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Sample records for acetyl cholinesterase activity

  1. Acetyl cholinesterase activity and muscle contraction in the sea urchin Lytechinus variegatus (Lamarck) following chronic phosphate exposure.

    PubMed

    Boettger, S Anne; McClintock, James B

    2012-03-01

    The common shallow-water sea urchin Lytechinus variegatus is capable of surviving inorganic phosphate exposures as high as 3.2 mg L(-1) and organic phosphate exposures of 1000 mg L(-1) . Nonetheless, chronic exposure to low, medium, and high-sublethal concentrations of organic phosphate inhibits the muscle enzyme acetyl cholinesterase (AChE), responsible for the break down of the neurotransmitter acetylcholine, as well as inhibiting contractions in the muscles associated with the Aristotle's lantern. AChE activity, measured in both a static enzyme assay and by vesicular staining, displayed concentration-dependent declines of activity in individuals maintained in organic phosphate for 4 weeks. The activity of AChE was not adversely affected by exposure to inorganic phosphate or seawater controls over the same time period. Maximum force of muscle contraction and rates of muscle contraction and relaxation also decreased with chronic exposure to increasing concentrations of organic phosphate. Chronic exposure to inorganic phosphates elicited no response except at the highest concentration, where the maximum force of muscular contraction increased compared to controls. These findings indicate that shallow-water populations of Lytechinus variegatus subjected to organic phosphate pollutants may display impaired muscular activity that is potentially related to the inhibition of the muscle relaxant enzyme AChE, and subsequently muscular overstimulation, and fatigue.

  2. Chemical Compositionand Anti-acetyl cholinesterase Activity of Flower Essential Oils of Artemisiaannuaat Different Flowering Stage

    PubMed Central

    Yu, Zhengwen; Wang, Bochu; Yang, Fumei; Sun, Qianyun; Yang, Zhannan; Zhu, Liancai

    2011-01-01

    The chemical composition of the essential oils of flower at the pre-flowering, full-flowering and post-flowering stage of A. annua was analyzed by GC and GC/MS and sixty-two components were identified. The main compounds in the pre-flowering oil were β-myrcene (37.71%), 1, 8-cineole (16.11%) and camphor (14.97%). The full-flowering oil contained predominantly caryophyllene (19.4%), germacrene D (18.1%), camphor (15.84%), 1, 8-cineole (10.6%) and (Z)-β-farnesene (9.43%). The major constituents identified in the post-flowering oil were camphor (16.62%), caryophyllene (16.27%), β-caryophyllene oxide (15.84%), β-farnesene (9.05%) and (-)-spathulenol (7.21%). The variety of anti-AChE activity of flower oil of A. annua at three flowering stage might be a result of the variety of the content and interaction of those terpenoids with anti-AChE activity. The greatest acetylcholinesterase inhibitory activity (IC50 = 0.13 ± 0.02 mg mL-1) was exhibited by the essential oil of flower of A. annua at post-flowering stage. PMID:24250353

  3. Serum acetyl cholinesterase as a biomarker of arsenic induced neurotoxicity in sprague-dawley rats.

    PubMed

    Patlolla, Anita K; Tchounwou, Paul B

    2005-04-01

    Arsenic is an environmental toxicant, and one of the major mechanisms by which it exerts its toxic effect is through an impairment of cellular respiration by inhibition of various mitochondrial enzymes, and the uncoupling of oxidative phosphorylation. Most toxicity of arsenic results from its ability to interact with sulfhydryl groups of proteins and enzymes, and to substitute phosphorus in a variety of biochemical reactions. Most toxicity of arsenic results from its ability to interact with sulfhydryl groups of proteins and enzymes, and to substitute phosphorus in a variety of biochemical reactions. Recent studies have pointed out that arsenic toxicity is associated with the formation of reactive oxygen species, which may cause severe injury/damage to the nervous system. The main objective of this study was to conduct biochemical analysis to determine the effect of arsenic trioxide on the activity of acetyl cholinesterase; a critical important nervous system enzyme that hydrolyzes the neurotransmitter acetylcholine. Four groups of six male rats each weighing an average 60 +/- 2 g were used in this study. Arsenic trioxide was intraperitoneally administered to the rats at the doses of 5, 10, 15, 20mg/kg body weight (BW), one dose per 24 hour given for five days. A control group was also made of 6 animals injected with distilled water without chemical. Following anaesthesia, blood specimens were immediately collected using heparinized syringes, and acetyl cholinesterase detection and quantification were performed in serum samples by spectrophotometry. Arsenic trioxide exposure significantly decreased the activity of cholinesterase in the Sprague-Dawley rats. Acetyl cholinesterase activities of 6895 +/- 822, 5697 +/- 468, 5069 +/- 624, 4054 +/- 980, and 3158 +/- 648 U/L were recorded for 0, 5, 10, 15, and 20 mg/kg, respectively; indicating a gradual decrease in acetyl cholinesterase activity with increasing doses of arsenic. These findings indicate that acetyl

  4. Acrylonitrile has Distinct Hormetic Effects on Acetyl-Cholinesterase Activity in Mouse Brain and Blood that are Modulated by Ethanol.

    PubMed

    Yuanqing, He; Suhua, Wang; Guangwei, Xing; Chunlan, Ren; Hai, Qian; Wenrong, Xu; Rongzhu, Lu; Aschner, Michael; Milatovic, Dejan

    2013-01-01

    Acrylonitrile(AN) is a neurotoxin both in animals and humans, but its effects on acetylcholinesterase (AChE) activity remain controversial. This study aimed to determine the dose-response effects of AN on AChE activity and the modulatory role of ethanol pre-treatment. A total of 144 Kunming mice were randomly divided into 18 groups: nine groups received 5% ethanol in their drinking water, and the remaining nine groups received regular tap water. One week later, both the ethanol and tap water only groups were given an intraperitoneal injection of AN at the following doses: 0 (control), 0.156, 0.3125, 0.625, 1.25, 2.5, 5, 10 or 20 mg AN/kg body weight. AChE activity was determined on whole blood and brain 24 h later. Blood AChE activity was higher in AN-injected mice than in controls at all doses. AChE activity in blood increased in a dose-dependent manner, peaking at 0.156 mg/kg, after which a gradual decrease ensued, displaying a β-typed dose-response relationship. In contrast, brain AChE activity, following a single AN injection, was consistently lower than in control mice, and continued to fall up to a dose of 0.313 mg/kg, and thereafter increased gradually with higher doses. Mice receiving a 20 mg/kg dose of AN exhibited AChE brain activity indistinguishable from that of control mice, demonstrating a typical U-typed dose-response relationship. The activity of AChE in the blood and brain of the AN + ethanol-treated groups displayed a shift to the right, and the magnitude of the decrease in AChE activity induced by AN was attenuated relative to the AN-only group. These results suggest that AN affects AChE activity in both mouse blood and brain in a hormetic manner. Pretreatment with ethanol modifies the effect of AN on AChE, indicating that parent AN has a more prominent role than its metabolites in modulating enzyme activity. PMID:23550232

  5. Sesquiterpene Lactones from Cynara cornigera: Acetyl Cholinesterase Inhibition and In Silico Ligand Docking.

    PubMed

    Hegazy, Mohamed-Elamir F; Ibrahim, Abeer Y; Mohamed, Tarik A; Shahat, Abdelaaty A; El Halawany, Ali M; Abdel-Azim, Nahla S; Alsaid, Mansour S; Paré, Paul W

    2016-01-01

    Wild artichoke (Cynara cornigera), a thistle-like perennial belonging to the Asteraceae family, is native to the Mediterranean region, northwestern Africa, and the Canary Islands. While the pleasant, albeit bitter, taste of the leaves and flowers is attributed to the sesquiterpene lactones cynaropicrin and cynarin, a comprehensive phytochemical investigation still needs to be reported. In this study seven sesquiterpene lactones were isolated from an aqueous methanol plant extract, including a new halogenated metabolite (1), the naturally isolated compound sibthorpine (2), and five metabolites isolated for the first time from C. cornigera. Structures were established by spectroscopic methods, including HREIMS, (1 )H, (13 )C, DEPT, (1 )H-(1 )H COSY, HMQC, and HMBC-NMR experiments as well as by X-ray analysis. The isolated bioactive nutrients were analyzed for their antioxidant and metal chelating activity. Compound 1 exhibited a potent metal chelating activity as well as a high antioxidant capacity. Moreover, select compounds were effective as acetyl cholinesterase inhibitors presenting the possibility for such compounds to be examined for anti-neurodegenerative activity. A computational pharmacophore elucidation and docking study was performed to estimate the pharmacophoric features and binding conformation of isolated compounds in the acetyl cholinesterase active site. PMID:26441064

  6. Cholinesterase activity in Japanese quail dusted with carbaryl

    USGS Publications Warehouse

    Hill, E.F.

    1979-01-01

    Japanese quail (Coturnix coturnix japonica) were dusted with 5% carbaryl to determine if this topical treatment would alter plasma and brain cholinesterase activities. Within 6 hours after dusting, plasma cholinesterase activity was depressed compared with controls, the depression averaging 20% for females and 27% for males. By 24 hours the cholinesterase activity of females had returned to normal, but the cholinesterase activity of males remained depressed. Brain cholinesterase activity was not affected by the treatment, and there were no overt toxic signs.

  7. [Methods for determination of cholinesterase activity].

    PubMed

    Dingová, D; Hrabovská, A

    2015-01-01

    Cholinesterases hydrolyze acetylcholine and thus they play a key role in a process of cholinergic neurotransmission. Changes in their activities are linked to many diseases (e.g Alzheimer disease, Parkinson disease, lipid disorders). Thus, it is important to determine their activity in a fast, simply and precise way. In this review, different approaches of studying cholinesterase activities (e.g pH-dependent, spectrophotometric, radiometric, histochemical methods or biosensors) are discussed. Comparisons, advantages or disadvantages of selected methods (e.g most widely used Ellman's assay, extremely sensitive Johnson Russell method or modern technique with golden nanoparticles) are presented. This review enables one to choose a suitable method for determination of cholinesterase activities with respect to laboratory equipment, type of analysis, pH, temperature scale or special conditions. PMID:26852525

  8. Biological Studies in Childhood Schizophrenia: Plasma and RBC Cholinesterase Activity

    ERIC Educational Resources Information Center

    Lucas, Alexander R.; And Others

    1971-01-01

    A comparison of plasma (pseudo) cholinesterase and erythrocyte (true) cholinesterase activity in 16 male childhood schizophrenic patients and 16 male nonpsychotic hospitalized controls revealed no significant differences between the two groups. (Author)

  9. Measuring cholinesterase activity in human saliva.

    PubMed

    Claus Henn, Birgit; McMaster, Suzanne; Padilla, Stephanie

    2006-10-01

    To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 different collection methods: a disposable plastic pipette, and a cotton-wool roll. A brief questionnaire was conducted each week to document changes in exposure to cholinesterase inhibitors for the duration of the sampling. To measure cholinesterase activity, an existing radiometric method was modified to make it suitable for human saliva. Using this method, cholinesterase activity was measurable in saliva, and duplicate samples showed reliable repeatability. Activity in both collection methods ranged from 3 to 265 nmol/h/ml saliva (mean = 52 +/- 37 [SD] nmol/h/ml saliva). For some individuals, enzyme activity was consistent over the five sampling weeks; for others, activity was highly variable. Coefficients of variation (CVs) were calculated to assess variability, and mean CVs were the same for both collection methods (about 35%). Adjusting for protein concentration in the pipette-collected samples did not change results. Both collection methods worked well for collecting between 1 and 3 ml saliva, but at the majority of visits (86%), participants preferred the cotton-wool roll. Results from this study suggest that saliva may be a useful indicator of potential neurotoxic effects from exposure to organophosphorus and carbamate pesticides, but that factors affecting variability should be explored further.

  10. MEASURING CHOLINESTERASE ACTIVITY IN HUMAN SALIVA

    EPA Science Inventory

    To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 differe...

  11. MEASURING CHOLINESTERASE ACTIVITY IN HUMAN SALIVA.

    EPA Science Inventory

    To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 differe...

  12. A new high activity plasma cholinesterase variant.

    PubMed Central

    Krause, A; Lane, A B; Jenkins, T

    1988-01-01

    A South African Afrikaans speaking family is reported in which a new high activity plasma cholinesterase variant was found to occur in the mother and son. The variant has the same electrophoretic mobility as the "usual' enzyme, but greater heat stability. Its higher specific activity is associated with a normal number of enzyme molecules. The variant may be inherited as a dominant trait, though its locus is uncertain. Images PMID:3225823

  13. Brain cholinesterase activities of passerine birds in forests sprayed with cholinesterase inhibiting insecticides

    USGS Publications Warehouse

    Zinkl, J.G.; Henny, C.J.; Shea, P.J.

