor

2015-06-01

Pomegranate juice and related products have long been used either in traditional medicine or as nutritional supplements claiming beneficial effects. Although there are several studies on this food plant, only a few studies have been performed with pomegranate juice or marketed products. The aim of this work is to evaluate the antioxidant effects of pomegranate juice on cellular models using hydrogen peroxide as an oxidizing agent or DPPH and superoxide radicals in cell free systems. The antiproliferative effects of the juice were measured on HeLa and PC-3 cells by the MTT assay and pharmacologically relevant enzymes (cyclooxygenases, xanthine oxidase, acetylcholinesterase and monoamine oxidase A) were selected for enzymatic inhibition assays. Pomegranate juice showed significant protective effects against hydrogen peroxide induced toxicity in the Artemia salina and HepG2 models; these effects may be attributed to radical scavenging properties of pomegranate as the juice was able to reduce DPPH and superoxide radicals. Moderate antiproliferative activities in HeLa and PC-3 cancer cells were observed. However, pomegranate juice was also able to inhibit COX-2 and MAO-A enzymes. This study reveals some mechanisms by which pomegranate juice may have interesting and beneficial effects in human health.

Changes in acetylcholinesterase, Na+,K+-ATPase, and Mg2+-ATPase activities in the frontal cortex and the hippocampus of hyper- and hypothyroid adult rats.

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Carageorgiou, Haris; Pantos, Constantinos; Zarros, Apostolos; Stolakis, Vasileios; Mourouzis, Iordanis; Cokkinos, Dennis; Tsakiris, Stylianos

2007-08-01

The thyroid hormones (THs) are crucial determinants of normal development and metabolism, especially in the central nervous system. The metabolic rate is known to increase in hyperthyroidism and decrease in hypothyroidism. The aim of this work was to investigate how changes in metabolism induced by THs could affect the activities of acetylcholinesterase (AChE), (Na+,K+)- and Mg2+-adenosinetriphosphatase (ATPase) in the frontal cortex and the hippocampus of adult rats. Hyperthyroidism was induced by subcutaneous administration of thyroxine (25 microg/100 g body weight) once daily for 14 days, and hypothyroidism was induced by oral administration of propylthiouracil (0.05%) for 21 days. All enzyme activities were evaluated spectrophotometrically in the homogenated brain regions of 10 three-animal pools. A region-specific behavior was observed concerning the examined enzyme activities in hyper- and hypothyroidism. In hyperthyroidism, AChE activity was significantly increased only in the hippocampus (+22%), whereas Na+,K+-ATPase activity was significantly decreased in the hyperthyroid rat hippocampus (-47%) and remained unchanged in the frontal cortex. In hypothyroidism, AChE activity was significantly decreased in the frontal cortex (-23%) and increased in the hippocampus (+21%). Na+,K+-ATPase activity was significantly decreased in both the frontal cortex (-35%) and the hippocampus (-43%) of hypothyroid rats. Mg2+-ATPase remained unchanged in the regions of both hyper- and hypothyroid rat brains. Our data revealed that THs affect the examined adult rat brain parameters in a region- and state-specific way. The TH-reduced Na+,K+-ATPase activity may increase the synaptic acetylcholine release and, thus, modulate AChE activity. Moreover, the above TH-induced changes may affect the monoamine neurotransmitter systems in the examined brain regions.

Buprofezin inhibits acetylcholinesterase activity in B-biotype Bemisia tabaci.

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Cottage, Emma L A; Gunning, Robin V

2006-01-01

B-biotype Bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and horticultural industries. Control of this insect is hampered by resistance to many acetylcholinesterase (AChE)-inhibiting insecticides, such as organophosphates and carbamates. Consequently, insect growth regulators such as buprofezin, which act by inhibiting chitin synthesis, are being investigated for use against B-biotype B. tabaci in Australia. This study discusses the effects of buprofezin on B. tabaciAChE.

Acetylcholinesterase inhibition-based biosensor for aluminum(III) chronoamperometric determination in aqueous media.

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Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

2014-05-07

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water . The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.

New Cinchona Oximes Evaluated as Reactivators of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Organophosphorus Compounds

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Maja Katalinić

2017-07-01

Full Text Available For the last six decades, researchers have been focused on finding efficient reactivators of organophosphorus compound (OP-inhibited acetylcholinesterase (AChE and butyrylcholinesterase (BChE. In this study, we have focused our research on a new oxime scaffold based on the Cinchona structure since it was proven to fit the cholinesterases active site and reversibly inhibit their activity. Three Cinchona oximes (C1, C2, and C3, derivatives of the 9-oxocinchonidine, were synthesized and investigated in reactivation of various OP-inhibited AChE and BChE. As the results showed, the tested oximes were more efficient in the reactivation of BChE and they reactivated enzyme activity to up to 70% with reactivation rates similar to known pyridinium oximes used as antidotes in medical practice today. Furthermore, the oximes showed selectivity towards binding to the BChE active site and the determined enzyme-oxime dissociation constants supported work on the future development of inhibitors in other targeted studies (e.g., in treatment of neurodegenerative disease. Also, we monitored the cytotoxic effect of Cinchona oximes on two cell lines Hep G2 and SH-SY5Y to determine the possible limits for in vivo application. The cytotoxicity results support future studies of these compounds as long as their biological activity is targeted in the lower micromolar range.

Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel.

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Bourne, Yves; Renault, Ludovic; Marchot, Pascale

2015-01-16

The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Selective radiolabeling and isolation of the hydrophobic membrane-binding domain of human erythrocyte acetylcholinesterase

International Nuclear Information System (INIS)

Roberts, W.L.; Rosenberry, T.L.

1986-01-01

The hydrophobic, membrane-binding domain of purified human erythrocyte acetylcholinesterase was labeled with the photoactivated reagent 3-(trifluoromethyl)-3-(m-[ 125 I]iodophenyl)diazirine. The radiolabel was incorporated when the enzyme was prepared in detergent-free aggregates, in detergent micelles, or in phospholipid liposomes, but the highest percentage of labeling occurred in the detergent-free aggregates. Papain digestion of the enzyme released the hydrophobic domain, and polyacrylamide gel electrophoresis in sodium dodecyl sulfate or gel exclusion chromatography demonstrated that the label was localized exclusively in the cleaved hydrophobic domain fragment. This fragment was purified in a three-step procedure. Digestion was conducted with papain attached to Sepharose CL-4B, and the supernatant was adsorbed to acridinium affinity resin to remove the hydrophilic enzyme fragment. The nonretained fragment associated with Triton X-100 micelles was then chromatographed on Sepharose CL-6B, and finally detergent was removed by chromatography on Sephadex LH-60 in an ethanol-formic acid solvent. The fragment exhibited an apparent molecular weight of 3100 on the Sephadex LH-60 column when compared with peptide standards. However, amino acid analysis of the purified fragment revealed only 1 mol each of histidine and glycine per mole of fragment in contrast to the 25-30 mole of amino acids expected on the basis of the molecular weight estimate. This result suggests a novel non-amino acid structure for the hydrophobic domain of human erythrocyte acetylcholinesterase

Screening for acetylcholinesterase inhibitory activity in cyanobacteria of the genus Nostoc

Czech Academy of Sciences Publication Activity Database

Zelík, Petr; Lukešová, Alena; Voloshko, L. N.; Štys, D.; Kopecký, Jiří

2009-01-01

Roč. 24, č. 2 (2009), s. 531-536 ISSN 1475-6366 R&D Projects: GA MŠk ME 874 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60660521 Keywords : acetylcholinesterase * bioactivity * inhibitors Subject RIV: EE - Microbiology, Virology Impact factor: 1.496, year: 2009

Phytochemical profiles, antioxidant and anti-acetylcholinesterasic activities of the leaf extracts of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire in different solvents.

Science.gov (United States)

Benamar, Houari; Rarivoson, Elonge; Tomassini, Lamberto; Frezza, Claudio; Marouf, Abderrazak; Bennaceur, Malika; Nicoletti, Marcello

2018-01-05

In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds.

A direct method to visualise the aryl acylamidase activity on cholinesterases in polyacrylamide gels

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Boopathy Rathanam

2000-12-01

Full Text Available Abstract Background In vertebrates, two types of cholinesterases exist, acetylcholinesterase and butyrylcholinesterase. The function of acetylcholinesterase is to hydrolyse acetylcholine, thereby terminating the neurotransmission at cholinergic synapse, while the precise physiological function of butyrylcholinesterase has not been identified. The presence of cholinesterases in tissues that are not cholinergically innervated indicate that cholinesterases may have functions unrelated to neurotransmission. Furthermore, cholinesterases display a genuine aryl acylamidase activity apart from their predominant acylcholine hydrolase activity. The physiological significance of this aryl acylamidase activity is also not known. The study on the aryl acylamidase has been, in part hampered by the lack of a specific method to visualise this activity. We have developed a method to visualise the aryl acylamidase activity on cholinesterase in polyacrylamide gels. Results The o-nitroaniline liberated from o-nitroacetanilide by the action of aryl acylamidase activity on cholinesterases, in the presence of nitrous acid formed a diazonium compound. This compound gave an azo dye complex with N-(1-napthyl-ethylenediamine, which appeared as purple bands in polyacrylamide gels. Treating the stained gels with trichloroacetic acid followed by Tris-HCl buffer helped in fixation of the stain in the gels. By using specific inhibitors for acetylcholinesterase and butyrylcholinesterase, respectively, differential staining for the aryl acylamidase activities on butyrylcholinesterase and acetylcholinesterase in a sample containing both these enzymes has been demonstrated. A linear relationship between the intensity of colour developed and activity of the enzyme was obtained. Conclusions A novel method to visualise the aryl acylamidase activity on cholinesterases in polyacrylamide gels has been developed.

Effects of experimentally-induced maternal hypothyroidism on crucial offspring rat brain enzyme activities.

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Koromilas, Christos; Liapi, Charis; Zarros, Apostolos; Stolakis, Vasileios; Tsagianni, Anastasia; Skandali, Nikolina; Al-Humadi, Hussam; Tsakiris, Stylianos

2014-06-01

Hypothyroidism is known to exert significant structural and functional changes to the developing central nervous system, and can lead to the establishment of serious mental retardation and neurological problems. The aim of the present study was to shed more light on the effects of gestational and/or lactational maternal exposure to propylthiouracil-induced experimental hypothyroidism on crucial brain enzyme activities of Wistar rat offspring, at two time-points of their lives: at birth (day-1) and at 21 days of age (end of lactation). Under all studied experimental conditions, offspring brain acetylcholinesterase (AChE) activity was found to be significantly decreased due to maternal hypothyroidism, in contrast to the two studied adenosinetriphosphatase (Na(+),K(+)-ATPase and Mg(2+)-ATPase) activities that were only found to be significantly altered right after birth (increased and decreased, respectively, following an exposure to gestational maternal hypothyroidism) and were restored to control levels by the end of lactation. As our findings regarding the pattern of effects that maternal hypothyroidism has on the above-mentioned crucial offspring brain enzyme activities are compared to those reported in the literature, several differences are revealed that could be attributed to both the mode of the experimental simulation approach followed as well as to the time-frames examined. These findings could provide the basis for a debate on the need of a more consistent experimental approach to hypothyroidism during neurodevelopment as well as for a further evaluation of the herein presented and discussed neurochemical (and, ultimately, neurodevelopmental) effects of experimentally-induced maternal hypothyroidism, in a brain region-specific manner. Copyright © 2014 ISDN. Published by Elsevier Ltd. All rights reserved.

The human amygdaloid complex: a cytologic and histochemical atlas using Nissl, myelin, acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase staining.

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Sims, K S; Williams, R S

1990-01-01

We examined the distribution of acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase enzyme activity in the human amygdala using histochemical techniques. Both methods revealed compartments of higher or lower enzyme activity, in cells or neuropil, which corresponded to the nuclear subdivisions of the amygdala as defined with classical Nissl and myelin methods. The boundaries between the histochemical compartments were usually so sharp that the identification of these nuclear subdivisions was enhanced. There was also variation of staining intensity within many of the nuclear subdivisions, such as the lateral and central nuclei, anterior amygdaloid area and the intercalated groups. This histochemical difference corresponded to more subtle differences in Nissl and myelin staining patterns, and suggests further structural subdivisions of potential functional significance. We present a revised scheme of anatomical parcellation of the human amygdala based upon serial analysis with all four techniques. Our expectation is that this will allow the delineation of a clearer homology between the cytoarchitectonic subdivisions of the human amygdala and those of experimental animals.

Synthesis, enzyme inhibitory kinetics mechanism and computational study of N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides as novel therapeutic agents for Alzheimer’s disease

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Muhammad Athar Abbasi

2018-06-01

Full Text Available The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1. The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2 in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl-4-methylbenzensulfonamide (3.This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a–j, using N,N-dimethylformamide (DMF as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides (5a–j. The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl-4-methyl-N-(2-propylbenzensulfonamide (5c showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM.The docking studies of synthesized ligands 5a–j were also carried out against acetylcholinesterase (PDBID 4PQE to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.

Acetylcholinesterase inhibition and antioxidant activity of essential oils from Schinus areira L. and Schinus longifolia (Lindl.) Speg.

Science.gov (United States)

Murray, Ana P; Gurovic, Maria S Vela; Rodriguez, Silvana A; Murray, María G; Ferrero, Adriana A

2009-06-01

The essential oils of Schinus areira L. and S. longifolia (Lindl.) Speg. (Anacardiaceae) have been studied for their in vitro anti-acetylcholinesterase and antioxidant activities. The chemical composition of the oils obtained by hydrodistillation was determined by GC-MS. Fruit and leaf oils of S. areira were analyzed separately. The essential oil from S. longifolia elicited marked enzymatic inhibition (IC50 = 20.0 +/- 1.0 microg/mL) and showed radical scavenger activity (IC50 = 25.2 +/- 2.4 microg/mL). The essential oil from S. areira leaves was more active than that of the fruits in both bioassays.

Antimicrobial and acetylcholinesterase inhibitory activities of Buddleja salviifolia (L.) Lam. leaf extracts and isolated compounds.

Science.gov (United States)

Pendota, S C; Aderogba, M A; Ndhlala, A R; Van Staden, J

2013-07-09

Buddleja salviifolia leaves are used for the treatment of eye infections and neurodegenerative conditions by various tribes in South Africa. This study was designed to isolate the phenolic constituents from the leaf extracts of Buddleja salviifolia and evaluate their antimicrobial and acetylcholinesterase (AChE) activities. Three phenolic compounds were isolated from the ethyl acetate fraction of a 20% aqueous methanol leaf extract of Buddleja salviifolia using Sephadex LH-20 and silica gel columns. Structure elucidation of the isolated compounds was carried out using spectroscopic techniques: mass spectrometry (ESI-TOF-MS) and NMR (1D and 2D). The extracts and isolated compounds were evaluated for antimicrobial and acetylcholinesterase activities using the microdilution technique. The bacteria used for the antimicrobial assays were Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli and Klebsiella pneumoniae. The isolated compounds were characterized as: 4'-hydroxyphenyl ethyl vanillate (1) a new natural product, acteoside (2) and quercetin (3). The crude extract, fractions and the isolated compounds from the leaves of the plant exhibited a broad spectrum of antibacterial activity. The EtOAc fraction exhibited good activity against Bacillus subtilis and Staphylococcus aureus with MIC values ranging from 780.0 to 390.0 µg/mL. Isolated compound 2 exhibited good activity against Staphylococcus aureus with an MIC value of 62.5 µg/mL. The hexane and DCM fractions of leaves showed the best activity against Candida albicans with MIC and MFC values of 390.0 µg/mL. In the AChE inhibitory test, among the tested extracts, the hexane fraction was the most potent with an IC50 value of 107.4 µg/mL, whereas for the isolated compounds, it was compound (3) (quercetin) with an IC50 value of 66.8 µg/mL. Activities demonstrated by the extracts and isolated compounds support the ethnopharmacological use of Buddleja salviifolia against eye

Screening of acetylcholinesterase inhibitors in marine organisms from the Caribbean Sea.

Science.gov (United States)

Castellanos, Fabio; Amaya-García, Fabián; Tello, Edisson; Ramos, Freddy Alejandro; Umaña, Adriana; Puyana, Mónica; Resende, Jackson A L C; Castellanos, Leonardo

2018-06-04

The acetylcholinesterase inhibitory activity of 89 organic extracts from marine organisms was evaluated through a TLC bioautography methodology. Extracts from soft corals (Eunicea and Plexaura) were the most active compared with extracts from sponges. The bioguided chemical study of the most active extract, obtained from Pseudoplexaura porosa, led to the isolation of a diterpene with spectroscopic properties consistent to those published to the cembrane Steylolide. However, further analysis by X-ray diffraction indicated that the compound was the 14-acetoxycrassine (1), correcting the structure reported to the Styelolide. Additionally, the acetylcholinesterase inhibitory activity of fourteen cembranoids (2-15) isolated from soft corals Eunicea knighti and Pseudoplexaura flagellosa was evaluated. Cembranoids 2, 3 and 4 were the most active compounds in the TLC bioassay. Then, the most promising cembranoids, 14-acetoxycrassine (1) and asperdiol (2), were tested quantitatively and they exhibited IC 50 values of 1.40 ± 0.113 and 0.358 ± 0.130 μM, respectively.

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

Science.gov (United States)

Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

2017-08-30

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

In Vitro Antioxidant Properties, HIV-1 Reverse Transcriptase and Acetylcholinesterase Inhibitory Effects of Traditional Herbal Preparations Sold in South Africa

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Johannes Van Staden

2010-10-01

Full Text Available The antioxidant potentials for fourteen multipurpose traditional herbal preparations sold in South Africa were determined using the DPPH radical scavenging, ferric reducing power and β-carotene-linoleic acid model system, the anti-HIV-1 reverse transcriptase (RT enzyme inhibitory effects using an ELISA kit and acetylcholinesterase (AChE enzyme inhibition using the microtitre plate assay. Nine of the herbal mixtures (Umzimba omubi, Umuthi wekukhwehlela ne zilonda, Mvusa ukunzi, Umpatisa inkosi, Imbiza ephuzwato, Vusa umzimba, Supreme one hundred, Sejeso herbal mixture Ingwe® and Ingwe® special muti exhibited higher antioxidant potentials, while only four (Imbiza ephuzwato, Ingwe® muthi mixture, Sejeso herbal mixture Ingwe® and African potato extractTM showed potent activity against the RT enzyme. Nine mixtures (Imbiza ephuzwato, Umpatisa inkosi, African potato extractTM, Sejeso herbal mixture Ingwe®, Vusa umzimba; Ingwe® muthi mixture, Ibhubezi™, Lion izifozonke Ingwe® and Ingwe® special muti showed AChE enzyme inhibitory activity greater than 50%. The observed activity exhibited by some of the herbal mixtures gives some credence to the manufacturers’ claims and goes part of the way towards validating their use against certain conditions such as oxidative stress, HIV/AIDS proliferation and some mental conditions. It is however, desirable to carry out further studies to determine the effects of mixing plant species/parts in one mixture on the antioxidant potency as well as isolating active constituents from the herbal mixtures.

Variation of Musca domestica L. acetylcholinesterase in Danish housefly populations

DEFF Research Database (Denmark)

Kristensen, Michael; Huang, Jing; Qiao, Chuan-Ling

2006-01-01

Anti-cholinesterase resistance is in many cases caused by modified acetylcholinesterase (MACE). A comparison was made of toxicological data and AChE activity gathered from 21 field populations and nine laboratory strains of houseflies, Musca domestica L., to elucidate the best way of generating...... data to provide advice for management strategies and gathering information for resistance risk assessment on the organophosphates azamethiphos and dimethoate and the carbamate methomyl, which have been the primary insecticides used against adult houseflies in Denmark. Cluster analysis was performed...... and > 2000 houseflies were assigned to one of three phenotypes based on total acetylcholinesterase activity as well as inhibition by azamethiphos, methomyl or omethoate. A cluster, i.e. a phenotype, with high total AChE activity and high sensitivity to azamethiphos and less sensitivity to inhibition...

Cyclovoltammetric acetylcholinesterase activity assay after inhibition and subsequent reactivation by using a glassy carbon electrode modified with palladium nanorods composited with functionalized C60 fullerene

International Nuclear Information System (INIS)

Ye, Cui; Zhong, Xia; Chai, Yaqin; Yuan, Ruo; Wang, Min-Qiang

2016-01-01

A glassy carbon electrode (GCE) was modified with a nanocomposite consisting of tetraoctylammonium bromide (TOAB), C 60 fullerene, and palladium nanorods (PdNRs). The PdNRs were hydrothermally prepared and had a typical width of 20 ± 2 nm. The nanocomposite forms stable films on the GCE and exhibits a reversible redox pair for the C 60 /C 60 − system while rendering the surface to be positively charged. The modified GCE was applied to fabricate an electrochemical biosensor for detecting acetylcholinesterase (AChE) by measurement of the amount of thiocholine formed from acetylthiocholine, best at a working voltage of −0.19 V (vs. SCE). The detection scheme is based on (a) measurement of the activity of ethyl paraoxon-inhibited AChE, and (b) measurement of AChE activity after reactivation with pralidoxime (2-PAM). Compared to the conventional methods using acetylthiocholine as a substrate, the dual method presented here provides data on the AChE activity after inhibition and subsequent reactivation, thereby yielding credible data on reactivated enzyme activity. The linear analytical range for AChE activity extends from 2.5 U L −1 to 250 kU·L −1 , and the detection limit is 0.83 U L −1 . (author)

A reversed-phase compatible thin-layer chromatography autography for the detection of acetylcholinesterase inhibitors.

Science.gov (United States)

Ramallo, I Ayelen; García, Paula; Furlan, Ricardo L E

2015-11-01

A dual readout autographic assay to detect acetylcholinesterase inhibitors present in complex matrices adsorbed on reversed-phase or normal-phase thin-layer chromatography plates is described. Enzyme gel entrapment with an amphiphilic copolymer was used for assay development. The effects of substrate and enzyme concentrations, pH, incubation time, and incubation temperature on the sensitivity and the detection limit of the assay were evaluated. Experimental design and response surface methodology were used to optimize conditions with a minimum number of experiments. The assay allowed the detection of 0.01% w/w of physostigmine in both a spiked Sonchus oleraceus L. extract chromatographed on normal phase and a spiked Pimenta racemosa (Mill.) J.W. Moore leaf essential oil chromatographed on reversed phase. Finally, the reversed-phase thin-layer chromatography assay was applied to reveal the presence of an inhibitor in the Cymbopogon citratus (DC.) Stapf essential oil. The developed assay is able to detect acetylcholinesterase inhibitors present in complex matrixes that were chromatographed in normal phase or reversed-phase thin-layer chromatography. The detection limit for physostigmine on both normal and reversed phase was of 1×10(-4) μg. The results can be read by a change in color and/or a change in fluorescence. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of Pinus species essential oils and their constituents.

Science.gov (United States)

Bonesi, Marco; Menichini, Federica; Tundis, Rosa; Loizzo, Monica R; Conforti, Filomena; Passalacqua, Nicodemo G; Statti, Giancarlo A; Menichini, Francesco

2010-10-01

This study aimed to investigate the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oils from Pinus nigra subsp. nigra, P. nigra var. calabrica, and P. heldreichii subsp. leucodermis. This activity is relevant to the treatment of Alzheimer's disease (AD), since cholinesterase drugs are currently the only drugs available to treat AD. P. heldreichii subsp. leucodermis exhibited the most promising activity, with IC(50) values of 51.1 and 80.6 microg/mL against AChE and BChE, respectively. An interesting activity against AChE was also observed with P. nigra subsp. nigra essential oil, with an IC(50) value of 94.4 microg/mL. Essential oils were analyzed by GC and GC-MS with the purpose of investigating their relationships with the observed activities. Among the identified constituents, terpinolene, beta-phellandrene, linalyl acetate, trans-caryophyllene, and terpinen-4-ol were tested. trans-Caryophyllene and terpinen-4-ol inhibited BChE with IC(50) values of 78.6 and 107.6 microg/mL, respectively. beta-Phellandrene was selective against AChE (IC(50) value of 120.2 microg/mL).

Acetylcholinesterase inhibitory activity of Thai traditional nootropic remedy and its herbal ingredients.

Science.gov (United States)

Tappayuthpijarn, Pimolvan; Itharat, Arunporn; Makchuchit, Sunita

2011-12-01

The incidence of Alzheimer disease (AD) is increasing every year in accordance with the increasing of elderly population and could pose significant health problems in the future. The use of medicinal plants as an alternative prevention or even for a possible treatment of the AD is, therefore, becoming an interesting research issue. Acetylcholinesterase (AChE) inhibitors are well-known drugs commonly used in the treatment of AD. The aim of the present study was to screen for AChE inhibitory activity of the Thai traditional nootropic recipe and its herbal ingredients. The results showed that ethanolic extracts of four out of twenty-five herbs i.e. Stephania pierrei Diels. Kaempfera parviflora Wall. ex Baker, Stephania venosa (Blume) Spreng, Piper nigrum L at 0.1 mg/mL showed % AChE inhibition of 89, 64, 59, 50; the IC50 were 6, 21, 29, 30 microg/mL respectively. The other herbs as well as combination of the whole recipe had no synergistic inhibitory effect on AChE activity. However some plants revealed antioxidant activity. More research should have be performed on this local wisdom remedy to verify the uses in scientific term.

An Unusual Dimeric Inhibitor of Acetylcholinesterase: Cooperative Binding of Crystal Violet

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Anders Allgardsson

2017-08-01

Full Text Available Acetylcholinesterase (AChE is an essential enzyme that terminates cholinergic transmission by a rapid hydrolysis of the neurotransmitter acetylcholine. AChE is an important target for treatment of various cholinergic deficiencies, including Alzheimer’s disease and myasthenia gravis. In a previous high throughput screening campaign, we identified the dye crystal violet (CV as an inhibitor of AChE. Herein, we show that CV displays a significant cooperativity for binding to AChE, and the molecular basis for this observation has been investigated by X-ray crystallography. Two monomers of CV bind to residues at the entrance of the active site gorge of the enzyme. Notably, the two CV molecules have extensive intermolecular contacts with each other and with AChE. Computational analyses show that the observed CV dimer is not stable in solution, suggesting the sequential binding of two monomers. Guided by the structural analysis, we designed a set of single site substitutions, and investigated their effect on the binding of CV. Only moderate effects on the binding and the cooperativity were observed, suggesting a robustness in the interaction between CV and AChE. Taken together, we propose that the dimeric cooperative binding is due to a rare combination of chemical and structural properties of both CV and the AChE molecule itself.

Enzyme Activities in Waste Water and Activated Sludge

DEFF Research Database (Denmark)

Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

1992-01-01

The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

In Search of an Effective in vivo Reactivator for Organophosphorus Nerve Agent-Inhibited Acetylcholinesterase in the Central Nervous System

Science.gov (United States)

2012-01-01

nerve agents, such as sarin (GB), cyclosarin (GF), and VX, are potent inhibitors of the enzyme cholinesterase (ChE). Their toxic effects are due to...three nerve agents. Keywords: acetylcholinesterase; brain; cholinesterase inhibition; cholinesterase reactivation; cyclosarin; diacetylmonoxime...attributed, at least in part, to nuclophilic impedance [Ekstrom et al., 2006a; b; Hoskovcova et al., 2007]. Other AChE- inhibitors , such as soman, become

Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates

International Nuclear Information System (INIS)

Schallreuter, Karin U.; University of Bradford; Elwary, Souna M.; Parkin, Susan M.; Wood, John M.

2007-01-01

The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 x 10 -3 M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. 45 Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H 2 O 2 -mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m 2 surface area with its calcium gradient in the 10 -3 M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue

Hydrogen peroxide modifies both activity and isoforms of acetylcholinesterase in human neuroblastoma SH-SY5Y cells

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Alba Garcimartín

2017-08-01

Full Text Available The involvement of cholinergic system and the reactive oxygen species (ROS in the pathogenesis of some degenerative diseases has been widely reported; however, the specific impact of hydrogen peroxide (H2O2 on the acetylcholinesterase (AChE activity as well as AChE isoform levels has not been clearly established. Hence, the purpose of present study is to clarify whether H2O2 alters these parameters.Human neuroblastoma SH-SY5Y cells were treated with H2O2 (1–1000 µM for 24 h and AChE activity and AChE and cytochrome c levels were evaluated. AChE activity was strongly increased from 1 µM to 1000 µM of H2O2. The results of the kinetic study showed that H2O2 affected Vmax but not Km; and also that H2O2 changed the sigmoid kinetic observed in control samples to hyperbolic kinetic. Thus, results suggest that H2O2 acts as an allosteric activators. In addition, H2O2, (100–1000 µM reduced the total AChE content and modified its isoform profile (mainly 50-, 70-, and 132-kDa·H2O2 from 100 µM to 1000 µM induced cytochrome c release confirming cell death by apoptosis. All these results together suggest: a the involvement of oxidative stress in the imbalance of AChE; and b treatment with antioxidant agents may be a suitable strategy to protect cholinergic system alterations promoted by oxidative stress. Keywords: Acetylcholinesterase, Hydrogen peroxide, Alternative splicing, Cell culture, Cell death

Acetylcholinesterase inhibitory, antioxidant, and antimicrobial activities of Salvia tomentosa Mill. essential oil

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ANDREY MARCHEV

2015-08-01

Full Text Available Chemical composition and bioactivity of essential oil from Salvia tomentosa Mill. natively grown in Bulgaria were investigated. GC-MS analysis identified 60 compounds which represented 98% of the oil constituents. The prevalent constituents were monoterpenes with eight dominant compounds being identified: borneol (10.3%, β-pinene (9%, camphor (7.9%, α-pinene (6%, camphene (4%, 1.8-cineole (3.8%, α-limonene (3.5% and β-caryophyllene (3%. The essential oil showed considerable acetylcholinesterase inhibitory activity (IC50=0.28±0.06 µg/mL, comparable with that of galanthamine. Study of antioxidant activity strongly suggested that the hydrogen atom transfer reaction was preferable over the electron transfer (ORAC=175.0±0.40 µM Trolox equivalents/g oil and FRAP=1.45±0.21 mM Trolox equivalents/g oil. The essential oil showed moderate antifungal and antibacterial activities against Candida albicans and Gram-positive bacteria, whereas it was almost inactive against the investigated Gram-negative strains. The results suggested that the essential oil of Bulgarian S. tomentosa could be considered as a prospective active ingredient for prevention of oxidative stress-related and neurodegenerative disorders in aromatherapy. Because of the high antioxidant capacity, the oil could be considered as natural supplement or antioxidant in cosmetics and food products.

Guarana (Paullinia cupana) ameliorates memory impairment and modulates acetylcholinesterase activity in Poloxamer-407-induced hyperlipidemia in rat brain.

Science.gov (United States)

Ruchel, Jader B; Braun, Josiane B S; Adefegha, Stephen A; Guedes Manzoni, Alessandra; Abdalla, Fátima H; de Oliveira, Juliana S; Trelles, Kelly; Signor, Cristiane; Lopes, Sônia T A; da Silva, Cássia B; Castilhos, Lívia G; Rubin, Maribel A; Leal, Daniela B R

2017-01-01

Hyperlipidemia is a risk factor for the development of cognitive dysfunction and atherosclerosis. Natural compounds have recently received special attention in relation to the treatment of disease due to their low cost and wide margin of safety. Thus, the aim of this study was to determine the possible preventive effect of guarana powder (Paullinia cupana) on memory impairment and acetylcholinesterase (AChE) activity in the brain structures of rats with Poloxamer-407-induced hyperlipidemia. Adult male Wistar rats were pretreated with guarana (12.5, 25 and 50mg/kg/day) and caffeine (0.2mg/kg/day) by gavage for a period of 30days. Simvastatin (0.04mg/kg) was administered as a comparative standard. Acute hyperlipidemia was induced with intraperitoneal injections of 500mg/kg of Poloxamer-407. Memory tests and evaluations of anxiety were performed. The cortex, cerebellum, hippocampus, hypothalamus and striatum were separated to assess acetylcholinesterase activity. Our results revealed that guarana powder was able to reduce the levels of TC and LDL-C in a manner similar to simvastatin. Guarana powder also partially reduced the liver damage caused by hyperlipidemia. Guarana was able to prevent changes in the activity of AChE and improve memory impairment due to hyperlipidemia. Guarana powder may therefore be a source of promising phytochemicals that can be used as adjuvant therapy in the management of hyperlipidemia and cognitive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Rosuvastatin ameliorates cognitive impairment in rats fed with high-salt and cholesterol diet via inhibiting acetylcholinesterase activity and amyloid beta peptide aggregation.

Science.gov (United States)

Husain, I; Akhtar, M; Abdin, M Zainul; Islamuddin, M; Shaharyar, M; Najmi, A K

2018-04-01

Amyloid beta (Aβ) peptide aggregation and cholinergic neurodegeneration are involved in the development of cognitive impairment. Therefore, in this article, we examined rosuvastatin (RSV), an oral hypolipidemic drug, to determine its potential as a dual inhibitor of acetylcholinesterase (AChE) and Aβ peptide aggregation for the treatment of cognitive impairment. Molecular docking study was done to examine the affinity of RSV with Aβ 1-42 and AChE in silico. We also employed neurobehavioral activity tests, biochemical estimation, and histopathology to study the anti-Aβ 1-42 aggregation capability of RSV in vivo. Molecular docking study provided evidence that RSV has the best binding conformer at its receptor site or active site of an enzyme. The cognitive impairment in female Wistar rats was induced by high-salt and cholesterol diet (HSCD) ad libitum for 8 weeks. RSV ameliorated serum cholesterol level, AChE activity, and Aβ 1-42 peptide aggregations in HSCD induced cognitive impairment. In addition, RSV-treated rats showed greater scores in the open field (locomotor activity) test. Moreover, the histopathological studies in the hippocampus and cortex of rat brain also supported that RSV markedly reduced the cognitive impairment and preserved the normal histoarchitectural pattern of the hippocampus and cortex. Taken together, these data indicate that RSV may act as a dual inhibitor of AChE and Aβ 1-42 peptide aggregation, therefore suggesting a therapeutic strategy for cognitive impairment treatment.

Biosensor for pesticide triazophos based on its inhibition of acetylcholinesterase and using a glassy carbon electrode modified with coral-like gold nanostructures supported on reduced graphene oxide

International Nuclear Information System (INIS)

Ju, Ke-Jian; Feng, Jin-Xia; Zhang, Qian-Li; Xu, Tian-Qi; Wei, Jie; Feng, Jiu-Ju; Wang, Ai-Jun

2015-01-01

A nanocomposite consisting of coral-like gold nanostructures on reduced graphene oxide (RGO) was synthesized with the assistance of dimethylbiguanide (DMBG). It was then fabricated on a glassy carbon electrode, coating with cysteamine in order to enable the immobilization of acetylcholinesterase (AChE) as a model enzyme whose activity of hydrolyzing the substrate of acetylthiocholine is inhibited by the pesticide triazophos. The biosensor has response to acetylthiocholine in the 0.3 ∼ 300 μM concentration range at 0.65 V (vs. SCE). The inhibition of the enzyme by triazophos can be determined in concentrations of up to 210 ppb, with a detection limit of 0.35 ppb of triazophos (S/N = 3). The biosensor is highly reproducible and acceptably stable. (author)

Chitooligosaccharides suppress the level of protein expression and acetylcholinesterase activity induced by Abeta25-35 in PC12 cells.

Science.gov (United States)

Lee, Sang-Hoon; Park, Jin-Sook; Kim, Se-Kwon; Ahn, Chang-Bum; Je, Jae-Young

2009-02-01

Clinical applications of acetylcholinesterase (AChE) inhibitors are widespread in Alzheimer's sufferers in order to activate central cholinergic system and alleviate cognitive deficits by inhibiting the hydrolysis of acetylcholine. In this study, six kinds of chitooligosaccharides (COSs) with different molecular weight and degree of deacetylation were examined for their inhibitory effects against AChE. The 90-COSs exhibited potent AChE inhibitory activities compared to 50-COSs, while 90-MMWCOS (1000-5000 Da) in the 90-COSs showed the highest activity. Cell culture experiment revealed that 90-MMWCOS suppressed the level of AChE protein expression and AChE activity induced by Abeta(25-35) in PC12 cell lines.

Quercetin treatment regulates the Na+,K+-ATPase activity, peripheral cholinergic enzymes, and oxidative stress in a rat model of demyelination.

Science.gov (United States)

Carvalho, Fabiano B; Gutierres, Jessié M; Beckmann, Diego; Santos, Rosmarini P; Thomé, Gustavo R; Baldissarelli, Jucimara; Stefanello, Naiara; Andrades, Amanda; Aiello, Graciane; Ripplinger, Angel; Lucio, Bruna M; Ineu, Rafael; Mazzanti, Alexandre; Morsch, Vera; Schetinger, Maria Rosa; Andrade, Cinthia M

2018-07-01

Quercetin is reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet has attracted the attention of the scientific community, resulting in a huge output of in vitro and in vivo (preclinical) studies. Therefore, we hypothesized that quercetin can protect Na + ,K + -ATPase activity in the central nervous system, reestablish the peripheral cholinesterases activities, and reduce oxidative stress during demyelination events in rats. In line with this expectation, our study aims to find out how quercetin acts on the Na + ,K + -ATPase activity in the central nervous system, peripheral cholinesterases, and stress oxidative markers in an experimental model of demyelinating disease. Wistar rats were divided into 4 groups: vehicle, quercetin, ethidium bromide (EB), and EB plus quercetin groups. The animals were treated once a day with vehicle (ethanol 20%) or quercetin 50 mg/kg for 7 (demyelination phase, by gavage) or 21 days (remyelination phase) after EB (0.1%, 10 μL) injection (intrapontine).The encephalon was removed, and the pons, hypothalamus, cerebral cortex, hippocampus, striatum, and cerebellum were dissected to verify the Na + ,K + -ATPase activity. Our results showed that quercetin protected against reduction in Na + ,K + -ATPase in the pons and cerebellum in the demyelination phase, and it increased the activity of this enzyme in the remyelination phase. During the demyelination, quercetin promoted the increase in acetylcholinesterase activity in whole blood and lymphocytes induced by EB, and it reduced the increase in acetylcholinesterase activity in lymphocytes in the remyelination phase. On day 7, EB increased the superoxide dismutase and decreased catalase activities, as well as increased the thiobarbituric acid-reactive substance levels. Taken together, these results indicated that quercetin regulates the Na + ,K + -ATPase activity, affects the alterations of redox state

Altered levels of acetylcholinesterase in Alzheimer plasma.

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María-Salud García-Ayllón

Full Text Available BACKGROUND: Many studies have been conducted in an extensive effort to identify alterations in blood cholinesterase levels as a consequence of disease, including the analysis of acetylcholinesterase (AChE in plasma. Conventional assays using selective cholinesterase inhibitors have not been particularly successful as excess amounts of butyrylcholinesterase (BuChE pose a major problem. PRINCIPAL FINDINGS: Here we have estimated the levels of AChE activity in human plasma by first immunoprecipitating BuChE and measuring AChE activity in the immunodepleted plasma. Human plasma AChE activity levels were approximately 20 nmol/min/mL, about 160 times lower than BuChE. The majority of AChE species are the light G(1+G(2 forms and not G(4 tetramers. The levels and pattern of the molecular forms are similar to that observed in individuals with silent BuChE. We have also compared plasma AChE with the enzyme pattern obtained from human liver, red blood cells, cerebrospinal fluid (CSF and brain, by sedimentation analysis, Western blotting and lectin-binding analysis. Finally, a selective increase of AChE activity was detected in plasma from Alzheimer's disease (AD patients compared to age and gender-matched controls. This increase correlates with an increase in the G(1+G(2 forms, the subset of AChE species which are increased in Alzheimer's brain. Western blot analysis demonstrated that a 78 kDa immunoreactive AChE protein band was also increased in Alzheimer's plasma, attributed in part to AChE-T subunits common in brain and CSF. CONCLUSION: Plasma AChE might have potential as an indicator of disease progress and prognosis in AD and warrants further investigation.

Substrate-Competitive Activity-Based Profiling of Ester Prodrug Activating Enzymes.

Science.gov (United States)

Xu, Hao; Majmudar, Jaimeen D; Davda, Dahvid; Ghanakota, Phani; Kim, Ki H; Carlson, Heather A; Showalter, Hollis D; Martin, Brent R; Amidon, Gordon L

2015-09-08

Understanding the mechanistic basis of prodrug delivery and activation is critical for establishing species-specific prodrug sensitivities necessary for evaluating preclinical animal models and potential drug-drug interactions. Despite significant adoption of prodrug methodologies for enhanced pharmacokinetics, functional annotation of prodrug activating enzymes is laborious and often unaddressed. Activity-based protein profiling (ABPP) describes an emerging chemoproteomic approach to assay active site occupancy within a mechanistically similar enzyme class in native proteomes. The serine hydrolase enzyme family is broadly reactive with reporter-linked fluorophosphonates, which have shown to provide a mechanism-based covalent labeling strategy to assay the activation state and active site occupancy of cellular serine amidases, esterases, and thioesterases. Here we describe a modified ABPP approach using direct substrate competition to identify activating enzymes for an ethyl ester prodrug, the influenza neuraminidase inhibitor oseltamivir. Substrate-competitive ABPP analysis identified carboxylesterase 1 (CES1) as an oseltamivir-activating enzyme in intestinal cell homogenates. Saturating concentrations of oseltamivir lead to a four-fold reduction in the observed rate constant for CES1 inactivation by fluorophosphonates. WWL50, a reported carbamate inhibitor of mouse CES1, blocked oseltamivir hydrolysis activity in human cell homogenates, confirming CES1 is the primary prodrug activating enzyme for oseltamivir in human liver and intestinal cell lines. The related carbamate inhibitor WWL79 inhibited mouse but not human CES1, providing a series of probes for analyzing prodrug activation mechanisms in different preclinical models. Overall, we present a substrate-competitive activity-based profiling approach for broadly surveying candidate prodrug hydrolyzing enzymes and outline the kinetic parameters for activating enzyme discovery, ester prodrug design, and

Screening of acetylcholinesterase inhibitors in snake venom by electrospray mass spectrometry

NARCIS (Netherlands)

Liesener, A.; Perchuc, Anna-Maria; Schöni, Reto; Schebb, Nils Helge; Wilmer, Marianne; Karst, U.

2007-01-01

An electrospray ionization/mass spectrometry (ESI/MS)-based assay for the determination of acetylcholinesterase (AChE)-inhibiting activity in snake venom was developed. It allows the direct monitoring of the natural AChE substrate acetylcholine (AC) and the respective product choline. The assay

Bovine nucleus caudatus acetylcholinesterase: active site determination and investigation of a dimeric form obtained by selective proteolysis

Energy Technology Data Exchange (ETDEWEB)

Landauer, P.; Ruess, K.P.; Lieflaender, M.

1984-09-01

The number of catalytic subunits of purified bovine nucleus caudatus acetylcholinesterase (E.C. 3.1.1.7) has been determined by active site labelling with (3H)diisopropyl fluorophosphate ((3H)DFP). The 10.5 S, 16 S, and 20 S forms were estimated to contain two, four, and six active sites, respectively, per molecule. A 4.8 S form, which showed a weak amphiphile-dependent activity behavior, was obtained by selective proteolytic digestion with pronase. The inability of the purified 4.8 S form to aggregate after detergent removal, and the molecular mass in the range of 130-165 kD under nondenaturating conditions, indicate that this form is a dimeric form, lacking those hydrophobic regions responsible for aggregation.

Surface display of recombinant Drosophila melanogaster acetylcholinesterase for detection of organic phosphorus and carbamate pesticides.

Directory of Open Access Journals (Sweden)

Jingquan Li

Full Text Available Acetylcholinesterase (AChE is commonly used for the detection of organophosphate (OP and carbamate (CB insecticides. However, the cost of this commercially available enzyme is high, making high-throughput insecticide detection improbable. In this study we constructed a new AChE yeast expression system in Saccharomyces cerevisiae for the expression of a highly reactive recombinant AChE originating from Drosophila melanogaster (DmAChE. Specifically, the coding sequence of DmAChE was fused with the 3'-terminal half of an α-agglutinin anchor region, along with an antigen tag for the detection of the recombinant protein. The target sequence was cloned into the yeast expression vector pYes-DEST52, and the signal peptide sequence was replaced with a glucoamylase secretion region for induced expression. The resultant engineered vector was transformed into S. cerevisiae. DmAChE was expressed and displayed on the cell surface after galactose induction. Our results showed that the recombinant protein displayed activity comparable to the commercial enzyme. We also detected different types of OP and CB insecticides through enzyme inhibition assays, with the expressed DmAChE showing high sensitivity. These results show the construction of a new yeast expression system for DmAChE, which can subsequently be used for detecting OP and CB insecticides with reduced economic costs.

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii

Science.gov (United States)

Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Background: Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. Objective: A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro. Materials and Methods: β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. Results: The factors investigated include the enzyme concentration (0.5%–2.5%), ultrasound time (10 min−3 0 min), and extraction temperature (30°C–50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. Conclusions: The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. SUMMARY The new method of adding enzyme directly to the

Novel Method of Preparation and Activity Research on Arctigenin from Fructus Arctii.

Science.gov (United States)

Cai, Enbo; Han, Jiahong; Yang, Limin; Zhang, Weiyuan; Zhao, Yan; Chen, Qiulian; Guo, Meng; He, Xinhong

2018-01-01

Arctigenin has many pharmacological activities with clinical significance and is derived from Arctium lappa L. However, the present extraction method is inefficient and does not have meaningful industrial production. A new method to directly prepare arctigenin was established by combining enzyme-assisted extraction and central composite design. Arctigenin's further pharmacological activity was also surveyed in vitro . β-D-Glucosidase, a food-grade enzyme, was added directly to the fruits of A. lappa L. to hydrolyze the arctiin to arctigenin, and the obtained samples were subsequently subjected to ethanol (30%, v/v) extraction. The pharmacological activity of the extraction and arctigenin was determined by inhibiting acetylcholinesterase (AChE) and scavenging nitrite. The factors investigated include the enzyme concentration (0.5%-2.5%), ultrasound time (10 min -3 0 min), and extraction temperature (30°C-50°C). From the analysis of the results by Design-Expert (V8.0.6), the optimal extraction conditions were obtained: enzyme concentration (1.4%), ultrasound time (25 min), and extraction temperature (45°C). The highest yield of arctigenin, obtained under the optimal conditions was 6.39%, representing an increase of 28.15% compared to the reference extraction without enzyme processing. The IC 50 values of the extraction and arctigenin, respectively, for inhibiting AChE were 0.572 mg/ml and 0.462 mg/ml, and those for nitrite-scavenging were 34.571 mg/ml and 17.49 mg/ml. The results demonstrate that using an enzyme directly in the production is an effective means for extracting arctigenin from Fructus arctii. The extraction has the activities of inhibiting AChE and scavenging nitrite, probably because there has arctigenin in it. It is implied that the extraction and arctigenin could contribute to human health in clinical applications. The new method of adding enzyme directly to the preparation of arctigenin was carried out instead of preparing arctigenin by two

Thermodynamic activity-based intrinsic enzyme kinetic sheds light on enzyme-solvent interactions.

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Grosch, Jan-Hendrik; Wagner, David; Nistelkas, Vasilios; Spieß, Antje C

2017-01-01

The reaction medium has major impact on biocatalytic reaction systems and on their economic significance. To allow for tailored medium engineering, thermodynamic phenomena, intrinsic enzyme kinetics, and enzyme-solvent interactions have to be discriminated. To this end, enzyme reaction kinetic modeling was coupled with thermodynamic calculations based on investigations of the alcohol dehydrogenase from Lactobacillus brevis (LbADH) in monophasic water/methyl tert-butyl ether (MTBE) mixtures as a model solvent. Substrate concentrations and substrate thermodynamic activities were varied separately to identify the individual thermodynamic and kinetic effects on the enzyme activity. Microkinetic parameters based on concentration and thermodynamic activity were derived to successfully identify a positive effect of MTBE on the availability of the substrate to the enzyme, but a negative effect on the enzyme performance. In conclusion, thermodynamic activity-based kinetic modeling might be a suitable tool to initially curtail the type of enzyme-solvent interactions and thus, a powerful first step to potentially understand the phenomena that occur in nonconventional media in more detail. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:96-103, 2017. © 2016 American Institute of Chemical Engineers.

Visualization of enzyme activities inside earthworm pores

Science.gov (United States)

Hoang, Duyen; Razavi, Bahar S.

2015-04-01

In extremely dynamic microhabitats as bio-pores made by earthworm, the in situ enzyme activities are assumed as a footprint of complex biotic interactions. Our study focused on the effect of earthworm on the enzyme activities inside bio-pores and visualizing the differences between bio-pores and earthworm-free soil by zymography technique (Spohn and Kuzyakov, 2013). For the first time, we aimed at quantitative imaging of enzyme activities in bio-pores. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). After two weeks when bio-pore systems were formed by earthworms, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine-aminopeptidase, and phosphatase. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. However, the differences in activity of cellobiohydrolase and leucine aminopeptidase between bio-pore and bulk soil were less pronounced. This demonstrated an applicability of zymography approach to monitor and to distinguish the in situ activity of hydrolytic enzymes in soil biopores.

Comparative study of acetylcholinesterase and glutathione S-transferase activities of closely related cave and surface Asellus aquaticus (Isopoda: Crustacea.

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Anita Jemec

Full Text Available The freshwater isopod crustacean Asellus aquaticus has recently been developed as an emerging invertebrate cave model for studying evolutionary and developmental biology. Mostly morphological and genetic differences between cave and surface A. aquaticus populations have been described up to now, while scarce data are available on other aspects, including physiology. The purpose of this study was to advance our understanding of the physiological differences between cave A. aquaticus and its surface-dwelling counterparts. We sampled two surface populations from the surface section of the sinking Pivka River (central Slovenia, Europe, i.e. locality Pivka Polje, and locality Planina Polje, and one cave population from the subterranean section of the sinking Pivka River, i.e. locality Planina Cave. Animals were sampled in spring, summer and autumn. We measured the activities of acetylcholinesterase (AChE and glutathione S-transferase (GST in individuals snap-frozen in the field immediately after collection. Acetylcholinesterase is likely related to animals' locomotor activity, while GST activity is related to the metabolic activity of an organism. Our study shows significantly lower AChE and GST activities in the cave population in comparison to both surface A. aquaticus populations. This confirms the assumption that cave A. aquaticus have lower locomotor and metabolic activity than surface A. aquaticus in their respective natural environments. In surface A. aquaticus populations, seasonal fluctuations in GST activity were observed, while these were less pronounced in individuals from the more stable cave environment. On the other hand, AChE activity was generally season-independent in all populations. To our knowledge, this is the first study of its kind conducted in A. aquaticus. Our results show that among closely related cave and surface A. aquaticus populations also physiological differences are present besides the morphological and genetic

Effect of thermal stress and water deprivation on the acetylcholinesterase activity of the pig brain and hypophyses

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Adejumo, D. O.; Egbunike, G. N.

1988-06-01

The effects of direct exposure of boars to thermal stress for 1 h daily for 5 days and to acute water deprivation for 24 or 48 h were studied on the acetylcholinesterase (AChE) activity of porcine brain and hypophysial regions. Mean ambient temperatures, respiratory rates and rectal temperatures in the open were significantly higher than inside the pen. Heat stress induced a rise in AChE activities in the pons, cerebellum, amygdala, hippocampus, hypothalamus, mid-brain and medulla oblongata. However, no significant changes were observed in the cerebral cortex, adenohypophysis and neurohypophysis. Water deprivation significantly ( Pmedulla oblongata were comparable to the amygdala in this respect. The adenohypophysis and neurohypophysis were relatively unaffected.

Chemical Composition and Acetylcholinesterase Inhibitory Activity of Essential Oils from Piper Species.

Science.gov (United States)

Xiang, Cai-Peng; Han, Jia-Xin; Li, Xing-Cong; Li, Yun-Hui; Zhang, Yi; Chen, Lin; Qu, Yan; Hao, Chao-Yun; Li, Hai-Zhou; Yang, Chong-Ren; Zhao, San-Jun; Xu, Min

2017-05-10

The essential oils (EOs) derived from aromatic plants such as Piper species are considered to play a role in alleviating neuronal ailments that are associated with inhibition of acetylcholinesterase (AChE). The chemical compositions of 23 EOs prepared from 16 Piper spp. were analyzed by both gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 76 compounds were identified in the EOs from the leaves and stems of 19 samples, while 30 compounds were detected in the EOs from the fruits of four samples. Sesquiterpenes and phenylpropanoids were found to be rich in these EOs, of which asaricin, caryophyllene, caryophyllene oxide, isospathulenol, (+)-spathulenol, and β-bisabolene are the major constituents. The EOs from the leaves and stems of Piper austrosinense, P. puberulum, P. flaviflorum, P. betle, and P. hispidimervium showed strong AChE inhibitory activity with IC 50 values in the range of 1.51 to 13.9 mg/mL. A thin-layer chromatography (TLC) bioautography assay was employed to identify active compound(s) in the most active EO from P. hispidimervium. The active compound was isolated and identified as asaricin, which gave an IC 50 value of 0.44 ± 0.02 mg/mL against AChE, comparable to galantamine with an IC 50 0.15 ± 0.01 mg/mL.

County-Scale Spatial Distribution of Soil Enzyme Activities and Enzyme Activity Indices in Agricultural Land: Implications for Soil Quality Assessment

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Xiangping Tan

2014-01-01

Full Text Available Here the spatial distribution of soil enzymatic properties in agricultural land was evaluated on a county-wide (567 km2 scale in Changwu, Shaanxi Province, China. The spatial variations in activities of five hydrolytic enzymes were examined using geostatistical methods. The relationships between soil enzyme activities and other soil properties were evaluated using both an integrated total enzyme activity index (TEI and the geometric mean of enzyme activities (GME. At the county scale, soil invertase, phosphatase, and catalase activities were moderately spatially correlated, whereas urease and dehydrogenase activities were weakly spatially correlated. Correlation analysis showed that both TEI and GME were better correlated with selected soil physicochemical properties than single enzyme activities. Multivariate regression analysis showed that soil OM content had the strongest positive effect while soil pH had a negative effect on the two enzyme activity indices. In addition, total phosphorous content had a positive effect on TEI and GME in orchard soils, whereas alkali-hydrolyzable nitrogen and available potassium contents, respectively, had negative and positive effects on these two enzyme indices in cropland soils. The results indicate that land use changes strongly affect soil enzyme activities in agricultural land, where TEI provides a sensitive biological indicator for soil quality.

Characterization of hepatic enzyme activity in older adults with dementia: potential impact on personalizing pharmacotherapy

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Campbell NL

2015-01-01

Full Text Available Noll L Campbell,1–4 Todd C Skaar,5 Anthony J Perkins,2 Sujuan Gao,2,3,6 Lang Li,7 Babar A Khan,2,3,5 Malaz A Boustani2,3,81College of Pharmacy, Purdue University, West Lafayette, 2Indiana University Center for Aging Research, 3Regenstrief Institute, 4Department of Pharmacy, Eskenazi Health Services, 5Division of Clinical Pharmacology, Department of Medicine, 6Department of Biostatistics, 7Department of Medical and Molecular Genetics, Indiana University School of Medicine, 8Center for Innovation and Implementation Science, Indiana University, Indianapolis, IN, USAObjective: To determine the frequency of pharmacogenomic variants and concurrent medications that may alter the efficacy and tolerability of acetylcholinesterase inhibitors (AChEIs.Materials and methods: A multisite cross-sectional study was carried out across four memory care practices in the greater Indianapolis area. Participants were adults aged 65 years and older with a diagnosis of probable or possible Alzheimer’s disease (AD (n=105. Blood samples and self-reported medication data were collected. Since two of the three AChEIs are metabolized by cytochrome P450 (CYP-2D6, we determined the frequency of functional genetic variants in the CYP2D6 gene and calculated their predicted CYP2D6-activity scores. Concurrent medication data were collected from self-reported medication surveys, and their predicted effect on the pharmacokinetics of AChEIs was determined based on their known effects on CYP2D6 and CYP3A4/5 enzyme activities.Results: Among the 105 subjects enrolled, 72% were female and 36% were African American. Subjects had a mean age of 79.6 years. The population used a mean of eight medications per day (prescription and nonprescription. The CYP2D6 activity score frequencies were 0 (3.8%, 0.5 (4.8%, 1.0 (36.2%, 1.5–2.0 (51.4%, and >2.0 (3.8%. Nineteen subjects (18.1% used a medication considered a strong or moderate inhibitor of CYP2D6, and eight subjects (7.6% used a

Lysosomal enzyme activation in irradiated mammary tumors

International Nuclear Information System (INIS)

Clarke, C.; Wills, E.D.

1976-01-01

Lysosomal enzyme activity of C3H mouse mammary tumors was measured quantitatively by a histochemical method. Following whole-body doses of 3600 rad or less no changes were observed in the lysosomal enzyme activity for 12 hr after the irradiation, but very large increases in acid phosphatase and β-naphthylamidase activity were, however, observed 24 hr after irradiation. Significant increases in enzyme activity were detected 72 hr after a dose of 300 rad and the increases of enzyme activity were dose dependent over the range 300 to 900 rad. Testosterone (80 mg/kg) injected into mice 2 hr before irradiation (850 rad) caused a significant increase of lysosomal enzyme activity over and above that of the same dose of irradiation alone. If the tumor-bearing mice were given 95 percent oxygen/5 percent carbon dioxide to breathe for 8 min before irradiation the effect of 850 rad on lysosomal acid phosphatase was increased to 160 percent/that of the irradiation given alone. Activitation of lysosomal enzymes in mammary tumors is an important primary or secondary consequence of radiation

Synthesis and Biological Evaluation of Novel Jatrorrhizine Derivatives with Amino Groups Linked at the 3-Position as Inhibitors of Acetylcholinesterase

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Xiaofei Jiang

2017-01-01

Full Text Available Jatrorrhizine was considered as one of the active constituents of Coptis chinensis Franch. Herein, jatrorrhizine derivatives with substituted amino groups linked at the 3-position were designed, synthesized, and biologically evaluated as inhibitors of acetylcholinesterase. Jatrorrhizine derivatives inhibited the activity of acetylcholinesterase (AChE to a greater extent than the lead compound jatrorrhizine. All these jatrorrhizine derivatives were proved to be potent inhibitors of acetylcholinesterase (AChE with submicromolar IC50 values, but less sensitive to butyrylcholinesterase (BuChE, which suggests that these jatrorrhizine derivatives are selective for AChE/BuChE. Compound 3g gave the most potent inhibitor activity for AChE (IC50 = 0.301 μM, which is greater than the lead compound jatrorrhizine. All these results demonstrated that these jatrorrhizine derivatives are potential inhibitors for AChE.

Epigenetics of dominance for enzyme activity

Indian Academy of Sciences (India)

Unknown

dimer over a wide range of H+ concentrations accounts for the epigenetics of dominance for enzyme activity. [Trehan K S ... The present study has been carried on acid phosphatase .... enzyme activity over mid parent value (table 3, col. 13),.

Acetylcholinesterase Inhibitory Activities of Flavonoids from the Leaves of Ginkgo biloba against Brown Planthopper

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Xiao Ding

2013-01-01

Full Text Available Ginkgo biloba is a traditional Chinese medicinal plant which has potent insecticidal activity against brown planthopper. The MeOH extract was tested in the acetylcholinesterase (AChE inhibitory assay with IC50 values of 252.1 μg/mL. Two ginkgolides and thirteen flavonoids were isolated from the leaves of Ginkgo biloba. Their structures were established on the basis of spectroscopic data interpretation. It revealed that the 13 isolated flavonoids were found to inhibit AChE with IC50 values ranging from 57.8 to 133.1 μg/mL in the inhibitory assay. AChE was inhibited dose dependently by all tested flavonoids, and compound 6 displayed the highest inhibitory effect against AChE with IC50 values of 57.8 μg/mL.

A simple radiometric in vitro assay for acetylcholinesterase inhibitors

International Nuclear Information System (INIS)

Guilarte, T.R.; Burns, H.D.; Dannals, R.F.; Wagner, H.N. Jr.

1983-01-01

A radiometric method for screening acetylcholinesterase inhibitors has been described. The method is based on the production of [ 14 C]carbon dioxide from the hydrolysis of acetylcholine. The inhibitory concentration at 50% (IC50) values for several known acetylcholinesterase inhibitors were in agreement with literature values. The new radiometric method is simple, inexpensive, and has the potential for automation

Spatial distribution of enzyme activities in the rhizosphere

Science.gov (United States)

Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

The rhizosphere, the tiny zone of soil surrounding roots, certainly represents one of the most dynamic habitat and interfaces on Earth. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. That is why there is an urgent need in spatially explicit methods for the determination of the rhizosphere extension and enzyme distribution. Recently, zymography as a new technique based on diffusion of enzymes through the 1 mm gel plate for analysis has been introduced (Spohn & Kuzyakov, 2013). We developed the zymography technique to visualize the enzyme activities with a higher spatial resolution. For the first time, we aimed at quantitative imaging of enzyme activities as a function of distance from the root tip and the root surface in the soil. We visualized the two dimensional distribution of the activity of three enzymes: β-glucosidase, phosphatase and leucine amino peptidase in the rhizosphere of maize using fluorogenically labelled substrates. Spatial-resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography visualized heterogeneity of enzyme activities along the roots. The activity of all enzymes was the highest at the apical parts of individual roots. Across the roots, the enzyme activities were higher at immediate vicinity of the roots (1.5 mm) and gradually decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify spatial distribution of enzyme activities in the rhizosphere hotspots. References Spohn, M., Kuzyakov, Y., 2013. Phosphorus mineralization can be driven by microbial need for carbon. Soil Biology & Biochemistry 61: 69-75

SERUM ACETYLCHOLINESTERASE LEVEL IN THE PATIENTS OF OPIOID (BROWN SUGAR) DEPENDENCE

OpenAIRE

Shah, Nilesh; Dave, Kirti

1992-01-01

The authors compared the serum acetylcholinesterase level in the patients of brown sugar dependence and the normal volunteers. Significantly lower level of serum acetylcholinesterase was found in patients of brown sugar dependence.

Effect of chlorpyrifos and enrofloxacin on selected enzymes in rats.

Science.gov (United States)

Barski, D; Spodniewska, A

2018-03-01

This study examined the effect of chlorpyrifos and/or enrofloxacin on the activity of acetylcholinesterase (AChE) in the blood and brain, and the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum. The experiment was conducted on Wistar strain rats. Chlorpyrifos was administered with a stomach tube at a dose of 0.04 LD50 for 28 days and enrofloxacin at a dose of 5 mg/kg bw for 5 consecutive days. The experiment found that enrofloxacin changed the activity of the enzymes under study only to a small extent. At the dose applied in the experiment, chlorpyrifos decreased the activity of AChE significantly, both in blood and in the brain, and increased the activity of ALT and AST in rat serum. The administration of chlorpyrifos in combination with enrofloxacin changed the activity of the enzymes under study only slightly. A weaker, but longer, inhibition of AChE activity in both blood and the brain was observed in this group compared to the animals exposed only to chlorpyrifos. However, although enrofloxacin, like chlorpyrifos, increases the activity of ALT and AST in serum, their combined administration did not increase the hepatotoxic effect. Copyright© by the Polish Academy of Sciences.

Design, synthesis and structure-activity relationships of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

Science.gov (United States)

Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio; Kogen, Hiroshi

2003-05-01

We have designed and synthesized a dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT) as a novel class of treatment drugs for Alzheimer's disease on the basis of a hypothetical model of the AChE active site. Dual inhibitions of AChE and SERT would bring about greater therapeutic effects than AChE inhibition alone and avoid adverse peripheral effects caused by excessive AChE inhibition. Compound (S)-6j exhibited potent inhibitory activities against AChE (IC(50)=101 nM) and SERT (IC(50)=42 nM). Furthermore, (S)-6j showed inhibitory activities of both AChE and SERT in mice brain following oral administration.

Enzymes and Enzyme Activity Encoded by Nonenveloped Viruses.

Science.gov (United States)

Azad, Kimi; Banerjee, Manidipa; Johnson, John E

2017-09-29

Viruses are obligate intracellular parasites that rely on host cell machineries for their replication and survival. Although viruses tend to make optimal use of the host cell protein repertoire, they need to encode essential enzymatic or effector functions that may not be available or accessible in the host cellular milieu. The enzymes encoded by nonenveloped viruses-a group of viruses that lack any lipid coating or envelope-play vital roles in all the stages of the viral life cycle. This review summarizes the structural, biochemical, and mechanistic information available for several classes of enzymes and autocatalytic activity encoded by nonenveloped viruses. Advances in research and development of antiviral inhibitors targeting specific viral enzymes are also highlighted.

Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

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Bi, Xiaodong; Liu, Zhen

2014-12-16

Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

The ultrasound technology for modifying enzyme activity

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Meliza Lindsay

2016-06-01

Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly aims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes efficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/inactivation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultrasonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

Lignin-degrading enzyme activities.

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Chen, Yi-ru; Sarkanen, Simo; Wang, Yun-Yan

2012-01-01

Over the past three decades, the activities of four kinds of enzyme have been purported to furnish the mechanistic foundations for macromolecular lignin depolymerization in decaying plant cell walls. The pertinent fungal enzymes comprise lignin peroxidase (with a relatively high redox potential), manganese peroxidase, an alkyl aryl etherase, and laccase. The peroxidases and laccase, but not the etherase, are expressed extracellularly by white-rot fungi. A number of these microorganisms exhibit a marked preference toward lignin in their degradation of lignocellulose. Interestingly, some white-rot fungi secrete both kinds of peroxidase but no laccase, while others that are equally effective express extracellular laccase activity but no peroxidases. Actually, none of these enzymes has been reported to possess significant depolymerase activity toward macromolecular lignin substrates that are derived with little chemical modification from the native biopolymer. Here, the assays commonly employed for monitoring the traditional fungal peroxidases, alkyl aryl etherase, and laccase are described in their respective contexts. A soluble native polymeric substrate that can be isolated directly from a conventional milled-wood lignin preparation is characterized in relation to its utility in next-generation lignin-depolymerase assays.

The ultrasound technology for modifying enzyme activity

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Meliza Lindsay Rojas

2016-01-01

Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly a ims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes ef ficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/in activation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultr asonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

Phytochemical Profile and Qualification of Biological Activity of an Isolated Fraction of Bellis perennis

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Thiago H Costa Marques

2013-01-01

Full Text Available This study describes the isolation and identification of apigenin-7-O-ghicopyranoside, a flavonoid isolated from the flowers of Bellis perennis L., Asteraceae, an species with a broad spectrum of biological activities. The in vitro antioxidant activity and the inhibition of the enzyme acetylcholinesterase were evaluated. The flavonoid showed strong in vitro antioxidant potential, because of the capacity of removal of hydroxyl radicals and nitric oxide, and also prevented the formation of thiobarbituric acid-reactive substances. These parameters were inhibited at the highest concentration of ApG at rates of 77.7%, 72% and 73.4%, respectively, in addition to inhibiting acetylcholinesterase, suggesting potential use in the treatment of neurodegenerative diseases.

Effects of chlorpyrifos on the transcription of CYP3A cDNA, activity of acetylcholinesterase, and oxidative stress response of goldfish (Carassius auratus).

Science.gov (United States)

Ma, Junguo; Liu, Yang; Niu, Daichun; Li, Xiaoyu

2015-04-01

Chlorpyrifos (CPF) is the widely used organophosphate pesticide in agriculture throughout the world. It has been found that CPF is relatively safe to human but highly toxic to fish. In this study, acute toxicity of CPF on goldfish was determined and then the transcription of goldfish cytochrome P450 (CYP) 3A was evaluated after 96 h of CPF exposure at concentrations of 15.3 [1/10 50% lethal concentration (LC50 )] or 51 μg L(-1) (1/3 LC50 ) of CPF. Meanwhile, the enzymatic activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT), total antioxidant activity (T-AOC), and the contents of malondialdehyde (MDA) in the liver or brain of goldfish were also determined. The results of acute toxicity testing showed that the 96-h LC50 of CPF to the goldfish was 153 μg L(-1) . Moreover, a length sequence of 1243 bp CYP3A cDNA encoding for 413 amino acids from goldfish liver was cloned. Polymerase chain reaction results reveal that CPF exposure downregulates CYP 3A transcription in goldfish liver, suggesting that goldfish CYP 3A may be not involved in CPF bioactivation. Finally, the results of biochemical assays indicate that 96 h of CPF exposure remarkably inhibits AChE activity in fish liver or brain, alters hepatic antioxidant enzyme activities, decreases brain T-AOC, and causes lipid peroxidation in fish liver. These results suggest that oxidative stress might be involved in CPF toxicity on goldfish. Copyright © 2013 Wiley Periodicals, Inc.

Alteration of paraoxonase, arylesterase and lactonase activities in people around fluoride endemic area of Tamil Nadu, India.

Science.gov (United States)

Arulkumar, Mani; Vijayan, Raji; Penislusshiyan, Sakayanathan; Sathishkumar, Palanivel; Angayarkanni, Jayaraman; Palvannan, Thayumanavan

2017-08-01

Toxicity due to excess fluoride concentration in drinking water is of great concern in people who rely only on the ground water as their water source in many region of the world. We collected samples and examined the toxicity of fluoride in a population residing at Salem, Dharmapuri and Krishnagiri districts of Tamil Nadu, India and measured HDL bound enzyme (PON1), erythrocyte membrane bound enzymes (acetylcholinesterase, AChE) and adenosine 5' triphosphatase (ATPases), plasma enzyme (butyrylcholinesterase, BChE) and rate limiting enzyme in heme biosynthesis (delta aminolevulinic acid dehydratase, δ-ALAD) activities. In fluorosis patients, formation of lipid peroxidation product was more in erythrocytes than in plasma. The observation further revealed that there was 50% reduction in the activity of HDL bound anti atherogenic enzyme-paraoxonase (PON1). The activities of membrane bound and signaling enzymes (acetylcholinesterase - AChE and adenosine 5' triphosphatase - ATPase) of erythrocyte were also diminished. These results suggested that there was defectiveness in the signaling and energy metabolism in fluorosis patients. Altered isoenzyme pattern of lactate dehydrogenase (LDH) in fluorosis samples was observed. Furthermore, the result suggested that both the heart (LDH 1) and liver (LDH 5) were most affected by fluoride toxicity. The study also provided reference values for tests which are used to predict the severity of fluoride toxicity. The toxic effect of fluoride was due to the collective effects on vital protective system rather than single factor. Copyright © 2017 Elsevier B.V. All rights reserved.

Concentration-dependent interactions of the organophosphates chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase

International Nuclear Information System (INIS)

Kaushik, R.; Rosenfeld, Clint A.; Sultatos, L.G.

2007-01-01

For many decades it has been thought that oxygen analogs (oxons) of organophosphorus insecticides phosphorylate the catalytic site of acetylcholinesterase by a mechanism that follows simple Michaelis-Menten kinetics. More recently, the interactions of at least some oxons have been shown to be far more complex and likely involve binding of oxons to a second site on acetylcholinesterase that modulates the inhibitory capacity of other oxon molecules at the catalytic site. The current study has investigated the interactions of chlorpyrifos oxon and methyl paraoxon with human recombinant acetylcholinesterase. Both chlorpyrifos oxon and methyl paraoxon were found to have k i 's that change as a function of oxon concentration. Furthermore, 10 nM chlorpyrifos oxon resulted in a transient increase in acetylthiocholine hydrolysis, followed by inhibition. Moreover, in the presence of 100 nM chlorpyrifos oxon, acetylthiocholine was found to influence both the K d (binding affinity) and k 2 (phosphorylation constant) of this oxon. Collectively, these results demonstrate that the interactions of chlorpyrifos oxon and methyl paraoxon with acetylcholinesterase cannot be described by simple Michaelis-Menten kinetics but instead support the hypothesis that these oxons bind to a secondary site on acetylcholinesterase, leading to activation/inhibition of the catalytic site, depending on the nature of the substrate and inhibitor. Additionally, these data raise questions regarding the adequacy of estimating risk of low levels of insecticide exposure from direct extrapolation of insecticide dose-response curves since the capacity of individual oxon molecules at low oxon levels could be greater than individual oxon molecules in vivo associated with the dose-response curve

Characterization and biological significance of deacetylase

International Nuclear Information System (INIS)

Dipaola, E.A.

1985-01-01

An attempt is made to clarify the mechanism by which the one known deacetylase inhibitor, sodium butyrate, works and to identify other inhibitors of deacetylase activity. In doing so it was hoped to characterize the enzyme and to better understand its role in regulating genomic expression. The data showed that deacetylases not only showed activity toward their natural histone substrates, but also toward free acetyllysine and to a lesser degree toward acetylcholine, the latter being the natural substrate for acetylcholinesterases. Conversely, acetylcholinesterase was shown to be able to deacetylate groups from acetyllysine and acetylated histones. Decamethonium bromide, a well-known binder of acetylcholinesterase would not absorb the deacetylase. Diisopropylfluorophosphate (DFP), an anti-cholinesterase, exhibited no inhibitory effect on deacetylase activity, while acetylcholinesterase showed little or no sensitivity to butyrate inhibition. These findings along with the use of 3 H-DFP binding to fingerprint enzyme bands on gels became the basic criteria for distinguishing between deacetylase and acetylcholinesterase activity

Effect of doxorubicin and daunorubicin on the activity of acetylcholinesterase in acute lymphoblastic leukamia

International Nuclear Information System (INIS)

Din, I.U.; Ali, A.

2011-01-01

Background: Our study was based on the alteration in the Michaelis Mentin parameters Apparent Michaelis Constant (aKm) and Apparent Maximum Velocity (aVm), which reflects activity of actyl cholinesterase (AChE). This activity decreases in Acute Lymphoblastic Leukaemia (ALL). This decrease in aKm and aVm values shows bad prognosis. Similarly the anticancer drugs like Daunorubicin and Doxorubicin further decreases the aKm and aVm values which worsen the prognosis. The objective of this study was to determine and compare the extent of inhibition of Acetylcholine Esterase by Daunorubicin and Doxorubicin in ALL. Methods: Study of 100 patients including both male and female children who's age ranged from 4 to 8 years and were advised doxorubicin and daunorubicin separately were tested by Ellman's method using acetylcholine iodide as substrate and 5,5-dithiobis 2-nitrobenzine as a colour reagent regardless of dose regimen i.e. (once in 3 week, small dose per week or a continuous infusion for 72 to 96 hours. Results: In this study the Michaelis Mentin parameters Apparent Michaelis Constant (aKm) and Apparent Maximum Velocity (aVm) of the enzyme were estimated both in normal individuals and in the patients and also during treatment with daunorubicin and doxorubicin. The value of Michaelis Mentin parameters, aKm, aVm and percentage activity of the enzyme in normal individual are 23, 70, and 100 respectively. The values of aKm, aVm and percentage activity of the enzyme were also estimated in the patients before and after treatment. The values of aKm and aVm in patients of acute lymphoblastic leukaemia and percentage activity of enzyme is decreased. After the treatment with daunorubicin and doxorubicin the values and activity is further decreased. Conclusion: We conclude that the drugs under study both decrease the enzyme activity but daunorubicin inhibits the enzyme more than doxorubicin. (author)

Screen-printed electrode modified with carbon black and chitosan: a novel platform for acetylcholinesterase biosensor development.