    1979-01-01

    Brain cholinesterase activities were determined in passerines collected from northwestern forests that had been sprayed with trichlorfon, acephate, and carbaryl at 0.56, 1.13 and 2.26 kg/ha. Trichlorfon and carbaryl inhibited cholinesterase activity slightly in only a few birds, primarily canopy dwellers. In contrast, acephate caused marked inhibition of cholinesterase activity in nearly all birds collected. The inhibition was present even 33 days after spraying. Some birds from the acephate-sprayed forests exhibited clinical signs compatible with acute acetylcholinesterase inhibition.

  14. MEASURING CHOLINESTERASE ACTIVITY IN HUMAN STUDIES.

    EPA Science Inventory


    Biomonitoring of organophosphorous and carbamate pesticides has focused primarily on the inhibition of blood cholinesterase. Blood biomonitoring, however, can be invasive, time-consuming, and costly, especially in young children and infants. Therefore, saliva biomonitoring ha...

  15. Computer simulation of the active site of human serum cholinesterase

    SciTech Connect

    Kefang Jiao; Song Li; Zhengzheng Lu

    1996-12-31

    The first 3D-structure of acetylchelinesterase from Torpedo California electric organ (T.AChE) was published by JL. Sussman in 1991. We have simulated 3D-structure of human serum cholinesterase (H.BuChE) and the active site of H.BuChE. It is discovered by experiment that the residue of H.BuChE is still active site after a part of H.BuChE is cut. For example, the part of 21KD + 20KD is active site of H.BuChE. The 20KD as it is. Studies on these peptides by Hemelogy indicate that two active peptides have same negative electrostatic potential maps diagram. These negative electrostatic areas attached by acetyl choline with positive electrostatic potency. We predict that 147...236 peptide of AChE could be active site because it was as 20KD as with negative electrostatic potential maps. We look forward to proving from other ones.

  16. Whole Blood Cholinesterase Activity in 20 Species of Wild Birds.

    PubMed

    Horowitz, Igal H; Yanco, Esty G; Landau, Shmulik; Nadler-Valency, Rona; Anglister, Nili; Bueller-Rosenzweig, Ariela; Apelbom-Halbersberg, Tal; Cuneah, Olga; Hanji, Vera; Bellaiche, Michel

    2016-06-01

    Clinical signs of organophosphate and carbamate intoxication in wild birds can be mistaken for those of other diseases, thus potentially delaying diagnosis and implementation of life-saving treatment. The objective of this study was to determine the reference interval for blood cholinesterase activity in 20 different wild avian species from 7 different orders, thereby compiling a reference database for wildlife veterinarians. Blood was collected from birds not suspected of having organophosphate or carbamate toxicosis, and the modified Michel method, which determines the change in blood pH that directly correlates with cholinesterase activity, was used to measure blood cholinesterase levels. Results of change in blood pH values ranged from 0.11 for the white-tailed eagle ( Haliaeetus albicilla ) to 0.90 for the honey buzzard ( Pernis apivorus ). The results showed that even within the same family, interspecies differences in normal cholinesterase blood activity were not uncommon. The findings emphasized the importance of determining reference intervals for avian blood cholinesterase activity at the species level.

  17. Whole Blood Cholinesterase Activity in 20 Species of Wild Birds.

    PubMed

    Horowitz, Igal H; Yanco, Esty G; Landau, Shmulik; Nadler-Valency, Rona; Anglister, Nili; Bueller-Rosenzweig, Ariela; Apelbom-Halbersberg, Tal; Cuneah, Olga; Hanji, Vera; Bellaiche, Michel

    2016-06-01

    Clinical signs of organophosphate and carbamate intoxication in wild birds can be mistaken for those of other diseases, thus potentially delaying diagnosis and implementation of life-saving treatment. The objective of this study was to determine the reference interval for blood cholinesterase activity in 20 different wild avian species from 7 different orders, thereby compiling a reference database for wildlife veterinarians. Blood was collected from birds not suspected of having organophosphate or carbamate toxicosis, and the modified Michel method, which determines the change in blood pH that directly correlates with cholinesterase activity, was used to measure blood cholinesterase levels. Results of change in blood pH values ranged from 0.11 for the white-tailed eagle ( Haliaeetus albicilla ) to 0.90 for the honey buzzard ( Pernis apivorus ). The results showed that even within the same family, interspecies differences in normal cholinesterase blood activity were not uncommon. The findings emphasized the importance of determining reference intervals for avian blood cholinesterase activity at the species level. PMID:27315378

  18. Modifications of a cholinesterase method for determination of erythrocyte cholinesterase activity in wild mammals.

    PubMed

    Donovan, D A; Zinkl, J G

    1994-04-01

    A method to determine erythrocyte cholinesterase (ChE) activity was modified for use in wild mammals. Erythrocyte ChE of California voles (Microtus californicus) was primarily acetylcholinesterase (AChE), which was similar to the brain and unlike plasma which was primarily butyrylcholinesterase (BChE). Triplicate erythrocyte AChE analyses from individual animals of several species of wild rodents revealed a mean coefficient of variation of 8.7% (SD = 4.3%). Erythrocyte ChE activity of several wild mammals of California revealed that mule deer (Odocoileus hemionus) had the highest erythrocyte AChE activity (1,514.5 mU/ml) and dusky-footed woodrats (Neotoma fuscipes) had the lowest activity (524.3 mU/ml). No ChE activity was found in erythrocytes of several species of birds and fish. PMID:8028108

  19. Automated conductimetric assay of human serum cholinesterase activity.

    PubMed

    Duffy, P; Wallach, J M

    1989-01-01

    Serum cholinesterase activity was determined by conductimetry using samples in the microliter range. Butyrylcholine iodide was demonstrated to be a convenient substrate for the conductimetric assay. Validation of the microassay was made by using either purified enzyme or control serum. In the range of 0-60 U/l, a linear relationship was demonstrated. Correlation with a reference spectrophotometric method was obtained with a slope of 1.18. An explanation of this value is proposed, as different hydrolysis rates were obtained with human sera, depending on the substrate used (butyrylthio- or butyryl-choline ester).

  20. Histochemical localization of cholinesterase activity in the dental epithelium of guinea pig teeth.

    PubMed

    Jayawardena, C K; Takano, Y

    2004-07-01

    Cholinesterase is known for its remarkable diversity in distribution and function. An association of this enzyme with proliferative and morpho-differentiating tissues has been reported in several species. Here we report on the first evidence of the presence of cholinesterase in the enamel organ of continuously erupting incisors and molars of the guinea pig. Frozen sections of the incisors and molars of the guinea pig were incubated for histochemical demonstration of cholinesterase activity by means of the thiocholine method as described by Karnovsky and Root. The cholinesterase activity was observed in several types of cells of the dental epithelium; cells forming the basal portion of the enamel organ, outer enamel epithelium and maturation stage ameloblasts of both the incisors and molars. In the crown analogue side, the outer enamel epithelial cells gained strong reactions for cholinesterase and maintained the reaction throughout the secretory and maturation stages of amelogenesis. In contrast, cholinesterase reactions were lacking in the inner enamel epithelium, pre-ameloblasts, and secretory ameloblasts. In the early stage of enamel maturation, ameloblasts began to show positive reactions for cholinesterase, which was upregulated in the incisal direction. Although both tooth types showed similar reactive patterns for cholinesterase at the growing ends, maturation ameloblasts depicted a different pattern of staining displaying the reactions only sporadically in molars. These data indicate the role of cholinesterase in the enamel organ in tooth morphogenesis and function of guinea pig teeth. PMID:15224211

  1. Evaluation of Candidate Genes for cholinesterase Activity in Farmworkers Exposed to organophosphorous Pesticides-Association of SNPs in BCHE

    EPA Science Inventory

    Background: Organophosphate pesticides act as cholinesterase inhibitors, and as such may give rise to potential neurological effects. Cholinesterase activity is a useful, indirect measurement of pesticide exposure, especially in high-risk individuals such as farmworkers. To und...

  2. Recovery of cholinesterase activity in mallard ducklings administered organophosphorus pesticides

    USGS Publications Warehouse

    Fleming, W.J.; Bradbury, S.P.

    1981-01-01

    Oral doses of the organophosphorus pesticides acephate, dicrotophos, fensulfothion, fonofos, malathion, and parathion were administered to mallard ducklings (Anas platyrhynchos), and brain and plasma cholinesterase (ChE) activities were determined for up to 77 d after dosing. In vivo recovery of brain ChE activity to within 2 standard deviations of the mean activity of undosed birds occurred within 8 d, after being depressed an average of 25-58% at 24 h after dosing. In vivo recovery of plasma ChE appeared as fast as or faster than that of brain, but the pattern of recovery was more erratic and therefore statistical comparison with brain ChE recovery was not attempted. In vitro tests indicated that the potential for dephosphorylation to contribute to in vivo recovery of inhibited brain ChE differed among chemical treatments. Some ducklings died as a result of organophosphate dosing. In an experiment in which ducklings within each treatment group received the same dose (mg/kg), the brain ChE activity in birds that died was less than that in birds that survived. Brain ChE activities in ducklings that died were significantly different among pesticide treatments: fensulfothion > parathion> acephate > malathion (p < 0.05).

  3. Brain cholinesterase activity of apparently normal wild birds

    USGS Publications Warehouse

    Hill, E.F.

    1988-01-01

    Organophosphorus and carbamate pesticides are potent anticholinesterase substances that have killed large numbers of wild birds of various species. Cause of death is diagnosed by demonstration of depressed brain cholinesterase (ChE) activity in combination with chemical detection of anticholinesterase residue in the affected specimen. ChE depression is determined by comparison of the affected specimen to normal ChE activity for a sample of control specimens of the same species, but timely procurement of controls is not always possible. Therefore, a reference file of normal whole brain ChE activity is provided for 48 species of wild birds from North America representing 11 orders and 23 families for use as emergency substitutes in diagnosis of anticholinesterase poisoning. The ChE values, based on 83 sets of wild control specimens from across the United States, are reproducible provided the described procedures are duplicated. Overall, whole brain ChE activity varied nearly three-fold among the 48 species represented, but it was usually similar for closely related species. However, some species were statistically separable in most families and some species of the same genus differed as much as 50%.

  4. Potential association of reduced cholinesterase activity with Trypanosoma evansi pathogenesis in buffaloes.

    PubMed

    Singh, Shanker K; Singh, Vivek K; Yadav, Brajesh K; Nakade, Udayraj P; Kumari, Priyambada; Srivastava, Mukesh K; Sharma, Abhishek; Choudhary, Soumen; Swain, Dilip; Garg, Satish K

    2016-07-30

    The present study aimed to investigate the association of cholinesterase activity with trypanosomosis in buffaloes. Thirty-three clinical cases of trypanosomosis in water buffaloes, found positive for trypomastigotes of T. evansi on blood smear examination, were divided into two groups based on clinical manifestations. Twenty diseased buffaloes revealing only common clinical signs were allocated to Group I, while the remaining 13 buffaloes showing common clinical manifestations along with neurological disturbances were allocated to Group II. Twelve clinically healthy buffaloes, free from any haemoprotozoa infection, were kept as healthy control (Group III). Blood samples were collected from buffaloes of all three groups to determine serum cholinesterase activity. Compared to buffaloes of healthy control group, cholinesterase activity in T. evansi-infected buffaloes of Group I and II was significantly (P<0.001) lower. However, no significant difference was observed in cholinesterase activity between the T. evansi-infected buffaloes exhibiting neurological disorders and no neurological disorders. Summing up, reduced cholinesterase activity seems to be associated with the pathogenesis of natural T. evansi infection and its clinical manifestations in buffaloes possibly by evading immune response. Further studies are warranted on association of cholinesterase activity in T. evansi-infected buffaloes with neurological disorders.