Science.gov (United States)

Talarico, Daria; Arduini, Fabiana; Amine, Aziz; Cacciotti, Ilaria; Moscone, Danila; Palleschi, Giuseppe

2016-10-01

We report a screen-printed electrode (SPE) modified with a dispersion of carbon black (CB) and chitosan by drop casting. A cyclic voltammetry technique towards ferricyanide, caffeic acid, hydroquinone, and thiocholine was performed and an improvement of the electrochemical response with respect to bare SPE as well as SPE modified only with chitosan was observed. The possibility to detect thiocholine at a low applied potential with high sensitivity was exploited and an acetylcholinesterase (AChE) biosensor was developed. A dispersion of CB, chitosan, and AChE was used to fabricate this biosensor in one step by drop casting. The enzymatic activity of the immobilized AChE was determined measuring the enzymatic product thiocholine at +300 mV. Owing to the capability of organophosphorus pesticides to inhibit AChE, this biosensor was used to detect these pollutants, and paraoxon was taken as model compound. The enzyme inhibition was linearly related to the concentration of paraoxon up to 0.5 μg L(-1), and a low detection limit equal to 0.05 μg L(-1) (calculated as 10% of inhibition) was achieved. This biosensor was challenged for paraoxon detection in drinking waters with satisfactory recovery values. The use of AChE embedded in a dispersion of CB and chitosan allowed an easy and fast production of a sensitive biosensor suitable for paraoxon detection in drinking waters at legal limit levels. Graphical Abstract Biosensors based on screen-printed electrodes modified with Acetylcholinesterase, Carbon Black, and Chitosan for organophosphorus pesticide detection.

Enzyme with rhamnogalacturonase activity.

NARCIS (Netherlands)

Kofod, L.V.; Andersen, L.N.; Dalboge, H.; Kauppinen, M.S.; Christgau, S.; Heldt-Hansen, H.P.; Christophersen, C.; Nielsen, P.M.; Voragen, A.G.J.; Schols, H.A.

1998-01-01

An enzyme exhibiting rhamnogalacturonase activity, capable of cleaving a rhamnogalacturonan backbone in such a manner that galacturonic acids are left as the non-reducing ends, and which exhibits activity on hairy regions from a soy bean material and/or on saponified hairy regions from a sugar beet

Effects of carbofuran, diuron, and nicosulfuron on acetylcholinesterase activity in goldfish (Carassius auratus).

Science.gov (United States)

Bretaud, S; Toutant, J P; Saglio, P

2000-10-01

Juvenile goldfish (Carassius auratus) were exposed to three widely used pesticides; carbofuran, diuron, and nicosulfuron. Acetylcholinesterase (AChE) activity and molecular forms of AChE were first characterized in brain and skeletal muscle of unexposed fish. Skeletal muscle had higher AChE activity than brain (306 and 215 nmol/min/mg protein, respectively). In brain, four molecular forms of AChE were found: A12, G4, G2, and G1. In the muscle, three molecular forms were found A12, A8, and G2. AChE activity was then evaluated in both tissues of fish exposed to different concentration of pesticides (5, 50, and 500 microg/L) for 6, 12, 24, and 48 h. In brain, AChE activity was significantly inhibited during all the periods of exposure in response to 50 microg/L (19-28%) and 500 microg/L (85-87%) carbofuran. Such effect was observed in the muscle only at 500 microg/L (86-92%). Carbofuran had no effect on the distribution of molecular forms. Significant inhibitions (9-12%) of brain AChE activity were also observed in response to diuron and nicosulfuron at 500 microg/L during all periods of exposure and for 50 microg/L nicosulfuron after 24 and 48 h. This study pointed out short-term effects of exposure to sublethal concentrations of the three pesticides, ranging among different chemical families, on brain and muscle AChE in goldfish. Copyright 2000 Academic Press.

Acetylcholinesterase Inhibition and Antioxidant Activity of N-trans-Caffeoyldopamine and N-trans-Feruloyldopamine

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Muamer Dizdar

2018-04-01

Full Text Available Phenolic acids and their derivatives found in nature are well-known for their potential biological activity. In this study, two amides derived from trans-caffeic/ferulic acid and dopamine were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR, mass spectrometry, proton and carbon-13 nuclear magnetic resonance spectroscopy. The compounds were tested for the inhibition of acetylcholinesterase (AChE from Electrophorus electricus and for antioxidant activity by scavenging 2,2-diphenyl-1-pycrylhydrazyl free radical (DPPH• and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS•+, reducing ferric ions, and ferrous ions chelation. N-trans-Feruloyldopamine displayed the highest inhibitory effect on AChE with half-maximal inhibitory concentration (IC50 values of 8.52 μM. In addition, an in silico study was done to determine the most favorable AChE cluster with the synthesized compounds. Further, these clusters were investigated for binding positions at the lowest free binding energy. Both synthesized hydroxycinnamates were found to be better antioxidants than the parent acids in in vitro tests applied. N-trans-Caffeoyldopamine showed the best antioxidant activity in the three tested methods—against non-biological stable free radicals IC50 5.95 μM for DPPH•, 0.24 μM for the ABTS•+ method, and for reducing power (ascorbic acid equivalent (AAE 822.45 μmol/mmol—while for chelation activity against Fe2+ ions N-trans-feruloyldopamine had slightly better antioxidant activity (IC50 3.17 mM.

Surface display and bioactivity of Bombyx mori acetylcholinesterase on Pichia pastoris

Science.gov (United States)

To construct the Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE), the gene for the anchor protein (AGa1) was obtained from Saccharomyces cerevisiae and was fused with the modified Bombyx mori acetylcholinesterase gene (bmace) and transformed int...

Two Step Synthesis of a Non-symmetric Acetylcholinesterase Reactivator

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Vit Koleckar

2007-08-01

Full Text Available The newly developed and very promising acetylcholinesterase reactivator (E-1- (2-hydroxyiminomethylpyridinium-4-(4-hydroxyiminomethylpyridinium-but-2-ene dibromide was prepared using two different pathways via a two-step synthesis involving the appropriate (E-1-(4-bromobut-2-enyl-2- or 4-hydroxyiminomethyl-pyridinium bromides. Afterwards, purities and yields of the desired product prepared by both routes were compared. Finally, its potency to reactivate several nerve agent-inhibited acetylcholinesterases was tested.

Effects of Lead+Selenium Interaction on Acetylcholinesterase Activity in Brain and Accumulation of Metal in Tissues of Oreochromis niloticus (L., 1758

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Gülsemin Şen

2017-06-01

Full Text Available The potential accumulation of lead in different tissues of Oreochromis niloticus and the effects of selenium in AChE inhibition caused by lead in brain were investigated. Juvenile O. niloticus samples were exposed to combination of 1 mg L-1 and 2 mg L-1 lead and 1mg L-1 lead+2mg L-1 selenium and 2mg L-1 lead+4mg L-1 selenium for 1, 7 and 15 days respectively. The accumulation of lead in gill, brain, liver and muscle tissues was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS as well as brain acetylcholinesterase (AChE, E.C.3.1.1.7 enzyme activity was also analyzed by spectrophotometric method. No mortality was observed during lead exposure in relation to time period and exposed concentrations. Lead accumulation was occurred in all tissues in relation to time. Maximum lead accumulation occurred in brain tissue, followed by the liver, gills and muscle tissues in relation to time period. Selenium caused decrease accumulation of lead in tissues (all selenium mixtures in muscle tissue on the first day, 1mg L-1 Pb+2mg L-1 selenium in gill tissue on the seventh day, in liver tissue on the seventh day except 2mg L-1 Pb+4mg L-1 selenium mixtures at the end of each of all three test periods. Inhibition of AChE activity was caused by the highest concentration and by the short-term effect of lead. Such effect of lead was eliminated by selenium mixture. Lead and selenium mixture were resulted an increase in activity on 15th day at the highest concentration. Selenium led to decrease in the accumulation of lead in the tissues and caused to improvement in the loss of AChE activity.

Quantitative structure-activity analysis of acetylcholinesterase inhibition by oxono and thiono analogues of organophosphorus compounds. (Reannouncement with new availability information)

Energy Technology Data Exchange (ETDEWEB)

Maxwell, D.M.; Brecht, K.M.

1992-02-01

A comparison of the bimolecular rate constants (ki) for inhibition of electric eel acetylcholinesterase (AChE) by the oxono (i.e., P=O) and thiono (i.e., P=S) analogues of parathion, methylparathion, leptophos, fonofos, sarin, and soman revealed that the oxono/thiono ratios of ki values varied from 14 for soman to 1240 for parathion. Analysis of the relative importance of the dissociation equilibrium constant and the phosphorylation rate constant in producing this variation in ki values indicated that the oxono analogues had phosphorylation rate constant values that varied in a narrow range from 8- to 14-fold greater than their thiono counterparts, while the oxono/thiono ratios for dissociation constants varied widely from 1 for soman to 82 for fonofos. The lower affinities of thiono analogues for AChE probably resulted from differences in the hydrophobic binding of oxono and thiono analogues to the active site of AChE, inasmuch as the hydrophobicities (i.e., octanol/water partition coefficients) of thiono organophosphorus compounds were much greater than the hydrophobicities of their oxono analogues. Quantitative structure-activity analysis indicated that the hydrophobic effects of oxono and thiono moieties correlated with log ki for AChE inhibition to a greater extent (r2 = 0.79) than their electronic effects (r2 equal to or less than 0.48). These observations suggest that the differences in hydrophobicity of oxono and thiono analogues of organophosphorus compounds may be as important as their electronic differences in determining their effectiveness as AChE inhibitors. Acetylcholinesterase, soman (GD), structure-activity analysis inhibition, oxono analogues, thiono analogues.

Photoperiodism and Enzyme Activity

Science.gov (United States)

Queiroz, Orlando; Morel, Claudine

1974-01-01

Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

Inhibition of Acetylcholinesterase and Fatty Acid Composition in Theobroma grandiflorum Seeds

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Casandra Valentina Itriago

2017-07-01

Full Text Available Theobroma grandiflorum is an important fruit tree from Sterculiaceae family, native to the Brazilian Amazon, known in the region as cupuaçu. The seeds have a high fat content (24% with characteristics that resemble those of cocoa (Theobroma cacao butter with potential applications in the cosmetic, pharmaceutical and food industries. The main objective of this work was to explore the seed fats from T. grandiflorum that were analyzed for fatty acid composition by Gas Chromatography with Flame Ionization Detector (GC-FID and to analyze their activity for acetylcholinesterase inhibition. Chromatographic analysis provided detection of nine fatty acids. The major fatty acids found in the species were oleic (40.0%, stearic (32.7%, arachidic (10.4% and palmitic (8.0%. The acetylcholinesterase inhibition by fats from seeds was over 40.48%. DOI: http://dx.doi.org/10.17807/orbital.v0i0.894 

Inhibition and Larvicidal Activity of Phenylpropanoids from Piper sarmentosum on Acetylcholinesterase against Mosquito Vectors and Their Binding Mode of Interaction.

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Arshia Hematpoor

Full Text Available Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are vectors of dengue fever and West Nile virus diseases. This study was conducted to determine the toxicity, mechanism of action and the binding interaction of three active phenylpropanoids from Piper sarmentosum (Piperaceae toward late 3rd or early 4th larvae of above vectors. A bioassay guided-fractionation on the hexane extract from the roots of Piper sarmentosum led to the isolation and identification of three active phenylpropanoids; asaricin 1, isoasarone 2 and trans-asarone 3. The current study involved evaluation of the toxicity and acetylcholinesterase (AChE inhibition of these compounds against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae. Asaricin 1 and isoasarone 2 were highly potent against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae causing up to 100% mortality at ≤ 15 μg/mL concentration. The ovicidal activity of asaricin 1, isoasarone 2 and trans-asarone 3 were evaluated through egg hatching. Asaricin 1 and isoasarone 2 showed potent ovicidal activity. Ovicidal activity for both compounds was up to 95% at 25μg/mL. Asaricin 1 and isoasarone 2 showed strong inhibition on acetylcholinesterase with relative IC50 values of 0.73 to 1.87 μg/mL respectively. These findings coupled with the high AChE inhibition may suggest that asaricin 1 and isoasarone 2 are neuron toxic compounds toward Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. Further computational docking with Autodock Vina elaborates the possible interaction of asaricin 1 and isoasarone 2 with three possible binding sites of AChE which includes catalytic triads (CAS: S238, E367, H480, the peripheral sites (PAS: E72, W271 and anionic binding site (W83. The binding affinity of asaricin 1 and isoasarone 2 were relatively strong with asaricin 1 showed a higher binding affinity in the anionic pocket.

Inhibition and Larvicidal Activity of Phenylpropanoids from Piper sarmentosum on Acetylcholinesterase against Mosquito Vectors and Their Binding Mode of Interaction.

Science.gov (United States)

Hematpoor, Arshia; Liew, Sook Yee; Chong, Wei Lim; Azirun, Mohd Sofian; Lee, Vannajan Sanghiran; Awang, Khalijah

2016-01-01

Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are vectors of dengue fever and West Nile virus diseases. This study was conducted to determine the toxicity, mechanism of action and the binding interaction of three active phenylpropanoids from Piper sarmentosum (Piperaceae) toward late 3rd or early 4th larvae of above vectors. A bioassay guided-fractionation on the hexane extract from the roots of Piper sarmentosum led to the isolation and identification of three active phenylpropanoids; asaricin 1, isoasarone 2 and trans-asarone 3. The current study involved evaluation of the toxicity and acetylcholinesterase (AChE) inhibition of these compounds against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae. Asaricin 1 and isoasarone 2 were highly potent against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae causing up to 100% mortality at ≤ 15 μg/mL concentration. The ovicidal activity of asaricin 1, isoasarone 2 and trans-asarone 3 were evaluated through egg hatching. Asaricin 1 and isoasarone 2 showed potent ovicidal activity. Ovicidal activity for both compounds was up to 95% at 25μg/mL. Asaricin 1 and isoasarone 2 showed strong inhibition on acetylcholinesterase with relative IC50 values of 0.73 to 1.87 μg/mL respectively. These findings coupled with the high AChE inhibition may suggest that asaricin 1 and isoasarone 2 are neuron toxic compounds toward Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. Further computational docking with Autodock Vina elaborates the possible interaction of asaricin 1 and isoasarone 2 with three possible binding sites of AChE which includes catalytic triads (CAS: S238, E367, H480), the peripheral sites (PAS: E72, W271) and anionic binding site (W83). The binding affinity of asaricin 1 and isoasarone 2 were relatively strong with asaricin 1 showed a higher binding affinity in the anionic pocket.

Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R

International Nuclear Information System (INIS)

Atsmon, Jacob; Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari; Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y.; Bartfeld, Daniel; Shulman, Avidor; Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit; Soreq, Hermona; Shaaltiel, Yoseph

2015-01-01

PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2 min before being exposed to 1.33 × LD 50 and 1.5 × LD 50 of toxin and 10 min after exposure to 1.5 × LD 50 survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t ½ ) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t ½ in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human study exhibited its safety

Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R

Energy Technology Data Exchange (ETDEWEB)

Atsmon, Jacob [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y. [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Bartfeld, Daniel [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shulman, Avidor, E-mail: avidors@protalix.com [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Soreq, Hermona [Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem (Israel); Shaaltiel, Yoseph [Protalix Biotherapeutics, Science Park, Carmiel (Israel)

2015-09-15

PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2 min before being exposed to 1.33 × LD{sub 50} and 1.5 × LD{sub 50} of toxin and 10 min after exposure to 1.5 × LD{sub 50} survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t{sub ½}) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t{sub ½} in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human study

The inhibitory effect of manganese on acetylcholinesterase activity enhances oxidative stress and neuroinflammation in the rat brain

International Nuclear Information System (INIS)

Santos, Dinamene; Milatovic, Dejan; Andrade, Vanda; Batoreu, M. Camila; Aschner, Michael; Marreilha dos Santos, A.P.

2012-01-01

Highlights: ► Acetylcholinesterase (AChE) is a target of Mn in the central nervous system. ► Mn inhibits AChE, representing a novel mechanistic finding for its mode of action. ► AChE inhibition may trigger or contribute to the development of oxidative stress. ► Excess Mn can trigger the release of inflammatory mediators. ► AChE activity may serve as an early biomarker of Mn neurotoxicity. -- Abstract: Background: Manganese (Mn) is a naturally occurring element and an essential nutrient for humans and animals. However, exposure to high levels of Mn may cause neurotoxic effects. The pathological mechanisms associated with Mn neurotoxicity are poorly understood, but several reports have established it is mediated, at least in part, by oxidative stress. Objectives: The present study was undertaken to test the hypothesis that a decrease in acetylcholinesterase (AChE) activity mediates Mn-induced neurotoxicity. Methods: Groups of 6 rats received 4 or 8 intraperitoneal (i.p.) injections of 25 mg MnCl 2 /kg/day, every 48 h. Twenty-four hours after the last injection, brain AChE activity and the levels of F 2 -isoprostanes (F 2 -IsoPs) and F 4 -neuroprostanes (F 4 -NPs) (biomarkers of oxidative stress), as well as prostaglandin E 2 (PGE 2 ) (biomarker of neuroinflammation) were analyzed. Results: The results showed that after either 4 or 8 Mn doses, brain AChE activity was significantly decreased (p 2 -IsoPs and PGE 2 levels, but only after 8 doses. In rats treated with 4 Mn doses, a significant increase (p 4 -NPs levels was found. To evaluate cellular responses to oxidative stress, we assessed brain nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) and Mn-superoxide dismutase (Mn-SOD, SOD2) protein expression levels. A significant increase in Mn-SOD protein expression (p < 0.05) and a trend towards increased Nrf2 protein expression was noted in rat brains after 4 Mn doses vs. the control group, but the expression of these proteins was decreased after 8 Mn

Effects of de-icing salt on soil enzyme activity

Energy Technology Data Exchange (ETDEWEB)

Guentner, M; Wilke, B M

1983-01-01

Effects of de-icing salt on dehydrogenase, urease, alkalinephosphatase and arylsulfatase activity of O/sub L/- and A/sub h/-horizons of a moder and a mull soil were investigated using a field experiment. Additions of 2.5 kg m/sup -2/ and 5.0 kg m/sup -2/ of de-icing salt reduced activities of most enzymes within four weeks. Eleven months after salt addition there was nearly no reduction of enzyme activity to be measured on salt treated soils. The percentage of reduced enzyme activity was generally higher in the moder soil. It was concluded that reductions of enzyme activity were due to decreases of microbial activity and not to inactivation of enzymes.

[Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay].

Science.gov (United States)

Lu, Tu-lin; Su, Lian-lin; Ji, De; Gu, Wei; Mao, Chun-qin

2015-09-01

Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

Science.gov (United States)

Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H

2011-02-17

Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

Measurement of enzyme activity.

Science.gov (United States)

Harris, T K; Keshwani, M M

2009-01-01

To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

Chemical Composition, Antioxidant and Anticholinesterase Activities of the Essential Oil of Salvia chrysophylla Staph

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Mehmet Emin Duru

2012-01-01

Full Text Available The essential oil from the aerial parts of Salvia chrysophylla Staph (Lamiaceae, endemic to Turkey, was investigated by using GC and GC-MS. Fifty-four of 55 components, represented 99.52% of the total oil were identified. The major components of the essential oil were found to be α-terpinenyl acetate (36.31%, β-caryophyllene (15.29%, linalool (8.12% and β-elemene (4.26%. The antioxidant activity of the oil was investigated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH and β-carotene/linoleic acid tests. Anticholinesterase activity was screened against acetylcholinesterase and butyrylcholinesterase which are the chief enzymes of Alzheimer’s diseases. The essential oil showed weak antioxidant activity. However, at 1 mg/mL concentration, the essential oil exhibited mild acetylcholinesterase (52.5±2.0% and modarate butyrylcholinesterase (76.5±2.7% inhibitory activity.

Effect of carbaryl (carbamate insecticide) on acetylcholinesterase activity of two strains of Daphnia magna (Crustacea, Cladocera).

Science.gov (United States)

Toumi, Hela; Bejaoui, Mustapha; Touaylia, Samir; Burga Perez, Karen F; Ferard, Jean François

2016-11-01

The present study was designed to investigate the effect of carbaryl (carbamate insecticide) on the acetylcholinesterase activity in two strains (same clone A) of the crustacean cladoceran Daphnia magna. Four carbaryl concentrations (0.4, 0.9, 1.8 and 3.7 µg L(-1)) were compared against control AChE activity. Our results showed that after 48 h of carbaryl exposure, all treatments induced a significant decrease of AChE activities whatever the two considered strains. However, different responses were registered in terms of lowest observed effect concentrations (LOEC: 0.4 µg L(-1) for strain 1 and 0.9 µg L(-1) for strains 2) revealing differences in sensitivity among the two tested strains of D. magna. These results suggest that after carbaryl exposure, the AChE activity responses can be also used as a biomarker of susceptibility. Moreover, our results show that strain1 is less sensitive than strain 2 in terms of IC50-48 h of AChE activity. Comparing the EC50-48 h of standard ecotoxicity test and IC50-48 h of AChE inhibition, there is the same order of sensitivity with both strains.

Soil enzyme dynamics in chlorpyrifos-treated soils under the influence of earthworms.

Science.gov (United States)

Sanchez-Hernandez, Juan C; Notario Del Pino, J; Capowiez, Yvan; Mazzia, Christophe; Rault, Magali

2018-01-15

Earthworms contribute, directly and indirectly, to contaminant biodegradation. However, most of bioremediation studies using these annelids focus on pollutant dissipation, thus disregarding the health status of the organism implied in bioremediation as well as the recovery of indicators of soil quality. A microcosm study was performed using Lumbricus terrestris to determine whether earthworm density (2 or 4individuals/kg wet soil) and the time of exposure (1, 2, 6, 12, and 18wk) could affect chlorpyrifos persistence in soil initially treated with 20mg active ingredientkg -1 wet soil. Additionally, selected earthworm biomarkers and soil enzyme activities were measured as indicators of earthworm health and soil quality, respectively. After an 18-wk incubation period, no earthworm was killed by the pesticide, but clear signs of severe intoxication were detected, i.e., 90% inhibition in muscle acetylcholinesterase and carboxylesterase (CbE) activities. Unexpectedly, the earthworm density had no significant impact on chlorpyrifos dissipation rate, for which the measured half-life ranged between 30.3d (control soils) and 44.5d (low earthworm density) or 36.7d (high earthworm density). The dynamic response of several soil enzymes to chlorpyrifos exposure was examined calculating the geometric mean and the treated-soil quality index, which are common enzyme-based indexes of microbial functional diversity. Both indexes showed a significant and linear increase of the global enzyme response after 6wk of chlorpyrifos treatment in the presence of earthworms. Examination of individual enzymes revealed that soil CbE activity could decrease chlorpyrifos-oxon impact upon the rest of enzyme activities. Although L. terrestris was found not to accelerate chlorpyrifos dissipation, a significant increase in the activity of soil enzyme activities was achieved compared with earthworm-free, chlorpyrifos-treated soils. Therefore, the inoculation of organophosphorus-contaminated soils with L

Antidotal effects of varthemia persica DC extract in organophosphate poisoning or warfare agents by measuring whole blood acetylcholinesterase

International Nuclear Information System (INIS)

Kalantari, H.; Siahapoosh, A.; Farsani, K. M.

2009-01-01

The organophosphates (ORPs) or war fare agents toxicity results from inhibition of acetylcholinesterase (AchE). phosphylation of the active serin of AchE leads to accumulation of acetylcholine in synaptic clefts leading to generalized cholinergic over-stimulation. Standard treatment of ORP poisoning includes a muscarinic antagonist such as Atropine, and acetylcholinesterase reactivator (oxime). Presently, oximes like abidoxime and pralidoxime are approved as antidotes against ORP poisoning but are considered to be rather ineffective against certain ORP. Like Soman. In this study, the protective effect of Varthemia persica DC extract on acetylcholinesterase was examined in rats. Animals in weight range of 200-225 g were divided in 8 groups. The negative control group received only 0.4 ml normal saline, reference group, received ethylparaoxone in dose of 50 percent of LD50, positive control group, received ethylparaoxone (50% LD50) and one minute later 50 mol of pralidoxime. Test group 1: received ethylparaoxone and one minute later single dose of methanolic extract of Varthemia persica (250 mg/kg), Test Group 2: daily received methanolic extract of V.persica (250 mg/kg) in six days and one minute after last dose of extract, ethylparaoxone (50% LD50) were injected, Test Group 3: received ethylparaoxone (50% LD50) and then six doses of methanolic extract of V.persica (250 mg/kg) in six continuous days. Test Group 4: received ethylparaoxone and then single dose of dichloromethane extract of V.persica (250 mg/kg). Test Group 5: received ethylparaoxone and one minute later single high dose of methanolic extract of V.persica (1000 mg/kg). Then blood withdrawn and acetylcholinesterase activity was measured according to modified Ellman's method. Only in groups which received extract of V. persica before and after injection of ethylparaoxone, the mean of acetylcholinesterase activity was significantly different with reference group (p 0.05) but no significant difference with

2-(2-(4-Benzoylpiperazin-1-ylethylisoindoline-1,3-dione derivatives: Synthesis, docking and acetylcholinesterase inhibitory evaluation as anti-alzheimer agents

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Ahmad Mohammadi-Farani

2017-01-01

Full Text Available Objective(s: Alzheimer’s disease (AD as progressive cognitive decline and the most common form of dementia is due to degeneration of the cholinergic neurons in the brain. Therefore, administration of the acetylcholinesterase (AChE inhibitors such as donepezil is the first choice for treatment of the AD. In the present study, we focused on the synthesis and anti-cholinesterase evaluation of new donepezil like analogs. Materials and Methods: A new series of phthalimide derivatives (compounds 4a-4j were synthesized via Gabriel protocol and subsequently amidation reaction was performed using various benzoic acid derivatives. Then, the corresponding anti-acetylcholinesterase activity of the prepared derivatives (4a-4j was assessed by utilization of the Ellman's test and obtained results were compared to donepezil. Besides, docking study was also carried out to explore the likely in silico binding interactions.  Results: According to the obtained results, electron withdrawing groups (Cl, F at position 3 and an electron donating group (methoxy at position 4 of the phenyl ring enhanced the acetylcholinesterase inhibitory activity. Compound 4e (m-Fluoro, IC50 = 7.1 nM and 4i (p-Methoxy, IC50 = 20.3 nM were the most active compounds in this series and exerted superior potency than donepezil (410 nM. Moreover, a similar binding mode was observed in silico for all ligands in superimposition state with donepezil into the active site of acetylcholinesterase. Conclusion: Studied compounds could be potential leads for discovery of novel anti-Alzheimer agents in the future.

Enzyme activity and kinetics in substrate-amended river sediments

Energy Technology Data Exchange (ETDEWEB)

Duddridge, J E; Wainwright, M

1982-01-01

In determining the effects of heavy metals in microbial activity and litter degradation in river sediments, one approach is to determine the effects of these pollutants on sediment enzyme activity and synthesis. Methods to assay amylase, cellulase and urease activity in diverse river sediments are reported. Enzyme activity was low in non-amended sediments, but increased markedly when the appropriate substrate was added, paralleling both athropogenic and natural amendment. Linear relationships between enzyme activity, length of incubation, sample size and substrate concentration were established. Sediment enzyme activity generally obeyed Michaelis-Menton kinetics, but of the three enzymes, urease gave least significant correlation coefficients when the data for substrate concentration versus activity was applied to the Eadie-Hofstee transformation of the Michaelis-Menten equation. K/sub m/ and V/sub max/ for amylase, cellulase and urease in sediments are reported. (JMT)

Enzyme Activity Experiments Using a Simple Spectrophotometer

Science.gov (United States)

Hurlbut, Jeffrey A.; And Others

1977-01-01

Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

Activation of interfacial enzymes at membrane surfaces

DEFF Research Database (Denmark)

Mouritsen, Ole G.; Andresen, Thomas Lars; Halperin, Avi

2006-01-01

A host of water-soluble enzymes are active at membrane surfaces and in association with membranes. Some of these enzymes are involved in signalling and in modification and remodelling of the membranes. A special class of enzymes, the phospholipases, and in particular secretory phospholipase A2 (s...

Effects of Chlorophenoxy Herbicides and Their Main Transformation Products on DNA Damage and Acetylcholinesterase Activity

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Sofia Benfeito

2014-01-01

Full Text Available Persistent pesticide transformation products (TPs are increasingly being detected among different environmental compartments, including groundwater and surface water. However, there is no sufficient experimental data on their toxicological potential to assess the risk associated with TPs, even if their occurrence is known. In this study, the interaction of chlorophenoxy herbicides (MCPA, mecoprop, 2,4-D and dichlorprop and their main transformation products with calf thymus DNA by UV-visible absorption spectroscopy has been assessed. Additionally, the toxicity of the chlorophenoxy herbicides and TPs was also assessed evaluating the inhibition of acetylcholinesterase activity. On the basis of the results found, it seems that AChE is not the main target of chlorophenoxy herbicides and their TPs. However, the results found showed that the transformation products displayed a higher inhibitory activity when compared with the parent herbicides. The results obtained in the DNA interaction studies showed, in general, a slight effect on the stability of the double helix. However, the data found for 4-chloro-2-methyl-6-nitrophenol suggest that this transformation product can interact with DNA through a noncovalent mode.

Activity assessment of microbial fibrinolytic enzymes.

Science.gov (United States)

Kotb, Essam

2013-08-01

Conversion of fibrinogen to fibrin inside blood vessels results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. In general, there are four therapy options: surgical operation, intake of antiplatelets, anticoagulants, or fibrinolytic enzymes. Microbial fibrinolytic enzymes have attracted much more attention than typical thrombolytic agents because of the expensive prices and the side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus. Microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases. There are several assay methods for these enzymes; this may due to the insolubility of substrate, fibrin. Existing assay methods can be divided into three major groups. The first group consists of assay of fibrinolytic activity with natural proteins as substrates, e.g., fibrin plate methods. The second and third groups of assays are suitable for kinetic studies and are based on the determination of hydrolysis of synthetic peptide esters. This review will deal primarily with the microorganisms that have been reported in literature to produce fibrinolytic enzymes and the first review discussing the methods used to assay the fibrinolytic activity.

New derivatives of 3,4-dihydroisoquinoline-3-carboxylic acid with free-radical scavenging, D-amino acid oxidase, acetylcholinesterase and butyrylcholinesterase inhibitory activity.

Science.gov (United States)

Solecka, Jolanta; Guśpiel, Adam; Postek, Magdalena; Ziemska, Joanna; Kawęcki, Robert; Lęczycka, Katarzyna; Osior, Agnieszka; Pietrzak, Bartłomiej; Pypowski, Krzysztof; Wyrzykowska, Agata

2014-09-30

A series of 3,4-dihydroisoquinoline-3-carboxylic acid derivatives were synthesised and tested for their free-radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS·+), superoxide anion radical (O2·-) and nitric oxide radical (·NO) assays. We also studied d-amino acid oxidase (DAAO), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity. Almost each of newly synthesised compounds exhibited radical scavenging capabilities. Moreover, several compounds showed moderate inhibitory activities against DAAO, AChE and BuChE. Compounds with significant free-radical scavenging activity may be potential candidates for therapeutics used in oxidative-stress-related diseases.

Detection of enzyme activity in decontaminated spices of industrial use

International Nuclear Information System (INIS)

Müller, R.; Theobald, R.

1995-01-01

A range of decontaminated spices of industrial use have been examinated for their enzymes (catalase, peroxidase, amylase, lipase activity). The genuine enzymes remain fully active in irradiated spices, whereas the microbial load is clearly reduced. In contrast steam treated spices no longer demonstrate enzyme activities. Steam treatment offers e.g. black pepper without lipase activity, which can no longer cause fat deterioration. Low microbial load in combination with clearly detectable enzyme activity in spices is an indication for irradiation, whereas, reduced microbial contamination combined with enzyme inactivation indicate steam treatment of raw material [de

Anti-acetylcholinesterase activity and antioxidant properties of extracts and fractions of Carpolobia lutea.

Science.gov (United States)

Nwidu, Lucky Legbosi; Elmorsy, Ekramy; Thornton, Jack; Wijamunige, Buddhika; Wijesekara, Anusha; Tarbox, Rebecca; Warren, Averil; Carter, Wayne Grant

2017-12-01

There is an unmet need to discover new treatments for Alzheimer's disease. This study determined the anti-acetylcholinesterase (AChE) activity, DPPH free radical scavenging and antioxidant properties of Carpolobia lutea G. Don (Polygalaceae). The objective of this study is to quantify C. lutea anti-AChE, DPPH free radical scavenging, and antioxidant activities and cell cytotoxicity. Plant stem, leaves and roots were subjected to sequential solvent extractions, and screened for anti-AChE activity across a concentration range of 0.02-200 μg/mL. Plant DPPH radical scavenging activity, reducing power, and total phenolic and flavonoid contents were determined, and cytotoxicity evaluated using human hepatocytes. Carpolobia lutea exhibited concentration-dependent anti-AChE activity. The most potent inhibitory activity for the stem was the crude ethanol extract and hexane stem fraction oil (IC 50  = 140 μg/mL); for the leaves, the chloroform leaf fraction (IC 50  = 60 μg/mL); and for roots, the methanol, ethyl acetate and aqueous root fractions (IC 50  = 0.3-3 μg/mL). Dose-dependent free radical scavenging activity and reducing power were observed with increasing stem, leaf or root concentration. Total phenolic contents were the highest in the stem: ∼632 mg gallic acid equivalents/g for a hexane stem fraction oil. Total flavonoid content was the highest in the leaves: ∼297 mg quercetin equivalents/g for a chloroform leaf fraction. At 1 μg/mL, only the crude ethanol extract oil was significantly cytotoxic to hepatocytes. Carpolobia lutea possesses anti-AChE activity and beneficial antioxidant capacity indicative of its potential development as a treatment of Alzheimer's and other diseases characterized by a cholinergic deficit.

Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon

Czech Academy of Sciences Publication Activity Database

Kuča, K.; Musilová, L.; Paleček, J.; Církva, Vladimír; Paar, M.; Musílek, K.; Hrabinová, M.; Pohanka, M.; Zdarová Karasová, J.; Jun, D.

2009-01-01

Roč. 14, č. 12 (2009), s. 4915-4921 ISSN 1420-3049 Grant - others:MO0(CZ) FZV0000604 Institutional research plan: CEZ:AV0Z40720504 Keywords : acetylcholinesterase * reactivator * oxime Subject RIV: CC - Organic Chemistry Impact factor: 1.738, year: 2009

EFFECT OF PESTICIDES ON RAT (Rattus norvegicus ERYTHROCYTES ANTIOXIDANT ENZYMES IN VITRO

Directory of Open Access Journals (Sweden)

Jasna Friščić

2014-10-01

Full Text Available Abstract: In the last century, maximum in herbicide production was achieved. Growing use of herbicides initiated the need for continuous evaluation of damaging effects of herbicides on human health and environment. Paraquat is the trade name for N,N′-dimethyl-4,4′-bipyridinium dichloride and one of the most widely used herbicides in the world. Although mechanism of paraquat toxicity remains undefined, a great portion of toxicity is attributed to the process of redox cycling. In this research, rat erythrocytes were exposed to various paraquat concentrations (0, 0.25, 0.5, 0.75, 1.25 mM. Changes in antioxidant enzymes activity, catalase and superoxide dismutase were determined, and also the activity of erythrocyte acetylcholinesterase. Obtained results show damaging effects of paraquat on erythrocytes due to oxidative stress.

New Acetylcholinesterase Inhibitors for Alzheimer's Disease

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Mona Mehta

2012-01-01

Full Text Available Acetylcholinesterase (AChE remains a highly viable target for the symptomatic improvement in Alzheimer's disease (AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AchE for myasthenia gravis had effectively proven that AchE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEI continue to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs in development and their respective mechanisms of actions. This pharmacological approach continues to be active with many promising compounds.

A Design of Portable Pesticide Residue Detection System Based on the Enzyme Electrode

Directory of Open Access Journals (Sweden)

Xia SUN

2013-03-01

Full Text Available In this paper, a portable detection system was designed based on amperometric acetylcholinesterase biosensor for rapidly detecting pesticide residues in fruits and vegetables. There were potentiostat, three electrode system, differential amplification circuit and double integral analog to digital (A/D circuit modules in this system. The measurement principle of this system was depended on the weak current from enzyme catalyzing substrate in acetylcholinesterase biosensor for detecting pesticide residues. The weak current generated by the enzyme biosensor was changed into 0-5 V standard voltage signal by this system as an output signal. The proposed system was investigated with eight kinds of standard pesticide of different concentrations, the results showed that the detection limits were all lower than 10 ng/kg. Thus, a new effective home-made system of detecting pesticide residues with portable, easy-to-use, fast response was developed. The pesticide residues rapid detection system can collect the weak current signal generated by electrochemical reaction and on-site detect the concentration of pesticide residues in real fruits and vegetables samples.

Effect of irradiation on lysosomal enzyme activation in cultured macrophages

International Nuclear Information System (INIS)

Clarke, C.; Wills, E.D.

1980-01-01

The effect of γrays on lysosomal enzyme activity of normal and immune macrophages of DBA/2 mice cultured in vitro has been studied. A dose of 500 rad did not significantly affect lysosomal enzyme activity 3 hours after irradiation but caused the activity to increase to 1.4 times the control value 22.5 hours after irradiation. 22.5 hours after a dose of 3000 rad the enzyme activity increased to 2.5 times the control. Lysosomal enzyme activity of the macrophages was also markedly increased by immunization of the mice with D lymphoma cells, before culture in vitro, but irradiation of these cells with a dose of 500 rad caused a further increase in lysosomal enzyme activity. The results indicate that immunization and irradiation both cause stimulation of lysosomal enzyme activity in macrophages but that the mechanisms of activation are unlikely to be identical. (author)

Modulation of the brain acetylcholinesterase activity after gamma irradiation or cytokine administration

International Nuclear Information System (INIS)

Clarencon, D.; Multon, E.; Galonnier, M.; Fournier, C.; Fatome, M.; Gourmelon, P.