  5. Potential association of reduced cholinesterase activity with Trypanosoma evansi pathogenesis in buffaloes.

    PubMed

    Singh, Shanker K; Singh, Vivek K; Yadav, Brajesh K; Nakade, Udayraj P; Kumari, Priyambada; Srivastava, Mukesh K; Sharma, Abhishek; Choudhary, Soumen; Swain, Dilip; Garg, Satish K

    2016-07-30

    The present study aimed to investigate the association of cholinesterase activity with trypanosomosis in buffaloes. Thirty-three clinical cases of trypanosomosis in water buffaloes, found positive for trypomastigotes of T. evansi on blood smear examination, were divided into two groups based on clinical manifestations. Twenty diseased buffaloes revealing only common clinical signs were allocated to Group I, while the remaining 13 buffaloes showing common clinical manifestations along with neurological disturbances were allocated to Group II. Twelve clinically healthy buffaloes, free from any haemoprotozoa infection, were kept as healthy control (Group III). Blood samples were collected from buffaloes of all three groups to determine serum cholinesterase activity. Compared to buffaloes of healthy control group, cholinesterase activity in T. evansi-infected buffaloes of Group I and II was significantly (P<0.001) lower. However, no significant difference was observed in cholinesterase activity between the T. evansi-infected buffaloes exhibiting neurological disorders and no neurological disorders. Summing up, reduced cholinesterase activity seems to be associated with the pathogenesis of natural T. evansi infection and its clinical manifestations in buffaloes possibly by evading immune response. Further studies are warranted on association of cholinesterase activity in T. evansi-infected buffaloes with neurological disorders. PMID:27369572

  6. Behavioral changes and cholinesterase activity of rats acutely treated with propoxur.

    PubMed

    Thiesen, F V; Barros, H M; Tannhauser, M; Tannhauser, S L

    1999-01-01

    Early assessment of neurological and behavioral effects is extremely valuable for early identification of intoxications because preventive measures can be taken against more severe or chronic toxic consequences. The time course of the effects of an oral dose of the anticholinesterase agent propoxur (8.3 mg/kg) was determined on behaviors displayed in the open-field and during an active avoidance task by rats and on blood and brain cholinesterase activity. Maximum inhibition of blood cholinesterase was observed within 30 min after administration of propoxur. The half-life of enzyme-activity recovery was estimated to be 208.6 min. Peak brain cholinesterase inhibition was also detected between 5 and 30 min of the pesticide administration, but the half-life for enzyme activity recovery was much shorter, in the range of 85 min. Within this same time interval of the enzyme effects, diminished motor and exploratory activities and decreased performance of animals in the active avoidance task were observed. Likewise, behavioral normalization after propoxur followed a time frame similar to that of brain cholinesterase. These data indicate that behavioral changes that occur during intoxication with low oral doses of propoxur may be dissociated from signs characteristic of cholinergic over-stimulation but accompany brain cholinesterase activity inhibition.

  7. Correlation between Cholinesterase and Paraoxonase 1 Activities:Case Series of Pesticide Poisoning Subjects

    PubMed Central

    Richard, S Austin; Frank, Elizabeth A; D'Souza, Cletus J M

    2013-01-01

    Introduction: Acute exposure to pesticide due to suicidal poisoning is the most extensive cause of pesticide exposure, compared with all other causes including agricultural or industrial exposure. Organophosphate (OP) and carbamate group of pesticides can inhibit acetylcholinesterase; on the other hand, paraoxonase1 can detoxify organophosphate poisoning by hydrolyzing organophosphate metabolites. Methods: We have compared the serum paraoxonase1 status and cholinesterase activity of subjects who attempted to commit suicide by consuming OP pesticide. Cholinesterase and paraoxonase1 activity were measured spectrophotometrically using butyrylthiocholine and phenyl acetate as substrates, respectively. Results: A positive correlation was found between serum paraoxonase1 activity and cholinesterase activity among pesticide consumed subjects. Conclusion: Our results suggest that subjects with higher paraoxonase1 activity may have a better chance of detoxifying the lethal effect of acute organophosphate poisoning. PMID:24163803

  8. [Change of cholinesterase relative activity under modulated ultra high frequency electromagnetic radiation in experiments in vitro].

    PubMed

    Pashovkina, M S; Pashovkin, T N

    2011-01-01

    Changes in the activity of enzyme cholinesterase (ChE) have been experimentally investigated under the influence of amplitude-modulated super-high-frequency electromagnetic radiation (carrier frequency of 2.375 MHz; power flux density of 8 mW/cm2, 20 mW/cm2 and 50 mW/cm2; modulation frequency range 10 to 210 Hz; exposure time 5 min). The appearance of peaks of the cholinesterase increased relative activity, as well as the changes in the direction and intensity of the reaction associated with the modulation frequency and power flux are observed at equal power flux densities and exposure times.

  9. Evaluation of Cholinesterase Activities During in Vivo Intoxication Using an Electrochemical Sensor Strip – Correlation With Intoxication Symptoms

    PubMed Central

    Pohanka, Miroslav; Novotný, Ladislav; Misík, Jan; Kuca, Kamil; Zdarova-Karasova, Jana; Hrabinova, Martina

    2009-01-01

    Cholinesterase activity in blood of laboratory rats was monitored. Rats were intoxicated with paraoxon at dosis of 0 – 65 – 125 – 170 – 250 – 500 nmol. The 250 nmol dose was found to be the LD50. An electrochemical sensor was found useful to provide information about cholinesterase activity. The decrease of cholinesterase activity was correlated to intoxication symptoms and mortality level. It was found that the symptoms of intoxication are not observed while at least 50% of cholinesterase activity in blood remains. The minimal cholinesterase activity essential to survival is around 10%, when compared with the initial state. No changes in levels of low moleculary weight antioxidants were observed. PMID:22412329

  10. Regional cholinesterase activity in white-throated sparrow brain is differentially affected by acephate (Orthene?)

    USGS Publications Warehouse

    Vyas, N.B.; Kuenzel, W.J.; Hill, E.F.; Romo, G.A.; Komaragiri, M.V.S.

    1996-01-01

    Effects of a 14-day dietary exposure to an organophosphorus pesticide, acephate (acetylphosphoramidothioic acid O,S-dimethyl ester), were determined on cholinesterase activity in three regions (basal ganglia, hippocampus, and hypothalamus) of the white-throated sparrow, Zonotrichia albicollis, brain. All three regions experienced depressed cholinesterase activity between 0.5-2 ppm acephate. The regions exhibited cholinesterase recovery at 2-16 ppm acephate; however, cholinesterase activity dropped and showed no recovery at higher dietary levels (>16 ppm acephate). Evidence indicates that the recovery is initiated by the magnitude of depression, not the duration. In general, as acephate concentration increased, differences in ChE activity among brain regions decreased. Three terms are introduced to describe ChE response to acephate exposure: (1) ChE resistance threshold, (2) ChE compensation threshold, and (3) ChE depression threshold. It is hypothesized that adverse effects to birds in the field may occur at pesticide exposure levels customarily considered negligible.

  11. Arylesterase Phenotype-Specific Positive Association Between Arylesterase Activity and Cholinesterase Specific Activity in Human Serum

    PubMed Central

    Aoki, Yutaka; Helzlsouer, Kathy J.; Strickland, Paul T.

    2014-01-01

    Context: Cholinesterase (ChE) specific activity is the ratio of ChE activity to ChE mass and, as a biomarker of exposure to cholinesterase inhibitors, has a potential advantage over simple ChE activity. Objective: To examine the association of several potential correlates (serum arylesterase/paraoxonase activity, serum albumin, sex, age, month of blood collection, and smoking) with plasma ChE specific activity. Methods: We analyzed data from 195 cancer-free controls from a nested case-control study, accounting for potential confounding. Results: Arylesterase activity had an independent, statistically significant positive association with ChE specific activity, and its magnitude was the greatest for the arylesterase phenotype corresponding to the QQ PON1192 genotype followed by phenotypes corresponding to QR and RR genotypes. Serum albumin was positively associated with ChE specific activity. Conclusions: Plasma arylesterase activity was positively associated with plasma ChE specific activity. This observation is consistent with protection conferred by a metabolic phenotype resulting in reduced internal dose. PMID:24473115

  12. Plasma and whole brain cholinesterase activities in three wild bird species in Mosul, IRAQ: In vitro inhibition by insecticides

    PubMed Central

    Alias, Ashraf S.; Al-Zubaidy, Muna H.I.; Mousa, Yaareb J.; Mohammad, Fouad K.

    2011-01-01

    Plasma and brain cholinesterase activities were determined in three wild bird species to assess their exposure to organophosphate and carbamate insecticides which are used in agriculture and public health. In the present study, we used an electrometric method for measurement of cholinesterase activities in the plasma and whole brain of three indigenous wild birds commonly found in northern Iraq. The birds used were apparently healthy adults of both sexes (8 birds/species, comprising 3–5 from each sex) of quail (Coturnix coturnix), collard dove (Streptopelia decaocto) and rock dove (Columba livia gaddi), which were captured in Mosul, Iraq. The mean respective cholinesterase activities (Δ pH/30 minutes) in the plasma and whole brain of the birds were as follows: quail (0.96 and 0.29), collard dove (0.97and 0.82) and rock dove (1.44 and 1.42). We examined the potential susceptibility of the plasma or whole brain cholinesterases to inhibition by selected insecticides. The technique of in vitro cholinesterase inhibition for 10 minutes by the organophosphate insecticides dichlorvos, malathion and monocrotophos (0.5 and 1.0 µM) and the carbamate insecticide carbaryl (5 and10 µM) in the enzyme reaction mixtures showed significant inhibition of plasma and whole brain cholinesterase activities to various extents. The data further support and add to the reported cholinesterase activities determined electrometrically in wild birds in northern Iraq. The plasma and whole brain cholinesterases of the birds are highly susceptible to inhibition by organophosphate and carbamate insecticides as determined by the described electrometric method, and the results further suggest the usefulness of the method in biomonitoring wild bird cholinesterases. PMID:22058655

  13. Effect of methylmercury on acetylcholinestrase and serum cholinesterase activity in monkeys, Macaca fascicularis

    SciTech Connect

    Petruccioli, L.; Turillazzi, P.G. )

    1991-05-01

    The consumption of fish and fish-derived products is the main pathway of human exposure to methylmercury (MeHg). Methylmercury levels vary widely in fish, depending on age, size, the position of the species in the food chain, and most of all, on pollution levels. MeHg affects the Acetylcholinesterase activity (AChE) and the serum Cholinesterase activity (BChE). Histoenzymatic studies showed that 100mg Methyoxyethylmercury chloride administered for 6 days to rats caused a reduction of AChE activity in the thalamus and an increase in different parts of the nervous central system. The present study aims at verifying whether the dose permitted by F.A.O. and doses 10 and 100 fold higher affect the Cholinesterase activity in primates, and whether there is a correlation between AChE and BChE.

  14. Evaluating the protective effects of vitamin C on serum and erythrocyte cholinesterase activity of male rats exposed to malathion

    PubMed Central

    Taherdehi, Faezeh Ghorbani; Nikravesh, Mohammad Reza; Jalali, Mehdi; Fazel, Alireza

    2016-01-01

    Introduction Malathion is one of organophosphate poisons (OPPs) that inhibit cholinesterase activity and induce oxidative stress in target organs, such as the reproductive system. The aim of this study was to assess the effects of Malathion on serum and erythrocyte cholinesterase activity in male rats and also to assess the protective effects of vitamin C in this regard. Methods This experimental study was performed in the Pharmacology Laboratory of the Pharmacy Faculty and in the Advanced Histology Techniques Laboratory of the Medical Faculty of Mashhad University of Medical Sciences (MUMS) in January 2014. Thirty male wistar rats, weighting 200–250 g, were divided into five groups of six. The different groups were exposed as follows: group 1: Malathion 50 mg/kg; group 2: Vitamin C; group 3: Malathion plus Vitamin C with the specified doses; sham group: normal saline; and control group: no exposure. After six weeks, 3 ml blood samples were taken from the rats, and titrimetric and Ellman methods were used to assess serum and erythrocyte cholinesterase activity, respectively. The data was analyzed by SPSS 16, and p < 0.05 was considered significant. Results The activities of serum and erythrocyte cholinesterase were inhibited significantly in the Malathion exposed group compared to the control group (p < 0.001). The administration of Vitamin C alone significantly increased the activities of serum and erythrocyte cholinesterase. The serum and erythrocyte cholinesterase inhibition showed improvement in the group that received both Malathion and Vitamin C. Conclusion Malathion reduced the activities of serum and erythrocyte cholinesterase in exposed animals. It probably has the same intoxication effects on people who are exposed. Improvement of cholinesterase activity by antioxidant effects of Vitamin C suggests that Vitamin C supplementation can be used to decrease side effects of OPP exposure. PMID:27648190

  15. Evaluating the protective effects of vitamin C on serum and erythrocyte cholinesterase activity of male rats exposed to malathion

    PubMed Central

    Taherdehi, Faezeh Ghorbani; Nikravesh, Mohammad Reza; Jalali, Mehdi; Fazel, Alireza

    2016-01-01

    Introduction Malathion is one of organophosphate poisons (OPPs) that inhibit cholinesterase activity and induce oxidative stress in target organs, such as the reproductive system. The aim of this study was to assess the effects of Malathion on serum and erythrocyte cholinesterase activity in male rats and also to assess the protective effects of vitamin C in this regard. Methods This experimental study was performed in the Pharmacology Laboratory of the Pharmacy Faculty and in the Advanced Histology Techniques Laboratory of the Medical Faculty of Mashhad University of Medical Sciences (MUMS) in January 2014. Thirty male wistar rats, weighting 200–250 g, were divided into five groups of six. The different groups were exposed as follows: group 1: Malathion 50 mg/kg; group 2: Vitamin C; group 3: Malathion plus Vitamin C with the specified doses; sham group: normal saline; and control group: no exposure. After six weeks, 3 ml blood samples were taken from the rats, and titrimetric and Ellman methods were used to assess serum and erythrocyte cholinesterase activity, respectively. The data was analyzed by SPSS 16, and p < 0.05 was considered significant. Results The activities of serum and erythrocyte cholinesterase were inhibited significantly in the Malathion exposed group compared to the control group (p < 0.001). The administration of Vitamin C alone significantly increased the activities of serum and erythrocyte cholinesterase. The serum and erythrocyte cholinesterase inhibition showed improvement in the group that received both Malathion and Vitamin C. Conclusion Malathion reduced the activities of serum and erythrocyte cholinesterase in exposed animals. It probably has the same intoxication effects on people who are exposed. Improvement of cholinesterase activity by antioxidant effects of Vitamin C suggests that Vitamin C supplementation can be used to decrease side effects of OPP exposure.

  16. Structural difference at the active site of dibucaine resistant variant of human plasma cholinesterase.

    PubMed Central

    Muensch, H; Yoshida, A; Altland, K; Jensen, W; Goedde, H W

    1978-01-01

    Human plasma cholinesterase from five different genotypes -- E1U E1U, E1U E1A, E1A E1A, E1U E1S, E1A E1S, and E1U E1U C5+ -- was purified 8,000 fold from serum by a two-step procedure involving chromatography on DEAE-cellulose and preparative disc electrophoresis. The esterases were labeled with diisopropyl-1, 3-C14-fluorophosphate (DFP) aminoethylated, and digested by trypsin. The trytic digests were subjected to high voltage electrophoresis, and the radioactive peptides were detected by radioautography. Comparison of the peptides revealed different electrophoretic mobilities of the usual and atypical (dibucaine resistant) plasma cholinesterase peptides. The results are consistent with a structural abnormality of the active center in the variant enzyme. No difference was observed an the esteratic site of the enzyme with C5 component. Images Fig. 1 PMID:677127

  17. Serum and Plasma Cholinesterase Activity in the Cape Griffon Vulture (Gyps coprotheres).

    PubMed

    Naidoo, Vinny; Wolter, Kerri

    2016-04-28

    Vulture (Accipitridae) poisonings are a concern in South Africa, with hundreds of birds dying annually. Although some of these poisonings are accidental, there has been an increase in the number of intentional baiting of poached rhinoceros (Rhinocerotidae) and elephant (Elephantidae) carcasses to kill vultures that alert officials to poaching sites by circling overhead. The primary chemicals implicated are the organophosphorous and carbamate compounds. Although most poisoning events can be identified by dead vultures surrounding the scavenged carcass, weak birds are occasionally found and brought to rehabilitation centers for treatment. The treating veterinarian needs to make an informed decision on the cause of illness or poisoning prior to treatment. We established the reference interval for serum and plasma cholinesterase activity in the Cape Griffon Vulture ( Gyps coprotheres ) as 591.58-1,528.26 U/L, providing a clinical assay for determining potential exposure to cholinesterase-depressing pesticides. Both manual and automated samplers were used with the butyrylthiocholine method. Species reference intervals for both serum and plasma cholinesterase showed good correlation and manual and automated measurements yielded similar results.

  18. Serum and Plasma Cholinesterase Activity in the Cape Griffon Vulture (Gyps coprotheres).

    PubMed

    Naidoo, Vinny; Wolter, Kerri

    2016-04-28

    Vulture (Accipitridae) poisonings are a concern in South Africa, with hundreds of birds dying annually. Although some of these poisonings are accidental, there has been an increase in the number of intentional baiting of poached rhinoceros (Rhinocerotidae) and elephant (Elephantidae) carcasses to kill vultures that alert officials to poaching sites by circling overhead. The primary chemicals implicated are the organophosphorous and carbamate compounds. Although most poisoning events can be identified by dead vultures surrounding the scavenged carcass, weak birds are occasionally found and brought to rehabilitation centers for treatment. The treating veterinarian needs to make an informed decision on the cause of illness or poisoning prior to treatment. We established the reference interval for serum and plasma cholinesterase activity in the Cape Griffon Vulture ( Gyps coprotheres ) as 591.58-1,528.26 U/L, providing a clinical assay for determining potential exposure to cholinesterase-depressing pesticides. Both manual and automated samplers were used with the butyrylthiocholine method. Species reference intervals for both serum and plasma cholinesterase showed good correlation and manual and automated measurements yielded similar results. PMID:26981685

  19. Recovery of cholinesterase activity in five avian species exposed to dicrotophos, an organophosphorus pesticide

    USGS Publications Warehouse

    Fleming, W.J.; Grue, C.E.

    1981-01-01

    The responses of brain and plasma cholinesterase (ChE) activities were examined in mallard ducks, bobwhite quail, barn owls, starlings, and common grackles given oral doses of dicrotophos, an organophosphorus insecticide. Up to an eightfold difference in response of brain ChE activity to dicrotophos was found among these species. Brain ChE activity recovered to within 2 SD of normal within 26 days after being depressed 55 to 64%. Recovery of brain ChE activity was similar among species and followed the model Y = a + b (log10X).

  20. Longitudinal Assessment of Blood Cholinesterase Activities over Two Consecutive Years among Latino Non-farmworkers and Pesticide-Exposed Farmworkers in North Carolina

    PubMed Central

    Quandt, Sara A; Pope, Carey N.; Chen, Haiying; Summers, Phillip; Arcury, Thomas A.

    2015-01-01

    Objective This study (1) describes patterns of whole blood total cholinesterase, acetylcholinesterase, and butyrylcholinesterase activities across the agricultural season, comparing farmworkers and non-farmworkers; and (2) explores differences between farmworkers' and non-farmworkers' likelihood of cholinesterase depression. Methods Blood samples from 210 Latino male farmworkers and 163 Latino workers with no occupational pesticide exposure collected eight times across two agricultural seasons were analyzed. Mean cholinesterase activity levels and depressions ≥15% were compared by month. Results Farmworkers had significantly lower total cholinesterase and butyrylcholinesterase activities in July and August and lower acetylcholinesterase activity in August. Farmworkers had significantly greater likelihood of cholinesterase depression for each cholinesterase measure across the agricultural season. Significance A repeated-measures design across two years with a non-exposed control group demonstrated anticholinesterase effects in farmworkers. Current regulations designed to prevent pesticide exposure are not effective. PMID:26247638

  1. Resistance in cholinesterase activity after an acute and subchronic exposure to azinphos-methyl in the freshwater gastropod Biomphalaria straminea.

    PubMed

    Bianco, Karina; Otero, Sofía; Oliver, Agustina Balazote; Nahabedian, Daniel; Kristoff, Gisela

    2014-11-01

    Organophosphorous and carbamates insecticides are ones of the most popular classes of pesticides used in agriculture. Its success relies on their high acute toxicity and rapid environmental degradation. These insecticides inhibit cholinesterase and cause severe effects on aquatic non-target species, particularly in invertebrates. Since the properties of cholinesterases may differ between species, it is necessary to characterize them before their use as biomarkers. Also organophosphorous and carbamates inhibit carboxylesterases and the use of both enzymes for biomonitoring is suggested. Azinphos-methyl is an organophosphorous insecticide used in several parts of the word. In Argentina, it is the most applied insecticide in fruit production in the north Patagonian region. It was detected with the highest frequency in superficial and groundwater of the region. This work aims to evaluate the sensitivity of B. straminea cholinesterases and carboxylesterases to the OP azinphos-methyl including estimations of 48 h NOEC and IC50 of the pesticide and subchronic effects at environmentally relevant concentrations. These will allow us to evaluate the possibility of using cholinesterase and carboxylesterase of B. straminea as sensitive biomarkers. Previously a partial characterization of these enzymes will be performed. As in most invertebrates, acetylthiocholine was the preferred hydrolyzed substrate of B. straminea ChE, followed by propionylthiocholine and being butyrylthiocholine hydrolysis very low. Cholinesterase activity of B. straminea was significantly inhibited by the selective cholinesterases inhibitor (eserine) and by the selective inhibitor of mammalian acethylcholinesterase (BW284c51). In contrast, iso-OMPA, a specific inhibitor of butyrylcholinesterase, did not inhibit cholinesterase activity. These results suggest that cholinesterase activity in total soft tissue of B. straminea corresponds to acethylcholinesterase. Carboxylesterases activity was one order of

  2. Cholinesterases from Plant Tissues

    PubMed Central

    Riov, J.; Jaffe, M. J.

    1973-01-01

    A cholinesterase was purified 36-fold from mung bean (Phaseolus aureus) roots by a combination of differential extraction media and gel filtration. The enzyme could be effectively extracted only by high salt concentration, indicating that it is probably membrane-bound. Methods used for assaying animal cholinesterases were tested, two of which were adapted for use with the bean cholinesterase. The bean enzyme hydrolyzed choline and noncholine esters but showed its highest affinity for acetylcholine and acetylthiocholine. The pH optimum was 8.5 for acetylthiocholine and 8.7 for acetylcholine. The Michaelis constants were 72 and 84 μm for acetylcholine and acetylthiocholine, respectively. The cholinesterase was relatively insensitive to eserine (half-maximum inhibition at 0.42 mm) but showed high sensitivity to neostigmine (half-maximum inhibition at 0.6 μm). Other animal cholinesterase inhibitors were also found to inhibit the bean enzyme but most of them at higher concentrations than are generally encountered. Choline stimulated enzymatic activity. The molecular weight of the cholinesterase was estimated to be greater than 200,000, but at least one smaller form was observed. It is suggested that the large form of cholinesterase is converted to the smaller form by proteolysis. PMID:16658363

  3. Lysine Acetylation Activates Mitochondrial Aconitase in the Heart

    PubMed Central

    Fernandes, Jolyn; Weddle, Alexis; Kinter, Caroline S.; Humphries, Kenneth M.; Mather, Timothy; Szweda, Luke I.; Kinter, Michael

    2015-01-01

    High throughput proteomics studies have identified several thousand acetylation sites on over one thousand proteins. Mitochondrial aconitase, the Krebs cycle enzyme that converts citrate to isocitrate, has been identified in many of these reports. Acetylated mitochondrial aconitase has also been identified as a target for sirtuin 3 (SIRT3) catalyzed deacetylation. However, the functional significance of mitochondrial aconitase acetylation has not been determined. Using in vitro strategies, mass spectrometric analyses, and an in vivo mouse model of obesity, we found a significant acetylation-dependent activation of aconitase. Isolated heart mitochondria subjected to in vitro chemical acetylation with either acetic anhydride or acetyl-CoA resulted in increased aconitase activity that was reversed with SIRT3 treatment. Quantitative mass spectrometry was used to measure acetylation at 21 lysine residues and found significant increases with both in vitro treatments. A high fat diet (60% kcal from fat) was used as an in vivo model and also showed significantly increased mitochondrial aconitase activity without changes in protein level. The high fat diet also produced increased aconitase acetylation at multiple sites as measured by the quantitative mass spectrometry assays. Treatment of isolated mitochondria from these mice with SIRT3 abolished the high fat diet-induced activation of aconitase and reduced acetylation. Finally, kinetic analyses found that the increase in activity was a result of increased maximal velocity and molecular modeling suggests the potential for acetylation at K144 to perturb the tertiary structure of the enzyme. The results of this study reveal a novel activation of mitochondrial aconitase by acetylation. PMID:26061789

  4. Salivary cholinesterase activity in children with organic and convential diets

    EPA Science Inventory

    Objective: Previous efforts to determine the health effects of pesticides have focused on quantifying acetylcholinesterase activity in blood. However, since blood draws can be difficult in young children, saliva biomonitoring has recently been explored as a feasible alternative....

  5. Sex and storage affect cholinesterase activity in blood plasma of Japanese quail

    USGS Publications Warehouse

    Hill, E.F.

    1989-01-01

    Freezing at -25?C had confounding effects on cholinesterase (ChE) activity in blood plasma from breeding female quail, but did not affect ChE activity in plasma from males. Plasma ChE activity of control females increased consistently during 28 days of storage while both carbamate- and cidrotophos-inhibited ChE decreased. Refrigeration of plasma at 4?C for 2 days had little effect of ChE activity. Plasma ChE activity was averaged about 34% higher in breeding males than in females. Extreme caution should be exercised in use of blood plasma for evaluation of anti ChE exposure in free-living birds.