1997-01-01

The central nervous system exhibits a functional radiosensitivity, with different abnormalities in the neuronal transmission. In particular we observed a decrease in AChE activity in the rat brain after a whole body gamma exposure. This could not be explained by a direct effect on the protein: the AChE is particularly radioresistant, since several hundred of grays are necessary to modify the in vitro enzymatic activity. Radiations have no effect on primary neuronal culture, and the in vivo radiogenic decrease in brain AChE activity could imply more complex mechanisms than nervous transmissions alone, involving the participation of several intercellular communication systems. The second part of our experimental results showed that both peripheral or central administration of IL-6 can reproduce the decrease in the brain AChE activity observed after an irradiation. The role of inflammatory mediators in the acute radiation syndrome is now well documented. The way these cellular mediators could activate the CNS remains unclear. An induction of messengers of IL-1 and TNF in different brain areas has been recently demonstrated. However, it could be mentioned that, by using primary neuronal cultures, neither the membranes-bound nor the release enzyme activities were modified by incubation with IL-6. On the other hand, when the primary neurons were plated with a subculture of glial cells, the release of enzyme was greatly reduced during a few hours after incubation with IL-6, but the membrane-bound enzyme, which represent more than 90% of the total activity, was not modified. Hence, the mechanisms by which cytokines act on the CNS seem to be more complex, with the participation of glial cells. We suggest that the peripheral early inflammatory response which occurs after irradiation might participate in the nervous damage. (N.C.)

A New Acetylcholinesterase Inhibitor from Green Glycosylation of Trachyloban-19-oic Acid by Mucor plumbeus.

Science.gov (United States)

Santos, Gabriel F Dos; Takahashi, Jacqueline A

2017-01-01

The in vitro metabolism of a widespread natural product, trachyloban-19-oic acid (1), by the fungal species Mucor plumbeus was studied in a sucrose-yeast liquid medium. Two products were isolated, and their structures were determined by spectroscopic means as 7β-hydroxytrachyloban-19-oic acid (5) and trachyloban-19-O-β-D-glucopyranosyl ester (6). To the best of our knowledge, compound 6 is herein reported by the first time in the literature. These compounds were assayed for acetylcholinesterase inhibition along with some related compounds. Compound 6 showed the highest acetylcholinesterase inhibitory activity at 10000 µg/mL among the tested compounds, a result (92.89%) comparable to the activity of the positive control, galanthamine (94.21%). Therefore, biotransformation of the natural product 1 by M. plumbeus produced a novel compound with potential as a new lead to develop anti-Alzheimer medicines.

A New Acetylcholinesterase Inhibitor from Green Glycosylation of Trachyloban-19-oic Acid by Mucor plumbeus

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GABRIEL F. DOS SANTOS

2017-10-01

Full Text Available ABSTRACT The in vitro metabolism of a widespread natural product, trachyloban-19-oic acid (1, by the fungal species Mucor plumbeus was studied in a sucrose-yeast liquid medium. Two products were isolated, and their structures were determined by spectroscopic means as 7β-hydroxytrachyloban-19-oic acid (5 and trachyloban-19-O-β-D-glucopyranosyl ester (6. To the best of our knowledge, compound 6 is herein reported by the first time in the literature. These compounds were assayed for acetylcholinesterase inhibition along with some related compounds. Compound 6 showed the highest acetylcholinesterase inhibitory activity at 10000 µg/mL among the tested compounds, a result (92.89% comparable to the activity of the positive control, galanthamine (94.21%. Therefore, biotransformation of the natural product 1 by M. plumbeus produced a novel compound with potential as a new lead to develop anti-Alzheimer medicines.

Enzyme specific activity in functionalized nanoporous supports

International Nuclear Information System (INIS)

Lei Chenghong; Soares, Thereza A; Shin, Yongsoon; Liu Jun; Ackerman, Eric J

2008-01-01

Here we reveal that enzyme specific activity can be increased substantially by changing the protein loading density (P LD ) in functionalized nanoporous supports so that the enzyme immobilization efficiency (I e , defined as the ratio of the specific activity of the immobilized enzyme to the specific activity of the free enzyme in solution) can be much higher than 100%. A net negatively charged glucose oxidase (GOX) and a net positively charged organophosphorus hydrolase (OPH) were entrapped spontaneously in NH 2 - and HOOC-functionalized mesoporous silica (300 A, FMS) respectively. The specific activity of GOX entrapped in FMS increased with decreasing P LD . With decreasing P LD , I e of GOX in FMS increased from 150%. Unlike GOX, OPH in HOOC-FMS showed increased specific activity with increasing P LD . With increasing P LD , the corresponding I e of OPH in FMS increased from 100% to>200%. A protein structure-based analysis of the protein surface charges directing the electrostatic interaction-based orientation of the protein molecules in FMS demonstrates that substrate access to GOX molecules in FMS is limited at high P LD , consequently lowering the GOX specific activity. In contrast, substrate access to OPH molecules in FMS remains open at high P LD and may promote a more favorable confinement environment that enhances the OPH activity

Design and synthesis of dual inhibitors of acetylcholinesterase and serotonin transporter targeting potential agents for Alzheimer's disease.

Science.gov (United States)

Kogen, Hiroshi; Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio

2002-10-03

Highly efficient acetylcholinesterase (AChE) and serotonin transporter (SERT) dual inhibitors, (S)-4 and (R)-13 were designed and synthesized on the basis of the hypothetical model of AChE active site. Both compounds showed potent inhibitory activities against AChE and SERT. [structure: see text

Acetylcholinesterase activity, cohabitation with floricultural workers, and blood pressure in Ecuadorian children.

Science.gov (United States)

Suarez-Lopez, Jose R; Jacobs, David R; Himes, John H; Alexander, Bruce H

2013-05-01

Acetylcholinesterase (AChE) inhibitors are commonly used pesticides that can effect hemodynamic changes through increased cholinergic stimulation. Children of agricultural workers are likely to have paraoccupational exposures to pesticides, but the potential physiological impact of such exposures is unclear. We investigated whether secondary pesticide exposures were associated with blood pressure and heart rate among children living in agricultural Ecuadorian communities. This cross-sectional study included 271 children 4-9 years of age [51% cohabited with one or more flower plantation workers (mean duration, 5.2 years)]. Erythrocyte AChE activity was measured using the EQM Test-mate system. Linear regression models were used to estimate associations of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate with AChE activity, living with flower workers, duration of cohabitation with a flower worker, number of flower workers in the child's home, and number of practices that might increase children's exposure to pesticides. Mean (± SD) AChE activity was 3.14 ± 0.49 U/mL. A 1-U/mL decrease in AChE activity was associated with a 2.86-mmHg decrease in SBP (95% CI: -5.20, -0.53) and a 2.89-mmHg decrease in DBP (95% CI: -5.00, -0.78), after adjustment for potential confounders. Children living with flower workers had lower SBP (-1.72 mmHg; 95% CI: -3.53, 0.08) than other children, and practices that might increase exposure also were associated with lower SBP. No significant associations were found between exposures and heart rate. Our findings suggest that subclinical secondary exposures to pesticides may affect vascular reactivity in children. Additional research is needed to confirm these findings.

EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

DEFF Research Database (Denmark)

De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G

2010-01-01

an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

Chemical composition of the essential oil and hexane extract of Salvia chionantha and their antioxidant and anticholinesterase activities.

Science.gov (United States)

Tel, Gülsen; Oztürk, Mehmet; Duru, Mehmet Emin; Harmandar, Mansur; Topçu, Gülaçti

2010-11-01

The essential oil and methyl ester of hexane extract of Salvia chionantha Boiss. were analysed by GC and GC-MS. Totally, 54 components were detected in the essential oil and all of them were fully determined. Germacrene D (25.03%), β-caryophyllene (8.71%), spathulenol (5.86%) and α-humulene (4.82%) were identified as the major compounds. In the methylated hexane extract, 3-hydroxy hexadecanoic acid (39.39%), 3-hydroxy tetradecanoic acid (12.66%) and palmitic acid (12.02%) were the major fatty acids elucidated. The antioxidant activity of the essential oil and the hexane extract was determined by using four complementary test systems; namely, β-carotene-linoleic acid, DPPH() scavenging, ABTS(+)* scavenging, and CUPRAC assays. In β-carotene-linoleic acid assay, the extract showed 81.2±0.1% lipid peroxidation inhibition at 0.8 mg/mL concentration, while in ABTS(+)* assay the essential oil exhibited 77.4±0.5% inhibition at same concentration. Since, acetylcholinesterase and butyrylcholinesterase enzymes are taking place in pathogenesis of Alzheimer's disease, in vitro anticholinesterase activity of the essential oil and the extract was also studied spectrophotometrically. At 0.5mg/mL concentration, the essential oil showed moderate acetylcholinesterase (56.7±1.9%) and butyrylcholinesterase (41.7±2.9%) inhibitory activity, while the extract was only exhibited activity (63.1±0.8%) against butyrylcholinesterase enzyme. Hence, the essential oil may be useful as a moderate anticholinesterase agent, particularly against acetylcholinesterase. Copyright © 2010 Elsevier Ltd. All rights reserved.

Synthesis, DNA Cleavage Activity, Cytotoxicity, Acetylcholinesterase Inhibition, and Acute Murine Toxicity of Redox-Active Ruthenium(II) Polypyridyl Complexes.

Science.gov (United States)

Alatrash, Nagham; Narh, Eugenia S; Yadav, Abhishek; Kim, Mahn-Jong; Janaratne, Thamara; Gabriel, James; MacDonnell, Frederick M

2017-07-06

Four mononuclear [(L-L) 2 Ru(tatpp)] 2+ and two dinuclear [(L-L) 2 Ru(tatpp)Ru(L-L) 2 ] 4+ ruthenium(II) polypyridyl complexes (RPCs) containing the 9,11,20,22-tetraazatetrapyrido[3,2-a:2',3'-c:3'',2''-l:2''',3'''-n]pentacene (tatpp) ligand were synthesized, in which L-L is a chelating diamine ligand such as 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (Me 4 phen) or 4,7-diphenyl-1,10-phenanthroline (Ph 2 phen). These Ru-tatpp analogues all undergo reduction reactions with modest reducing agents, such as glutathione (GSH), at pH 7. These, plus several structurally related but non-redox-active RPCs, were screened for DNA cleavage activity, cytotoxicity, acetylcholinesterase (AChE) inhibition, and acute mouse toxicity, and their activities were examined with respect to redox activity and lipophilicity. All of the redox-active RPCs show single-strand DNA cleavage in the presence of GSH, whereas none of the non-redox-active RPCs do. Low-micromolar cytotoxicity (IC 50 ) against malignant H358, CCL228, and MCF7 cultured cell lines was mainly restricted to the redox-active RPCs; however, they were substantially less toxic toward nonmalignant MCF10 cells. The IC 50 values for AChE inhibition in cell-free assays and the acute toxicity of RPCs in mice revealed that whereas most RPCs show potent inhibitory action against AChE (IC 50 values <15 μm), Ru-tatpp complexes as a class are surprisingly well tolerated in animals relative to other RPCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection of Extracellular Enzyme Activities in Ganoderma neo-japonicum

OpenAIRE

Jo, Woo-Sik; Park, Ha-Na; Cho, Doo-Hyun; Yoo, Young-Bok; Park, Seung-Chun

2011-01-01

The ability of Ganoderma to produce extracellular enzymes, including β-glucosidase, cellulase, avicelase, pectinase, xylanase, protease, amylase, and ligninase was tested in chromogenic media. β-glucosidase showed the highest activity, among the eight tested enzymes. In particular, Ganoderma neo-japonicum showed significantly stronger activity for β-glucosidase than that of the other enzymes. Two Ganoderma lucidum isolates showed moderate activity for avicelase; however, Ganoderma neo-japonic...

Distribution of intravenously administered acetylcholinesterase inhibitor and acetylcholinesterase activity in the adrenal gland: 11C-donepezil PET study in the normal rat.

Science.gov (United States)

Watabe, Tadashi; Naka, Sadahiro; Ikeda, Hayato; Horitsugi, Genki; Kanai, Yasukazu; Isohashi, Kayako; Ishibashi, Mana; Kato, Hiroki; Shimosegawa, Eku; Watabe, Hiroshi; Hatazawa, Jun

2014-01-01

Acetylcholinesterase (AChE) inhibitors have been used for patients with Alzheimer's disease. However, its pharmacokinetics in non-target organs other than the brain has not been clarified yet. The purpose of this study was to evaluate the relationship between the whole-body distribution of intravenously administered (11)C-Donepezil (DNP) and the AChE activity in the normal rat, with special focus on the adrenal glands. The distribution of (11)C-DNP was investigated by PET/CT in 6 normal male Wistar rats (8 weeks old, body weight  = 220 ± 8.9 g). A 30-min dynamic scan was started simultaneously with an intravenous bolus injection of (11)C-DNP (45.0 ± 10.7 MBq). The whole-body distribution of the (11)C-DNP PET was evaluated based on the Vt (total distribution volume) by Logan-plot analysis. A fluorometric assay was performed to quantify the AChE activity in homogenized tissue solutions of the major organs. The PET analysis using Vt showed that the adrenal glands had the 2nd highest level of (11)C-DNP in the body (following the liver) (13.33 ± 1.08 and 19.43 ± 1.29 ml/cm(3), respectively), indicating that the distribution of (11)C-DNP was the highest in the adrenal glands, except for that in the excretory organs. The AChE activity was the third highest in the adrenal glands (following the small intestine and the stomach) (24.9 ± 1.6, 83.1 ± 3.0, and 38.5 ± 8.1 mU/mg, respectively), indicating high activity of AChE in the adrenal glands. We demonstrated the whole-body distribution of (11)C-DNP by PET and the AChE activity in the major organs by fluorometric assay in the normal rat. High accumulation of (11)C-DNP was observed in the adrenal glands, which suggested the risk of enhanced cholinergic synaptic transmission by the use of AChE inhibitors.

Distribution of intravenously administered acetylcholinesterase inhibitor and acetylcholinesterase activity in the adrenal gland: 11C-donepezil PET study in the normal rat.

Directory of Open Access Journals (Sweden)

Tadashi Watabe

Full Text Available PURPOSE: Acetylcholinesterase (AChE inhibitors have been used for patients with Alzheimer's disease. However, its pharmacokinetics in non-target organs other than the brain has not been clarified yet. The purpose of this study was to evaluate the relationship between the whole-body distribution of intravenously administered (11C-Donepezil (DNP and the AChE activity in the normal rat, with special focus on the adrenal glands. METHODS: The distribution of (11C-DNP was investigated by PET/CT in 6 normal male Wistar rats (8 weeks old, body weight  = 220 ± 8.9 g. A 30-min dynamic scan was started simultaneously with an intravenous bolus injection of (11C-DNP (45.0 ± 10.7 MBq. The whole-body distribution of the (11C-DNP PET was evaluated based on the Vt (total distribution volume by Logan-plot analysis. A fluorometric assay was performed to quantify the AChE activity in homogenized tissue solutions of the major organs. RESULTS: The PET analysis using Vt showed that the adrenal glands had the 2nd highest level of (11C-DNP in the body (following the liver (13.33 ± 1.08 and 19.43 ± 1.29 ml/cm(3, respectively, indicating that the distribution of (11C-DNP was the highest in the adrenal glands, except for that in the excretory organs. The AChE activity was the third highest in the adrenal glands (following the small intestine and the stomach (24.9 ± 1.6, 83.1 ± 3.0, and 38.5 ± 8.1 mU/mg, respectively, indicating high activity of AChE in the adrenal glands. CONCLUSIONS: We demonstrated the whole-body distribution of (11C-DNP by PET and the AChE activity in the major organs by fluorometric assay in the normal rat. High accumulation of (11C-DNP was observed in the adrenal glands, which suggested the risk of enhanced cholinergic synaptic transmission by the use of AChE inhibitors.

Rosmarinus officinalis L. leaf extract improves memory impairment and affects acetylcholinesterase and butyrylcholinesterase activities in rat brain.

Science.gov (United States)

Ozarowski, Marcin; Mikolajczak, Przemyslaw L; Bogacz, Anna; Gryszczynska, Agnieszka; Kujawska, Malgorzata; Jodynis-Liebert, Jadwiga; Piasecka, Anna; Napieczynska, Hanna; Szulc, Michał; Kujawski, Radoslaw; Bartkowiak-Wieczorek, Joanna; Cichocka, Joanna; Bobkiewicz-Kozlowska, Teresa; Czerny, Boguslaw; Mrozikiewicz, Przemyslaw M

2013-12-01

Rosmarinus officinalis L. leaf as part of a diet and medication can be a valuable proposal for the prevention and treatment of dementia. The aim of the study was to assess the effects of subchronic (28-fold) administration of a plant extract (RE) (200 mg/kg, p.o.) on behavioral and cognitive responses of rats linked with acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity and their mRNA expression level in the hippocampus and frontal cortex. The passive avoidance test results showed that RE improved long-term memory in scopolamine-induced rats. The extract inhibited the AChE activity and showed a stimulatory effect on BuChE in both parts of rat brain. Moreover, RE produced a lower mRNA BuChE expression in the cortex and simultaneously an increase in the hippocampus. The study suggests that RE led to improved long-term memory in rats, which can be partially explained by its inhibition of AChE activity in rat brain. © 2013. Published by Elsevier B.V. All rights reserved.

An appraisal of the enzyme stability-activity trade-off.

Science.gov (United States)

Miller, Scott R

2017-07-01

A longstanding idea in evolutionary physiology is that an enzyme cannot jointly optimize performance at both high and low temperatures due to a trade-off between stability and activity. Although a stability-activity trade-off has been observed for well-characterized examples, such a trade-off is not imposed by any physical chemical constraint. To better understand the pervasiveness of this trade-off, I investigated the stability-activity relationship for comparative biochemical studies of purified orthologous enzymes identified by a literature search. The nature of this relationship varied greatly among studies. Notably, studies of enzymes with low mean synonymous nucleotide sequence divergence were less likely to exhibit the predicted negative correlation between stability and activity. Similarly, a survey of directed evolution investigations of the stability-activity relationship indicated that these traits are often uncoupled among nearly identical yet phenotypically divergent enzymes. This suggests that the presumptive trade-off often reported for investigations of enzymes with high mean sequence divergence may in some cases instead be a consequence of the degeneration over time of enzyme function in unselected environments, rather than a direct effect of thermal adaptation. The results caution against the general assertion of a stability-activity trade-off during enzyme adaptation. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Acetylcholinesterase activity in the terrestrial snail Xeropicta derbentina transplanted in apple orchards with different pesticide management strategies

Energy Technology Data Exchange (ETDEWEB)

Mazzia, Christophe, E-mail: christophe.mazzia@univ-avignon.f [Universite d' Avignon et des Pays de Vaucluse, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, ' Abeilles et Environnement' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France); Capowiez, Yvan [INRA, UR 1115 ' Plante et Systemes Horticoles' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France); Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo (Spain); Koehler, Heinz-R. [Animal Physiological Ecology, Institute for Evolution and Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Triebskorn, Rita [Animal Physiological Ecology, Institute for Evolution and Ecology, University of Tuebingen, Konrad-Adenauer-Str. 20, D-72072 Tuebingen (Germany); Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Blumenstrasse 13, D-72108 Rottenburg (Germany); Rault, Magali [Universite d' Avignon et des Pays de Vaucluse, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, ' Abeilles et Environnement' , Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 9 France (France)

2011-01-15

Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilitate comparison of multiple sites in a short time. We released specimens of the terrestrial snail Xeropicta derbentina in each 5 of two kinds of apple orchards with either conventional or organic management strategies plus in a single abandoned orchard. After one month, individuals were retrieved in order to measure acetylcholinesterase (AChE) activity. Mean values of AChE activity were significantly reduced in all conventional apple orchards compared to the others. Results show that the measurement of biomarkers such as AChE inhibition in transplated X. derbentina could be useful in the environmental risk assessment of post-authorized pesticides. - Snails as sentinel species to evaluate insecticide impacts in apple orchards.

Acetylcholinesterase activity in the terrestrial snail Xeropicta derbentina transplanted in apple orchards with different pesticide management strategies

International Nuclear Information System (INIS)

Mazzia, Christophe; Capowiez, Yvan; Sanchez-Hernandez, Juan C.; Koehler, Heinz-R.; Triebskorn, Rita; Rault, Magali

2011-01-01

Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilitate comparison of multiple sites in a short time. We released specimens of the terrestrial snail Xeropicta derbentina in each 5 of two kinds of apple orchards with either conventional or organic management strategies plus in a single abandoned orchard. After one month, individuals were retrieved in order to measure acetylcholinesterase (AChE) activity. Mean values of AChE activity were significantly reduced in all conventional apple orchards compared to the others. Results show that the measurement of biomarkers such as AChE inhibition in transplated X. derbentina could be useful in the environmental risk assessment of post-authorized pesticides. - Snails as sentinel species to evaluate insecticide impacts in apple orchards.

Extracellular enzyme activity assay as indicator of soil microbial functional diversity and activity

DEFF Research Database (Denmark)

Hendriksen, Niels Bohse; Winding, Anne

2012-01-01

Extracellular enzyme activity assay as indicator of soil microbial functional diversity and activity Niels Bohse Hendriksen, Anne Winding. Department of Environmental Science, Aarhus University, 4000 Roskilde, Denmark Soils provide numerous essential ecosystem services such as carbon cycling...... of soil microbial functions is still needed. In soil, enzymes originate from a variety of organisms, notably fungi and bacteria and especially hydrolytic extracellular enzymes are of pivotal importance for decomposition of organic substrates and biogeochemical cycling. Their activity will reflect...... the functional diversity and activity of the microorganisms involved in decomposition processes. Their activity has been measured by the use of fluorogenic model substrates e.g. methylumbelliferyl (MUF) substrates for a number of enzymes involved in the degradation of polysacharides as cellulose, hemicellulose...

Histochemical study of reaction of the nucleus supraopticus of rat brain to irradiation with 500 Gy

International Nuclear Information System (INIS)

Dosoudilova, M.; Kamarad, V.

1987-01-01

The activities were described of some enzymes in nucleus supraopticus of the rat brain at an early interval (5 min) after gamma irradiation with 500 Gy, at a dose rate of 6.9 Gy per minute. The study was performed using cryostat sections. The activities of the following enzymes were shown: alkaline phosphatase, acid phosphatase, ATP-splitting enzyme, thiaminepyrophosphatase, butyrylcholinesterase, acetylcholinesterase, glycero-3-phosphate-dehydrogenase, succinate dehydrogenase, acid nonspecific esterase, and beta glucuronidase. After irradiation, increased activities of acid phosphatase, thiaminepyrophosphatase, and acetylcholinesterase was observed in perikarya of magnocelullar neurons of the nucleus, whereas the activities of other enzymes were weak when compared to controls. A significant decrease in the activity of acidic nonspecific esterase was found. In contrast to the controls, blood capillaries showed increased activities of ATP-splitting enzyme, butyrylcholinesterase, thiaminepyrophosphatase. The activities of alkaline phosphatase and acid phosphatase were not changed. No activity of other enzymes was observed in that site. (author). 13 refs

Is acetylcholinesterase a biomarker of susceptibility in Daphnia magna (Crustacea, Cladocera) after deltamethrin exposure?

Science.gov (United States)

Toumi, Héla; Boumaiza, Moncef; Millet, Maurice; Radetski, Claudemir Marcos; Felten, Vincent; Férard, Jean François

2015-02-01

In the present study, we explored the possibility of using the acetylcholinesterase (AChE) as a biomarker after deltamethrin (pyrethroid insecticide) exposure with three strains of the cladoceran Daphnia magna. Four calculated time-weighted deltamethrin concentrations (20.1, 40.3, 80.6 and 161.3 ng L(-1)) were compared against control acetylcholinesterase activity. Our results showed that after 48 h of deltamethrin exposure, all treatments induced a significant decrease of AChE activities whatever the three considered strains. However, diverse responses were registered in terms of lowest observed effect concentrations (LOEC: 80.6 ng L(-1) for strain 1 and 20.1 ng L(-1) for strains 2 and 3) revealing differences in sensitivity among the three tested strains of D. magna. Our results suggest that after deltamethrin exposure, the AChE activity responses can be also used as a biomarker of susceptibility (i.e., variation of strain specific response). Moreover, our results show that strain 1 is the less sensitive in terms of IC50-48 h of AChE, whereas it became the most sensitive when considering the EC50-48 h estimated in the standard ecotoxicity test. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular modeling and anticholinesterasic activity of novel 2-arylaminocyclohexyl N,N-dimethylcarbamates

Energy Technology Data Exchange (ETDEWEB)

Bagatin, Mariane C.; Candido, Augusto A.; Basso, Ernani A.; Gauze, Gisele F., E-mail: gfgbandoch@uem.br [Universidade Estadual de Maringa (UEM), PR (Brazil). Departamento de Quimica; Pinheiro, Glaucia M. S.; Hoeehr, Nelci F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Ciencias Medicas. Departamento de Patologia Clinica; Machinski Junior, Miguel; Mossini, Simone A.G. [Universidade Estadual de Maringa (UEM), PR (Brazil). Departamento de Ciencias Basicas da Saude

2013-11-15

This work reports a detailed theoretical and experimental study of the novel isomer series cis- and trans-2-arylaminocyclohexyl N,N-dimethylcarbamates as potential inhibitors of cholinesterases. In vitro inhibition assay by Ellman's method with human blood samples showed that the new carbamates are selective to the inhibition of enzyme butyrylcholinesterase (BuChE) with maximum inhibition of 90% and IC{sub 50} of 6 and 8 mmol L{sup -1} for the more actives compounds of the series. Molecular modeling studies point to significant differences for the conformations of the compounds in the active sites of enzymes BuChE and acetylcholinesterase (AChE). The results show that the compounds interact more effectively with the active site of enzyme BuChE since the carbamate group is close to the key residues of the catalytic triad. (author)

Molecular modeling and anticholinesterasic activity of novel 2-arylaminocyclohexyl N,N-dimethylcarbamates

International Nuclear Information System (INIS)

Bagatin, Mariane C.; Candido, Augusto A.; Basso, Ernani A.; Gauze, Gisele F.; Pinheiro, Glaucia M. S.; Hoeehr, Nelci F.; Machinski Junior, Miguel; Mossini, Simone A.G.

2013-01-01

This work reports a detailed theoretical and experimental study of the novel isomer series cis- and trans-2-arylaminocyclohexyl N,N-dimethylcarbamates as potential inhibitors of cholinesterases. In vitro inhibition assay by Ellman's method with human blood samples showed that the new carbamates are selective to the inhibition of enzyme butyrylcholinesterase (BuChE) with maximum inhibition of 90% and IC 50 of 6 and 8 mmol L -1 for the more actives compounds of the series. Molecular modeling studies point to significant differences for the conformations of the compounds in the active sites of enzymes BuChE and acetylcholinesterase (AChE). The results show that the compounds interact more effectively with the active site of enzyme BuChE since the carbamate group is close to the key residues of the catalytic triad. (author)

Design, synthesis and evaluation of some N-methylenebenzenamine derivatives as selective acetylcholinesterase (AChE) inhibitor and antioxidant to enhance learning and memory.

Science.gov (United States)

Shrivastava, Sushant K; Srivastava, Pavan; Upendra, T V R; Tripathi, Prabhash Nath; Sinha, Saurabh K

2017-02-15

Series of some 3,5-dimethoxy-N-methylenebenzenamine and 4-(methyleneamino)benzoic acid derivatives comprising of N-methylenebenzenamine nucleus were designed, synthesized, characterized, and assessed for their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory, and antioxidant activity thereby improving learning and memory in rats. The IC 50 values of all the compound along with standard were determined on AChE and BChE enzyme. The free radical scavenging activity was also assessed by in vitro DPPH (2,2-diphenyl-1-picryl-hydrazyl) and hydrogen peroxide radical scavenging assay. The selective inhibitions of all compounds were observed against AChE in comparison with standard donepezil. The enzyme kinetic study of the most active compound 4 indicated uncompetitive AChE inhibition. The docking studies of compound 4 exhibited the worthy interaction on active-site gorge residues Phe330 and Trp279 responsible for its high affinity towards AChE, whereas lacking of the BChE inhibition was observed due to a wider gorge binding site and absence of important aromatic amino acids interactions. The ex vivo study confirmed AChE inhibition abilities of compound 4 at brain site. Further, a considerable decrease in escape latency period of the compound was observed in comparison with standard donepezil through in vivo Spatial Reference Memory (SRM) and Spatial Working Memory (SWM) models which showed the cognition-enhancing potential of compound 4. The in vivo reduced glutathione (GSH) estimation on rat brain tissue homogenate was also performed to evaluate free radical scavenging activity substantiated the antioxidant activity in learning and memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential anti-cholinesterase and β-site amyloid precursor protein cleaving enzyme 1 inhibitory activities of cornuside and gallotannins from Cornus officinalis fruits.

Science.gov (United States)

Bhakta, Himanshu Kumar; Park, Chan Hum; Yokozawa, Takako; Tanaka, Takashi; Jung, Hyun Ah; Choi, Jae Sue

2017-07-01

Cholinesterase (ChE) and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors are promising agents for the treatment of Alzheimer's disease (AD). In the present study, we examined the inhibitory activity of seven compounds isolated from the fruits of Cornus officinalis, cornuside, polymeric proanthocyanidins, 1,2,3-tri-O-galloyl-β-D-glucose, 1,2,3,6-tetra-O-galloyl-β-D-glucose, tellimagrandin I, tellimagrandin II, and isoterchebin, against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE1. All of the compounds displayed concentration-dependent in vitro inhibitory activity toward the ChEs and BACE1. Among them, tellimagrandin II exhibited the best inhibitory activity toward ChEs, whereas the best BACE1 inhibitor was 1,2,3,6-tetra-O-galloyl-β-D-glucose. Isoterchebin and polymeric proanthocyanidins were also significant ChE inhibitors. The kinetic and docking studies demonstrated that all compounds interacted with both the catalytic active sites and the peripheral anionic sites of the ChEs and BACE1. Tellimagrandin II, isoterchebin, and the polymeric proanthocyanidins exhibited concentration-dependent inhibition of peroxynitrite-mediated protein tyrosine nitration. In conclusion, we identified significant ChE and BACE1 inhibitors from Corni Fructus that could have value as new multi-targeted compounds for anti-AD agents.

Nootropic activity of Celastrus paniculatus seed.

Science.gov (United States)

Bhanumathy, M; Harish, M S; Shivaprasad, H N; Sushma, G

2010-03-01

The effect of Celastrus paniculatus Willd. (Celastraceae) seed aqueous extract on learning and memory was studied using elevated plus maze and passive avoidance test (sodium nitrite induced amnesia rodent model). The aqueous seed extract was administered orally in two different doses to rats (350 and 1050 mg/kg) and to mice (500 and 1500 mg/kg). The results were compared to piracetam (100 mg/kg, p.o.) used as a standard drug. Chemical hypoxia was induced by subcutaneous administration of sodium nitrite (35 mg/kg), immediately after acquisition training. In elevated plus maze and sodium nitrite-induced amnesia model, Celastrus paniculatus extract has showed statistically significant improvement in memory process when compared to control. The estimation of acetylcholinesterase enzyme in rat brain supports the plus maze and passive avoidance test by reducing acetylcholinesterase activity which helps in memory performance. The study reveals that the aqueous extract of Celastrus paniculatus seed has dose-dependent cholinergic activity, thereby improving memory performance. The mechanism by which Celastrus paniculatus enhances cognition may be due to increased acetylcholine level in rat brain.

Descriptive and predictive assessment of enzyme activity and enzyme related processes in biorefinery using IR spectroscopy and chemometrics

DEFF Research Database (Denmark)

Baum, Andreas

the understanding of the structural properties of the extracted pectin. Secondly, enzyme kinetics of biomass converting enzymes was examined in terms of measuring enzyme activity by spectral evolution profiling utilizing FTIR. Chemometric multiway methods were used to analyze the tensor datasets enabling the second......-order calibration advantage (reference Theory of Analytical chemistry). As PAPER 3 illustrates the method is universally applicable without the need of any external standards and was exemplified by performing quantitative enzyme activity determinations for glucose oxidase, pectin lyase and a cellolytic enzyme blend...... (Celluclast 1.5L). In PAPER 4, the concept is extended to quantify enzyme activity of two simultaneously acting enzymes, namely pectin lyase and pectin methyl esterase. By doing so the multiway methods PARAFAC, TUCKER3 and NPLS were compared and evaluated towards accuracy and precision....

General discussion about enzymes activities of radiation injury

International Nuclear Information System (INIS)

Vucicevic, M.; Sukalo, I.

1989-01-01

Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

General discussion about enzymes activities of radiation injury

Energy Technology Data Exchange (ETDEWEB)

Vucicevic, M; Sukalo, I [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1989-07-01

Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

Actinomycete enzymes and activities involved in straw saccharification

Energy Technology Data Exchange (ETDEWEB)

McCarthy, A J; Ball, A S [Liverpool Univ. (UK). Dept. of Genetics and Microbiology

1990-01-01

This research programme has been directed towards the analysis of actinomycete enzyme systems involved in the degradation of plant biomass (lignocellulose.) The programme was innovative in that a novel source of enzymes was systematically screened and wheat straw saccharifying activity was the test criterion. Over 200 actinomycete strains representing a broad taxonomic range were screened. A range of specific enzyme activities were involved and included cellulase, xylanase, arabinofuranosidase, acetylesterase, {beta}-xylosidase and {beta}-glucosidase. Since hemicellulose (arabinoxylan) was the primary source of sugar, xylanases were characterized. The xylan-degrading systems of actinomycetes were complex and nonuniform, with up to six separate endoxylanases identified in active strains. Except for microbispora bispora, actinomycetes were found to be a poor source of cellulase activity. Evidence for activity against the lignin fraction of straw was produced for a range of actinomycete strains. While modification reactions were common, cleavage of inter-monomer bonds, and utilization of complex polyphenolic compounds were restricted to two strains: Thermomonospora mesophila and Streptomyces badius. Crude enzyme preparations from actinomycetes can be used to generate sugar, particularly pentoses, directly from cereal straw. The potential for improvements in yield rests with the formulation to cooperative enzyme combinations from different strains. The stability properties of enzymes from thermophilic strains and the general neutral to alkali pH optima offer advantages in certain process situations. Actinomycetes are a particularly rich source of xylanases for commercial application and can rapidly solubilise a lignocarbohydrate fraction of straw which may have both product and pretreatment potential. 31 refs., 4 figs., 5 tabs.

Thermodynamic Activity-Based Progress Curve Analysis in Enzyme Kinetics.

Science.gov (United States)

Pleiss, Jürgen

2018-03-01

Macrokinetic Michaelis-Menten models based on thermodynamic activity provide insights into enzyme kinetics because they separate substrate-enzyme from substrate-solvent interactions. Kinetic parameters are estimated from experimental progress curves of enzyme-catalyzed reactions. Three pitfalls are discussed: deviations between thermodynamic and concentration-based models, product effects on the substrate activity coefficient, and product inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immobilized enzyme reactor chromatography: Optimization of protein retention and enzyme activity in monolithic silica stationary phases

International Nuclear Information System (INIS)

Besanger, Travis R.; Hodgson, Richard J.; Green, James R.A.; Brennan, John D.

2006-01-01

Our group recently reported on the application of protein-doped monolithic silica columns for immobilized enzyme reactor chromatography, which allowed screening of enzyme inhibitors present in mixtures using mass spectrometry for detection. The enzyme was immobilized by entrapment within a bimodal meso/macroporous silica material prepared by a biocompatible sol-gel processing route. While such columns proved to be useful for applications such as screening of protein-ligand interactions, significant amounts of entrapped proteins leached from the columns owing to the high proportion of macropores within the materials. Herein, we describe a detailed study of factors affecting the morphology of protein-doped bioaffinity columns and demonstrate that specific pH values and concentrations of poly(ethylene glycol) can be used to prepare essentially mesoporous columns that retain over 80% of initially loaded enzyme in an active and accessible form and yet still retain sufficient porosity to allow pressure-driven flow in the low μL/min range. Using the enzyme γ-glutamyl transpeptidase (γ-GT), we further evaluated the catalytic constants of the enzyme entrapped in capillary columns with different silica morphologies as a function of flowrate and backpressure using the enzyme reactor assay mode. It was found that the apparent activity of the enzyme was highest in mesoporous columns that retained high levels of enzyme. In such columns, enzyme activity increased by ∼2-fold with increases in both flowrate (from 250 to 1000 nL/min) and backpressure generated (from 500 to 2100 psi) during the chromatographic activity assay owing to increases in k cat and decreases in K M , switching from diffusion controlled to reaction controlled conditions at ca. 2000 psi. These results suggest that columns with minimal macropore volumes (<5%) are advantageous for the entrapment of soluble proteins for bioaffinity and bioreactor chromatography

Inhibition of existing denitrification enzyme activity by chloramphenicol

Science.gov (United States)

Brooks, M.H.; Smith, R.L.; Macalady, D.L.

1992-01-01

Chloramphenicol completely inhibited the activity of existing denitrification enzymes in acetylene-block incubations with (i) sediments from a nitrate-contaminated aquifer and (ii) a continuous culture of denitrifying groundwater bacteria. Control flasks with no antibiotic produced significant amounts of nitrous oxide in the same time period. Amendment with chloramphenicol after nitrous oxide production had begun resulted in a significant decrease in the rate of nitrous oxide production. Chloramphenicol also decreased (>50%) the activity of existing denitrification enzymes in pure cultures of Pseudomonas denitrificans that were harvested during log- phase growth and maintained for 2 weeks in a starvation medium lacking electron donor. Short-term time courses of nitrate consumption and nitrous oxide production in the presence of acetylene with P. denitrificans undergoing carbon starvation were performed under optimal conditions designed to mimic denitrification enzyme activity assays used with soils. Time courses were linear for both chloramphenicol and control flasks, and rate estimates for the two treatments were significantly different at the 95% confidence level. Complete or partial inhibition of existing enzyme activity is not consistent with the current understanding of the mode of action of chloramphenicol or current practice, in which the compound is frequently employed to inhibit de novo protein synthesis during the course of microbial activity assays. The results of this study demonstrate that chloramphenicol amendment can inhibit the activity of existing denitrification enzymes and suggest that caution is needed in the design and interpretation of denitrification activity assays in which chloramphenicol is used to prevent new protein synthesis.