  6. Development of organophosphate hydrolase activity in a bacterial homolog of human cholinesterase

    NASA Astrophysics Data System (ADS)

    Legler, Patricia; Boisvert, Susanne; Compton, Jaimee; Millard, Charles

    2014-07-01

    We applied a combination of rational design and directed evolution (DE) to Bacillus subtilis p-nitrobenzyl esterase (pNBE) with the goal of enhancing organophosphorus acid anhydride hydrolase (OPAAH) activity. DE started with a designed variant, pNBE A107H, carrying a histidine homologous with human butyrylcholinesterase G117H to find complementary mutations that further enhance its OPAAH activity. Five sites were selected (G105, G106, A107, A190, and A400) within a 6.7 Å radius of the nucleophilic serine O?. All 95 variants were screened for esterase activity with a set of five substrates: pNP-acetate, pNP-butyrate, acetylthiocholine, butyrylthiocholine, or benzoylthiocholine. A microscale assay for OPAAH activity was developed for screening DE libraries. Reductions in esterase activity were generally concomitant with enhancements in OPAAH activity. One variant, A107K, showed an unexpected 7-fold increase in its kcat/Km for benzoylthiocholine, demonstrating that it is also possible to enhance the cholinesterase activity of pNBE. Moreover, DE resulted in at least three variants with modestly enhanced OPAAH activity compared to wild type pNBE. A107H/A190C showed a 50-fold increase in paraoxonase activity and underwent a slow time- and temperature-dependent change affecting the hydrolysis of OPAA and ester substrates. Structural analysis suggests that pNBE may represent a precursor leading to human cholinesterase and carboxylesterase 1 through extension of two vestigial specificity loops; a preliminary attempt to transfer the Ω-loop of BChE into pNBE is described. pNBE was tested as a surrogate scaffold for mammalian esterases. Unlike butyrylcholinesterase and pNBE, introducing a G143H mutation (equivalent to G117H) did not confer detectable OP hydrolase activity on human carboxylesterase 1. We discuss the importance of the oxyanion-hole residues for enhancing the OPAAH activity of selected serine hydrolases.

  7. Diagnosis of anticholinesterase poisoning in birds: Effects of environmental temperature and underfeeding on cholinesterase activity

    USGS Publications Warehouse

    Rattner, B.A.

    1982-01-01

    Brain cholinesterase (ChE) activity has been used extensively to monitor exposure to organophosphorus (OP) and carbamate (CB) insecticides in wild birds. A series of factorial experiments was conducted to assess the extent to which noncontaminant-related environmental conditions might affect brain ChE activity and thereby confound the diagnosis of OP and CB intoxication. Underfeeding (restricting intake to 50% of control for 21 d or fasting for 1-3 d) or exposure to elevated temperature (36 + 1?C for 1 d) caused only slight reductions (10-17%) in brain AChE activity in adult male Japanese quail (Coturnix coturnix japonica). This degree of 'reduction' in brain AChE activity is considerably less than the 50% 'inhibition' criterion employed in the diagnosis of insecticide-induced mortality, but nevertheless approaches the 20% 'inhibition' level used as a conservative estimate of sublethal exposure to a known insecticide application.

  8. Brain cholinesterase activity of nestling great egrets, snowy egrets, and black-crowned night-herons

    USGS Publications Warehouse

    Custer, T.W.; Ohlendorf, H.M.

    1989-01-01

    Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbmate pesticides. Brain ChE activity in the young of altricial species increase with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus) collected from a colony in Texas increased significantly with age and did not differ among individuals from different nests. Brain ChE activity of nestling snowy egrets (Egretta thula) and black-crowned night -herons (Nycticorax nycticorax) collected in one colony each from Rhode Island, Texas, and California also increased significantly with age and did not differ among individuals from different nests or colonies. This study further demonstrates that age must be considered when evaluating exposure of nestling altricial birds to ChE inhibitors.

  9. Brain cholinesterase activity of nestling great egrets snowy egrets and black-crowned night-herons

    USGS Publications Warehouse

    Custer, T.W.; Ohlendorf, H.M.

    1989-01-01

    Inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. Brain ChE activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus) collected from a colony in Texas (USA) increased significantly with age and did not differ among individuals from different nests. Brain ChE activity of nestling snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) collected in one colony each from Rhode Island, Texas and California (USA) also increased significantly with age and did not differ among individuals from different nests or colonies. This study further demonstrates that age must be considered when evaluating exposure of nestling altricial birds to ChE inhibitors.

  10. Brain cholinesterase activity of nestling great egrets, snowy egrets and black-crowned night-herons.

    PubMed

    Custer, T W; Ohlendorf, H M

    1989-07-01

    inhibition of brain cholinesterase (ChE) activity in birds is often used to diagnose exposure or death from organophosphorus or carbamate pesticides. Brain ChE activity in the young of altricial species increases with age; however, this relationship has only been demonstrated in the European starling (Sturnus vulgaris). Brain ChE activity of nestling great egrets (Casmerodius albus) collected from a colony in Texas (USA) increased significantly with age and did not differ among individuals from different nests. Brain ChE activity of nestling snowy egrets (Egretta thula) and black-crowned night-herons (Nycticorax nycticorax) collected in one colony each from Rhode Island, Texas and California (USA) also increased significantly with age and did not differ among individuals from different nests or colonies. This study further demonstrates that age must be considered when evaluating exposure of nestling altricial birds to ChE inhibitors.

  11. Brain cholinesterase activities of birds from forests sprayed with trichlorfon (Dylox) and carbaryl (Sevin-4-oil)

    USGS Publications Warehouse

    Zinkl, J.G.; Henny, C.J.; DeWeese, L.R.

    1977-01-01

    Brain cholinesterase activities were determined in birds from forests sprayed with Dylox2 at 1.13 kg/hectare (1 lb/acre ? active ingredient [a.i.]) or Sevin-4-oil2 at 1.13 kg/hectare (1 lb/acre ? a.i.) for up to 5 days postspray. Of ten bird species evaluated from the Dylox spray area, four species represented by six individuals had values which were depressed more than 2 standard deviations below the mean. Three of these activities (two species) were about 20% less than the mean. Of 12 species evaluated from the Sevin-4-oil spraying, three individuals representing three species had depressed values. One value was depressed greater than 20% below the mean. Half of the depressed activities were in canopy-dwelling birds collected on the day of spray.

  12. Temperature: a prolonged confounding factor on cholinesterase activity in the tropical reef fish Acanthochromis polyacanthus.

    PubMed

    Botté, Emmanuelle S; Smith-Keune, Carolyn; Jerry, Dean R

    2013-09-15

    Cholinesterase activity usually decreases in fish exposed to anticholinesterase compounds such as organophosphate and carbamate pesticides. Here we show that tropical reef fish Acanthochromis polyacanthus (or spiny damsel) also exhibits a decrease in ChE activity when exposed to elevated temperature from 28°C to 32°C or 34°C after 4 days. We further demonstrate that the decline persists even after 7 days of recovery at control temperature. This is the first report of a drop in ChE activity in fish as temperature increases. Our results strongly suggest the need for long-term monitoring of water temperature in the field prior to sampling A. polyacanthus for toxicology studies, as temperature is a prolonged and confounding factor for ChE activity in this species.

  13. Cholinesterases inhibitory and antioxidant activities of Harpagophytum procumbens from in vitro systems.

    PubMed

    Georgiev, Milen I; Alipieva, Kalina; Orhan, Ilkay Erdogan

    2012-02-01

    A previous report showed that extracts of cell suspension and transformed root cultures of Harpagophytum procumbens (commonly known as Devil's claw), an African plant with high medicinal value, exhibit strong antiinflammatory characteristics. The present work tests the ability of extracts, phenylethanoid-containing fractions and the major phenylethanoid glycoside isolated from the Devil's claw cultures, to inhibit acetylcholinesterase and butyrylcholinesterase, and the antioxidant activity in iron-related systems (e.g. ferric-reducing antioxidant power and ferrous ion-chelating capacity). The results indicated that the phenylethanoid fractions may be attractive for various commercial purposes since they displayed significant cholinesterase inhibitory activity (even higher than that of pure galanthamine in the case of butyrylcholinesterase inhibition assay). Crude methanolic extracts from cell and hairy root cultures of Devil's claw exhibited strong ferrous ion-chelating capacity (1.5-2 times higher than pure butylated hydroxyanisole, used as positive standard). PMID:21721061

  14. Secondary metabolites of Seseli rigidum: Chemical composition plus antioxidant, antimicrobial and cholinesterase inhibition activity.

    PubMed

    Stankov-Jovanović, V P; Ilić, M D; Mitić, V D; Mihajilov-Krstev, T M; Simonović, S R; Nikolić Mandić, S D; Tabet, J C; Cole, R B

    2015-01-01

    Extracts of different polarity obtained from various plant parts (root, leaf, flower and fruit) of Seseli rigidum were studied by different antioxidant assays: DPPH and ABTS radical scavenging activity, by total reducing power method as well as via total content of flavonoids and polyphenols. Essential oils of all plant parts showed weak antioxidant characteristics. The inhibitory concentration range of the tested extracts, against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and fungi Candida albicans and Aspergillus niger was 0.01-1.50 mg/mL and of a microbicidal 0.02-3.00 mg/mL. In the interaction with cholinesterase, all essential oils proved effective as inhibitors. The highest percentage of inhibition versus human and horse cholinesterase was shown by root essential oil (38.20% and 48.30%, respectively) among oils, and root hexane extract (40.56% and 50.65% respectively). Essential oils and volatile components of all plant parts were identified by GC, GC-MS and headspace/GC-MS. Statistical analysis of the ensemble of results showed that the root essential oil composition differed significantly from essential oils of other parts of the plant. Taking into account all of the studied activities, the root hexane extract showed the best overall properties. By means of high performance liquid chromatography coupled to high resolution mass spectrometry, the 30 most abundant constituents were identified in extracts of different polarity. The presence of identified constituents was linked to observed specific biological activities, thus designating compounds potentially responsible for each exhibited activity. PMID:25863020

  15. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    PubMed

    Cong, Nguyen Van; Phuong, Nguyen Thanh; Bayley, Mark

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition.

  16. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    PubMed

    Cong, Nguyen Van; Phuong, Nguyen Thanh; Bayley, Mark

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition. PMID:19054558

  17. PON1 status does not influence cholinesterase activity in Egyptian agricultural workers exposed to chlorpyrifos

    SciTech Connect

    Ellison, Corie A.; Crane, Alice L.; Bonner, Matthew R.; Knaak, James B.; Browne, Richard W.; Lein, Pamela J.; Olson, James R.

    2012-12-15

    Animal studies have shown that paraoxonase 1 (PON1) genotype can influence susceptibility to the organophosphorus pesticide chlorpyrifos (CPF). However, Monte Carlo analysis suggests that PON1 genotype may not affect CPF-related toxicity at low exposure conditions in humans. The current study sought to determine the influence of PON1 genotype on the activity of blood cholinesterase as well as the effect of CPF exposure on serum PON1 in workers occupationally exposed to CPF. Saliva, blood and urine were collected from agricultural workers (n = 120) from Egypt's Menoufia Governorate to determine PON1 genotype, blood cholinesterase activity, serum PON1 activity towards chlorpyrifos-oxon (CPOase) and paraoxon (POase), and urinary levels of the CPF metabolite 3,5,6-trichloro-2-pyridinol (TCPy). The PON1 55 (P ≤ 0.05) but not the PON1 192 genotype had a significant effect on CPOase activity. However, both the PON1 55 (P ≤ 0.05) and PON1 192 (P ≤ 0.001) genotypes had a significant effect on POase activity. Workers had significantly inhibited AChE and BuChE after CPF application; however, neither CPOase activity nor POase activity was associated with ChE depression when adjusted for CPF exposure (as determined by urinary TCPy levels) and stratified by PON1 genotype. CPOase and POase activity were also generally unaffected by CPF exposure although there were alterations in activity within specific genotype groups. Together, these results suggest that workers retained the capacity to detoxify chlorpyrifos-oxon under the exposure conditions experienced by this study population regardless of PON1 genotype and activity and that effects of CPF exposure on PON1 activity are minimal. -- Highlights: ► CPF exposure resulted in an increase in TCPy and decreases in BuChE and AChE. ► CPOase activity decreased in subjects with the PON1 55LM and PON1 55 MM genotypes. ► Neither PON1 genotype nor CPOase activity had an effect on BuChE or AChE inhibition.