Modification of polymer surfaces to enhance enzyme activity and stability

DEFF Research Database (Denmark)

Hoffmann, Christian

Enzyme immobilization is an important concept for the development of improved biocatalytic processes, primarily through facilitated separation procedures. However, enzyme immobilization usually comes at a price of reduced biocatalytic activity. For this reason, different immobilization methods have...... already been developed, combining the same goal to improve enzyme activity, stability and selectivity. Polymer materials have shown, due to their easy processibility and versatile properties, high potential as enzyme support. However, in order to achieve improved enzyme performance, the combination...... on their tailored surface modification in order to obtain improved enzyme-support systems. Firstly, an off-stoichiometric thiol-ene (OSTE) thermosetting material was used for the development of a screening platform allowing the investigation of micro-environmental effects and their impact on the activity...

Xanthone and Flavone Derivatives as Dual Agents with Acetylcholinesterase Inhibition and Antioxidant Activity as Potential Anti-Alzheimer Agents

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Inês Cruz

2017-01-01

Full Text Available Alzheimer’s disease (AD is a multifactorial neurodegenerative disorder that is associated with the elderly. The current therapy that is used to treat AD is based mainly on the administration of acetylcholinesterase (AChE inhibitors. Due to their low efficacy there is a considerable need for other therapeutic strategies. Considering that the malfunctions of different, but interconnected, biochemical complex pathways play an important role in the pathogenesis of this disease, a promising therapy may consist in administration of drugs that act on more than a target on biochemical scenery of AD. In this work, the synthesis and evaluation of xanthone and flavone derivatives as antioxidants with AChE inhibitory activity were accomplished. Among the obtained compounds, Mannich bases 3 and 14 showed capacity to inhibit AChE and antioxidant property, exerting dual activity. Moreover, for the most promising AChE inhibitors, docking studies on the target have been performed aiming to predict the binding mechanism. The results presented here may help to identify new xanthone and flavone derivatives as dual anti-Alzheimer agents with AChE inhibitory and antioxidant activities.

Acetylcholinesterase activity in seabirds affected by the Prestige oil spill on the Galician coast (Spain)

Energy Technology Data Exchange (ETDEWEB)

Oropesa, Ana-Lourdes; Perez-Lopez, Marcos; Hernandez, David; Soler, Francisco [Toxicology Area, Faculty of Veterinary Science (UEX), Avda. de la Universidad s/n. 10071 Caceres (Spain); Garcia, Jesus-Pablo [Toxicology Area, National Centre of Environmental Health, Instituto de Salud Carlos III, Majadahonda, Madrid (Spain); Fidalgo, Luis-Eusebio; Lopez-Beceiro, Ana [Rof Codina Clinical Hospital, Faculty of Veterinary Science (USC), Estrada de Granxa s/n. 27003 Lugo (Spain)

2007-01-01

In November 2002, the tanker Prestige broke in two and sank at the bottom of the ocean spilling about 70,000 t of fuel oil, which reached the coast of Galicia. It was considered the largest spill in maritime history, greatly affecting marine and related avian species. The spilled fuel oil contained high concentrations of polycyclic aromatic hydrocarbons (PAHs). Many species were affected and were found dead, although ongoing research is still being carried out on the sublethal effects. In this sense, little is known about the action of PAHs on Cholinesterase activity in seabirds. Consequently, the purpose of this study was to provide more information on the neurotoxicity of fuel oil on the seabirds most affected by the Prestige accident: common guillemot, Atlantic puffin and razorbill. On the other hand, data on normal values of acetylcholinesterase (AChE) activity were obtained to supply non-exposed values in seabirds. The oil spill produced a clear inhibitory effect on brain AChE activity in common guillemot (16%, p {<=} 0.01) and razorbill (22%, p {<=} 0.01), but not in Atlantic puffin (4%). Physiological levels of brain AChE, expressed in nmol acetylcholine hydrolysed min{sup -} {sup 1} mg{sup -} {sup 1} protein were similar in non-exposed common guillemot (388.6 {+-} 95.0) and Atlantic puffin (474.0 {+-} 60.7), however, razorbill values were higher (644.6 {+-} 66.9). (author)

ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

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Rıdvan KIZILKAYA

1998-03-01

Full Text Available This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**, extractable Mn (r = 0.74**, exchangable K (r = 0.73** and total P content of soil (r = 0.81*. Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71* and extractable Cu (r = 0.74* were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*, exchangable Ca (r = 0.74*, exchangable Mg (r = 0.71*, exchangable total basic cations (r = 0.79* and extractable Cu (r = 0.70* had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84** affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97** had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70* affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82* and salt content (r = 0.83** of samples.

Finding Biomass Degrading Enzymes Through an Activity-Correlated Quantitative Proteomics Platform (ACPP)

Science.gov (United States)

Ma, Hongyan; Delafield, Daniel G.; Wang, Zhe; You, Jianlan; Wu, Si

2017-04-01

The microbial secretome, known as a pool of biomass (i.e., plant-based materials) degrading enzymes, can be utilized to discover industrial enzyme candidates for biofuel production. Proteomics approaches have been applied to discover novel enzyme candidates through comparing protein expression profiles with enzyme activity of the whole secretome under different growth conditions. However, the activity measurement of each enzyme candidate is needed for confident "active" enzyme assignments, which remains to be elucidated. To address this challenge, we have developed an Activity-Correlated Quantitative Proteomics Platform (ACPP) that systematically correlates protein-level enzymatic activity patterns and protein elution profiles using a label-free quantitative proteomics approach. The ACPP optimized a high performance anion exchange separation for efficiently fractionating complex protein samples while preserving enzymatic activities. The detected enzymatic activity patterns in sequential fractions using microplate-based assays were cross-correlated with protein elution profiles using a customized pattern-matching algorithm with a correlation R-score. The ACPP has been successfully applied to the identification of two types of "active" biomass-degrading enzymes (i.e., starch hydrolysis enzymes and cellulose hydrolysis enzymes) from Aspergillus niger secretome in a multiplexed fashion. By determining protein elution profiles of 156 proteins in A. niger secretome, we confidently identified the 1,4-α-glucosidase as the major "active" starch hydrolysis enzyme (R = 0.96) and the endoglucanase as the major "active" cellulose hydrolysis enzyme (R = 0.97). The results demonstrated that the ACPP facilitated the discovery of bioactive enzymes from complex protein samples in a high-throughput, multiplexing, and untargeted fashion.

Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions

Science.gov (United States)

Allison, S. D.; Jastrow, J. D.

2004-12-01

Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

Enzyme hydration, activity and flexibility : A neutron scattering approach

International Nuclear Information System (INIS)

Kurkal-Siebert, V.; Finney, J.L.; Daniel, R.M.; Smith, Jeremy C.

2006-01-01

Recent measurements have demonstrated enzyme activity at hydrations as low as 3%. The question of whether the hydration-induced enzyme flexibility is important for activity is addressed by performing picosecond dynamic neutron scattering experiments on pig liver esterase powders at various temperatures as well as solutions. At all temperatures and hydrations investigated here, significant quasielastic scattering intensity is found in the protein, indicating the presence of anharmonic, diffusive motion. As the hydration increases a temperature-dependent dynamical transition appears and strengthens involving additional diffusive motion. At low temperature, increasing hydration resulted in lower flexibility of the enzyme. At higher temperatures, systems containing sufficient number of water molecules interacting with the protein exhibit increased flexibility. The implication of these results is that, although the additional hydration-induced diffusive motion and flexibility at high temperatures in the enzyme detected here may be related to increased activity, they are not required for the enzyme to function

Integrated Use of Biomarkers (O : N Ratio and Acetylcholinesterase Inhibition) on Aulacomya ater (Molina, 1782) (Bivalvia: Mytilidae) as a Criteria for Effects of Organophosphate Pesticide Exposition

Science.gov (United States)

Führer, Eduardo; Rudolph, Anny; Espinoza, Claudio; Díaz, Rodrigo; Gajardo, Marisol; Camaño, Nuria

2012-01-01

The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E) on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L−1 (LC50−96 hours). Concentrations between 0.2 and 1.61 μg L−1 were able to inhibit significantly the AChE activity, and concentrations between 0.8 and 1.61 μg L−1 stimulate ammonia excretion and decrease oxygen : ammonia-N (O : N) ratio, with respect to the control group. A. ater proved to be a species sensitive to pesticide exposure and easy to handle in lab conditions. Thus, it is recommended as a bioindicator for use in programs of environmental alertness in the Eastern South Pacific coastal zone. PMID:22619673

Characterization of Lignanamides from Hemp (Cannabis sativa L.) Seed and Their Antioxidant and Acetylcholinesterase Inhibitory Activities.

Science.gov (United States)

Yan, Xiaoli; Tang, Jiajing; dos Santos Passos, Carolina; Nurisso, Alessandra; Simões-Pires, Claudia Avello; Ji, Mei; Lou, Hongxiang; Fan, Peihong

2015-12-16

Hemp seed is known for its content of fatty acids, proteins, and fiber, which contribute to its nutritional value. Here we studied the secondary metabolites of hemp seed aiming at identifying bioactive compounds that could contribute to its health benefits. This investigation led to the isolation of 4 new lignanamides, cannabisin M (2), cannabisin N (5), cannabisin O (8), and 3,3'-demethyl-heliotropamide (10), together with 10 known lignanamides, among which 4 was identified for the first time from hemp seed. Structures were established on the basis of NMR, HR-MS, UV, and IR as well as by comparison with the literature data. Lignanamides 2, 7, and 9-14 showed good antioxidant activity, among which 7, 10, and 13 also inhibited acetylcholinesterase in vitro. The newly identified compounds in this study add to the diversity of hemp seed composition, and the bioassays implied that hemp seed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.

High-performance liquid chromatography-mass spectrometry-based acetylcholinesterase assay for the screening of inhibitors in natural extracts

NARCIS (Netherlands)

de Jong, C.F.; Derks, R.J.E.; Bruyneel, B.; Niessen, W.M.A.; Irth, H.

2006-01-01

The present paper describes a High-performance liquid chromatography-mass spectrometry (LC-MS) methodology for the screening of acetylcholinesterase (AChE) inhibitors in natural extracts. AChE activity of sample components is monitored by a post-column biochemical assay that is based on the

Isolation of a tyrosine-activating enzyme from baker's yeast

NARCIS (Netherlands)

Ven, A.M. van de; Koningsberger, V.V.; Overbeek, J.Th.G.

1958-01-01

The extracts of ether-CO2-frozen baker's yeast contain enzymes that catalyze the ATP-linked amino acid activation by way of pyrophosphate elimination. From the extract a tyrosine-activating enzyme could be isolated, which, judging from ultracentrifugation and electrophoretic data, was about 70% pure

Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus

Directory of Open Access Journals (Sweden)

L.B.M. Maifrino

1997-05-01

Full Text Available The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE histochemical technique in whole-mount preparations. Neuronal density was 1,500 ± 116 neurons/cm2 (mean ± SEM in the esophagus, 8,900 ± 1,518 in the stomach, 9,000 ± 711 in the jejunum and 13,100 ± 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 µm2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease

Benefits of statistical molecular design, covariance analysis, and reference models in QSAR: a case study on acetylcholinesterase

Science.gov (United States)

Andersson, C. David; Hillgren, J. Mikael; Lindgren, Cecilia; Qian, Weixing; Akfur, Christine; Berg, Lotta; Ekström, Fredrik; Linusson, Anna

2015-03-01

Scientific disciplines such as medicinal- and environmental chemistry, pharmacology, and toxicology deal with the questions related to the effects small organic compounds exhort on biological targets and the compounds' physicochemical properties responsible for these effects. A common strategy in this endeavor is to establish structure-activity relationships (SARs). The aim of this work was to illustrate benefits of performing a statistical molecular design (SMD) and proper statistical analysis of the molecules' properties before SAR and quantitative structure-activity relationship (QSAR) analysis. Our SMD followed by synthesis yielded a set of inhibitors of the enzyme acetylcholinesterase (AChE) that had very few inherent dependencies between the substructures in the molecules. If such dependencies exist, they cause severe errors in SAR interpretation and predictions by QSAR-models, and leave a set of molecules less suitable for future decision-making. In our study, SAR- and QSAR models could show which molecular sub-structures and physicochemical features that were advantageous for the AChE inhibition. Finally, the QSAR model was used for the prediction of the inhibition of AChE by an external prediction set of molecules. The accuracy of these predictions was asserted by statistical significance tests and by comparisons to simple but relevant reference models.

Distribution of enzyme activity hotspots induced by earthworms in top- and subsoil

Science.gov (United States)

Hoang, D. T. T.

2016-12-01

Earthworms (Lumbricus terrestris L.) not only affect soil physics, but they also boost microbial activities and consequently create important hotspots of microbial mediated carbon and nutrient turnover through their burrowing activity. However, it is still unknown to which extend earthworms change the enzyme distribution and activity inside their burrows in top- and subsoil horizons. We hypothesized that earthworm burrows, which are enriched in available substrates, have higher percentage of enzyme activity hotspots than soil without earthworms, and that enzyme activities decreased with increasing depth because of the increasing recalcitrance of organic matter in subsoil. We visualized enzyme distribution inside and outside of worm burrows (biopores) by in situ soil zymography and measured enzyme kinetics of 6 enzymes - β-glucosidase (GLU), cellobiohydrolase (CBH), xylanase (XYL), chitinase (NAG), leucine aminopeptidase (LAP) and acid phosphatase (APT) - in pore and bulk soil material up to 105 cm. Zymography showed a heterogeneous distribution of hotspots in worm burrows. The hotspot areas was 2.4 to 14 times larger in the burrows than in soil without earthworms. However, the dispersion index of hotspot distribution showed more aggregated hotspots in soil without earthworms than in soil with earthworms and burrow wall. Enzyme activities decreased with depth, by a factor of 2 to 8 due to fresh C input from the soil surface. Compared to bulk soil, enzyme activities in topsoil biopores were up to 11 times higher for all enzymes, but in the subsoil activities of XYL, NAG and APT were lower in earthworm biopores than bulk soil. In conclusion, hotspots were twice as concentrated close to earthworm burrows as in surrounding soil. Earthworms exerted stronger effects on enzyme activities in biopores in the topsoil than in subsoil. Keywords: Earthworms, hotspots, enzyme activities, enzyme distribution, subsoil

HPLC-DAD fingerprinting analysis, antioxidant activities of Tithonia diversifolia (Hemsl.) A. Gray leaves and its inhibition of key enzymes linked to Alzheimer's disease.

Science.gov (United States)

Ojo, Oluwafemi Adeleke; Ojo, Adebola Busola; Ajiboye, Basiru Olaitan; Olaiya, Oluranti; Okesola, Mary Abiola; Boligon, Aline Augusti; de Campos, Marli Matiko Anraku; Oyinloye, Babatunji Emmanuel; Kappo, Abidemi Paul

2018-01-01

Tithonia diversifolia (Hemsl.) A. Gray leaves have long been used to manage neurodegenerative diseases without scientific basis. This study characterized the phenolic constituents, evaluated the antioxidant properties of phenolic extracts from T. diversifolia leaves used as traditional medicine in Africa and its inhibition of key enzymes linked to Alzheimer's disease. The extract was rich in phenolic acids (gallic acid, chlorogenic acid, caffeic acid and p -coumaric acid) and flavonoids (apigenin) and had 1,1-diphenyl-2-picryl-hydrazil radical scavenging abilities (IC 50  = 41.05 μg. mL -1 ), 2,2-Azino-bis3-ethylbenthiazoline-6sulphonic acid radical scavenging ability (IC 50  = 33.51 μg. mL -1 ), iron chelation (IC 50  = 38.50 μg. mL -1 ), reducing power (Fe 3+ - Fe 2+ ) (7.34 AAEmg/100 g), inhibited acetylcholinesterase (IC 50  = 39.27 μg mL -1 ) and butyrylcholinesterase (IC 50  = 35.01 μg mL -1 ) activities. These results reveal the leaf as a rich source of phenolic compounds with antioxidant and cholinesterase inhibitory activity.

Chaperone-like activities of α-synuclein: α-Synuclein assists enzyme activities of esterases

International Nuclear Information System (INIS)

Ahn, Misun; Kim, SeungBum; Kang, Mira; Ryu, Yeonwoo; Doohun Kim, T.

2006-01-01

α-Synuclein, a major constituent of Lewy bodies (LBs), has been implicated to play a critical role in the pathogenesis of Parkinson's disease (PD), although the physiological function of α-synuclein has not yet been known. Here we have shown that α-synuclein, which has no well-defined secondary or tertiary structure, can protect the enzyme activity of microbial esterases against stress conditions such as heat, pH, and organic solvents. In particular, the flexibility of α-synuclein and its C-terminal region seems to be important for complex formation, but the structural integrity of the C-terminal region may not be required for stabilization of enzyme activity. In addition, atomic force microscopy (AFM) and in vivo enzyme assays showed highly specific interactions of esterases with α-synuclein. Our results indicate that α-synuclein not only protects the enzyme activity of microbial esterases in vitro, but also can stabilize the active conformation of microbial esterases in vivo

DNA damage, acetylcholinesterase activity and lysosomal stability in native and transplanted mussels (Mytilus edulis) in areas close to coastal chemical dumping sites in Denmark

DEFF Research Database (Denmark)

Rank, Jette; Lehtonen, Kari K.; Strand, Jakob

2007-01-01

Biomarkers of genotoxicity (DNA damage, measured as tail moment in the Comet assay), neurotoxicity (acetylcholinesterase inhibition, AChE) and general stress (lysosomal membrane stability, LMS) were studied in native and transplanted blue mussels (Mytilus edulis) in coastal areas of western Denmark...... of chemical pollution complex, as seen especially in the variability in results on DNA damage, and also in regard to AChE activity. These investigations further stress the importance of understanding the effects of natural factors (salinity, temperature, water levels, rain and storm events) in correct...

HPRT Enzyme Activity of Blood Cells From Patients With Downs Syndrome

International Nuclear Information System (INIS)

Sbubber, E.K.; Abdul-Rahman, M.H.; Sultan, A.F.; Hamamy, H.A.

1998-01-01

Hypoxanthine phosphoribosyl transferase (HPRT) enzyme activity was determined in erythrocytes from 16 children (aged below one year to 11 year) with down s syndrome using 8-C 14 Hypoxanthine and radioeleelrophorsis techniques. Significant (P<0.01) reduction in HPRT enzyme activity was seen in D S children compared to that of 18 (age and sex matched) healthy children. Pure 21 - trisomic erythrocytes expressed lower enzyme activity than mosaic cell. Mothers of D S children showed significantly (P<0.01) lower enzyme activity than mothers of normal children . Reduced activity of HPRT enzyme was also observed in PHA-stimulated lymphocytes of DS children and their mothers. These results indicated that deficiency of HPRT in D S patients may contribute to the abnormal purine metabolism associated with the symptomatology of this syndrome

Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

Science.gov (United States)

Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

2016-10-01

Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

Chaperone-Like Activity of ß-Casein and Its Effect on Residual in Vitro Activity of Food Enzymes

DEFF Research Database (Denmark)

Sulewska, Anna Maria

ABSTRACT Activity of endogenous enzymes may cause browning of fruits and vegetables. These enzymes can be inactivated, for example by heat treatment, but the response of enzymes to heat treatment depends on many factors. Foods are very complex systems and the stability of enzymes......-casein on the enzymatic activity of three targets was tested by monitoring enzyme activity after heat treatment and by measuring the intensity of scattered light during and after heat treatment. β-Casein was shown to interact at elevated temperatures with three selected targets:horseradish peroxidase, tyrosinase from......, residual activity of horseradish peroxidase was lower in samples containing BSA than in samples without any addition. Horseradish peroxidase heated with BSA did not regain activity within one hour after treatment. BSA is often added to enzyme solutions to prevent enzyme adhesion to vial surfaces...

Measurement of acetylcholinesterase (AChE) activity in living brain by positron emission tomography (PET)

Energy Technology Data Exchange (ETDEWEB)

Irie, Toshiaki [National Inst. of Radiological Sciences, Chiba (Japan)

1999-07-01

Central cholinergic neuronal system has been known to be related to learning and memory, and its deficit is found in the brain of Alzheimer's disease (AD) and other degenerative disorders. Postmortem studies have shown that acetylcholinesterase (AChE), one of biochemical markers of central cholinergic nerve system, is consistently reduced in the cerebral cortex of patients with Alzheimer's disease (AD). Non-invasive mapping and/or measuring AChE activity in the living brain by positron emission tomography (PET) would be a useful tool for assessment of cholinergic dysfunction in AD and other disorders, and provide a direct method for validation of therapeutic efficacy of drugs, AChE inhibitors. We have challenged to measure AChE activity using tracers of substrate type, radiolabelled acetylcholine analogs, which are lipophilic enough to go across blood brain barrier and are metabolically trapped by AChE in the brain. The analogs designed, N-methylpiperidyl esters, were evaluated in terms of their metabolic rate and specificity against AChE. Studies examining the response to AChE activity showed metabolic accumulation of some analogs responded well to changes in cortical AChE activity in an animal model of AD. The study was further applied to living human by PET using [{sup 11}C]N-methylpiperidyl-4-acetate (MP4A), which was chosen on the basis of its reactivity and specificity suitable for the human cortical AChE. Regional cerebral metabolic rate of MP4A reflecting AChE activity was quantitatively determined using three compartment model analysis of dynamic PET data and the arterial input function obtained by TLC-radioluminography or plasma samples. The kinetic analyses showed that AChE activities estimated were well agree with those of postmortem examination in cerebral cortices and thalamus in healthy subjects, and that there was significant reduction of cortical AChE activity in patients with AD. The results suggest feasibility of the present method for

Concentration profiles near an activated enzyme.

Science.gov (United States)

Park, Soohyung; Agmon, Noam

2008-09-25

When a resting enzyme is activated, substrate concentration profile evolves in its vicinity, ultimately tending to steady state. We use modern theories for many-body effects on diffusion-influenced reactions to derive approximate analytical expressions for the steady-state profile and the Laplace transform of the transient concentration profiles. These show excellent agreement with accurate many-particle Brownian-dynamics simulations for the Michaelis-Menten kinetics. The steady-state profile has a hyperbolic dependence on the distance of the substrate from the enzyme, albeit with a prefactor containing the complexity of the many-body effects. These are most conspicuous for the substrate concentration at the surface of the enzyme. It shows an interesting transition as a function of the enzyme turnover rate. When it is high, the contact concentration decays monotonically to steady state. However, for slow turnover it is nonmonotonic, showing a minimum due to reversible substrate binding, then a maximum due to diffusion of new substrate toward the enzyme, and finally decay to steady state. Under certain conditions one can obtain a good estimate for the critical value of the turnover rate constant at the transition.

Extraction of Active Enzymes from "Hard-to-Break-Cells"

DEFF Research Database (Denmark)

Ottaviani, Alessio; Tesauro, Cinzia; Fjelstrup, S

We present the utilization of a rolling circle amplification (RCA) based assay to investigate the extraction efficiency of active enzymes from a class of “hard-to-break” cells, yeast Saccaramyces cerevisiae. Current analyses of microorganisms, such as pathogenic bacteria, parasites or particular...... life stages of microorganisms (e.g. spores from bacteria or fungi) is hampered by the lack of efficient lysis protocols that preserve the activity and integrity of the cellular content. Presented herein is a flexible scheme to screen lysis protocols for active enzyme extraction. We also report a gentle...... yet effective approach for extraction of active enzymes by entrapping cells in microdroplets. Combined effort of optimized extraction protocols and effective analytical approaches is expected to generate impact in future disease diagnosis and environmental safety....

Stimulation of Escherichia coli DNA photoreactivating enzyme activity by adenosine 5'-triphosphate

International Nuclear Information System (INIS)

Koka, P.

1984-01-01

A purification procedure consisting of Biorex-70, single-stranded DNA-agarose, and ultraviolet (UV) light irradiated DNA-cellulose chromatography has been adopted for the Escherichia coli photoreactivating enzyme, to obtain enzyme preparations that are free of extraneous nucleic acid or nucleotides. The purification yields high specific activities (75 000 pmol h -1 mg -1 ) with a 50% recovery. Enzyme preparations have also been obtained from UV-irradiated DNA-cellulose by exposure to visible light. These enzyme preparations contain oligoribonucleotides, up to 26 nucleotides in length in relation to DNA size markers, but these are not essential for enzymatic activity. When the enzyme is preincubated with exogenous ATP a 10-fold stimulation in the enzyme activity has been observed. It has been determined by polyacrylamide gel electrophoresis and high-voltage diethylaminoethyl paper electrophoresis that the light-released enzyme samples from a preincubated and washed mixture of the enzyme, [γ- 32 P]ATP, and UV-irradiated DNA-cellulose contained exogenous [γ- 32 P], which eluted with the enzyme-containing fractions when subjected to Bio-Gel P-30 chromatography. GTP caused a slight enhancement of the enzyme activity while ADP strongly inhibited photoreactivation, at the same concentration and conditions. Higher (X5) concentrations of ADP and adenosine 5'-(β, γ-methylenetriphosphate) totally inhibited the enzyme activity. Dialysis of a photoreactivating enzyme preparation against a buffer solution containing 1 mM ATP caused a 9-fold stimulation of the enzyme activity. In addition, there is an apparent hydrolysis of ATP during photoreactivation as measured by the release of 32 P from [γ- 32 P]ATP

Enzyme activity measurement via spectral evolution profiling and PARAFAC

DEFF Research Database (Denmark)

Baum, Andreas; Meyer, Anne S.; Garcia, Javier Lopez

2013-01-01

The recent advances in multi-way analysis provide new solutions to traditional enzyme activity assessment. In the present study enzyme activity has been determined by monitoring spectral changes of substrates and products in real time. The method relies on measurement of distinct spectral...... fingerprints of the reaction mixture at specific time points during the course of the whole enzyme catalyzed reaction and employs multi-way analysis to detect the spectral changes. The methodology is demonstrated by spectral evolution profiling of Fourier Transform Infrared (FTIR) spectral fingerprints using...

Patterns of functional enzyme activity in fungus farming ambrosia beetles.

Science.gov (United States)

De Fine Licht, Henrik H; Biedermann, Peter H W

2012-06-06

In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose components of the ray

Synthesis of 1-[11c]methylpiperidin-4-yl propionate ([11c]pmp) for in vivo measurements of acetylcholinesterase activity

International Nuclear Information System (INIS)

Snyder, Scott E.; Tluczek, Louis; Jewett, Douglas M.; Nguyen, Thinh B.; Kuhl, David E.; Kilbourn, Michael R.

1998-01-01

Synthesis of 1-[ 11 C]methylpiperidin-4-yl propionate ([ 11 C]PMP), an in vivo substrate for acetylcholinesterase, is reported. An improved preparation of 4-piperidinyl propionate (PHP), the immediate precursor for radiolabeling, was accomplished in three steps from 4-hydroxypiperidine by (a) protection of the amine as the benzyl carbamate, (b) acylation with propionyl chloride, and (c) deprotection of the carbamate by catalytic hydrogenation. The final product was obtained in an overall 82% yield. Reaction of the free base form of PHP with [ 11 C]methyl trifluoromethanesulfonate at room temperature in N,N-dimethylformamide, followed by high performance liquid chromatography (HPLC) purification, provided [ 11 C]PMP in 57% radiochemical yield, >99% radiochemical purity, and >1500 Ci/mmol at the end of synthesis. The total synthesis time from end-of-bombardment was 35 min. [ 11 C]PMP can thus be reliably prepared for routine clinical studies of acetylcholinesterase in human brain using positron emission tomography

Bivalent ligands derived from Huperzine A as acetylcholinesterase inhibitors.

Science.gov (United States)

Haviv, H; Wong, D M; Silman, I; Sussman, J L

2007-01-01

The naturally occurring alkaloid Huperzine A (HupA) is an acetylcholinesterase (AChE) inhibitor that has been used for centuries as a Chinese folk medicine in the context of its source plant Huperzia Serrata. The potency and relative safety of HupA rendered it a promising drug for the ameliorative treatment of Alzheimer's disease (AD) vis-à-vis the "cholinergic hypothesis" that attributes the cognitive decrements associated with AD to acetylcholine deficiency in the brain. However, recent evidence supports a neuroprotective role for HupA, suggesting that it could act as more than a mere palliative. Biochemical and crystallographic studies of AChE revealed two potential binding sites in the active-site gorge of AChE, one of which, the "peripheral anionic site" at the mouth of the gorge, was implicated in promoting aggregation of the beta amyloid (Abeta) peptide responsible for the neurodegenerative process in AD. This feature of AChE facilitated the development of dual-site binding HupA-based bivalent ligands, in hopes of concomitantly increasing AChE inhibition potency by utilizing the "chelate effect", and protecting neurons from Abeta toxicity. Crystal structures of AChE allowed detailed modeling and docking studies that were instrumental in enhancing the understanding of underlying principles of bivalent inhibitor-enzyme dynamics. This monograph reviews two categories of HupA-based bivalent ligands, in which HupA and HupA fragments serve as building blocks, with a focus on the recently solved crystallographic structures of Torpedo californica AChE in complex with such bifunctional agents. The advantages and drawbacks of such structured-based drug design, as well as species differences, are highlighted and discussed.

A Simple and Accurate Method for Measuring Enzyme Activity.

Science.gov (United States)

Yip, Din-Yan

1997-01-01

Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

Evolutionary transitions in enzyme activity of ant fungus gardens.

Science.gov (United States)

De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G; Boomsma, Jacobus J

2010-07-01

Fungus-growing (attine) ants and their fungal symbionts passed through several evolutionary transitions during their 50 million year old evolutionary history. The basal attine lineages often shifted between two main cultivar clades, whereas the derived higher-attine lineages maintained an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens are targeted primarily toward partial degradation of plant cell walls, reflecting a plesiomorphic state of nondomesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major breakdown of cell walls. The adaptive significance of the lower-attine symbiont shifts remains unclear. One of these shifts was obligate, but digestive advantages remained ambiguous, whereas the other remained facultative despite providing greater digestive efficiency.

Droplet-based microfluidics for dose-response assay of enzyme inhibitors by electrochemical method.

Science.gov (United States)

Gu, Shuqing; Lu, Youlan; Ding, Yaping; Li, Li; Zhang, Fenfen; Wu, Qingsheng

2013-09-24

A simple but robust droplet-based microfluidic system was developed for dose-response enzyme inhibition assay by combining concentration gradient generation method with electrochemical detection method. A slotted-vials array and a tapered tip capillary were used for reagents introduction and concentration gradient generation, and a polydimethylsiloxane (PDMS) microfluidic chip integrated with microelectrodes was used for droplet generation and electrochemical detection. Effects of oil flow rate and surfactant on electrochemical sensing were investigated. This system was validated by measuring dose-response curves of three types of acetylcholinesterase (AChE) inhibitors, including carbamate pesticide, organophosphorus pesticide, and therapeutic drugs regulating Alzheimer's disease. Carbaryl, chlorpyrifos, and tacrine were used as model analytes, respectively, and their IC50 (half maximal inhibitory concentration) values were determined. A whole enzyme inhibition assay was completed in 6 min, and the total consumption of reagents was less than 5 μL. This microfluidic system is applicable to many biochemical reactions, such as drug screening and kinetic studies, as long as one of the reactants or products is electrochemically active. Copyright © 2013 Elsevier B.V. All rights reserved.

In-vitro screening of acetylcholinesterase inhibitory activity of extracts from Palestinian indigenous flora in relation to the treatment of Alzheimer’s disease

Directory of Open Access Journals (Sweden)

Mohammed Saleem Ali-Shtayeh

2014-09-01

Full Text Available Background: Cholinesterase inhibitory therapy serves as a strategy for the treatment of Alzheimer’s disease (AD. Several acetylcholinesterase inhibitors (AChEIs are used for the symptomatic treatment of AD. These compounds have been reported to have adverse effects, including gastrointestinal disturbances. This study was therefore partly aimed at investigating in vitro possible AChEIs in herbal medicines traditionally used in Palestine to treat cognitive disorders, and to point out the role of these plants as potential sources for development of newly potent and safe natural therapeutic agents of AD. Assay of AChE activity plays an important role in vitro characterization of drugs including potential treatments for AD. The most widely used method, is based on Ellman’s method. The reactant used in this method shows chemical reactivity with oxime antidots and thiol leading to false positive reactions. A new alternative assay could be of high interest. Methods: The effect on AChE activity of 92 extracts of 47 medicinal plants were evaluated using a new micro-well plate AChE activity (NA-FB and Ellman’s assays. In addition, antioxidant activity using DPPH was determined. Results: The main advantages of the new method (NA-FB is that the colorimetric change is better observable visually allowing spectrophotometric as well as colorimetric assay, and does not show any chemical reactivity with thiol. 67.4% and 37% of extracts inhibited AChE by >50% using the NA-FB and Ellman’s assays, respectively. Using NA-FB assay, 84 extracts interacted reversibly with the enzyme, of which Mentha spicata (94.8%, Foeniculum vulgare (89.81, and Oxalis pes-caprae (89.21 were most potent, and 8 showed irreversible inhibition of which leaves of Lupinus pilosus (92.02% were most active. Antioxidant activity was demonstrated by 73 extracts Majorana syriaca (IC50 0.21mg/ml, and Rosmarinus officinalis (0.38 were the most active. Conclusions: NA-FB assay has shown to be

Light-regulation of enzyme activity in anacystis nidulans (Richt.).

Science.gov (United States)

Duggan, J X; Anderson, L E

1975-01-01

The effect of light on the levels of activity of six enzymes which are light-modulated in higher plants was examined in the photosynthetic procaryot Anacystis nidulans. Ribulose-5-phosphate kinase (EC 2.7.1.19) was found to be light-activated in vivo and dithiothreitol-activated in vitro while glucose-6-phosphate dehydrogenase (EC 1.1.1.49) was light-inactivated and dithiothreitol-inactivated. The enzymes fructose-1,6-diphosphate phosphatase (EC 3.1.3.11), sedoheptulose-1,7-diphosphate phosphatase, NAD- and NADP-linked glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12; EC 1.2.1.13) were not affected by light treatment of the intact algae, but sedoheptulose-diphosphate phosphatase and the glyceraldehyde-3-phosphate dehydrogenases were dithiothreitol-activated in crude extracts. Light apparently controls the activity of the reductive and oxidative pentose phosphate pathway in this photosynthetic procaryot as in higher plants, through a process which probably involves reductive modulation of enzyme activity.

[Distribution of acetylcholinesterase activity in the digestive system of the gastropod molluscs Littorina littorea and Achatina fulica].

Science.gov (United States)

Zaĭtseva, O V; Kuznetsova, T V

2008-01-01

With the use of the histochemical procedure for the demonstration of acetylcholinesterase (AchE) activity, the distribution cholinergic regulatory elements was studied in the esophagus, the pharynx, the stomach, the liver (the digestive gland) and the intestine in sea and terrestrial gastropod molluscs that differed in their general organization level, lifestyle, habitat and feeding type. In both molluscs, all the parts of the digestive tract contained the significant amount of intraepithelial AchE-positive cells of the open type, single subepithelial neurons and the nervous fibers localized among the muscle cells of the wall of the organs. The basal processes of the AchE-positive intraepithelial cells were shown to form the intraepithelial nerve plexus and to pass under the epithelium. The peculiarities and common principles in the distribution of the nervous elements detected, their possible function and the regulatory role in the digestion in gastropod molluscs and other animals are discussed.

Activity enhancement of ligninolytic enzymes of Trametes versicolor ...

African Journals Online (AJOL)

Suspended cultures of white-rot fungus, Trametes versicolor, supplemented with bagasse powder showed a concentration dependent enhancement in the ligninolytic enzymes activity in liquid shake cultures. 2% (w/v) bagasse powder improved greater stability to the enzymes. The optimum pH is 3.5 and the optimum ...

Sublethal Effects of Insecticide Exposure on Megacopta cribraria (Fabricius) Nymphs: Key Biological Traits and Acetylcholinesterase Activity.

Science.gov (United States)

Miao, Jin; Reisig, Dominic D; Li, Guoping; Wu, Yuqing

2016-01-01

Megacopta cribraria F. (Hemiptera: Plataspidae), the kudzu bug, is an invasive insect pest of U.S. soybean. At present, insecticide application is the primary and most effective control option for M. cribraria In this study, the potential effects of sublethal and low-lethal concentrations (LC10 and LC40) of three common insecticides on key biological traits and acetylcholinesterase (AChE) activity of the treated nymphal stage of insect were assessed. The results show that the sublethal concentration of imidacloprid significantly reduced adult emergence rate of M. cribraria A low-lethal concentration of imidacloprid significantly increased nymphal development time, but significantly decreased adult emergence rate and adult longevity. Both sublethal and low-lethal concentrations of acephate caused an increase in nymphal development time and a reduction in adult emergence rate and adult longevity. Fecundity of females was significantly reduced only by exposure to low-lethal concentrations of acephate. Sublethal and low-lethal concentrations of bifenthrin increased nymphal development time, but significantly decreased adult emergence rate. In addition, we found that the AChE activity of M. cribraria was significantly increased only by LC40 imidacloprid, but strongly inhibited by acephate. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

Temperature and UV light affect the activity of marine cell-free enzymes

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B. Thomson

2017-09-01

Full Text Available Microbial extracellular enzymatic activity (EEA is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells. Experiments were run to assess how cell-free enzymes (excluding microbes respond to ultraviolet radiation (UVR and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase, β-glucosidase, (BGase, and leucine aminopeptidase (LAPase. Environmentally relevant UVR (i.e. in situ UVR levels measured at our site reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C, likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

Synthesis, Biological Evaluation and Molecular Modelling of 2′-Hydroxychalcones as Acetylcholinesterase Inhibitors

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Sri Devi Sukumaran

2016-07-01

Full Text Available A series of 2′-hydroxy- and 2′-hydroxy-4′,6′-dimethoxychalcones was synthesised and evaluated as inhibitors of human acetylcholinesterase (AChE. The majority of the compounds were found to show some activity, with the most active compounds having IC50 values of 40–85 µM. Higher activities were generally observed for compounds with methoxy substituents in the A ring and halogen substituents in the B ring. Kinetic studies on the most active compounds showed that they act as mixed-type inhibitors, in agreement with the results of molecular modelling studies, which suggested that they interact with residues in the peripheral anionic site and the gorge region of AChE.

A Review on the Effects of Supercritical Carbon Dioxide on Enzyme Activity

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Marie Zarevúcka

2010-01-01

Full Text Available Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO2. The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability.

Structural characterization of acetylcholinesterase 1 from the sand fly Lutzomyia longipalpis (Diptera: Psychodidae).

Science.gov (United States)

Coutinho-Abreu, I V; Balbino, V Q; Valenzuela, J G; Sonoda, I V; Ramalho-Ortigão, J M

2007-07-01

Acetylcholinesterase (AChE) plays a key role in cholinergic impulse transmission, and it is the target enzyme for organophosphorus and carbamate insecticides. Two genes, AceI and AceII, have been characterized from different insect species, and point mutations in either gene can lead to significant resistance to these classes of insecticides. In this report, we describe the partial characterization of the AceI gene from Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae), and we show that the possibility exists for the development of a resistant phenotype to organophosphates and carbamates in sand flies. Our results point to the presence of a single AceI gene in L. longipalpis (LlAce1) and that AChE activity is inhibited by organophosphorus at a concentration of 5 x 10(-5) M. Regarding insecticide resistance, analysis of the truncated LlAce1 cDNA suggests that a single missense mutation leading to a glycine-to-serine substitution at amino acid position 119 (G119S) may arise in L. longipalpis, similar to what has been detected in Anopheles gambiae s.s. Another missense mutation involved in resistant phenotypes, F331W, detected in Culex tritaeniorhynchus Giles, is less likely to occur in L. longipalpis, because it faces codon constraint in this sand fly species. Comparison of the three-dimensional structures of the deduced amino acid sequence of the truncated LLAChE1 with that of An. gambiae and Cx. tritaeniorhynchus also suggests that similar structural modifications due to the missense amino acid changes in the active site gorge are detected in all three insects.

Patterns of functional enzyme activity in fungus farming ambrosia beetles

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De Fine Licht Henrik H

2012-06-01

Full Text Available Abstract Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae, wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily

Caffeine Inhibits Acetylcholinesterase, But Not Butyrylcholinesterase

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Petr Dobes

2013-05-01

Full Text Available Caffeine is an alkaloid with a stimulant effect in the body. It can interfere in transmissions based on acetylcholine, epinephrine, norepinephrine, serotonin, dopamine and glutamate. Clinical studies indicate that it can be involved in the slowing of Alzheimer disease pathology and some other effects. The effects are not well understood. In the present work, we focused on the question whether caffeine can inhibit acetylcholinesterase (AChE and/or, butyrylcholinesterase (BChE, the two enzymes participating in cholinergic neurotransmission. A standard Ellman test with human AChE and BChE was done for altering concentrations of caffeine. The test was supported by an in silico examination as well. Donepezil and tacrine were used as standards. In compliance with Dixon’s plot, caffeine was proved to be a non-competitive inhibitor of AChE and BChE. However, inhibition of BChE was quite weak, as the inhibition constant, Ki, was 13.9 ± 7.4 mol/L. Inhibition of AChE was more relevant, as Ki was found to be 175 ± 9 µmol/L. The predicted free energy of binding was −6.7 kcal/mol. The proposed binding orientation of caffeine can interact with Trp86, and it can be stabilize by Tyr337 in comparison to the smaller Ala328 in the case of human BChE; thus, it can explain the lower binding affinity of caffeine for BChE with reference to AChE. The biological relevance of the findings is discussed.

Current and emerging strategies for organophosphate decontamination: special focus on hyperstable enzymes.

Science.gov (United States)

Jacquet, Pauline; Daudé, David; Bzdrenga, Janek; Masson, Patrick; Elias, Mikael; Chabrière, Eric

2016-05-01

Organophosphorus chemicals are highly toxic molecules mainly used as pesticides. Some of them are banned warfare nerve agents. These compounds are covalent inhibitors of acetylcholinesterase, a key enzyme in central and peripheral nervous systems. Numerous approaches, including chemical, physical, and biological decontamination, have been considered for developing decontamination methods against organophosphates (OPs). This work is an overview of both validated and emerging strategies for the protection against OP pollution with special attention to the use of decontaminating enzymes. Considerable efforts have been dedicated during the past decades to the development of efficient OP degrading biocatalysts. Among these, the promising biocatalyst SsoPox isolated from the archaeon Sulfolobus solfataricus is emphasized in the light of recently published results. This hyperthermostable enzyme appears to be particularly attractive for external decontamination purposes with regard to both its catalytic and stability properties.

Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

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Shihui Wang

2016-02-01

Full Text Available Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation of enzyme activity is attributed to its conformational modifications. This review comprehensively addresses the stability and activity of the intact enzymes in various non-aqueous systems, such as organic solvents, ionic liquids, sub-/super-critical fluids and their combined mixtures. It has been revealed that critical factors such as Log P, functional groups and the molecular structures of the solvents define the microenvironment surrounding the enzyme molecule and affect enzyme tertiary and secondary structure, influencing enzyme catalytic properties. Therefore, it is of high importance for biocatalysis in non-aqueous media to elucidate the links between the microenvironment surrounding enzyme surface and its stability and activity. In fact, a better understanding of the correlation between different non-aqueous environments and enzyme structure, stability and activity can contribute to identifying the most suitable reaction medium for a given biotransformation.

Visualization of enzyme activities inside earthworm biopores by in situ soil zymography

Science.gov (United States)

Thu Duyen Hoang, Thi; Razavi, Bahar. S.; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

Earthworms can strongly activate microorganisms, increase microbial and enzyme activities and consequently the turnover of native soil organic matter. In extremely dynamic microhabitats and hotspots as biopores made by earthworms, the in situ enzyme activities are a footprint of complex biotic interactions. The effect of earthworms on the alteration of enzyme activities inside biopores and the difference between bio-pores and earthworm-free soil was visualized by in situ soil zymography (Spohn and Kuzyakov, 2014). For the first time, we prepared quantitative imaging of enzyme activities in biopores. Furthermore, we developed the zymography technique by direct application of a substrate saturated membrane to the soil to obtain better spatial resolution. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). Simultaneously, maize seed was sown in the soil. Control soil box with maize and without earthworm was prepared in the same way. After two weeks when bio-pore systems were formed by earthworm, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine aminopeptidase) and phosphatase. Followed by non-destructive zymography, biopore samples and control soil were destructively collected to assay enzyme kinetics by fluorogenically labeled substrates method. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. These differences were further confirmed by fluorimetric microplate enzyme assay detected significant difference of Vmax in four above mentioned enzymes. Vmax of β-glucosidase, chitinase, xylanase and phosphatase in biopores is 68%, 108%, 50% and 49% higher than that of control soil. However, no difference in cellobiohydrolase and leucine aminopeptidase kinetics between biopores and control soil were detected. This indicated little effect of earthworms on protein and cellulose transformation in soil

Dihydroagarofuranoid Sesquiterpenes as Acetylcholinesterase Inhibitors from Celastraceae Plants: Maytenus disticha and Euonymus japonicus.

Science.gov (United States)

Alarcón, Julio; Cespedes, Carlos L; Muñoz, Evelyn; Balbontin, Cristian; Valdes, Francisco; Gutierrez, Margarita; Astudillo, Luis; Seigler, David S

2015-12-02

Natural cholinesterase inhibitors have been found in many biological sources. Nine compounds with agarofuran (epoxyeudesmane) skeletons were isolated from seeds and aerial parts of Maytenus disticha and Euonymus japonicus. The identification and structural elucidation of compounds were based on spectroscopic data analyses. All compounds had inhibitory acetylcholinesterase (AChE) activity. These natural compounds, which possessed mixed or uncompetitive mechanisms of inhibitory activity against AChE, may be considered as models for the design and development of new naturally occurring drugs for management strategies for neurodegenerative diseases. This is the first report of these chemical structures for seeds of M. disticha.

Detoxification enzymes activities in deltamethrin and bendiocarb ...

African Journals Online (AJOL)

Detoxification enzymes activities in deltamethrin and bendiocarb resistant and susceptible malarial vectors ( Anopheles gambiae ) breeding in Bichi agricultural and residential sites, Kano state, Nigeria.

Fluorogenic Substrates for Visualizing Acidic Organelle Enzyme Activities.

Directory of Open Access Journals (Sweden)

Fiona Karen Harlan

Full Text Available Lysosomes are acidic cytoplasmic organelles that are present in all nucleated mammalian cells and are involved in a variety of cellular processes including repair of the plasma membrane, defense against pathogens, cholesterol homeostasis, bone remodeling, metabolism, apoptosis and cell signaling. Defects in lysosomal enzyme activity have been associated with a variety of neurological diseases including Parkinson's Disease, Lysosomal Storage Diseases, Alzheimer's disease and Huntington's disease. Fluorogenic lysosomal staining probes were synthesized for labeling lysosomes and other acidic organelles in a live-cell format and were shown to be capable of monitoring lysosomal metabolic activity. The new targeted substrates were prepared from fluorescent dyes having a low pKa value for optimum fluorescence at the lower physiological pH found in lysosomes. They were modified to contain targeting groups to direct their accumulation in lysosomes as well as enzyme-cleavable functions for monitoring specific enzyme activities using a live-cell staining format. Application to the staining of cells derived from blood and skin samples of patients with Metachromatic Leukodystrophy, Krabbe and Gaucher Diseases as well as healthy human fibroblast and leukocyte control cells exhibited localization to the lysosome when compared with known lysosomal stain LysoTracker® Red DND-99 as well as with anti-LAMP1 Antibody staining. When cell metabolism was inhibited with chloroquine, staining with an esterase substrate was reduced, demonstrating that the substrates can be used to measure cell metabolism. When applied to diseased cells, the intensity of staining was reflective of lysosomal enzyme levels found in diseased cells. Substrates specific to the enzyme deficiencies in Gaucher or Krabbe disease patient cell lines exhibited reduced staining compared to that in non-diseased cells. The new lysosome-targeted fluorogenic substrates should be useful for research

Visualization of Enzyme Activities in Earthworm Biopores by In Situ Soil Zymography.

Science.gov (United States)

Razavi, Bahar S; Hoang, Duyen; Kuzyakov, Yakov

2017-01-01

Earthworms produce biopores with strongly increased microbial and enzyme activities and consequently they form microbial hotspots in soil. In extremely dynamic microhabitats and hotspots such as earthworm biopores, the in situ enzyme activities are a footprint of process rates and complex biotic interactions. The effect of earthworms on enzyme activities inside biopores, relative to earthworm-free soil, can be visualized by in situ soil zymography. Here, we describe the details of the approach and discuss its advantages and limitations. Direct zymography provides high spatial resolution for quantitative images of enzyme activities in biopores.

Effects of protease and non-starch polysaccharide enzyme on performance, digestive function, activity and gene expression of endogenous enzyme of broilers.

Directory of Open Access Journals (Sweden)

Lin Yuan

Full Text Available Three hundred one-day-old male broiler chickens (Ross-308 were fed corn-soybean basal diets containing non-starch polysaccharide (NSP enzyme and different levels of acid protease from 1 to 42 days of age to investigate the effects of exogenous enzymes on growth performance, digestive function, activity of endogenous digestive enzymes in the pancreas and mRNA expression of pancreatic digestive enzymes. For days 1-42, compared to the control chickens, average daily feed intake (ADFI and average daily gain (ADG were significantly enhanced by the addition of NSP enzyme in combination with protease supplementation at 40 or 80 mg/kg (p<0.05. Feed-to-gain ratio (FGR was significantly improved by supplementation with NSP enzymes or NSP enzyme combined with 40 or 80 mg/kg protease compared to the control diet (p<0.05. Apparent digestibility of crude protein (ADCP was significantly enhanced by the addition of NSP enzyme or NSP enzyme combined with 40 or 80 mg/kg protease (p<0.05. Cholecystokinin (CCK level in serum was reduced by 31.39% with NSP enzyme combined with protease supplementation at 160 mg/kg (p<0.05, but the CCK level in serum was increased by 26.51% with NSP enzyme supplementation alone. After 21 days, supplementation with NSP enzyme and NSP enzyme combined with 40 or 80 mg/kg protease increased the activity of pancreatic trypsin by 74.13%, 70.66% and 42.59% (p<0.05, respectively. After 42 days, supplementation with NSP enzyme and NSP enzyme combined with 40 mg/kg protease increased the activity of pancreatic trypsin by 32.45% and 27.41%, respectively (p<0.05. However, supplementation with NSP enzyme and 80 or 160 mg/kg protease decreased the activity of pancreatic trypsin by 10.75% and 25.88%, respectively (p<0.05. The activities of pancreatic lipase and amylase were significantly higher in treated animals than they were in the control group (p<0.05. Supplementation with NSP enzyme, NSP enzyme combined with 40 or 80 mg/kg protease increased

Nanocaged enzymes with enhanced catalytic activity and increased stability against protease digestion

Science.gov (United States)

Zhao, Zhao; Fu, Jinglin; Dhakal, Soma; Johnson-Buck, Alexander; Liu, Minghui; Zhang, Ting; Woodbury, Neal W.; Liu, Yan; Walter, Nils G.; Yan, Hao

2016-01-01

Cells routinely compartmentalize enzymes for enhanced efficiency of their metabolic pathways. Here we report a general approach to construct DNA nanocaged enzymes for enhancing catalytic activity and stability. Nanocaged enzymes are realized by self-assembly into DNA nanocages with well-controlled stoichiometry and architecture that enabled a systematic study of the impact of both encapsulation and proximal polyanionic surfaces on a set of common metabolic enzymes. Activity assays at both bulk and single-molecule levels demonstrate increased substrate turnover numbers for DNA nanocage-encapsulated enzymes. Unexpectedly, we observe a significant inverse correlation between the size of a protein and its activity enhancement. This effect is consistent with a model wherein distal polyanionic surfaces of the nanocage enhance the stability of active enzyme conformations through the action of a strongly bound hydration layer. We further show that DNA nanocages protect encapsulated enzymes against proteases, demonstrating their practical utility in functional biomaterials and biotechnology. PMID:26861509

Nanocaged enzymes with enhanced catalytic activity and increased stability against protease digestion

Science.gov (United States)

Zhao, Zhao; Fu, Jinglin; Dhakal, Soma; Johnson-Buck, Alexander; Liu, Minghui; Zhang, Ting; Woodbury, Neal W.; Liu, Yan; Walter, Nils G.; Yan, Hao

2016-02-01

Cells routinely compartmentalize enzymes for enhanced efficiency of their metabolic pathways. Here we report a general approach to construct DNA nanocaged enzymes for enhancing catalytic activity and stability. Nanocaged enzymes are realized by self-assembly into DNA nanocages with well-controlled stoichiometry and architecture that enabled a systematic study of the impact of both encapsulation and proximal polyanionic surfaces on a set of common metabolic enzymes. Activity assays at both bulk and single-molecule levels demonstrate increased substrate turnover numbers for DNA nanocage-encapsulated enzymes. Unexpectedly, we observe a significant inverse correlation between the size of a protein and its activity enhancement. This effect is consistent with a model wherein distal polyanionic surfaces of the nanocage enhance the stability of active enzyme conformations through the action of a strongly bound hydration layer. We further show that DNA nanocages protect encapsulated enzymes against proteases, demonstrating their practical utility in functional biomaterials and biotechnology.

A Comparative Analysis of Perinatal Development of Barrel Cortex in Rat, Mouse and Guinea Pig Using Acetylcholinesterase Histochemistry

OpenAIRE

ŞENDEMİR, Erdoğan

2014-01-01

The role of acetylcholinesterase (AChE) in the developing neocortex was reexamined by comparing its expression in rats, mice and guinea pigs, following the protocol for acetylcholinesterase histochemistry (described in Sendemir et al., 1996) in order to determine the suitability of the breeding colony at UludaÛ University for use as an animal model. A total of 103 pups as well as two adult animals of each species were used. In the rat pups, acetylcholinesterase-rich patches were d...

Activity of certain enzymes in cadmium-poisoned chicks

Energy Technology Data Exchange (ETDEWEB)

Kench, J E; Gubb, P J.D.

1970-01-01

Activities of a number of enzymes in the liver and other tissues of newly hatched cadmium poisoned chicks have been compared with those of normal controls before and after incubation with Cd/sup +2/ at a concentration similar to that present in vivo. Concentrations of Cd/sup +2/ in the various cellular fractions were determined, after wet oxidation, by atomic absorption spectrophotometry. Interaction of Cd/sup +2/ with enzymes may provide information on the localization of enzymes within mitochondria and other cellular structures. 7 references.

Acotiamide hydrochloride (Z-338) enhances gastric motility and emptying by inhibiting acetylcholinesterase activity in rats.

Science.gov (United States)

Kawachi, Masanao; Matsunaga, Yugo; Tanaka, Takao; Hori, Yuko; Ito, Katsunori; Nagahama, Kenji; Ozaki, Tomoko; Inoue, Naonori; Toda, Ryoko; Yoshii, Kazuyoshi; Hirayama, Masamichi; Kawabata, Yoshihiro; Takei, Mineo

2011-09-01

In clinical trials, acotiamide hydrochloride (acotiamide: Z-338) has been reported to be useful in the treatment of functional dyspepsia. Here, we investigated the effects of acotiamide on gastric contraction and emptying activities in rats in comparison with itopride hydrochloride (itopride) and mosapride citrate (mosapride). We also examined in vitro the compound's inhibitory effect on acetylcholinesterase (AChE) activity derived from rat stomach. In in vivo studies, acotiamide (30 and 100mg/kg s.c.) and itopride (100mg/kg s.c.) markedly enhanced normal gastric antral motility in rats. In gastric motility dysfunction models, acotiamide (100mg/kg s.c.) and itopride (100mg/kg s.c.) improved both gastric antral hypomotility and the delayed gastric emptying induced by clonidine, an α(2)-adrenoceptor agonist. In contrast, mosapride (10mg/kg s.c.) had no effect on these models. Like the AChE inhibitors itopride (30 mg/kg s.c.) and neostigmine (10 μg/kg s.c.), acotiamide (10mg/kg s.c.) also clearly enhanced gastric body contractions induced by electrical stimulation of the vagus, which were abolished by atropine and hexamethonium, whereas mosapride (3 and 10mg/kg s.c.) did not. In in vitro studies, acotiamide concentration-dependently inhibited rat stomach-derived AChE activity (IC(50)=2.3 μmol/l). In addition, stomach tissue concentrations of acotiamide after administration at 10mg/kg s.c. were sufficient to produce inhibition of AChE activity in rat stomach. These results suggest that acotiamide stimulates gastric motility and improves gastric motility dysfunction in rats by inhibiting AChE activity, and may suggest a role for acotiamide in improving gastric motility dysfunction in patients with functional dyspepsia. Copyright © 2011 Elsevier B.V. All rights reserved.

Development Of Enzyme Digestive Activity Of Blue Crab Portunus Pelagicus Larvae

OpenAIRE

Nikhlani, Andi; Sukarti, Komsanah

2017-01-01

Seed production continuity of Portunus pelagicus larvae had been conducted but the results were still un-consistent Digestive activity was known to be associated with the type of feed consumed by larvae. Amylase, lipase, and trypsin enzymes were used as a biological indicators to measure the digestion of feed. The aim of this study was to describe the activity of digestive enzymes in blue swimming crab larvae. Digestive enzyme activity data obtained was presented in graphical form and anal...

Pathogenicity and cell wall-degrading enzyme activities of some ...

African Journals Online (AJOL)

Dr. J. T. Ekanem

2005-12-17

Dec 17, 2005 ... be attributed to the activities of these cell wall degrading enzymes. Keywords: Cowpea ... bacteria have long been known to produce enzymes capable of ... Inoculated seeds were sown in small plastic pots filled with steam- ...

Plant carbohydrate binding module enhances activity of hybrid microbial cellulase enzyme

Directory of Open Access Journals (Sweden)

Caitlin Siobhan Byrt

2012-11-01

Full Text Available A synthetic, highly active cellulase enzyme suitable for in planta production may be a valuable tool for biotechnological approaches to develop transgenic biofuel crops with improved digestibility. Here, we demonstrate that the addition of a plant derived carbohydrate binding module (CBM to a synthetic glycosyl hydrolase (GH improved the activity of the hydrolase in releasing sugar from plant biomass. A CEL-HYB1-CBM enzyme was generated by fusing a hybrid microbial cellulase, CEL-HYB1, with the carbohydrate-binding module (CBM of the tomato (Solanum lycopersicum SlCel9C1 cellulase. CEL-HYB1 and CEL-HYB1-CBM enzymes were produced in vitro using Pichia pastoris and the activity of these enzymes was tested using CMC, MUC and native crystalline cellulose assays. The presence of the CBM substantially improved the endo-glucanase activity of CEL-HYB1, especially against the native crystalline cellulose encountered in Sorghum plant cell walls. These results indicate that addition of an endogenous plant derived CBM to cellulase enzymes may enhance hydrolytic activity.

Synthesis, docking and acetylcholinesterase inhibitory assessment of 2-(2-(4-Benzylpiperazin-1-yl)ethyl)isoindoline-1,3-dione derivatives with potential anti-Alzheimer effects

Science.gov (United States)

2013-01-01

Background Alzheimer’s disease (AD) as neurodegenerative disorder, is the most common form of dementia accounting for about 50-60% of the overall cases of dementia among persons over 65 years of age. Low acetylcholine (ACh) concentration in hippocampus and cortex areas of the brain is one of the main reasons for this disease. In recent years, acetylcholinesterase (AChE) inhibitors like donepezil with prevention of acetylcholine hydrolysis can enhance the duration of action of acetylcholine in synaptic cleft and improve the dementia associated with Alzheimer’s disease. Results Design, synthesis and assessment of anticholinesterase activity of 2-(2-(4-Benzylpiperazin-1-yl)ethyl)isoindoline-1,3-dione derivatives showed prepared compounds can function as potential acetylcholinesterase inhibitor. Among 12 synthesized derivatives, compound 4a with ortho chlorine moiety as electron withdrawing group exhibited the highest potency in these series (IC50 = 0.91 ± 0.045 μM) compared to donepezil (IC50 = 0.14 ± 0.03 μM). The results of the enzyme inhibition test (Ellman test) showed that electron withdrawing groups like Cl, F and NO2 can render the best effect at position ortho and para of the phenyl ring. But compound 4g with methoxy group at position 3(meta) afforded a favorable potency (IC50 = 5.5 ± 0.7 μM). Furthermore, docking study confirmed a same binding mode like donepezil for compound 4a. Conclusions Synthesized compounds 4a-4l could be proposed as potential anticholinesterase agents. PMID:23758724

Synthesis, Docking and Acetylcholinesterase Inhibitory Assessment of 2-(2-(4-Benzylpiperazin-1-YlEthylIsoindoline-1,3-Dione Derivatives with Potential Anti-Alzheimer Effects

Directory of Open Access Journals (Sweden)

Ahmad Mohammadi-Farani

2013-06-01

Full Text Available Background:Alzheimer’s disease (AD as neurodegenerative disorder, is the most common form of dementia accounting for about 50-60% of the overall cases of dementia among persons over 65 years of age. Low acetylcholine (ACh concentration in hippocampus and cortex areas of the brain is one of the main reasons for this disease. In recent years, acetylcholinesterase (AChE inhibitors like donepezil with prevention of acetylcholine hydrolysis can enhance the duration of action of acetylcholine in synaptic cleft and improve the dementia associated with Alzheimer’s disease.Results:Design, synthesis and assessment of anticholinesterase activity of 2-(2-(4-Benzylpiperazin-1-ylethylisoindoline-1,3-dione derivatives showed prepared compounds can function as potential acetylcholinesterase inhibitor. Among 12 synthesized derivatives, compound 4a with ortho chlorine moiety as electron withdrawing group exhibited the highest potency in these series (IC50 = 0.91 ± 0.045 μM compared to donepezil (IC50 = 0.14 ± 0.03 μM. The results of the enzyme inhibition test (Ellman test showed that electron withdrawing groups like Cl, F and NO2 can render the best effect at position ortho and para of the phenyl ring. But compound 4g with methoxy group at position 3(meta afforded a favorable potency (IC50 = 5.5 ± 0.7 μM. Furthermore, docking study confirmed a same binding mode like donepezil for compound 4a.Conclusions:Synthesized compounds 4a-4l could be proposed as potential anticholinesterase agents.

Reveal the response of enzyme activities to heavy metals through in situ zymography.

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Duan, Chengjiao; Fang, Linchuan; Yang, Congli; Chen, Weibin; Cui, Yongxing; Li, Shiqing

2018-07-30

Enzymes in the soil are vital for assessing heavy metal soil pollution. Although the presence of heavy metals is thought to change the soil enzyme system, the distribution of enzyme activities in heavy metal polluted-soil is still unknown. For the first time, using soil zymography, we analyzed the distribution of enzyme activities of alfalfa rhizosphere and soil surface in the metal-contaminated soil. The results showed that the growth of alfalfa was significantly inhibited, and an impact that was most pronounced in seedling biomass and chlorophyll content. Catalase activity (CAT) in alfalfa decreased with increasing heavy metal concentrations, while malondialdehyde (MDA) content continually increased. The distribution of enzyme activities showed that both phosphatase and β-glucosidase activities were associated with the roots and were rarely distributed throughout the soil. In addition, the total hotspot areas of enzyme activities were the highest in extremely heavy pollution soil. The hotspot areas of phosphatase were 3.4%, 1.5% and 7.1% under none, moderate and extremely heavy pollution treatment, respectively, but increased from 0.1% to 0.9% for β-glucosidase with the increasing pollution levels. Compared with the traditional method of enzyme activities, zymography can directly and accurately reflect the distribution and extent of enzyme activity in heavy metals polluted soil. The results provide an efficient research method for exploring the interaction between enzyme activities and plant rhizosphere. Copyright © 2018 Elsevier Inc. All rights reserved.

Analogous β-Carboline Alkaloids Harmaline and Harmine Ameliorate Scopolamine-Induced Cognition Dysfunction by Attenuating Acetylcholinesterase Activity, Oxidative Stress, and Inflammation in Mice

Science.gov (United States)

Li, Shu-Ping; Wang, Yu-Wen; Qi, Sheng-Lan; Zhang, Yun-Peng; Deng, Gang; Ding, Wen-Zheng; Ma, Chao; Lin, Qi-Yan; Guan, Hui-Da; Liu, Wei; Cheng, Xue-Mei; Wang, Chang-Hong

2018-01-01

The analogous β-carboline alkaloids, harmaline (HAL) and harmine (HAR), possess a variety of biological properties, including acetylcholinesterase (AChE) inhibitory activity, antioxidant, anti-inflammatory, and many others, and have great potential for treating Alzheimer’s disease (AD). However, studies have showed that the two compounds have similar structures and in vitro AChE inhibitory activities but with significant difference in bioavailability. The objective of this study was to comparatively investigate the effects of HAL and HAR in memory deficits of scopolamine-induced mice. In the present study, mice were pretreated with HAL (2, 5, and 10 mg/kg), HAR (10, 20, and 30 mg/kg) and donepezil (5 mg/kg) by intragastrically for 7 days, and were daily intraperitoneal injected with scopolamine (1 mg/kg) to induce memory deficits and then subjected to behavioral evaluation by Morris water maze. To further elucidate the underlying mechanisms of HAL and HAR in improving learning and memory, the levels of various biochemical factors and protein expressions related to cholinergic function, oxidative stress, and inflammation were examined. The results showed that HAL and HAR could effectively ameliorate memory deficits in scopolamine-induced mice. Both of them exhibited an enhancement in cholinergic function by inhibiting AChE and inducing choline acetyltransferase (ChAT) activities, and antioxidant defense via increasing the antioxidant enzymes activities of superoxide dismutase and glutathione peroxidase, and reducing maleic diadehyde production, and anti-inflammatory effects through suppressing myeloperoxidase, tumor necrosis factor α, and nitric oxide as well as modulation of critical neurotransmitters such as acetylcholine (ACh), choline (Ch), L-tryptophan (L-Trp), 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (γ-GABA), and L-glutamic acid (L-Glu). Furthermore, the regulations of HAL on cholinergic function, inflammation, and neurotransmitters were more

Natural monomeric form of fetal bovine serum acetylcholinesterase lacks the C-terminal tetramerization domain.

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Saxena, Ashima; Hur, Regina S; Luo, Chunyuan; Doctor, Bhupendra P

2003-12-30

Acetylcholinesterase isolated from fetal bovine serum (FBS AChE) was previously characterized as a globular tetrameric form. Analysis of purified preparations of FBS AChE by gel permeation chromatography revealed the presence of a stable, catalytically active, monomeric form of this enzyme. The two forms could be distinguished from each other based on their molecular weight, hydrodynamic properties, kinetic properties, thermal stability, and the type of glycans they carry. No differences between the two forms were observed for the binding of classical inhibitors such as edrophonium and propidium or inhibitors that are current or potential drugs for the treatment of Alzheimer's disease such as (-) huperzine A and E2020; tacrine inhibited the monomeric form 2-3-fold more potently than the tetrameric form. Sequencing of peptides obtained from an in-gel tryptic digest of the monomer and tetramer by tandem mass spectrometry indicated that the tetramer consists of 583 amino acid residues corresponding to the mature form of the enzyme, whereas the monomer consists of 543-547 amino acid residues. The subunit molecular weight of the protein component of the monomer (major species) was determined to be 59 414 Da and that of the tetramer as 64 239 Da. The N-terminal of the monomer and the tetramer was Glu, suggesting that the monomer is not a result of truncation at the N-terminal. The only differences detected were at the C-terminus. The tetramer yielded the expected C-terminus, CSDL, whereas the C-terminus of the monomer yielded a mixture of peptides, of which LLSATDTLD was the most abundant. These results suggest that monomeric FBS AChE is trimmed at the C-terminus, and the results are consistent with the involvement of C-terminal amino acids in the assembly of monomers into tetramers.

DNA-directed control of enzyme-inhibitor complex formation: a modular approach to reversibly switch enzyme activity

NARCIS (Netherlands)

Janssen, B.M.G.; Engelen, W.; Merkx, M.

2015-01-01

DNA-templated reversible assembly of an enzyme–inhibitor complex is presented as a new and highly modular approach to control enzyme activity. TEM1-ß-lactamase and its inhibitor protein BLIP were conjugated to different oligonucleotides, resulting in enzyme inhibition in the presence of template

Micropollutant degradation via extracted native enzymes from activated sludge.

Science.gov (United States)

Krah, Daniel; Ghattas, Ann-Kathrin; Wick, Arne; Bröder, Kathrin; Ternes, Thomas A

2016-05-15

A procedure was developed to assess the biodegradation of micropollutants in cell-free lysates produced from activated sludge of a municipal wastewater treatment plant (WWTP). This proof-of-principle provides the basis for further investigations of micropollutant biodegradation via native enzymes in a solution of reduced complexity, facilitating downstream protein analysis. Differently produced lysates, containing a variety of native enzymes, showed significant enzymatic activities of acid phosphatase, β-galactosidase and β-glucuronidase in conventional colorimetric enzyme assays, whereas heat-deactivated controls did not. To determine the enzymatic activity towards micropollutants, 20 compounds were spiked to the cell-free lysates under aerobic conditions and were monitored via LC-ESI-MS/MS. The micropollutants were selected to span a wide range of different biodegradabilities in conventional activated sludge treatment via distinct primary degradation reactions. Of the 20 spiked micropollutants, 18 could be degraded by intact sludge under assay conditions, while six showed reproducible degradation in the lysates compared to the heat-deactivated negative controls: acetaminophen, N-acetyl-sulfamethoxazole (acetyl-SMX), atenolol, bezafibrate, erythromycin and 10,11-dihydro-10-hydroxycarbamazepine (10-OH-CBZ). The primary biotransformation of the first four compounds can be attributed to amide hydrolysis. However, the observed biotransformations in the lysates were differently influenced by experimental parameters such as sludge pre-treatment and the addition of ammonium sulfate or peptidase inhibitors, suggesting that different hydrolase enzymes were involved in the primary degradation, among them possibly peptidases. Furthermore, the transformation of 10-OH-CBZ to 9-CA-ADIN was caused by a biologically-mediated oxidation, which indicates that in addition to hydrolases further enzyme classes (probably oxidoreductases) are present in the native lysates. Although the

Novel and viable acetylcholinesterase target site for developing effective and environmentally safe insecticides.

Science.gov (United States)

Pang, Yuan-Ping; Brimijoin, Stephen; Ragsdale, David W; Zhu, Kun Yan; Suranyi, Robert

2012-04-01

Insect pests are responsible for human suffering and financial losses worldwide. New and environmentally safe insecticides are urgently needed to cope with these serious problems. Resistance to current insecticides has resulted in a resurgence of insect pests, and growing concerns about insecticide toxicity to humans discourage the use of insecticides for pest control. The small market for insecticides has hampered insecticide development; however, advances in genomics and structural genomics offer new opportunities to develop insecticides that are less dependent on the insecticide market. This review summarizes the literature data that support the hypothesis that an insect-specific cysteine residue located at the opening of the acetylcholinesterase active site is a promising target site for developing new insecticides with reduced off-target toxicity and low propensity for insect resistance. These data are used to discuss the differences between targeting the insect-specific cysteine residue and targeting the ubiquitous catalytic serine residue of acetylcholinesterase from the perspective of reducing off-target toxicity and insect resistance. Also discussed is the prospect of developing cysteine-targeting anticholinesterases as effective and environmentally safe insecticides for control of disease vectors, crop damage, and residential insect pests within the financial confines of the present insecticide market.

Acetylcholinesterase concentrations in heparinized blood of Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Tully, Thomas N; Osofsky, Anna; Jowett, Peter L H; Hosgood, Giselle

2003-12-01

Organophosphate and carbamate pesticides inhibit acetylcholinesterase (AChE) at nerve synapses. Blood samples from 22 Hispaniolan Amazon parrots (Amazona ventralis) were assayed for cholinesterase levels by two different techniques. Using the modified Michel method, the whole-blood cholinesterase activity levels ranged from 0.082 to 0.616 deltapH/hr with a mean value of 0.35 deltapH/hr. A reference range (0.08-0.62 deltapH/hr) for cholinesterase was established in birds. The modified Ellman spectrophotometric method was used to measure AChE activity by adding acetylthiocholine or pseudocholinesterase (plasma cholinesterase) activity by adding butyrylthiocholine. The reference range of the AChE activity using the modified Ellman spectrophotometric method was 0-1.12 micromol/ml/min with a mean of 0.48 micromol/ml/min, and for pseudocholinesterase the range was 0.09-0.98 micromol/ml/min with a mean of 0.53 micromol/ml/min.

Activation of lysosomal enzymes and tumour regression caused by irradiation and steroid hormones

International Nuclear Information System (INIS)

Ball, A.; Barratt, G.M.; Wills, E.D.

1982-01-01

The lysosomal enzyme activity and membrane permeability of mouse C3H mammary tumours has been studied using quantitative cytochemical methods following irradiation of the tumours with doses of 1500, 3500 or 6000 rad ν rays. No change in the lysosomal enzyme activity was observed immediately after irradiation, but increased enzyme activity and increased membrane permeability were observed 24 hr after irradiation with doses of 3500 or 6000 rad. Twenty-four hours after injection of prednisolone there was a marked increase of lysosomal membrane permeability and enzyme activity, and injection of prednisolone soon after irradiation enhanced the effect of irradiation. After a dose of 6000 rad and prednisolone, the lysosomal membrane permeability increased to 191% of the control and the enzyme activity to 326% of the value of the control tumours. Measurement of tumour size after irradiation or after a combined treatment with irradiation and prednisolone showed that a close correlation exists between tumour regression and lysosomal enzyme activity. The experiments support the view that lysosomal enzymes play an important role in tumour regression following irradiation. (author)

Hfq stimulates the activity of the CCA-adding enzyme

Directory of Open Access Journals (Sweden)

Betat Heike

2007-10-01

Full Text Available Abstract Background The bacterial Sm-like protein Hfq is known as an important regulator involved in many reactions of RNA metabolism. A prominent function of Hfq is the stimulation of RNA polyadenylation catalyzed by E. coli poly(A polymerase I (PAP. As a member of the nucleotidyltransferase superfamily, this enzyme shares a high sequence similarity with an other representative of this family, the tRNA nucleotidyltransferase that synthesizes the 3'-terminal sequence C-C-A to all tRNAs (CCA-adding enzyme. Therefore, it was assumed that Hfq might not only influence the poly(A polymerase in its specific activity, but also other, similar enzymes like the CCA-adding enzyme. Results Based on the close evolutionary relation of these two nucleotidyltransferases, it was tested whether Hfq is a specific modulator acting exclusively on PAP or whether it also influences the activity of the CCA-adding enzyme. The obtained data indicate that the reaction catalyzed by this enzyme is substantially accelerated in the presence of Hfq. Furthermore, Hfq binds specifically to tRNA transcripts, which seems to be the prerequisite for the observed effect on CCA-addition. Conclusion The increase of the CCA-addition in the presence of Hfq suggests that this protein acts as a stimulating factor not only for PAP, but also for the CCA-adding enzyme. In both cases, Hfq interacts with RNA substrates, while a direct binding to the corresponding enzymes was not demonstrated up to now (although experimental data indicate a possible interaction of PAP and Hfq. So far, the basic principle of these stimulatory effects is not clear yet. In case of the CCA-adding enzyme, however, the presented data indicate that the complex between Hfq and tRNA substrate might enhance the product release from the enzyme.

Carotenoid-cleavage activities of crude enzymes from Pandanous amryllifolius.