  18. Symptoms and cholinesterase activity among rural residents living near cotton fields in Nicaragua.

    PubMed Central

    Keifer, M; Rivas, F; Moon, J D; Checkoway, H

    1996-01-01

    OBJECTIVES: To explore whether symptoms resulted from pesticide spray drift on residentially exposed populations in rural Nicaragua. METHODS: 100 residents, each 10 years of age or older, were randomly selected from a Nicaraguan community surrounded by actively sprayed cotton fields (the exposed community) and from a socioeconomically similar community far from agricultural spraying (the control community). Subjects working with pesticides were excluded, and the study was conducted at the end of the 1990 cotton spraying season (August-December). Demographic information, exposure questions, and prevalence of 11 acute symptoms and 17 chronic symptoms were gathered from a structured interview. Finger stick erythrocyte cholinesterase (AChE) was measured with a portable colorimeter. Acute symptoms were grouped according to their previously known associations with cholinesterase (ChE) inhibitors into four ordinal categories (asymptomatic, non-specific, possible, probable). RESULTS: Residents from the exposed community were significantly more likely to report recently sighting a spray plane near their community, exposure to pesticide from drift, crossing recently sprayed fields, eating home grown food, and feeling ill after drift exposure. The mean AChE value was significantly lower for residents of the exposed community (4.9 v 5.3 IU/dl). The proportion of subjects complaining of one or more chronic or acute symptoms was significantly higher for the exposed community (87%) than for the controls (53%). Odds ratios for residents in the exposed community, by symptom categories, were non-specific 1.6 (95% confidence interval (95% CI) 0-8 to 3.2), possible 4.1 (95% CI 1.7 to 10.2), and probable 9.93 (95% CI 2-9 to 34.4). CONCLUSION: These findings indicate a strong association between exposure to aerial pesticides and symptoms. This study should be replicated with more quantitative exposure measures, for if confirmed, the results have relevance for millions in rural

  19. Comparative analysis of cholinesterase activities in food animals using modified Ellman and Michel assays

    PubMed Central

    Askar, Kasim Abass; Kudi, A. Caleb; Moody, A. John

    2011-01-01

    This study investigated correlations between modified Ellman and Michel assay methods for measuring cholinesterase (ChE) activities. It also established a foundation for the applicability of measuring ChE activities in food animal species as biochemical biomarkers for evaluating exposure to and effects of organophosphorus and carbamate pesticides. Measuring ChE activities in blood and tissue is currently the most important method of confirming the diagnosis of such exposure. The study also characterized the level of ChE activity in the selected organs/tissues of these animals and determined the best organ/tissue in which to measure ChE activity. The ChE activities were found to be higher in cattle than in sheep and higher in erythrocytes than in plasma and serum. The anticoagulant heparin significantly affects AChE activity in plasma compared with ethylenediamine tetra-acetic acid (EDTA). Of the different tissues tested, the mean of ChE activities was found to be highest in tissue from liver, followed by lung, muscle, kidney, and heart for sheep and cattle. In pigs, the ChE activities tested higher in kidney, liver, lung, muscle, and heart. The highest activities of ChE were found in pigs, followed by cattle and sheep. There was no significant difference between the modified Ellman and Michel method, but the percentage coefficient of variance (%CV) values were higher when the Michel method was used. PMID:22468023

  20. Recovery of brain and plasma cholinesterase activities in ducklings exposed to organophosphorus pesticides

    USGS Publications Warehouse

    Fleming, W.J.

    1981-01-01

    Brain and plasma cholinesterase (ChE) activities were determined for mallard ducklings (Anas platyrhynchos) exposed to dicrotophos and fenthion. Recovery rates of brain ChE did not differ between ducklings administered a single oral dose vs. a 2-week dietary dose of these organophosphates. Exposure to the organophosphates, followed by recovery of brain ChE, did not significantly affect the degree of brain ChE inhibition or the recovery of ChE activity at a subsequent exposure. Recovery of brain ChE activity followed the general model Y = a + b(logX) with rapid recovery to about 50% of normal, followed by a slower rate of recovery until normal ChE activity levels were attained. Fenthion and dicrotophos-inhibited brain ChE were only slightly reactivated in vitro by pyridine-2-aldoxime methiodide, which suggested that spontaneous reactivation was not a primary method of recovery of ChE activity. Recovery of brain ChE activity can be modeled for interpretation of sublethal inhibition of brain ChE activities in wild birds following environmental applications of organophosphates. Plasma ChE activity is inferior to brain ChE activity for environmental monitoring, because of its rapid recovery and large degree of variation among individuals.

  1. Muscular cholinesterase and lactate dehydrogenase activities in deep-sea fish from the NW Mediterranean.

    PubMed

    Koenig, Samuel; Solé, Montserrat

    2014-03-01

    Organisms inhabiting submarine canyons can be potentially exposed to higher inputs of anthropogenic chemicals than their counterparts from the adjacent areas. To find out to what extend this observation applies to a NW Mediterranean canyon (i.e. Blanes canyon) off the Catalan coast, four deep-sea fish species were collected from inside the canyon (BC) and the adjacent open slope (OS). The selected species were: Alepocephalus rostratus, Lepidion lepidion, Coelorinchus mediterraneus and Bathypterois mediterraneus. Prior to the choice of an adequate sentinel species, the natural variation of the selected parameters (biomarkers) in relation to factors such as size, sex, sampling depth and seasonality need to be characterised. In this study, the activities of cholinesterases (ChEs) and lactate dehydrogenase (LDH) enzymes were determined in the muscle of the four deep-sea fish. Of all ChEs, acetylcholinesterase (AChE) activity was dominant and selected for further monitoring. Overall, AChE activity exhibited a significant relationship with fish size whereas LDH activity was mostly dependent on the sex and gonadal development status, although in a species-dependent manner. The seasonal variability of LDH activity was more marked than for AChE activity, and inside-outside canyon (BC-OS) differences were not consistent in all contrasted fish species, and in fact they were more dependent on biological traits. Thus, they did not suggest a differential stress condition between sites inside and outside the canyon. PMID:24296242

  2. Muscular cholinesterase and lactate dehydrogenase activities in deep-sea fish from the NW Mediterranean.

    PubMed

    Koenig, Samuel; Solé, Montserrat

    2014-03-01

    Organisms inhabiting submarine canyons can be potentially exposed to higher inputs of anthropogenic chemicals than their counterparts from the adjacent areas. To find out to what extend this observation applies to a NW Mediterranean canyon (i.e. Blanes canyon) off the Catalan coast, four deep-sea fish species were collected from inside the canyon (BC) and the adjacent open slope (OS). The selected species were: Alepocephalus rostratus, Lepidion lepidion, Coelorinchus mediterraneus and Bathypterois mediterraneus. Prior to the choice of an adequate sentinel species, the natural variation of the selected parameters (biomarkers) in relation to factors such as size, sex, sampling depth and seasonality need to be characterised. In this study, the activities of cholinesterases (ChEs) and lactate dehydrogenase (LDH) enzymes were determined in the muscle of the four deep-sea fish. Of all ChEs, acetylcholinesterase (AChE) activity was dominant and selected for further monitoring. Overall, AChE activity exhibited a significant relationship with fish size whereas LDH activity was mostly dependent on the sex and gonadal development status, although in a species-dependent manner. The seasonal variability of LDH activity was more marked than for AChE activity, and inside-outside canyon (BC-OS) differences were not consistent in all contrasted fish species, and in fact they were more dependent on biological traits. Thus, they did not suggest a differential stress condition between sites inside and outside the canyon.

  3. Insights into cholinesterase inhibitory and antioxidant activities of five Juniperus species.

    PubMed

    Orhan, Nilufer; Orhan, Ilkay Erdogan; Ergun, Fatma

    2011-09-01

    In vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory and antioxidant activities of the aqueous and ethanol extracts of the leaves, ripe fruits, and unripe fruits of Juniperus communis ssp. nana, Juniperus oxycedrus ssp. oxycedrus, Juniperus sabina, Juniperus foetidissima, and Juniperus excelsa were investigated in the present study. Cholinesterase inhibition of the extracts was screened using ELISA microplate reader. Antioxidant activity of the extracts was tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically. The extracts had low or no inhibition towards AChE, whereas the leaf aqueous extract of J. foetidissima showed the highest BChE inhibition (93.94 ± 0.01%). The leaf extracts usually exerted higher antioxidant activity. We herein describe the first study on anticholinesterase and antioxidant activity by the methods of ferrous ion-chelating, superoxide radical scavenging, and ferric-reducing antioxidant power (FRAP) assays of the mentioned Juniperus species.

  4. The effects of chlorpyrifos on cholinesterase activity and foraging behavior in the dragonfly, Anax junius (Odonata)

    USGS Publications Warehouse

    Brewer, S.K.; Atchison, G.J.

    1999-01-01

    We examined head capsule cholinesterase (ChE) and foraging behavior in nymphs of the dragonfly, Anax junius, exposed for 24 h to 0.2, 0.6 and 1.0 ??g l-1 of the organophosphorus (OP) insecticide, chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate]. The invertebrate community is an important component of the structure and function of wetland ecosystems, yet the potential effects of insecticides on wetland ecosystems are largely unknown. Our objectives were to determine if exposure to environmentally realistic concentrations of chlorpyrifos affected foraging behavior and ChE activity in head capsules of dragonfly nymphs. Nymphs were exposed to different concentrations of chlorpyrifos and different prey densities in a factorial design. ChE activities and foraging behaviors of treated nymphs were not statistically different (p ??? 0.05) from control groups. Prey density effects exerted a greater effect on dragonfly foraging than toxicant exposures. Nymphs offered higher prey densities exhibited more foraging behaviors but also missed their prey more often. High variability in ChE activities within the control group and across treated groups precluded determination of relationships between ChE and foraging behaviors. It appears that A. junius is relatively tolerant of chlorpyrifos, although the concentrations we tested have been shown in other work to adversely affect the prey base; therefore the introduction of this insecticide may have indirect adverse affects on top invertebrate predators such as Odonata.

  5. The relationship between total cholinesterase activity and mortality in four butterfly species.

    PubMed

    Bargar, Timothy A

    2012-09-01

    The relationship between total cholinesterase activity (TChE) and mortality in four butterfly species (great southern white [Ascia monuste], common buckeye [Junonia coenia], painted lady [Vanessa cardui], and julia butterflies [Dryas julia]) was investigated. Acute contact toxicity studies were conducted to evaluate the response (median lethal dose [LD50] and TChE) of the four species following exposure to the organophosphate insecticide naled. The LD50 for these butterflies ranged from 2.3 to 7.6 µg/g. The average level of TChE inhibition associated with significant mortality ranged from 26 to 67%, depending on the species. The lower bounds of normal TChE activity (2 standard deviations less than the average TChE for reference butterflies) ranged from 8.4 to 12.3 µM/min/g. As a percentage of the average reference TChE activity for the respective species, the lower bounds were similar to the inhibition levels associated with significant mortality, indicating there was little difference between the dose resulting in significant TChE inhibition and that resulting in mortality. PMID:22740147

  6. The relationship between total cholinesterase activity and mortality in four butterfly species

    USGS Publications Warehouse

    Bargar, Timothy A.

    2012-01-01

    The relationship between total cholinesterase activity (TChE) and mortality in four butterfly species (great southern white [Ascia monuste], common buckeye [Junonia coenia], painted lady [Vanessa cardui], and julia butterflies [Dryas julia]) was investigated. Acute contact toxicity studies were conducted to evaluate the response (median lethal dose [LD50] and TChE) of the four species following exposure to the organophosphate insecticide naled. The LD50 for these butterflies ranged from 2.3 to 7.6 μg/g. The average level of TChE inhibition associated with significant mortality ranged from 26 to 67%, depending on the species. The lower bounds of normal TChE activity (2 standard deviations less than the average TChE for reference butterflies) ranged from 8.4 to 12.3 μM/min/g. As a percentage of the average reference TChE activity for the respective species, the lower bounds were similar to the inhibition levels associated with significant mortality, indicating there was little difference between the dose resulting in significant TChE inhibition and that resulting in mortality.

  7. Cytochemical localization of cholinesterase activity at the giant synapse of the squid.

    PubMed

    Brzin, M; Tennyson, V M; Dettbarn, W D

    1975-06-01

    The giant synapse of squid stellate ganglion is a chemical synapse where the transmitter substance is not known. The components of the ACh-system are present in squid nervous tissue in large quantities. However externally applied cholinergic drugs have no effect on junctional transmission. Using the Copper thiocholine method for electron microscopic cytochemistry the reaction product was found at the axolemmal surface, in the cisternae of the endoplasmic reticulum of neurons and occasionally between the infoldings of the sheat cells surounding the axons. Abundant deposits of end product are observed in the extracellular space in the proximity to junctional region. However, the localization of the cytochemical end product at the junctional region proper was observed frequently, but not consistently. Radiometric measurements of enzyme activity have revealed that neither specific inhibitors nor specific substrates generaly used for differentiation of cholinesterases in mammalian nervous tissue can be employed for differentiation of squid enzymes. Considering the permeability barriers imposed for external acetylcholine by cytoplasmic processes and the high enzyme activity of structures surrounding the giant synapse, the possibility that acetylcholine may still be a candidate for the missing transmitter is discussed.

  8. Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity

    USGS Publications Warehouse

    Hoffman, D.J.; Eastin, W.C.