Science.gov (United States)

Ningrum, Andriati; Schreiner, Matthias

2014-11-01

Carotenoid degradation products, known as norisoprenoids, are aroma-impact compounds in several plants. Pandan wangi is a common name of the shrub Pandanus amaryllifolius. The genus name 'Pandanus' is derived from the Indonesian name of the tree, pandan. In Indonesia, the leaves from the plant are used for several purposes, e.g., as natural colorants and flavor, and as traditional treatments. The aim of this study was to determine the cleavage of β-carotene and β-apo-8'-carotenal by carotenoid-cleavage enzymes isolated from pandan leaves, to investigate dependencies of the enzymatic activities on temperature and pH, to determine the enzymatic reaction products by using Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrophotometry (HS-SPME GC/MS), and to investigate the influence of heat treatment and addition of crude enzyme on formation of norisoprenoids. Crude enzymes from pandan leaves showed higher activity against β-carotene than β-apo-8'-carotenal. The optimum temperature of crude enzymes was 70°, while the optimum pH value was 6. We identified β-ionone as the major volatile reaction product from the incubations of two different carotenoid substrates, β-carotene and β-apo-8'-carotenal. Several treatments, e.g., heat treatment and addition of crude enzymes in pandan leaves contributed to the norisoprenoid content. Our findings revealed that the crude enzymes from pandan leaves with carotenoid-cleavage activity might provide a potential application, especially for biocatalysis, in natural-flavor industry. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Enzyme activities by indicator of quality in organic soil

Science.gov (United States)

Raigon Jiménez, Mo; Fita, Ana Delores; Rodriguez Burruezo, Adrián

2016-04-01

The analytical determination of biochemical parameters, as soil enzyme activities and those related to the microbial biomass is growing importance by biological indicator in soil science studies. The metabolic activity in soil is responsible of important processes such as mineralization and humification of organic matter. These biological reactions will affect other key processes involved with elements like carbon, nitrogen and phosphorus , and all transformations related in soil microbial biomass. The determination of biochemical parameters is useful in studies carried out on organic soil where microbial processes that are key to their conservation can be analyzed through parameters of the metabolic activity of these soils. The main objective of this work is to apply analytical methodologies of enzyme activities in soil collections of different physicochemical characteristics. There have been selective sampling of natural soils, organic farming soils, conventional farming soils and urban soils. The soils have been properly identified conserved at 4 ° C until analysis. The enzyme activities determinations have been: catalase, urease, cellulase, dehydrogenase and alkaline phosphatase, which bring together a representative group of biological transformations that occur in the soil environment. The results indicate that for natural and agronomic soil collections, the values of the enzymatic activities are within the ranges established for forestry and agricultural soils. Organic soils are generally higher level of enzymatic, regardless activity of the enzyme involved. Soil near an urban area, levels of activities have been significantly reduced. The vegetation cover applied to organic soils, results in greater enzymatic activity. So the quality of these soils, defined as the ability to maintain their biological productivity is increased with the use of cover crops, whether or spontaneous species. The practice of cover based on legumes could be used as an ideal choice

One-year monitoring of core biomarker and digestive enzyme responses in transplanted zebra mussels (Dreissena polymorpha).

Science.gov (United States)

Palais, F; Dedourge-Geffard, O; Beaudon, A; Pain-Devin, S; Trapp, J; Geffard, O; Noury, P; Gourlay-Francé, C; Uher, E; Mouneyrac, C; Biagianti-Risbourg, S; Geffard, A

2012-04-01

A 12-month active biomonitoring study was performed in 2008-2009 on the Vesle river basin (Champagne-Ardenne, France) using the freshwater mussel Dreissena polymorpha as a sentinel species; allochthonous mussels originating from a reference site (Commercy) were exposed at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle river basin. Selected core biomarkers (acetylcholinesterase (AChE) activity, glutathione-S transferase (GST) activity, metallothionein concentration), along with digestive enzyme activities (amylase, endocellulase) and energy reserve concentrations (glycogen, lipids), were monitored throughout the study in exposed mussels. At the Fismes and Ardre sites (downstream basin), metallic and organic contamination levels were low but still high enough to elicit AChE and GST activity induction in exposed mussels (chemical stress); besides, chemical pollutants had no apparent deleterious effects on mussel condition. At the Bouy and Sept-Saulx sites (upstream basin), mussels obviously suffered from adverse food conditions which seriously impaired individual physiological state and survival (nutritional stress); food scarcity had however no apparent effects on core biomarker responses. Digestive enzyme activities responded to both chemical and nutritional stresses, the increase in energy outputs (general adaptation syndrome-downstream sites) or the decrease in energy inputs (food scarcity-upstream sites) leading to mid- or long-term induction of digestive carbohydrase activities in exposed mussels (energy optimizing strategy). Complex regulation patterns of these activities require nevertheless the use of a multi-marker approach to allow data interpretation. Besides, their sensitivity to natural confounding environmental factors remains to be precised.

Effect of diffusion on enzyme activity in a microreactor

NARCIS (Netherlands)

Swarts, J.W.; Kolfschoten, R.C.; Jansen, M.C.A.A.; Janssen, A.E.M.; Boom, R.M.

2010-01-01

To establish general rules for setting up an enzyme microreactor system, we studied the effect of diffusion on enzyme activity in a microreactor. As a model system we used the hydrolysis of ortho-nitrophenyl-ß-d-galactopyranoside by ß-galactosidase from Kluyveromyces lactis. We found that the

Differentiation between activity of digestive enzymes of Brachionus calyciflorus and extracellular enzymes of its epizooic bacteria

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Wilko H. AHLRICHS

2009-08-01

Full Text Available The rotifer Brachionus calyciflorus was examined by scanning electron microscopy (SEM for surface-attached, i.e. epizootic, bacteria to ascertain their specific localization and thus find out if we could discern between rotifer and bacterial enzyme activity. The lorica of B. calyciflorus was colonized by one distinct type of bacteria, which originated from the algal culture used for rotifer feeding. The corona, posterior epidermis and foot of all inspected individuals were always without attached bacteria. The density of the attached bacteria was higher with the increasing age of B. calyciflorus: while young individuals were colonized by ~ tens of bacterial cells, older ones had on average hundreds to thousands of attached bacteria. We hypothesize that epizooic bacteria may produce the ectoenzymes phosphatases and β-N-acetylhexosaminidases on the lorica, but not on the corona of B. calyciflorus. Since enzyme activities of epizooic bacteria may influence the values and interpretation of bulk rotifer enzyme activities, we should take the bacterial contribution into account.

Enzyme activities in reclaimed coal mine spoils and soils

Energy Technology Data Exchange (ETDEWEB)

Fresquez, P R; Aldon, E F; Lindemann, W C

1987-11-01

The segregation and stockpiling of topsoil material may reduce enzymatic activities that may hinder normal nutrient cycling processes in reclaimed minelands. The effects of topsoiling and reclamation age on dehydrogenase, nitrogenase, phosphatase, arylsulphatase, amylase, cellulase, invertase and urease activities were evaluated on three reclaimed non-top-soiled and five reclaimed topsoiled areas and compared with an indisturbed reference soil. Three months after topsoiling and revegetation, activities of the enzymes in the reclaimed areas, with the exception of dehydrogenase, were statistically equal to activities of the undisturbed soil. Most enzymes, including dehydrogenase, peaked in the next 1 or 2 years after reclamation with topsoiling and declined thereafter. A 4-year-old topsoiled site (revegetated in 1978) was statistically similar to the undisturbed soil. Amylase activity, however, was significantly lower after the fourth year compared to the undisturbed soil. The non-topsoiled areas, even after 6, 7 and 8 years, appeared to have lower enzyme activities than the younger topsoiled areas or the undisturbed soil. This trend was supported by the finding that the 4-year-old topsoiled site was more enzymatically similar to the undisturbed soil than was the 8-year-old non-topsoiled site (revegetated in 1974). The low enzyme acitivities found in the non-topsoiled areas may be a result of their adverse chemical and physical properties, as well as the low diversity of microorganisms. These studies demonstrate the value of topsoil use for early establishment of soil processes in reclaimed areas. 3 figs., 19 refs., 8 tabs.

Bifunctional phenolic-choline conjugates as anti-oxidants and acetylcholinesterase inhibitors

Czech Academy of Sciences Publication Activity Database

Šebestík, Jaroslav; Marques, S. M.; Falé, P. L.; Santos, S.; Arduíno, D. M.; Cardoso, S. M.; Oliveira, S. M.; Serralheiro, M. L. M.; Santos, A. M.

Roč. 26, č. 4 (485), s. 497 ISSN 1475-6366 Institutional research plan: CEZ:AV0Z40550506 Keywords : acetylcholinesterase inhibitors * antioxidants * hybrid ligands * anti-neurodegeneratives * Alzheimer´s disease Subject RIV: CC - Organic Chemistry

Phytobiotic Utilization as Feed Additive in Feed for Pancreatic Enzyme Activity of Broiler Chicken

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Sri Purwanti

2015-09-01

Full Text Available This research was conducted to evaluate the effect of turmeric water extract, garlic and combination turmeric and garlic as a feed additive in the broiler diet on pancreatic enzyme activity of broiler chicken. Effectivity of treatments was assessed by addition of phytobiotic (control, 015% zinc bacitracin, 2.5% TE, 2.0% GE, 2.5% TGE which were arranged Completely Randomized Design with 4 replications. The variables measured were pancreatic enzyme activity(amylase enzyme activity, protease enzyme activity  and lipase enzyme activity.The results showed that enzyme protein activity content of 2.5% TE supplementation is also high at 82.02 U/ml, then supplemented 2.5% TGE, 2.0% GE, negative control and positive control respectively 75.98 ; 72.02; 68.74; and 66.57 U/ml. The lipase enzyme activity whereas the negative control and a positive control differ significantly higher (P<0.05 to treatment with the addition of 2.5% TE, 2.0% GE and 2.5% TGE phytobiotic. The research concluded that the incorporation of 2.5% TE, 2% GE and combined 2.5% TGE as feed additive enhanced pancreatic enzyme activity.

The effect of curcumin in the ectonucleotidases and acetylcholinesterase activities in synaptosomes from the cerebral cortex of cigarette smoke-exposed rats.

Science.gov (United States)

Jaques, Jeandre Augusto Dos Santos; Rezer, João Felipe Peres; Gonçalves, Jamile Fabbrin; Spanevello, Rosélia Maria; Gutierres, Jessié Martins; Pimentel, Victor Câmera; Thomé, Gustavo Roberto; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina; Leal, Daniela Bitencourt Rosa

2011-12-01

With the evidence that curcumin may be a potent neuroprotective agent and that cigarette smoke is associated with a decline in the cognitive performance as our bases, we investigated the activities of Ecto-Nucleoside Triphosphate Diphosphohydrolase (NTPDase), 5'-nucleotidase and acetylcholinesterase (AChE) in cerebral cortex synaptosomes from cigarette smoke-exposed rats treated with curcumin (Cur). The experimental procedures entailed two sets of experiments. In the first set, the groups were vehicle, Cur 12·5, 25 and 50 mg·kg(-1) ; those in the second set were vehicle, smoke, smoke and Cur 12·5, 25 and 50 mg·kg(-1) . Curcumin prevented the increased NTPDase, 5'-nucleotidase and AChE activities caused by smoke exposure. We suggest that treatment with Cur was protective because the decrease of ATP and acetylcholine (ACh) concentrations is responsible for cognitive impairment, and both ATP and ACh have key roles in neurotransmission. Copyright © 2011 John Wiley & Sons, Ltd.

[The restoration of the enzyme activity of chernozem soil after gamma-irradiation].

Science.gov (United States)

Denisova, T V; Kazeev, K Sh

2006-01-01

The Influence of gamma-radiation by dozes 1, 5, 10 and 20 kGy on enzyme activity of ordinary chemozem were studied. Dynamics of the restoration of the enzyme activity after the influence of gamma-radiation in model experiments in 3, 30, 90 and 180 days was investigated. The doze 1 kGy did no statistically significant influence on the investigated enzymes. Dehydrogenase is more radiosensitive enzyme than catalase. Values of the saccharase activity differed a significant variation so in most cases it has not been registered statistically significant changes. In 90-180 days of the incubation enzymes activity was restored up to control values. Dehydrogenase activity in 180 days in variants with dozes 10 and 20 kGy was restored up to a level of the control, over variants with dozes 1 and 5 kGy--is higher than the control over 78% and 23% accordingly. Saccharase activity in 180 days after the influence of gamma-radiation with a doze 20 kGy was on 61% lower than the control.

Dynamic relationships between microbial biomass, respiration, inorganic nutrients and enzyme activities: informing enzyme based decomposition models

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Daryl L Moorhead

2013-08-01

Full Text Available We re-examined data from a recent litter decay study to determine if additional insights could be gained to inform decomposition modeling. Rinkes et al. (2013 conducted 14-day laboratory incubations of sugar maple (Acer saccharum or white oak (Quercus alba leaves, mixed with sand (0.4% organic C content or loam (4.1% organic C. They measured microbial biomass C, carbon dioxide efflux, soil ammonium, nitrate, and phosphate concentrations, and β-glucosidase (BG, β-N-acetyl-glucosaminidase (NAG, and acid phosphatase (AP activities on days 1, 3, and 14. Analyses of relationships among variables yielded different insights than original analyses of individual variables. For example, although respiration rates per g soil were higher for loam than sand, rates per g soil C were actually higher for sand than loam, and rates per g microbial C showed little difference between treatments. Microbial biomass C peaked on day 3 when biomass-specific activities of enzymes were lowest, suggesting uptake of litter C without extracellular hydrolysis. This result refuted a common model assumption that all enzyme production is constitutive and thus proportional to biomass, and/or indicated that part of litter decay is independent of enzyme activity. The length and angle of vectors defined by ratios of enzyme activities (BG/NAG versus BG/AP represent relative microbial investments in C (length, and N and P (angle acquiring enzymes. Shorter lengths on day 3 suggested low C limitation, whereas greater lengths on day 14 suggested an increase in C limitation with decay. The soils and litter in this study generally had stronger P limitation (angles > 45˚. Reductions in vector angles to < 45˚ for sand by day 14 suggested a shift to N limitation. These relational variables inform enzyme-based models, and are usually much less ambiguous when obtained from a single study in which measurements were made on the same samples than when extrapolated from separate studies.

An evaluation on elastase enzyme activity in gingival crevicular fluid in periodontitis

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Qujeq D

2003-08-01

Full Text Available Statement of Problem: Changes in protein levels, host calls enzymes and inflammatory mediators in gingival"ncrevicular Fluid (GCF are considered as diagnostic indicators of Periodontitis."nPurpose: he aim of the present study was to measure the elastase enzyme activity in gingival crevicular Fluid"namong patients with periodontitis."nMaterial and Methods: In this study, 52 periodontitis patients (experimental group and 51 healthy subjects"nwithout any gingival inflammatio (control group were participated. Subjects of the periodontitis group"nshowed pockets of 4-5 mm depth without gingival enlargement and recession or pockets of 1-2 mm depth"nwith gingival recession. For enzyme activity measurement, lOOu,! of gingival fluid of each sample was mixed"nwith lOOu! of enzyme substrate on the tube. The mixture was incubated at 34°c for lh with a buffer solution"nof 1ml volume and absorbance was read at 410nm with spectrophotometer. The enzyme activity differences"nbetween two groups were analyzed by student t test."nResults: The elastase enzyme activity in gingival crevicular fluid in subjects with periodontium destruction"nand control subjects was 153±11.3 and 52.7±10.4 enzyme unit in ml per minute, respectively. The difference"nbetween groups was statistically significant (PO.05."nConclusion: Based on the findings of this study, the measurement of elastae enzyme activity could be a useful"nindication of tissue changes that may ultimately manifest clinically as periodontitis.

Remote enzyme activation using gold coated magnetite as antennae for radio frequency fields

Science.gov (United States)

Collins, Christian B.; Ackerson, Christopher J.

2018-02-01

The emerging field of remote enzyme activation, or the ability to remotely turn thermophilic increase enzyme activity, could be a valuable tool for understanding cellular processes. Through exploitation of the temperature dependence of enzymatic processes and high thermal stability of thermophilic enzymes these experiments utilize nanoparticles as `antennae' that convert radiofrequency (RF) radiation into local heat, increasing activity of the enzymes without increasing the temperature of the surrounding bulk solution. To investigate this possible tool, thermolysin, a metalloprotease was covalently conjugated to 4nm gold coated magnetite particles via peptide bond formation with the protecting ligand shell. RF stimulated protease activity at 17.76 MHz in a solenoid shaped antenna, utilizing both electric and magnetic field interactions was investigated. On average 40 percent higher protease activity was observed in the radio frequency fields then when bulk heating the sample to the same temperature. This is attributed to electrophoretic motion of the nanoparticle enzyme conjugates and local regions of heat generated by the relaxation of the magnetite cores with the oscillating field. Radio frequency local heating of nanoparticles conjugated to enzymes as demonstrated could be useful in the activation of specific enzymes in complex cellular environments.

Sesquiterpenes produced by endophytic fungus Phomopsis cassiae with antifungal and acetylcholinesterase inhibition activities; Sesquiterpenos produzidos pelo fungo endofitico Phomopsis cassiae com atividade antifungica e inibidora de acetilcolinesterase

Energy Technology Data Exchange (ETDEWEB)

Zanardi, Lisineia M.; Bolzani, Vanderlan da S.; Cavalheiro, Alberto J.; Silva, Dulce H. Siqueira; Trevisan, Henrique C.; Araujo, Angela R. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Silva, Geraldo H. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Centro de Ciencias Exatas e Tecnologia; Teles, Helder L. [Universidade Federal do Mato Grosso (UFMT), Rondonopolis, MT (Brazil). Dept. de Ciencias Biologicas; Young, Maria Claudia M., E-mail: araujoar@iq.unesp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Seccao de Fisiologia e Bioquimica de Plantas

2012-07-01

Two new diastereoisomeric cadinanes sesquiterpenes 3,9-dihydroxycalamenene (1-2), along with the known 3-hydroxycalamen-8-one (3) and aristelegone-A (4), were isolated from ethyl acetate extract of Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures, including relative stereochemistry, were determined on the basis of detailed interpretation of 2D NMR spectra and comparison with related known compounds. Compounds 1-4 displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as inhibition of acetylcholinesterase. (author)

Synthesis of 1-[{sup 11}c]methylpiperidin-4-yl propionate ([{sup 11}c]pmp) for in vivo measurements of acetylcholinesterase activity

Energy Technology Data Exchange (ETDEWEB)

Snyder, Scott E. E-mail: snyderse@umich.edu; Tluczek, Louis; Jewett, Douglas M.; Nguyen, Thinh B.; Kuhl, David E.; Kilbourn, Michael R

1998-11-01

Synthesis of 1-[{sup 11}C]methylpiperidin-4-yl propionate ([{sup 11}C]PMP), an in vivo substrate for acetylcholinesterase, is reported. An improved preparation of 4-piperidinyl propionate (PHP), the immediate precursor for radiolabeling, was accomplished in three steps from 4-hydroxypiperidine by (a) protection of the amine as the benzyl carbamate, (b) acylation with propionyl chloride, and (c) deprotection of the carbamate by catalytic hydrogenation. The final product was obtained in an overall 82% yield. Reaction of the free base form of PHP with [{sup 11}C]methyl trifluoromethanesulfonate at room temperature in N,N-dimethylformamide, followed by high performance liquid chromatography (HPLC) purification, provided [{sup 11}C]PMP in 57% radiochemical yield, >99% radiochemical purity, and >1500 Ci/mmol at the end of synthesis. The total synthesis time from end-of-bombardment was 35 min. [{sup 11}C]PMP can thus be reliably prepared for routine clinical studies of acetylcholinesterase in human brain using positron emission tomography.

Ligninolytic enzyme activities in mycelium of some wild and ...

African Journals Online (AJOL)

Lignin is probably one of the most recalcitrant compounds synthesized by plants. This compound is degraded by few microorganisms. White-rot fungi have been extensively studied due to its powerful ligninolytic enzymes. In this study, ligninolytic enzyme activities of different fungal species (six commercial and 13 wild) were ...

Glutathione regulation-based dual-functional upconversion sensing-platform for acetylcholinesterase activity and cadmium ions.

Science.gov (United States)

Fang, Aijin; Chen, Hongyu; Li, Haitao; Liu, Meiling; Zhang, Youyu; Yao, Shouzhuo

2017-01-15

A dual-functional platform for the sensing of acetylcholinesterase (AChE) activity and cadmium ions (Cd 2+ ) was developed based on the fluorescence resonance energy transfer (FRET) between NaYF 4 :Yb,Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) via glutathione regulation. The detection mechanism is based on the fact that AuNPs can quench the fluorescence of UCNPs. AChE catalyzes the hydrolysis of acetylthiocholine (ATC) into thiocholine which reacts with AuNPs by S-Au conjunction and results the aggregation of AuNPs and change in fluorescence of UCNPs. Therefore, the AChE activity can be detected through the changes of the color of solution and fluorescence recovery of UCNPs. However, the presence of glutathione (GSH) can protect AuNPs from aggregation and enlarge the inter-particle distance between AuNPs and UCNPs. When Cd 2+ is added into the stable mixture of AuNPs, GSH and AChE/ATC, Cd 2+ could interact with GSH to form a spherical shaped (GSH) 4 Cd complex, which decreases the free GSH on the surface of AuNPs to weaken the stability of AuNPs and lead to the easily aggregation of them in the system. The aggregated-AuNPs are released from the surface of UCNPs, which results in the fluorescence of UCNPs gradually recovered. Under the optimized conditions, the detection limits of AChE activity and Cd 2+ are estimated to be 0.015mU/mL and 0.2µM, respectively. The small molecules regulated dual-functional platform based on UCNPs/AuNPs is a simple, label-free method and can be applied for the turn-on fluorescence detection of AChE activity in human serum and Cd 2+ in real water samples. The present work demonstrates a general strategy for the design of small molecules regulated multifunctional platform and will be expanded for different areas in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Arisugacins A and B, novel and selective acetylcholinesterase inhibitors from Penicillium sp. FO-4259. I. Screening, taxonomy, fermentation, isolation and biological activity.

Science.gov (United States)

Kuno, F; Otoguro, K; Shiomi, K; Iwai, Y; Omura, S

1996-08-01

An in vitro screening method for selective acetylcholinesterase (AChE) inhibitors was established. Inhibitory activity of AChE and butyrylcholinesterase (BuChE) was measured and the culture broths of microorganisms that showed selective inhibition against AChE were characterized. By using this method, a strain producing the novel and selective inhibitors of AChE, arisugacins A and B, was picked out among over seven thousand microorganisms tested. Arisugacins were obtained as white powders from the culture broth together with three known compounds, territrems B and C and cyclopenin that also showed selective inhibition against AChE. Arisugacins and territrems are members of the meroterpenoid compounds. They showed potent inhibitory activities against AChE with IC50 values in range of 1.0 approximately 25.8 nM. Furthermore, they showed greater than 2,000-fold more potent inhibition against AChE than BuChE.

Characterization of acetylcholinesterase-inhibition by itopride.

Science.gov (United States)

Iwanaga, Y; Kimura, T; Miyashita, N; Morikawa, K; Nagata, O; Itoh, Z; Kondo, Y

1994-11-01

Itopride is a gastroprokinetic benzamide derivative. This agent inhibited both electric eel acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BuChE). The IC50 of itopride with AChE (2.04 +/- 0.27 microM) was, however, 100-fold less than that with BuChE, whereas in the case of neostigmine with AChE (11.3 +/- 3.4 nM), it was 10-fold less. The recovery of AChE activity inhibited by 10(-7) M neostigmine was partial, but that inhibited by up to 3 x 10(-5) M itopride was complete when the reaction mixture was subjected to ultrafiltration. Double reciprocal plots of the experimental data showed that both Km and Vmax were affected by itopride, suggesting that the inhibition is a "mixed" type, although primarily being an uncompetitive one. The inhibitory effect of itopride on cholinesterase (ChE) activity in guinea pig gastrointestine was much weaker than that on pure AChE. However, in the presence of a low dose of diisopropyl fluorophosphate, just enough to inhibit BuChE but not AChE, the IC50s of itopride against ChE activities were found to be about 0.5 microM. In conclusion, itopride exerts reversible and a "mixed" type of inhibition preferably against AChE. The IC50 of itopride for electric eel and guinea pig gastrointestinal AChE inhibition was 200 times and 50 times as large as that of neostigmine, respectively.

Assessing joint toxicity of four organophosphate and carbamate insecticides in common carp (Cyprinus carpio) using acetylcholinesterase activity as an endpoint.

Science.gov (United States)

Wang, Yanhua; Chen, Chen; Zhao, Xueping; Wang, Qiang; Qian, Yongzhong

2015-07-01

Mixtures of organophosphate (OP) and carbamate (CB) pesticides are commonly detected in freshwater ecosystems. These pesticides inhibit the activity of acetylcholinesterase (AChE) and have potential to interfere with behaviors that may be essential for the survival of species. Although the effects of individual anticholinesterase insecticides on aquatic species have been studied for decades, the neurotoxicity of mixtures is still poorly understood. In the present study, brain AChE inhibition in carp (Cyprinus carpio) exposed to a series of concentrations of the organophosphates (malathion and triazophos) as well as the carbamates (fenobucarb and carbosulfan) was measured. In equitoxic mixtures, the observed AChE activity inhibition of the malathion plus triazophos, and triazophos plus carbosulfan mixtures, was synergism. In equivalent concentration mixtures, the combination of malathion plus fenobucarb mixture conformed to synergism, while the observed AChE activity inhibition of the remaining pairings was less than additive. Single pesticide risk assessments are likely to underestimate the impacts of these insecticides on carps in aquatic environment where mixtures occur. Moreover, mixtures of pesticides that have been commonly reported in aquatic ecosystems may pose a more important challenge than previously anticipated. Copyright © 2014 Elsevier Inc. All rights reserved.

Activity of selected hydrolytic enzymes in Allium sativum L. anthers.

Science.gov (United States)

Winiarczyk, Krystyna; Gębura, Joanna

2016-05-01

The aim of the study was to determine enzymatic activity in sterile Allium sativum anthers in the final stages of male gametophyte development (the stages of tetrads and free microspores). The analysed enzymes were shown to occur in the form of numerous isoforms. In the tetrad stage, esterase activity was predominant, which was manifested by the greater number of isoforms of the enzyme. In turn, in the microspore stage, higher numbers of isoforms of acid phosphatases and proteases were detected. The development of sterile pollen grains in garlic is associated with a high level of protease and acid phosphatase activity and lower level of esterase activities in the anther locule. Probably this is the first description of the enzymes activity (ACPH, EST, PRO) in the consecutives stages of cell wall formation which is considered to be one of the causes of male sterility in flowering plant. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cholinesterase inhibitory activity and structure elucidation of a new phytol derivative and a new cinnamic acid ester from Pycnanthus angolensis

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Taiwo O. Elufioye

Full Text Available ABSTRACT The leaves of Pycnanthus angolensis (Welw. Warb., Myristicaceae, are used as memory enhancer and anti-ageing in Nigerian ethnomedicine. This study aimed at evaluating the cholinesterase inhibitory property as well as isolates the bioactive compounds from the plant. The acetylcholinesterase and butyrylcholinesterase inhibitory potentials of extracts, fractions, and isolated compounds were evaluated by colorimetric and TLC bioautographic assay techniques. The extract inhibited both enzymes with activity increasing with purification, ethyl acetate fraction being most active fraction at 65.66 ± 1.06% and 49.38 ± 1.66% against acetylcholinesterase and butyrylcholinesterase, respectively while the supernatant had 77.44 ± 1.18 inhibition against acetylcholinesterase. Two new bioactive compounds, (2E, 18E-3,7,11,15,18-pentamethylhenicosa-2,18-dien-1-ol (named eluptol and [12-(4-hydroxy-3-methyl-oxo-cyclopenta-1,3-dien-1yl-11-methyl-dodecyl](E-3-(3,4-dimethylphenylprop-2-enoate (named omifoate A were isolated from the plant with IC50 of 22.26 µg/ml (AChE, 34.61 µg/ml (BuChE and 6.51 µg/ml (AChE, 9.07 µg/ml (BuChE respectively. The results showed that the plant has cholinesterase inhibitory activity which might be responsible for its memory enhancing action, thus justifying its inclusion in traditional memory enhancing preparations

A comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced memory impairments in rats

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Talha Jawaid

2015-01-01

Full Text Available The comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced neuroinflammation in albino Wistar rats was studied. Male albino rats were administered with scopolamine to induce memory impairment. The standard nootropic agent, piracetam (200 mg/kg b.w., [i.p.], perindopril (0.1 mg/kg b.w., [i.p.], enalapril (0.1 mg/kg b.w., [i.p.], and ramipril (0.1 mg/kg b.w., [i.p.] were administered in different group of animals for 5 days. On 5 th day, scopolamine (1 mg/kg b.w., i.p. was administered after 60 min of the last dose of test drug. Memory function was evaluated in Morris water maze (MWM test and pole climbing test (PCT. Biochemical estimations like glutathione (GSH, malondialdehyde (MDA, and acetylcholinesterase activity in the brain were estimated after completion of behavior study. All three test groups shows improvement in learning and memory in comparison to control group. Perindopril treated group showed a more effective significant decrease in escape latency time and transfer latency time compared to enalapril and ramipril treated group on day 4 in MWM test and PCT, respectively. Perindopril shows a significant reduction in MDA level and acetylcholinesterase activity and a significant rise in GSH level compared to enalapril and ramipril. The finding of this study indicates that Perindopril is more effective in memory retention compared to enalapril and ramipril.

Optimization of Enzyme Co-Immobilization with Sodium Alginate and Glutaraldehyde-Activated Chitosan Beads.

Science.gov (United States)

Gür, Sinem Diken; İdil, Neslihan; Aksöz, Nilüfer

2018-02-01

In this study, two different materials-alginate and glutaraldehyde-activated chitosan beads-were used for the co-immobilization of α-amylase, protease, and pectinase. Firstly, optimization of multienzyme immobilization with Na alginate beads was carried out. Optimum Na alginate and CaCl 2 concentration were found to be 2.5% and 0.1 M, respectively, and optimal enzyme loading ratio was determined as 2:1:0.02 for pectinase, protease, and α-amylase, respectively. Next, the immobilization of multiple enzymes on glutaraldehyde-activated chitosan beads was optimized (3% chitosan concentration, 0.25% glutaraldehyde with 3 h of activation and 3 h of coupling time). While co-immobilization was successfully performed with both materials, the specific activities of enzymes were found to be higher for the enzymes co-immobilized with glutaraldehyde-activated chitosan beads. In this process, glutaraldehyde was acting as a spacer arm. SEM and FTIR were used for the characterization of activated chitosan beads. Moreover, pectinase and α-amylase enzymes immobilized with chitosan beads were also found to have higher activity than their free forms. Three different enzymes were co-immobilized with these two materials for the first time in this study.

Cholinesterase Enzymes Inhibitors from the Leaves of Rauvolfia Reflexa and Their Molecular Docking Study

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Vikneswaran Murugaiyah

2013-03-01

Full Text Available Plants of the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders. Rauvolfia reflexa, a member of the family, has been used as an antidote for poisons and to treat malaria. The dichloromethane, ethanol and methanol extracts from the leaves of Rauvolfia reflexa showed potential acetylcholinesterase (AChE and butyrylcholinesterase (BChE inhibitory activities, with IC50 values in the 8.49 to 52.23 g/mL range. Further cholinesterase inhibitory-guided isolation of these extracts afforded four bioactive compounds, namely: (E-3-(3,4,5-trimethoxyphenylacrylic acid (1, (E-methyl 3-(4-hydroxy-3,5-dimethoxyphenyl acrylate (2, 17-methoxycarbonyl-14-heptadecaenyl-4-hydroxy-3-methoxycinnamate (3 and 1,2,3,4-tetrahydro-1-oxo-β-carboline (4. The isolated compounds showed moderate cholinesterase inhibitory activity compared to the reference standard, physostigmine. Compounds 1 and 2 showed the highest inhibitory activity against AChE (IC50 = 60.17 µM and BChE (IC50 = 61.72 µM, respectively. Despite having similar molecular weight, compounds 1 and 2 were structurally different according to their chemical substitution patterns, leading to their different enzyme inhibition selectivity. Compound 2 was more selective against BChE, whereas compound 1 was a selective inhibitor of AChE. Molecular docking revealed that both compounds 1 and 2 were inserted, but not deeply into the active site of the cholinesterase enzymes.

Cholinesterase enzymes inhibitors from the leaves of Rauvolfia reflexa and their molecular docking study.

Science.gov (United States)

Fadaeinasab, Mehran; Hadi, A Hamid A; Kia, Yalda; Basiri, Alireza; Murugaiyah, Vikneswaran

2013-03-25

Plants of the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders. Rauvolfia reflexa, a member of the family, has been used as an antidote for poisons and to treat malaria. The dichloromethane, ethanol and methanol extracts from the leaves of Rauvolfia reflexa showed potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, with IC50 values in the 8.49 to 52.23 g/mL range. Further cholinesterase inhibitory-guided isolation of these extracts afforded four bioactive compounds, namely: (E)-3-(3,4,5-trimethoxyphenyl)acrylic acid (1), (E)-methyl 3-(4-hydroxy-3,5-dimethoxyphenyl) acrylate (2), 17-methoxycarbonyl-14-heptadecaenyl-4-hydroxy-3-methoxycinnamate (3) and 1,2,3,4-tetrahydro-1-oxo-β-carboline (4). The isolated compounds showed moderate cholinesterase inhibitory activity compared to the reference standard, physostigmine. Compounds 1 and 2 showed the highest inhibitory activity against AChE (IC50 = 60.17 µM) and BChE (IC50 = 61.72 µM), respectively. Despite having similar molecular weight, compounds 1 and 2 were structurally different according to their chemical substitution patterns, leading to their different enzyme inhibition selectivity. Compound 2 was more selective against BChE, whereas compound 1 was a selective inhibitor of AChE. Molecular docking revealed that both compounds 1 and 2 were inserted, but not deeply into the active site of the cholinesterase enzymes.

Effect of adult onset hypothyroidism on behavioral parameters and acetylcholinesterase isoforms activity in specific brain regions of male mice.

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Vasilopoulou, Catherine G; Constantinou, Caterina; Giannakopoulou, Dimitra; Giompres, Panagiotis; Margarity, Marigoula

2016-10-01

Thyroid hormones (TH) are essential for normal development and function of mammalian central nervous system (CNS); TH dysregulation has been implicated in several cognitive and behavioral deficits related to dysfunctions of neurotransmitter systems. In the present study, we investigated the effects of adult onset hypothyroidism on the activity of acetylcholinesterase (AChE) and on related behavioral parameters. For this purpose we used adult male Balb/cJ mice that were divided randomly into euthyroid and hypothyroid animal groups. Animals were rendered hypothyroid through administration of 1% w/v KClO4 in their drinking water for 8weeks. At the end of the treatment, learning/memory procedures were examined through step-through passive avoidance task while fear/anxiety was assessed using elevated plus-maze (EPM) and open-field (OF) tests. AChE activity was determined colorimetrically in two different fractions, salt-soluble fraction (SS) (containing mainly the G1 isoform) and detergent-soluble fraction (DS) (containing mainly the G4 isoform) in cerebral cortex, cerebellum, midbrain, hippocampus and striatum. Our results indicate that adult onset hypothyroidism caused significant memory impairment and increased fear/anxiety. Moreover, the activity of both isoforms of AChE was reduced in all brain regions examined in a brain region- and isoform-specific manner. Copyright © 2016. Published by Elsevier Inc.

Revealing hidden effect of earthworm on C distribution and enzyme activity

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Razavi, Bahar S.; Hoang, Duyen; Kuzyakov, Yakov

2017-04-01

Despite its importance for terrestrial nutrient and carbon cycling, the spatial organization and localization of microbial activity in soil and in biopores is poorly understood. We hypothesized that biopores created by earthworm play a critical role in reducing the gap of SOM input and microbial activities between topsoil and subsoil. Accordingly, Carbon (C) allocation by earthworms was related to enzyme distribution along soil profile. For the first time we visualized spatial distribution of enzyme activities (β-glucosidase, chitinase and acid phosphatase) and C allocation (by 14C imaging) in earthworm biopores in topsoil and subsoil. Soil zymography (an in situ method for the analysis of the two-dimensional distribution of enzyme activity in soil) was accompanied with 14C imaging (a method that enables to trace distribution of litter and C in soil profile) to visualize change of enzyme activities along with SOM incorporation by earthworms from topsoil to subsoil. Experiment was set up acquiring rhizoboxes (9×1×50 cm) filled up with fresh soil and 3 earthworms (L. terrestris), which were then layered with 14C-labeled plant-litter of 0.3 MBq on the soil surface. 14C imaging and zymography have been carried out after one month. Activities of all enzymes regardless of their nutrient involvement (C, N, P) were higher in the biopores than in bulk soil, but the differences were larger in topsoil compared to subsoil. Among three enzymes, Phosphatase activity was 4-times higher in the biopore than in the bulk soil. Phosphatase activity was closely associated with edge of burrows and correlate positively with 14C activity. These results emphasized especial contribution of hotspheres such as biopores to C allocation in subsoil - which is limited in C input and nutrients - and in stimulation of microbial and enzymatic activity by input of organic residues, e.g. by earthworms. In conclusion, biopore increased enzymatic mobilization of nutrients (e.g. P) inducing allocation

Molecular dynamics explorations of active site structure in designed and evolved enzymes.