    1981-01-01

    The effects of external exposure of mallard (Anas platyrhynchos) eggs to malathion, diazinon, and parathion were examined using formulations and concentrations similar to field applications. Treatment with aqueous emulsion simulated exposure at the rate of 100 gal per acre (153 liters/hectare) with three to six different doses per compound with treatment at 3 and 8 days of embryonic development. Treatment with a nontoxic oil vehicle simulated exposure at the rate of 11 gal per acre (16.8 liters/hectare) with three to six different doses per compound. The order of embryotoxicity on a pounds-per-acre basis was parathion > diazinon > malathion with either vehicle. However, the potential hazard under conditions of up to five times the maximum field level of application was greater for malathion because of the high permissible level of application for malathion on certain crops. Parathion, the most embryotoxic of the three, had the most pronounced effects when an oil vehicle was used, as reflected by an LC50 of about 2 lb of active ingredient per acre, stunted growth, and a high frequency of malformations involving distortion of the axial skeleton, particularly in the cervical region. All three compounds resulted in significant depression of plasma and brain cholinesterase activity, but parathion caused the most depression throughout development, which was still apparent in hatchlings. Treatment with either distilled water or oil vehicle alone did not result in any of these effects seen with organophosphorous insecticides.

  9. Characterizing biological variability in livestock blood cholinesterase activity for biomonitoring organophosphate nerve agent exposure

    SciTech Connect

    Halbrook, R.S.; Shugart, L.R.; Watson, A.P.; Munro, N.B.; Linnabary, R.D. )

    1992-09-01

    A biomonitoring protocol, using blood cholinesterase (ChE) activity in livestock as a monitor of potential organophosphate nerve agent exposure during the planned destruction of US unitary chemical warfare agent stockpiles, is described. The experimental design included analysis of blood ChE activity in individual healthy sheep, horses, and dairy and beef cattle during a 10- to 12-month period. Castrated and sexually intact males, pregnant and lactating females, and adult and immature animals were examined through at least one reproductive cycle. The same animals were used throughout the period of observation and were not exposed to ChE-inhibiting organophosphate or carbamate compounds. A framework for an effective biomonitoring protocol within a monitoring area includes establishing individual baseline blood ChE activity for a sentinel group of 6 animals on the bases of blood samples collected over a 6-month period, monthly collection of blood samples for ChE-activity determination during monitoring, and selection of adult animals as sentinels. Exposure to ChE-inhibiting compounds would be suspected when all blood ChE activity of all animals within the sentinel group are decreased greater than 20% from their own baseline value. Sentinel species selection is primarily a logistical and operational concern; however, sheep appear to be the species of choice because within-individual baseline ChE activity and among age and gender group ChE activity in sheep had the least variability, compared with data from other species. This protocol provides an effective and efficient means for detecting abnormal depressions in blood ChE activity in livestock and can serve as a valuable indicator of the extent of actual plume movement and/or deposition in the event of organophosphate nerve agent release.

  10. Bird predation on cutworms (Lepidoptera: Noctuidae) in wheat fields and chlorpyrifos effects on brain cholinesterase activity

    USGS Publications Warehouse

    McEwen, L.C.; DeWeese, L.R.; Schladweiler, P.

    1986-01-01

    Horned larks, Eremophila alpestris (L.), and McCown's longspurs, Calcarius mccownii (Lawrence), were collected at intervals from two winter wheat fields in Montana [USA] after aerial application of chlorpyrifos to control cutworms. Both bird species had a high (95-100%) incidence of Lepidoptera, mostly pale western cutworms, Agrotis orthogonia Morrison, in their stomachs at 3 days postspray. Incidence of cutworms and other insects in stomachs of birds from sprayed fields was lower at 9 and 16 days postspray than in control birds, presumably due to insecticide-caused reduction of insects. Effects of birds on population dynamics of insect pests in wheat are unknown, but birds do contribute to cutworm mortality. Predation is one of the limiting factors to cutworm increase and can supplement insecticidal control. Brain cholinesterase activity in horned larks collected from the sprayed fields at 3 and 9 days postspray was significantly lower than in unexposed larks, but at 16 days the difference was not significant. Although nontarget birds clearly were exposed to chlorpyrifos and manifested a sublethal physiological response, toxic effects were less severe than those resulting from endrin application for cutworm control in wheat. More study is needed of larger chlorpyrifos-treated fields under a variety of conditions to fully assess effects on nontarget life.

  11. Ultrastructural study and cholinesterase activity of paired capillaries in the newt brain.

    PubMed

    Ciani, F; Franceschini, V

    1984-01-01

    We have investigated the ultrastructural and histochemical (AChE and BuChE) features of intracerebral vessels in newt. The blood vessels of the newt brain are paired and end in a closed loop. The two limbs, each of them has delineate the lumen by one endothelial cell, are enclosed within a single basement membrane and are separated from each other by a thin intercapillary wall. The brain capillaries are un-fenestrated and the overlapping endothelial cells were connected by clefts. Ependymal astrocytes extensively ensheath the surface of brain capillaries, but the sheats are incomplete. Pericytes and mast cells are frequently sandwiched in the endothelial basal lamina. Microglial cells are also present adjacent to cerebral vessels. The newt cerebral capillaries are characterized by high levels of AChE. This enzyme is localized in the basal membrane and in extracellular spaces between the overlapping endothelial cells. The vascular walls are instead deprived of BuChE activity. The non-nervous role of cholinesterases is discussed.

  12. Composites of silica with immobilized cholinesterase incorporated into polymeric shell

    NASA Astrophysics Data System (ADS)

    Payentko, Victoriya; Matkovsky, Alexander; Matrunchik, Yulia

    2015-02-01

    Synthetic approaches for new nanocomposite materials with relatively high cholinesterase activity have been developed. The peculiarity of the formation of such systems is the introduction of cholinesterase into polymer with subsequent incorporation on the ready-made silica particles and into the polysiloxane matrixes during sol-gel synthesis. Evaluation of the cholinesterase activity has been fulfilled through the imitation of the acetylcholine chloride decomposition reaction. Values of activity for cholinesterase nanocomposites demonstrated in this work are higher than those for the native cholinesterase. The higher activity of cholinesterase contained in nanocomposites was found for those prepared using highly dispersed silica.

  13. A modular treatment of molecular traffic through the active site of cholinesterase

    PubMed Central

    Botti, SA; Felder, CE; Lifson, S; Sussman, JL; Silman, I

    1999-01-01

    We present a model for the molecular traffic of ligands, substrates, and products through the active site of cholinesterases (ChEs). First, we describe a common treatment of the diffusion to a buried active site of cationic and neutral species. We then explain the specificity of ChEs for cationic ligands and substrates by introducing two additional components to this common treatment. The first module is a surface trap for cationic species at the entrance to the active-site gorge that operates through local, short-range electrostatic interactions and is independent of ionic strength. The second module is an ionic-strength-dependent steering mechanism generated by long-range electrostatic interactions arising from the overall distribution of charges in ChEs. Our calculations show that diffusion of charged ligands relative to neutral isosteric analogs is enhanced approximately 10-fold by the surface trap, while electrostatic steering contributes only a 1.5- to 2-fold rate enhancement at physiological salt concentration. We model clearance of cationic products from the active-site gorge as analogous to the escape of a particle from a one-dimensional well in the presence of a linear electrostatic potential. We evaluate the potential inside the gorge and provide evidence that while contributing to the steering of cationic species toward the active site, it does not appreciably retard their clearance. This optimal fine-tuning of global and local electrostatic interactions endows ChEs with maximum catalytic efficiency and specificity for a positively charged substrate, while at the same time not hindering clearance of the positively charged products. PMID:10545346

  14. Cholinesterase inhibitory activity of isoquinoline alkaloids from three Cryptocarya species (Lauraceae).

    PubMed

    Wan Othman, Wan Nurul Nazneem; Liew, Sook Yee; Khaw, Kooi Yeong; Murugaiyah, Vikneswaran; Litaudon, Marc; Awang, Khalijah

    2016-09-15

    Alzheimer's disease is the most common form of dementia among older adults. Acetylcholinesterase and butyrylcholinesterase are two enzymes involved in the breaking down of the neurotransmitter acetylcholine. Inhibitors for these enzymes have potential to prolong the availability of acetylcholine. Hence, the search for such inhibitors especially from natural products is needed in developing potential drugs for Alzheimer's disease. The present study investigates the cholinesterase inhibitory activity of compounds isolated from three Cryptocarya species towards acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Nine alkaloids were isolated; (+)-nornantenine 1, (-)-desmethylsecoantofine 2, (+)-oridine 3, (+)-laurotetanine 4 from the leaves of Cryptocarya densiflora BI., atherosperminine 5, (+)-N-methylisococlaurine 6, (+)-N-methyllaurotetanine 7 from the bark of Cryptocarya infectoria Miq., 2-methoxyatherosperminine 8 and (+)-reticuline 9 from the bark of Cryptocarya griffithiana Wight. In general, most of the alkaloids showed higher inhibition towards BChE as compared to AChE. The phenanthrene type alkaloid; 2-methoxyatherosperminine 8, exhibited the most potent inhibition against BChE with IC50 value of 3.95μM. Analysis of the Lineweaver-Burk (LB) plot of BChE activity over a range of substrate concentration suggested that 2-methoxyatherosperminine 8 exhibited mixed-mode inhibition with an inhibition constant (Ki) of 6.72μM. Molecular docking studies revealed that 2-methoxyatherosperminine 8 docked well at the choline binding site and catalytic triad of hBChE (butyrylcholinesterase from Homo sapiens); hydrogen bonding with Tyr 128 and His 438 residues respectively. PMID:27492195

  15. Aspirin inhibits glucose-6-phosphate dehydrogenase activity in HCT 116 cells through acetylation: Identification of aspirin-acetylated sites

    PubMed Central

    Ai, Guoqiang; Dachineni, Rakesh; Kumar, D. Ramesh; Alfonso, Lloyd F.; Marimuthu, Srinivasan; Bhat, G. Jayarama

    2016-01-01

    Glucose-6-phosphate dehydrogenase (G6PD) catalyzes the first reaction in the pentose phosphate pathway, and generates ribose sugars, which are required for nucleic acid synthesis, and nicotinamide adenine dinucleotide phosphate (NADPH), which is important for neutralization of oxidative stress. The expression of G6PD is elevated in several types of tumor, including colon, breast and lung cancer, and has been implicated in cancer cell growth. Our previous study demonstrated that exposure of HCT 116 human colorectal cancer cells to aspirin caused acetylation of G6PD, and this was associated with a decrease in its enzyme activity. In the present study, this observation was expanded to HT-29 colorectal cancer cells, in order to compare aspirin-mediated acetylation of G6PD and its activity between HCT 116 and HT-29 cells. In addition, the present study aimed to determine the acetylation targets of aspirin on recombinant G6PD to provide an insight into the mechanisms of inhibition. The results demonstrated that the extent of G6PD acetylation was significantly higher in HCT 116 cells compared with in HT-29 cells; accordingly, a greater reduction in G6PD enzyme activity was observed in the HCT 116 cells. Mass spectrometry analysis of aspirin-acetylated G6PD (isoform a) revealed that aspirin acetylated a total of 14 lysine residues, which were dispersed throughout the length of the G6PD protein. One of the important amino acid targets of aspirin included lysine 235 (K235, in isoform a) and this corresponds to K205 in isoform b, which has previously been identified as being important for catalysis. Acetylation of G6PD at several sites, including K235 (K205 in isoform b), may mediate inhibition of G6PD activity, which may contribute to the ability of aspirin to exert anticancer effects through decreased synthesis of ribose sugars and NADPH. PMID:27356773

  16. Pharmacokinetics and effects on serum cholinesterase activities of organophosphorus pesticides acephate and chlorpyrifos in chimeric mice transplanted with human hepatocytes.

    PubMed

    Suemizu, Hiroshi; Sota, Shigeto; Kuronuma, Miyuki; Shimizu, Makiko; Yamazaki, Hiroshi

    2014-11-01

    Organophosphorus pesticides acephate and chlorpyrifos in foods have potential to impact human health. The aim of the current study was to investigate the pharmacokinetics of acephate and chlorpyrifos orally administered at lowest-observed-adverse-effect-level doses in chimeric mice transplanted with human hepatocytes. Absorbed acephate and its metabolite methamidophos were detected in serum from wild type mice and chimeric mice orally administered 150mg/kg. Approximately 70% inhibition of cholinesterase was evident in plasma of chimeric mice with humanized liver (which have higher serum cholinesterase activities than wild type mice) 1day after oral administrations of acephate. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated plasma concentrations of acephate and chlorpyrifos in humans were consistent with reported concentrations. Acephate cleared similarly in humans and chimeric mice but accidental/incidental overdose levels of chlorpyrifos cleared (dependent on liver metabolism) more slowly from plasma in humans than it did in mice. The data presented here illustrate how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of toxicological potential of organophosphorus pesticides.