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Osuna, Sílvia; Jiménez-Osés, Gonzalo; Noey, Elizabeth L; Houk, K N

2015-04-21

This Account describes the use of molecular dynamics (MD) simulations to reveal how mutations alter the structure and organization of enzyme active sites. As proposed by Pauling about 70 years ago and elaborated by many others since then, biocatalysis is efficient when functional groups in the active site of an enzyme are in optimal positions for transition state stabilization. Changes in mechanism and covalent interactions are often critical parts of enzyme catalysis. We describe our explorations of the dynamical preorganization of active sites using MD, studying the fluctuations between active and inactive conformations normally concealed to static crystallography. MD shows how the various arrangements of active site residues influence the free energy of the transition state and relates the populations of the catalytic conformational ensemble to the enzyme activity. This Account is organized around three case studies from our laboratory. We first describe the importance of dynamics in evaluating a series of computationally designed and experimentally evolved enzymes for the Kemp elimination, a popular subject in the enzyme design field. We find that the dynamics of the active site is influenced not only by the original sequence design and subsequent mutations but also by the nature of the ligand present in the active site. In the second example, we show how microsecond MD has been used to uncover the role of remote mutations in the active site dynamics and catalysis of a transesterase, LovD. This enzyme was evolved by Tang at UCLA and Codexis, Inc., and is a useful commercial catalyst for the production of the drug simvastatin. X-ray analysis of inactive and active mutants did not reveal differences in the active sites, but relatively long time scale MD in solution showed that the active site of the wild-type enzyme preorganizes only upon binding of the acyl carrier protein (ACP) that delivers the natural acyl group to the active site. In the absence of bound ACP

Spatial distribution of enzyme activities along the root and in the rhizosphere of different plants

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Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

Extracellular enzymes are important for decomposition of many biological macromolecules abundant in soil such as cellulose, hemicelluloses and proteins. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. So far acquisition of in situ data about local activity of different enzymes in soil has been challenged. That is why there is an urgent need in spatially explicit methods such as 2-D zymography to determine the variation of enzymes along the roots in different plants. Here, we developed further the zymography technique in order to quantitatively visualize the enzyme activities (Spohn and Kuzyakov, 2013), with a better spatial resolution We grew Maize (Zea mays L.) and Lentil (Lens culinaris) in rhizoboxes under optimum conditions for 21 days to study spatial distribution of enzyme activity in soil and along roots. We visualized the 2D distribution of the activity of three enzymes:β-glucosidase, leucine amino peptidase and phosphatase, using fluorogenically labelled substrates. Spatial resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography shows different pattern of spatial distribution of enzyme activity along roots and soil of different plants. We observed a uniform distribution of enzyme activities along the root system of Lentil. However, root system of Maize demonstrated inhomogeneity of enzyme activities. The apical part of an individual root (root tip) in maize showed the highest activity. The activity of all enzymes was the highest at vicinity of the roots and it decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify

Chemical Composition and Cholinesterase Inhibitory Activity of Different Parts of Daucus aristidis Coss. Essential Oils from Two Locations in Algeria

OpenAIRE

Mebarka Lamamra; Hocine Laouer; Smain Amira; Ilkay Erdogan Orhan; Fatma Sezer Senol; Betul Demirci; Salah Akkal

2017-01-01

The chemical composition of the essential oils obtained by hydrodistillation from the different parts of Daucus aristidis Coss. (syn. Ammiopsis aristidis Batt.) (Apiaceae) from two locations (Ghoufi and Bousaada) in East of Algeria, was investigated for the first time by GC and GC-MS and evaluated for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, the enzymes linked to Alzheimer’s disease, by a spectrophotometric method of Ellman using ELISA m...

Biochemical toxicology studies of methomyl and its kinetic reaction with cholinesterase in rats

International Nuclear Information System (INIS)

Tawfik, S.M.; Abdel-Hamid, F.M.

2001-01-01

The effect of the pesticide methomyl on acetylcholinesterase activities in brain and blood of male rats in vivo and the kinetics involved in their reaction in vitro were studied. Also, its effect on peroxidase action of catalase in vivo was studied using 14C - formate. The results showed that methomyl is a competitive inhibitor for acetylcholinesterase and the concentration levels that caused 50% inhibition of the enzyme activity were 2.1 x 10-2 M and 1.9 x 10-4 for brain and blood- Ache, respectively. The inhibition of acetylcholinesterase activity decreased to 67.5 % at the time of appearance of toxicity symptoms. The radioactivity eliminated in both the expired air and in urine was reduced

Chlorpyrifos and chlorpyrifos-oxon inhibit axonal growth by interfering with the morphogenic activity of acetylcholinesterase

International Nuclear Information System (INIS)

Yang Dongren; Howard, Angela; Bruun, Donald; Ajua-Alemanj, Mispa; Pickart, Cecile; Lein, Pamela J.

2008-01-01

A primary role of acetylcholinesterase (AChE) is regulation of cholinergic neurotransmission by hydrolysis of synaptic acetylcholine. In the developing nervous system, however, AChE also functions as a morphogenic factor to promote axonal growth. This raises the question of whether organophosphorus pesticides (OPs) that are known to selectively bind to and inactivate the enzymatic function of AChE also interfere with its morphogenic function to perturb axonogenesis. To test this hypothesis, we exposed primary cultures of sensory neurons derived from embryonic rat dorsal root ganglia (DRG) to chlorpyrifos (CPF) or its oxon metabolite (CPFO). Both OPs significantly decreased axonal length at concentrations that had no effect on cell viability, protein synthesis or the enzymatic activity of AChE. Comparative analyses of the effects of CPF and CPFO on axonal growth in DRG neurons cultured from AChE nullizygous (AChE -/- ) versus wild type (AChE +/+ ) mice indicated that while these OPs inhibited axonal growth in AChE +/+ DRG neurons, they had no effect on axonal growth in AChE -/- DRG neurons. However, transfection of AChE -/- DRG neurons with cDNA encoding full-length AChE restored the wild type response to the axon inhibitory effects of OPs. These data indicate that inhibition of axonal growth by OPs requires AChE, but the mechanism involves inhibition of the morphogenic rather than enzymatic activity of AChE. These findings suggest a novel mechanism for explaining not only the functional deficits observed in children and animals following developmental exposure to OPs, but also the increased vulnerability of the developing nervous system to OPs

Influence of long-term fertilization on soil enzyme activities

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Alina Dora SAMUEL

2009-05-01

Full Text Available Soil enzyme activities (actual and potential dehydrogenase, catalase, acid and alkaline phosphatase were determined in the 0–10, 10–20, and 20–30 cm layers of a brown luvic soil submitted to a complex fertilization experiment with different types of green manure. It was found that each activity decreased with increasing sampling depth. It should be emphasized that greenmanuring of maize led to a significant increase in each of the five enzymatic activities determined. The enzymatic indicators of soil quality calculated from the values of enzymatic activities showed the order: lupinus + rape + oat > lupinus > vetch + oat + ryegrass > lupinus + oat + vetch > unfertilized plot. This order means that by determination of enzymatic activities valuable information can be obtained regarding fertility status of soils. There were significant correlations of soil enzyme activities with chemical properties.

A metal-based inhibitor of NEDD8-activating enzyme.

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Hai-Jing Zhong

Full Text Available A cyclometallated rhodium(III complex [Rh(ppy(2(dppz](+ (1 (where ppy=2-phenylpyridine and dppz=dipyrido[3,2-a:2',3'-c]phenazine dipyridophenazine has been prepared and identified as an inhibitor of NEDD8-activating enzyme (NAE. The complex inhibited NAE activity in cell-free and cell-based assays, and suppressed the CRL-regulated substrate degradation and NF-κB activation in human cancer cells with potency comparable to known NAE inhibitor MLN4924. Molecular modeling analysis suggested that the overall binding mode of 1 within the binding pocket of the APPBP1/UBA3 heterodimer resembled that for MLN4924. Complex 1 is the first metal complex reported to suppress the NEDDylation pathway via inhibition of the NEDD8-activating enzyme.

Natural sesquiterpen lactones as acetylcholinesterase inhibitors

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HOMA HAJIMEHDIPOOR

2014-06-01

Full Text Available Background and the purpose of the study: The amount of elder people who suffer from Alzheimer disease is continuously increasing every year. Cholinesterase inhibitors have shown to be effective in alleviating the symptoms of the disease, thus opening a field of research for these treatments. Herbal products, owning a reputation as effective agents in many biological studies are now drawing attention for inhibiting acetylcholinesterase, in other words, Alzheimer disease. In the present study, the ability of three sesquiterpene lactones from Inula oculus-christi and I. aucheriana to inhibit AChE has been evaluated through Ellman assay.Materials and Methods: Gaillardin and pulchellin C were obtained from I. oculus-christi and britannin from I. aucheriana by chromatographic methods. They were dissolved in methanol in concentration of 3 mg/mL and the AChEI activity of the compounds was determined by Ellman method using Acethylthiocholine iodide as the substrate and 5, 5′-dithiobis-2-nitrobenzoic acid as the reagent, in 96-well plates at 405 nm.Results: AChEI activity of the examined compounds was obtained as 67.0, 25.2 and 10.9% in concentration of 300 µg/L for gaillardin, britannin and pulchellin C, respectively.Conclusion: Among the three sesquiterpene lactones, gaillardin with 67% inhibition of AChE could be considered a good candidate for future Alzheimer studies.

Enzyme activity screening of thermophilic bacteria isolated from Dusun Tua Hot Spring, Malaysia

Science.gov (United States)

Msarah, Marwan; Ibrahim, Izyanti; Aqma, Wan Syaidatul

2018-04-01

Thermophilic bacteria have biotechnological importance due to the availability of unique enzymes which are stable in extreme circumstances. The aim of this study includes to isolate thermophilic bacteria from hot spring and screen for important enzyme activities. Water samples from the Dusun Tua Hot Spring were collected and the physiochemical characterisation of water was measured. Eight thermophilic bacteria were isolated and determined to have at least three strong enzyme activity including protease, lipase, amylase, cellulase, pectinase and xylanase. The results showed that HuluC2 displayed all the enzyme activities and can be further studied.

Understanding drivers of peatland extracellular enzyme activity in the PEATcosm experiment: mixed evidence for enzymic latch hypothesis

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Karl J. Romanowicz; Evan S. Kane; Lynette R. Potvin; Aleta L. Daniels; Randy Kolka; Erik A. Lilleskov

2015-01-01

Aims. Our objective was to assess the impacts of water table position and plant functional groups on peatland extracellular enzyme activity (EEA) framed within the context of the enzymic latch hypothesis. Methods. We utilized a full factorial experiment with 2 water table (WT) treatments (high and low) and 3 plant functional...

Old and new acetylcholinesterase inhibitors for Alzheimer's disease.

Science.gov (United States)

Galimberti, Daniela; Scarpini, Elio

2016-10-01

To date, pharmacological treatment of Alzheimer's disease (AD) includes Acetylcholinesterase Inhibitors (AChEIs) for mild-to-moderate AD, and memantine for moderate-to-severe AD. AChEIs reversibly inhibit acetylcholinesterase (AChE), thus increasing the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission. These drugs provide symptomatic short-term benefits, without clearly counteracting the progression of the disease. On the wake of successful clinical trials which lead to the marketing of AChEIs donepezil, rivastigmine and galantamine, many compounds with AChEI properties have been developed and tested mainly in Phase I-II clinical trials in the last twenty years. Here, we review clinical trials initiated and interrupted, and those ongoing so far. Despite many clinical trials with novel AChEIs have been carried out after the registration of those currently used to treat mild to moderate AD, none so far has been successful in a Phase III trial and marketed. Alzheimer's disease is a complex multifactorial disorder, therefore therapy should likely address not only the cholinergic system but also additional neurotransmitters. Moreover, such treatments should be started in very mild phases of the disease, and preventive strategies addressed in elderly people.

Subcellular distribution of histone-degrading enzyme activities from rat liver

International Nuclear Information System (INIS)

Heinrich, P.C.; Raydt, G.; Puschendorf, B.; Jusic, M.

1976-01-01

Chromatin prepared from liver tissue contains a histone-degrading enzyme activity with a pH optimum of 7.5-8.0, whereas chromatin isolated from purified nuclei is devoid of it. The histone-degrading enzyme activity was assayed with radioactively labelled total histones from Ehrlich ascites tumor cells. Among the different subcellular fractions assayed, only lysosomes and mitochondria exhibited histone-degrading enzymes. A pH optimum around 4.0-5.0 was found for the lysosomal fraction, whereas 7.5-8.0 has been found for mitochondria. Binding studies of frozen and thawed lysosomes or mitochondria to proteinase-free chromatin demonstrate that the proteinase associated with chromatin isolated from frozen tissue originates from damaged mitochondria. The protein degradation patterns obtained after acrylamide gel electrophoresis are similar for the chromatin-associated and the mitochondrial proteinase and different from that obtained after incubation with lysosomes. The chromatin-associated proteinase as well as the mitochondrial proteinase are strongly inhibited by 1.0 mM phenylmethanesulfonyl fluoride. Weak inhibition is found for lysosomal proteinases at pH 5. Kallikrein-trypsin inhibitor, however, inhibits lysosomal proteinase activity and has no effect on either chromatin-associated or mitochondrial proteinases. The higher template activity of chromatin isolated from a total homogenate compared to chromatin prepared from nuclei may be due to the presence of this histone-degrading enzyme activity. (orig.) [de

Gaseous environment of plants and activity of enzymes of carbohydrate catabolism

International Nuclear Information System (INIS)

Ivanov, B.F.; Zemlyanukhin, A.A.; Igamberdiev, A.U.; Salam, A.M.M.

1989-01-01

The authors investigated the action of hypoxia and high CO 2 concentration in the atmosphere on activity of phosphofructokinase, aldolase, glucose phosphate isomerase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, alcohol dehydrogenase, and isocitrate lyase in pea seedlings (Pisum sativum L.), corn scutella (Zea mays L.), and hemp cotyledons (Cannabis sativa L.). The first 4-12h of hypoxia witnessed suppression of enzymes of the initial stages of glycolysis (glucose-6-phosphate isomerase, phosphofructokinase)and activation of enzymes of its final stages (alcohol dehydrogenase and lactate dehydrogenase) and enzymes linking glycolysis and the pentose phosphate pathway (aldolase and glucose-6-phosphate dehydrogenase). An excess of CO 2 in the environment accelerated and amplified this effect. At the end of a 24-h period of anaerobic incubation, deviations of enzyme activity from the control were leveled in both gaseous environments. An exception was observed in the case of phosphofructokinase, whose activity increased markedly at this time in plants exposed to CO 2 . Changes in activity of the enzymes were coupled with changes in their kinetic parameters (apparent K m and V max values). The activity of isocitrate lyase was suppressed in both variants of hypoxic gaseous environments, a finding that does not agree with the hypothesis as to participation of the glyoxylate cycle in the metabolic response of plants to oxygen stress. Thus, temporary inhibition of the system of glycolysis and activation of the pentose phosphate pathway constituted the initial response of the plants to O 2 stress, and CO 2 intensified this metabolic response

Molecular evaluation of herbal compounds as potent inhibitors of acetylcholinesterase for the treatment of Alzheimer's disease.

Science.gov (United States)

Chen, Yan-Xiu; Li, Guan-Zeng; Zhang, Bin; Xia, Zhang-Yong; Zhang, Mei

2016-07-01

Alzheimer's disease (AD) is a progressive disease and the predominant cause of dementia. Common symptoms include short-term memory loss, and confusion with time and place. Individuals with AD depend on their caregivers for assistance, and may pose a burden to them. The acetylcholinesterase (AChE) enzyme is a key target in AD and inhibition of this enzyme may be a promising strategy in the drug discovery process. In the present study, an inhibitory assay was carried out against AChE using total alkaloidal plants and herbal extracts commonly available in vegetable markets. Subsequently, molecular docking simulation analyses of the bioactive compounds present in the plants were conducted, as well as a protein‑ligand interaction analysis. The stability of the docked protein‑ligand complex was assessed by 20 ns molecular dynamics simulation. The inhibitory assay demonstrated that Uncaria rhynchophylla and Portulaca oleracea were able to inhibit AChE. In addition, molecular docking simulation analyses indicated that catechin present in Uncaria rhynchophylla, and dopamine and norepinephrine present in Portulaca oleracea, had the best docking scores and interaction energy. In conclusion, catechin in Uncaria rhynchophylla, and dopamine and norepinephrine in Portulaca oleracea may be used to treat AD.

Intraperitoneal Exposure to Nano/Microparticles of Fullerene (C60) Increases Acetylcholinesterase Activity and Lipid Peroxidation in Adult Zebrafish (Danio rerio) Brain

Science.gov (United States)

Dal Forno, Gonzalo Ogliari; Kist, Luiza Wilges; de Azevedo, Mariana Barbieri; Fritsch, Rachel Seemann; Pereira, Talita Carneiro Brandão; Britto, Roberta Socoowski; Guterres, Sílvia Stanisçuaski; Külkamp-Guerreiro, Irene Clemes; Bonan, Carla Denise; Monserrat, José María; Bogo, Maurício Reis

2013-01-01

Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure. PMID:23865059

Mass Spectrometry to Identify New Biomarkers of Nerve Agent Exposure

Science.gov (United States)

2010-04-01

preparations. Improving thermal stability by mutagene- sis or by selecting enzyme candidates in an extremophile biotope, e.g. thermophilic bacteria [36...target for oganophosphorus agent (OP) binding to enzymes is the active site serine in the consensus sequence GlyXSerXGly of acetylcholinesterase. By...human plasma. Task 6. Use a second method, for example enzyme activity assays or immunoprecipitation, to confirm the identity of soman-labeled proteins

Ultrasound assisted intensification of enzyme activity and its properties: a mini-review.

Science.gov (United States)

Nadar, Shamraja S; Rathod, Virendra K

2017-08-22

Over the last decade, ultrasound technique has emerged as the potential technology which shows large applications in food and biotechnology processes. Earlier, ultrasound has been employed as a method of enzyme inactivation but recently, it has been found that ultrasound does not inactivate all enzymes, particularly, under mild conditions. It has been shown that the use of ultrasonic treatment at appropriate frequencies and intensity levels can lead to enhanced enzyme activity due to favourable conformational changes in protein molecules without altering its structural integrity. The present review article gives an overview of influence of ultrasound irradiation parameters (intensity, duty cycle and frequency) and enzyme related factors (enzyme concentration, temperature and pH) on the catalytic activity of enzyme during ultrasound treatment. Also, it includes the effect of ultrasound on thermal kinetic parameters and Michaelis-Menten kinetic parameters (k m and V max ) of enzymes. Further, in this review, the physical and chemical effects of ultrasound on enzyme have been correlated with thermodynamic parameters (enthalpy and entropy). Various techniques used for investigating the conformation changes in enzyme after sonication have been highlighted. At the end, different techniques of immobilization for ultrasound treated enzyme have been summarized.

ATPase Activity Measurements by an Enzyme-Coupled Spectrophotometric Assay.

Science.gov (United States)

Sehgal, Pankaj; Olesen, Claus; Møller, Jesper V

2016-01-01

Enzymatic coupled assays are usually based on the spectrophotometric registration of changes in NADH/NAD(+) or NADPH/NADP(+) absorption at 340 nm accompanying the oxidation/reduction of reactants that by dehydrogenases and other helper enzymes are linked to the activity of the enzymatic reaction under study. The present NADH-ATP-coupled assay for ATPase activity is a seemingly somewhat complicated procedure, but in practice adaptation to performance is easily acquired. It is a more safe and elegant method than colorimetric methods, but not suitable for handling large number of samples, and also presupposes that the activity of the helper enzymes is not severely affected by the chemical environment of the sample in which it is tested.

Interrogating the activities of conformational deformed enzyme by single-molecule fluorescence-magnetic tweezers microscopy

Science.gov (United States)

Guo, Qing; He, Yufan; Lu, H. Peter

2015-01-01

Characterizing the impact of fluctuating enzyme conformation on enzymatic activity is critical in understanding the structure–function relationship and enzymatic reaction dynamics. Different from studying enzyme conformations under a denaturing condition, it is highly informative to manipulate the conformation of an enzyme under an enzymatic reaction condition while monitoring the real-time enzymatic activity changes simultaneously. By perturbing conformation of horseradish peroxidase (HRP) molecules using our home-developed single-molecule total internal reflection magnetic tweezers, we successfully manipulated the enzymatic conformation and probed the enzymatic activity changes of HRP in a catalyzed H2O2–amplex red reaction. We also observed a significant tolerance of the enzyme activity to the enzyme conformational perturbation. Our results provide a further understanding of the relation between enzyme behavior and enzymatic conformational fluctuation, enzyme–substrate interactions, enzyme–substrate active complex formation, and protein folding–binding interactions. PMID:26512103

Acetylcholinesterase (AChE) gene modification in transgenic animals: functional consequences of selected exon and regulatory region deletion.

Science.gov (United States)

Camp, Shelley; Zhang, Limin; Marquez, Michael; de la Torre, Brian; Long, Jeffery M; Bucht, Goran; Taylor, Palmer

2005-12-15

AChE is an alternatively spliced gene. Exons 2, 3 and 4 are invariantly spliced, and this sequence is responsible for catalytic function. The 3' alternatively spliced exons, 5 and 6, are responsible for AChE disposition in tissue [J. Massoulie, The origin of the molecular diversity and functional anchoring of cholinesterases. Neurosignals 11 (3) (2002) 130-143; Y. Li, S. Camp, P. Taylor, Tissue-specific expression and alternative mRNA processing of the mammalian acetylcholinesterase gene. J. Biol. Chem. 268 (8) (1993) 5790-5797]. The splice to exon 5 produces the GPI anchored form of AChE found in the hematopoietic system, whereas the splice to exon 6 produces a sequence that binds to the structural subunits PRiMA and ColQ, producing AChE expression in brain and muscle. A third alternative RNA species is present that is not spliced at the 3' end; the intron 3' of exon 4 is used as coding sequence and produces the read-through, unanchored form of AChE. In order to further understand the role of alternative splicing in the expression of the AChE gene, we have used homologous recombination in stem cells to produce gene specific deletions in mice. Alternatively and together exon 5 and exon 6 were deleted. A cassette containing the neomycin gene flanked by loxP sites was used to replace the exon(s) of interest. Tissue analysis of mice with exon 5 deleted and the neomycin cassette retained showed very low levels of AChE expression, far less than would have been anticipated. Only the read-through species of the enzyme was produced; clearly the inclusion of the selection cassette disrupted splicing of exon 4 to exon 6. The selection cassette was then deleted in exon 5, exon 6 and exons 5 + 6 deleted mice by breeding to Ella-cre transgenic mice. AChE expression in serum, brain and muscle has been analyzed. Another AChE gene targeted mouse strain involving a region in the first intron, found to be critical for AChE expression in muscle cells [S. Camp, L. Zhang, M. Marquez, B

Heterogeneity of hydrolytic enzyme activities under drought: imaging and quantitative analysis

Science.gov (United States)

Sanaullah, Muhammad; Razavi, Bahar S.; Kuzyakov, Yakov

2015-04-01

The zymography-based "snap-shoot" of enzyme activities in the rhizosphere is challenging to detect the in situ microbial response to global climate change. We developed in situ soil zymography and used it for identification and localization of hotspots of β-glucosidase activity in the rhizosphere of maize under drought stress (30% of field capacity). The zymographic signals were especially high at root tips and were much stronger for activity of β-glucosidase under drought as compared with optimal moisture (70% of field capacity). This distribution of enzyme activity was confirmed by fluorogenically labelled substrates applied directly to the root exudates. The activity of β-glucosidase in root exudates (produced by root and microorganism associated on the root surface), sampled within 1 hour after zymography was significantly higher by drought stressed plants as compared with optimal moisture. In contrast, the β-glucosidase activity in destructively sampled rhizosphere soil was lower under drought stress compared with optimal moisture. Furthermore, drought stress did not affected β-glucosidase activity in bulk soil, away from rhizosphere. Consequently, we conclude that higher release of mucilage by roots und drought stimulated β-glucosidase activity in the rhizosphere. Thus, the zymography revealed plant-mediated mechanisms accelerating β-glucosidase activity under drought at the root-soil interface. So, coupling of zymography and enzyme assays in the rhizosphere and non-rhizosphere soil enables precise mapping the changes in two-dimensional distribution of enzyme activities due to climate change within dynamic soil interfaces.

Adsorption and enzyme activity of asparaginase at lipid Langmuir and Langmuir-Blodgett films

International Nuclear Information System (INIS)

Rocha Junior, Carlos da; Caseli, Luciano

2017-01-01

In this present work, the surface activity of the enzyme asparaginase was investigated at the air-water interface, presenting surface activity in high ionic strengths. Asparaginase was incorporated in Langmuir monolayers of the phospholipid dipalmitoylphosphatidylcholine (DPPC), forming a mixed film, which was characterized with surface pressure-area isotherms, surface potential-area isotherms, polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), and Brewster angle microscopy (BAM). The adsorption of the enzyme at the air-water interface condensed the lipid monolayer and increased the film compressibility at high surface pressures. Amide bands in the PM-IRRAS spectra were identified, with the C−N and C =O dipole moments lying parallel to monolayer plane, revealing the structuring of the enzyme into α-helices and β-sheets. The floating monolayers were transferred to solid supports as Langmuir-Blodgett (LB) films and characterized with fluorescence spectroscopy and atomic force microscopy. Catalytic activities of the films were measured and compared to the homogenous medium. The enzyme accommodated in the LB films preserved more than 78% of the enzyme activity after 30 days, in contrast for the homogeneous medium, which preserved less than 13%. The method presented in this work not only allows for an enhanced catalytic activity, but also can help explain why certain film architectures exhibit better performance. - Highlights: • Biomembranes are mimicked with Langmuir monolayers. • Asparaginase is incorporated into the lipid monolayer. • Enzyme adsorption is confirmed with tensiometry and infrared spectroscopy. • Langmuir-Blodgett films of the enzyme present enzyme activity.

Adsorption and enzyme activity of asparaginase at lipid Langmuir and Langmuir-Blodgett films

Energy Technology Data Exchange (ETDEWEB)

Rocha Junior, Carlos da; Caseli, Luciano, E-mail: lcaseli@unifesp.br

2017-04-01

In this present work, the surface activity of the enzyme asparaginase was investigated at the air-water interface, presenting surface activity in high ionic strengths. Asparaginase was incorporated in Langmuir monolayers of the phospholipid dipalmitoylphosphatidylcholine (DPPC), forming a mixed film, which was characterized with surface pressure-area isotherms, surface potential-area isotherms, polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), and Brewster angle microscopy (BAM). The adsorption of the enzyme at the air-water interface condensed the lipid monolayer and increased the film compressibility at high surface pressures. Amide bands in the PM-IRRAS spectra were identified, with the C−N and C =O dipole moments lying parallel to monolayer plane, revealing the structuring of the enzyme into α-helices and β-sheets. The floating monolayers were transferred to solid supports as Langmuir-Blodgett (LB) films and characterized with fluorescence spectroscopy and atomic force microscopy. Catalytic activities of the films were measured and compared to the homogenous medium. The enzyme accommodated in the LB films preserved more than 78% of the enzyme activity after 30 days, in contrast for the homogeneous medium, which preserved less than 13%. The method presented in this work not only allows for an enhanced catalytic activity, but also can help explain why certain film architectures exhibit better performance. - Highlights: • Biomembranes are mimicked with Langmuir monolayers. • Asparaginase is incorporated into the lipid monolayer. • Enzyme adsorption is confirmed with tensiometry and infrared spectroscopy. • Langmuir-Blodgett films of the enzyme present enzyme activity.

Experimental Strategy to Discover Microbes with Gluten-degrading Enzyme Activities.

Science.gov (United States)

Helmerhorst, Eva J; Wei, Guoxian

2014-05-05

Gluten proteins contained in the cereals barley, rye and wheat cause an inflammatory disorder called celiac disease in genetically predisposed individuals. Certain immunogenic gluten domains are resistant to degradation by mammalian digestive enzymes. Enzymes with the ability to target such domains are potentially of clinical use. Of particular interest are gluten-degrading enzymes that would be naturally present in the human body, e.g. associated with resident microbial species. This manuscript describes a selective gluten agar approach and four enzyme activity assays, including a gliadin zymogram assay, designed for the selection and discovery of novel gluten-degrading microorganisms from human biological samples. Resident and harmless bacteria and/or their derived enzymes could potentially find novel applications in the treatment of celiac disease, in the form of a probiotic agent or as a dietary enzyme supplement.

Neuroprotective and neurological properties of Melissa officinalis

DEFF Research Database (Denmark)

López, Víctor; Martín, Sara; Gómez-Serranillos, Maria Pilar

2009-01-01

and affinity to the GABA(A)-benzodiazepine receptor). The results suggest that the plant has a significant (P radical scavenging properties were also investigated in cells and in cell free systems, where this plant was shown......Melissa officinalis has traditionally been used due to its effects on nervous system. Both methanolic and aqueous extracts were tested for protective effects on the PC12 cell line, free radical scavenging properties and neurological activities (inhibition of MAO-A and acetylcholinesterase enzymes...... to be a good free radical scavenger. The MAO-A bioassay was also performed to detect possible antidepressant activities demonstrating that both extracts inhibited this enzyme, which has a key role in neurotransmitters metabolism. However, no activity was detected in the acetylcholinesterase and GABA assays...

Hydrolytic enzyme activity enhanced by Barium supplementation

Directory of Open Access Journals (Sweden)

Camilo Muñoz

2016-10-01

Full Text Available Hydrolysis of polymers is a first and often limiting step during the degradation of plant residues. Plant biomass is generally a major component of waste residues and a major renewable resource to obtain a variety of secondary products including biofuels. Improving the performance of enzymatic hydrolysis of plant material with minimum costs and limiting the use of additional microbial biomass or hydrolytic enzymes directly influences competitiveness of these green biotechnological processes. In this study, we cloned and expressed a cellulase and two esterases recovered from environmental thermophilic soil bacterial communities and characterize their optimum activity conditions including the effect of several metal ions. Results showed that supplementing these hydrolytic reactions with Barium increases the activity of these extracellular hydrolytic enzymes. This observation represents a simple but major improvement to enhance the efficiency and competitiveness of this process within an increasingly important biotechnological sector.

Evaluation of the organophosphorus hydrolase enzyme activity in creams and investigation of its stability

Directory of Open Access Journals (Sweden)

Mariye Rajaie

2016-06-01

Full Text Available The main purpose of this project is investigation of the organophosphorus hydrolase (OPH enzyme activity in water in oil (w/o and oil in water (o/w creams and investigation of the OPH enzyme stability in formulated creams. OPH enzyme was extracted and purified from strain flavobacterium. The w/o and o/w creams were prepared using different formulations. In order to achieve an emulsion with maximum stability, appropriate percentage of the cream components was selected by studying different formulations and the physical and chemical stability of the produced cream were considered. 5Uenzyme/90gcream enzyme was used for each formulation. To measure the enzyme activity in creams, extraction method was used and enzyme activity was determined based on parathion hydrolysis. The thermal stability of OPH in both types of w/o and o/w creams was studied at 4 and 30  °C for various time periods. The average enzyme activity was about 0.0065 U/gcream and 0.018 U/gcream for w/o and o/w creams respectivly. According to the results, the relative activity at 4 °C was reduced to 50% after 26 and 45 days in w/o and o/w creams, respectivly. The results showed that the OPH enzyme activity in o/w cream was 2.6 times more than that of w/o cream, because of the higher hydrophobicity of o/w cream compared to w/o. The OPH enzyme stability in o/w cream was greater in comparison to w/o cream. The OPH enzyme was active for nearly 2 months on o/w creams at 4 °C .

Mineralogical impact on long-term patterns of soil nitrogen and phosphorus enzyme activities

Science.gov (United States)

Mikutta, Robert; Turner, Stephanie; Meyer-Stüve, Sandra; Guggenberger, Georg; Dohrmann, Reiner; Schippers, Axel

2014-05-01

Soil chronosequences provide a unique opportunity to study microbial activity over time in mineralogical diverse soils of different ages. The main objective of this study was to test the effect of mineralogical properties, nutrient and organic matter availability over whole soil pro-files on the abundance and activity of the microbial communities. We focused on microbio-logical processes involved in nitrogen and phosphorus cycling at the 120,000-year Franz Josef soil chronosequence. Microbial abundances (microbial biomass and total cell counts) and enzyme activities (protease, urease, aminopeptidase, and phosphatase) were determined and related to nutrient contents and mineralogical soil properties. Both, microbial abundances and enzyme activities decreased with soil depth at all sites. In the organic layers, microbial biomass and the activities of N-hydrolyzing enzymes showed their maximum at the intermediate-aged sites, corresponding to a high aboveground biomass. In contrast, the phosphatase activity increased with site age. The activities of N-hydrolyzing enzymes were positively correlated with total carbon and nitrogen contents, whereas the phosphatase activity was negatively correlated with the phosphorus content. In the mineral soil, the enzyme activities were generally low, thus reflecting the presence of strongly sorbing minerals. Sub-strate-normalized enzyme activities correlated negatively to clay content as well as poorly crystalline Al and Fe oxyhydroxides, supporting the view that the evolution of reactive sec-ondary mineral phases alters the activity of the microbial communities by constraining sub-strate availability. Our data suggest a strong mineralogical influence on nutrient cycling par-ticularly in subsoil environments.

Seasonal variation in the temperature sensitivity of proteolytic enzyme activity in temperate forest soils

Science.gov (United States)

Brzostek, Edward R.; Finzi, Adrien C.

2012-03-01

Increasing soil temperature has the potential to alter the activity of the extracellular enzymes that mobilize nitrogen (N) from soil organic matter (SOM) and ultimately the availability of N for primary production. Proteolytic enzymes depolymerize N from proteinaceous components of SOM into amino acids, and their activity is a principal driver of the within-system cycle of soil N. The objectives of this study were to investigate whether the soils of temperate forest tree species differ in the temperature sensitivity of proteolytic enzyme activity over the growing season and the role of substrate limitation in regulating temperature sensitivity. Across species and sampling dates, proteolytic enzyme activity had relatively low sensitivity to temperature with a mean activation energy (Ea) of 33.5 kJ mol-1. Ea declined in white ash, American beech, and eastern hemlock soils across the growing season as soils warmed. By contrast, Eain sugar maple soil increased across the growing season. We used these data to develop a species-specific empirical model of proteolytic enzyme activity for the 2009 calendar year and studied the interactive effects of soil temperature (ambient or +5°C) and substrate limitation (ambient or elevated protein) on enzyme activity. Declines in substrate limitation had a larger single-factor effect on proteolytic enzyme activity than temperature, particularly in the spring. There was, however, a large synergistic effect of increasing temperature and substrate supply on proteolytic enzyme activity. Our results suggest limited increases in N availability with climate warming unless there is a parallel increase in the availability of protein substrates.

Arabinogalactan proteins: focus on carbohydrate active enzymes

Directory of Open Access Journals (Sweden)

Eva eKnoch

2014-06-01

Full Text Available Arabinogalactan proteins (AGPs are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/ involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development.

Hypothyroidism Enhanced Ectonucleotidases and Acetylcholinesterase Activities in Rat Synaptosomes can be Prevented by the Naturally Occurring Polyphenol Quercetin.

Science.gov (United States)

Baldissarelli, Jucimara; Santi, Adriana; Schmatz, Roberta; Abdalla, Fátima Husein; Cardoso, Andréia Machado; Martins, Caroline Curry; Dias, Glaecir R Mundstock; Calgaroto, Nicéia Spanholi; Pelinson, Luana Paula; Reichert, Karine Paula; Loro, Vania Lucia; Morsch, Vera Maria Melchiors; Schetinger, Maria Rosa Chitolina

2017-01-01

Thyroid hormones have an influence on the functioning of the central nervous system. Furthermore, the cholinergic and purinergic systems also are extensively involved in brain function. In this context, quercetin is a polyphenol with antioxidant and neuroprotective properties. This study investigated the effects of (MMI)-induced hypothyroidism on the NTPDase, 5'-nucleotidase, adenosine deaminase (ADA), and acetylcholinesterase (AChE) activities in synaptosomes of rats and whether the quercetin can prevent it. MMI at a concentration of 20 mg/100 mL was administered for 90 days in the drinking water. The animals were divided into six groups: control/water (CT/W), control/quercetin 10 mg/kg, control/quercetin 25 mg/kg, methimazole/water (MMI/W), methimazole/quercetin 10 mg/kg (MMI/Q10), and methimazole/quercetin 25 mg/kg (MMI/Q25). On the 30th day, hormonal dosing was performed to confirm hypothyroidism, and the animals were subsequently treated with 10 or 25 mg/kg quercetin for 60 days. NTPDase activity was not altered in the MMI/W group. However, treatment with quercetin decreased ATP and ADP hydrolysis in the MMI/Q10 and MMI/Q25 groups. 5'-nucleotidase activity increased in the MMI/W group, but treatments with 10 or 25 mg/kg quercetin decreased 5'-nucleotidase activity. ADA activity decreased in the CT/25 and MMI/Q25 groups. Furthermore, AChE activity was reduced in all groups with hypothyroidism. In vitro tests also demonstrated that quercetin per se decreased NTPDase, 5'-nucleotidase, and AChE activities. This study demonstrated changes in the 5'-nucleotidase and AChE activities indicating that purinergic and cholinergic neurotransmission are altered in this condition. In addition, quercetin can alter these parameters and may be a promising natural compound with important neuroprotective actions in hypothyroidism.

Enzyme activity of a Phanerochaete chrysosporium cellobiohydrolase

African Journals Online (AJOL)

The aim of this study was to produce a secreted, heterologously expressed Phanerochaete chrysosporium cellobiohydrolase (CBHI.1) protein that required no in vitro chemical refolding and to investigate the cellulolytic activity of the clone expressing the glutathione S-transferase (GST) fused CBHI.1 protein. Plate enzyme ...

Enzyme activity in bioregulator-treated tomato (Solanum ...

African Journals Online (AJOL)

USER

2010-05-31

May 31, 2010 ... African Journal of Biotechnology Vol. 9(22), pp. 3264-3271, 31 ... In this work, spectrophotometric analysis ... most stable enzymes in vegetables and its thermal destruc-tion ... proteins, carbohydrates, lipids and allelochemicals (Hedin et al., 1995) ..... activities isolated from corn root plasma membrane. Plant.