  17. Divergent effects of postmortem ambient temperature on organophosphorus- and carbamate-inhibited brain cholinesterase activity in birds

    USGS Publications Warehouse

    Hill, E.F.

    1989-01-01

    Time- and temperature-dependent postmortem changes in inhibited brain cholinesterase (ChE) activity may confound diagnosis of field poisoning of wildlife by anticholinesterase pesticide. Carbamate-inhibited ChE activity may return to normal within 1 to 2 days of exposure of intact carcass to moderate ambient temperature (18-32C). Organophosphorus-inhibited ChE activity becomes more depressed over the same time. Uninhibited ChE activity was resilient to above freezing temperature to 32C for 1 day and 25C for 3 days. Carbamate- and organophosphorus-inhibited ChE can be separated by incubation of homogenate for 1 hour at physiological temperatures; carbamylated ChE can be readily reactivated while phosphorylated ChE cannot.

  18. RAPID ESTIMATION OF SERUM CHOLINESTERASE ACTIVITY USING THE ASTRUP MICRO EQUIPMENT.

    PubMed

    JOHNSON, J K; WHITEHEAD, T P

    1965-07-01

    A rapid micro technique for the estimation of serum cholinesterase is described. Acetylcholine bromide is incubated with serum within the capillary of the Astrup electrode. The enzyme hydrolyses the substrate with the liberation of acetic acid. This causes a fall of pH which is seen on the galvanometer of the instrument and the rate of this fall is shown to be proportional to enzyme concentration. The method has been calibrated in international units and compared with a more conventional technique. The values found in homozygotes with normal dibucaine-resistant enzymes and in heterozygotes are reported, together with their dibucaine and fluoride numbers. PMID:14318694

  19. Design, synthesis and biological evaluation of benzo[e][1,2,4]triazin-7(1H)-one and [1,2,4]-triazino[5,6,1-jk]carbazol-6-one derivatives as dual inhibitors of beta-amyloid aggregation and acetyl/butyryl cholinesterase.

    PubMed

    Catto, Marco; Berezin, Andrey A; Lo Re, Daniele; Loizou, Georgia; Demetriades, Marina; De Stradis, Angelo; Campagna, Francesco; Koutentis, Panayiotis A; Carotti, Angelo

    2012-12-01

    Alzheimer's disease (AD) onset and progression are associated with the dysregulation of multiple and complex physiological processes and a successful therapeutic approach should therefore address more than one target. Two new chemical entities, the easily accessible heterocyclic scaffolds 1,3-diphenylbenzo[e][1,2,4]triazin-7(1H)-one (benzotriazinone I) and 2-phenyl-6H-[1,2,4]triazino[5,6,1-jk]carbazol-6-one (triazafluoranthenone II), were explored for their multitarget-directed inhibition of beta-amyloid (Aβ) fibrillization and acetyl- (AChE) and/or butyryl- (BChE) cholinesterase, three valuable targets for AD therapy. Introduction of appropriate amine substituents at positions 6 and 5 on scaffold I and II, respectively, allowed the preparation of a series of compounds that were tested as Aβ(1-40) aggregation and cholinesterase inhibitors. Potent inhibitors of Aβ self-aggregation were discovered and among them benzotriazinone 7 exhibited an outstanding IC(50) equal to 0.37 μM. Compounds bearing a basic amine linked to the heterocyclic scaffold through a linear alkyl chain of varying length also afforded good ChE inhibitors. In particular, benzotriazinone 24 and triazafluoranthenone 38 were endowed with an interesting multiple activity, the former displaying IC(50) values of 1.4, 1.5 and 1.9 μM on Aβ aggregation and AChE and BChE inhibition, respectively, and the latter showing IC(50) values of 1.4 and an outstanding 0.025 μM in the Aβ aggregation and BChE inhibition, respectively. Benzotriazinone 24 and triazafluoranthenone 29, selected owing to their suitable aqueous solubility and Aβ aggregation inhibition, were submitted to a time course kinetic assay followed with thioflavin T (ThT) spectrofluorimetry, circular dichroism (CD) and transmission electron microscopy (TEM). Experimental data indicated that 24 acted at a low concentration ratio (10 μM 24 vs. 50 μM Aβ), stabilizing the unstructured Aβ peptide and inhibiting fibrillogenesis, and that 29

  20. Alkaloids from Hippeastrum argentinum and Their Cholinesterase-Inhibitory Activities: An in Vitro and in Silico Study.

    PubMed

    Ortiz, Javier E; Pigni, Natalia B; Andujar, Sebastián A; Roitman, German; Suvire, Fernando D; Enriz, Ricardo D; Tapia, Alejandro; Bastida, Jaume; Feresin, Gabriela E

    2016-05-27

    Two new alkaloids, 4-O-methylnangustine (1) and 7-hydroxyclivonine (2) (montanine and homolycorine types, respectively), and four known alkaloids were isolated from the bulbs of Hippeastrum argentinum, and their cholinesterase-inhibitory activities were evaluated. These compounds were identified using GC-MS, and their structures were defined by physical data analysis. Compound 2 showed weak butyrylcholinesterase (BuChE)-inhibitory activity, with a half-maximal inhibitory concentration (IC50) value of 67.3 ± 0.09 μM. To better understand the experimental results, a molecular modeling study was also performed. The combination of a docking study, molecular dynamics simulations, and quantum theory of atoms in molecules calculations provides new insight into the molecular interactions of compound 2 with BuChE, which were compared to those of galantamine.

  1. Alkaloids from Hippeastrum argentinum and Their Cholinesterase-Inhibitory Activities: An in Vitro and in Silico Study.

    PubMed

    Ortiz, Javier E; Pigni, Natalia B; Andujar, Sebastián A; Roitman, German; Suvire, Fernando D; Enriz, Ricardo D; Tapia, Alejandro; Bastida, Jaume; Feresin, Gabriela E

    2016-05-27

    Two new alkaloids, 4-O-methylnangustine (1) and 7-hydroxyclivonine (2) (montanine and homolycorine types, respectively), and four known alkaloids were isolated from the bulbs of Hippeastrum argentinum, and their cholinesterase-inhibitory activities were evaluated. These compounds were identified using GC-MS, and their structures were defined by physical data analysis. Compound 2 showed weak butyrylcholinesterase (BuChE)-inhibitory activity, with a half-maximal inhibitory concentration (IC50) value of 67.3 ± 0.09 μM. To better understand the experimental results, a molecular modeling study was also performed. The combination of a docking study, molecular dynamics simulations, and quantum theory of atoms in molecules calculations provides new insight into the molecular interactions of compound 2 with BuChE, which were compared to those of galantamine. PMID:27096334

  2. Acetylation of Werner syndrome protein (WRN): relationships with DNA damage, DNA replication and DNA metabolic activities

    PubMed Central

    Lozada, Enerlyn; Yi, Jingjie; Luo, Jianyuan; Orren, David K.

    2014-01-01

    Loss of WRN function causes Werner Syndrome, characterized by increased genomic instability, elevated cancer susceptibility and premature aging. Although WRN is subject to acetylation, phosphorylation and sumoylation, the impact of these modifications on WRN’s DNA metabolic function remains unclear. Here, we examined in further depth the relationship between WRN acetylation and its role in DNA metabolism, particularly in response to induced DNA damage. Our results demonstrate that endogenous WRN is acetylated somewhat under unperturbed conditions. However, levels of acetylated WRN significantly increase after treatment with certain DNA damaging agents or the replication inhibitor hydroxyurea. Use of DNA repair-deficient cells or repair pathway inhibitors further increase levels of acetylated WRN, indicating that induced DNA lesions and their persistence are at least partly responsible for increased acetylation. Notably, acetylation of WRN correlates with inhibition of DNA synthesis, suggesting that replication blockage might underlie this effect. Moreover, WRN acetylation modulates its affinity for and activity on certain DNA structures, in a manner that may enhance its relative specificity for physiological substrates. Our results also show that acetylation and deacetylation of endogenous WRN is a dynamic process, with sirtuins and other histone deacetylases contributing to WRN deacetylation. These findings advance our understanding of the dynamics of WRN acetylation under unperturbed conditions and following DNA damage induction, linking this modification not only to DNA damage persistence but also potentially to replication stalling caused by specific DNA lesions. Our results are consistent with proposed metabolic roles for WRN and genomic instability phenotypes associated with WRN deficiency. PMID:24965941

  3. Effect of temperature and pH on carbamoylation and phosphorylation of serum cholinesterases. Theoretical interpretation of activation energies in complex reactions

    PubMed Central

    Simeon, Vera; Reiner, Elsa; Vernon, C. A.

    1972-01-01

    1. The effect of temperature and pH was studied on the kinetics of inhibition of horse serum and human serum cholinesterase by four organophosphorus compounds and five carbamates. 2. For all compounds, and at each pH and temperature, the inhibition followed the kinetics of a bimolecular reaction with the inhibitor in excess, and with a negligible concentration of the Michaelis complex. 3. The second-order rate constants (ka) for inhibition of human serum cholinesterase by one organophosphate and one carbamate increased from 5° to 40°C with an apparent activation energy of 46kJ/mol (11kcal/mol). 4. The ka constant for inhibition of horse serum cholinesterase increased with temperature from 5° to 30°C, and then decreased from 30° to 40°C. The theoretical interpretation of such an unusual effect of temperature is derived. 5. The increase of ka with pH (human serum cholinesterase) followed the dissociation curve for a single group on the enzyme (pK7.5). 6. Rate constants for decarbamoylation (k+3) were determined, and the time-course of inhibition was calculated from the ka and k+3 constants. PMID:4677141

  4. Synthesis of Novel 3-Aryl-N-Methyl-1,2,5,6-Tetrahydropyridine Derivatives by Suzuki coupling: As Acetyl Cholinesterase Inhibitors

    PubMed Central

    Prasad, S.B. Benaka; Kumar, Y.C. Sunil; Kumar, C.S. Ananda; Sadashiva, C.T; Vinaya, K; Rangappa, K.S

    2007-01-01

    Alzheimer’s disease (AD) is a neurodegenerative disorder affecting the central nervous system, which is also associated with progressive loss of memory and cognition. The development of numerous structural classes of compounds with different pharmacological profile could be an evolving, promising therapeutic approach for the treatment of AD. Thus, providing a symptomatic treatment for this disease are cholinomimetics with the pharmacological profile of Acetylcholinesterase (AChE) inhibitors. In view of this, we have synthesized novel 3-aryl-N-methyl-1,2,5,6-tetrahydropyridine derivatives 5a-k by Suzuki coupling and screened the efficacy of these derivatives for their AChE inhibitor activity. PMID:19662135

  5. Chronic exposure to cigarette smoke during gestation results in altered cholinesterase enzyme activity and behavioral deficits in adult rat offspring: potential relevance to schizophrenia.

    PubMed

    Zugno, Alexandra I; Fraga, Daiane B; De Luca, Renata D; Ghedim, Fernando V; Deroza, Pedro F; Cipriano, Andreza L; Oliveira, Mariana B; Heylmann, Alexandra S A; Budni, Josiane; Souza, Renan P; Quevedo, João

    2013-06-01

    Prenatal cigarette smoke exposure (PCSE) has been associated with physiological and developmental changes that may be related to an increased risk for childhood and adult neuropsychiatric diseases. The present study investigated locomotor activity and cholinesterase enzyme activity in rats, following PCSE and/or ketamine treatment in adulthood. Pregnant female Wistar rats were exposed to 12 commercially filtered cigarettes per day for a period of 28 days. We evaluated motor activity and cholinesterase activity in the brain and serum of adult male offspring that were administered acute subanesthetic doses of ketamine (5, 15 and 25 mg/kg), which serves as an animal model of schizophrenia. To determine locomotor activity, we used the open field test. Cholinesterase activity was assessed by hydrolysis monitored spectrophotometrically. Our results show that both PCSE and ketamine treatment in the adult offspring induced increase of locomotor activity. Additionally, it was observed increase of acetylcholinesterase and butyrylcholinesterase activity in the brain and serum, respectively. We demonstrated that animals exposed to cigarettes in the prenatal period had increased the risk for psychotic symptoms in adulthood. This also occurs in a dose-dependent manner. These changes provoke molecular events that are not completely understood and may result in abnormal behavioral responses found in neuropsychiatric disorders, such as schizophrenia.

  6. Cholinesterase and glutathione-S-transferase activities in freshwater invertebrates as biomarkers to assess pesticide contamination.

    PubMed

    Domingues, Inês; Agra, Ana Raquel; Monaghan, Kieran; Soares, Amadeu M V M; Nogueira, António J A

    2010-01-01

    Studies investigating the use of biomarkers in pesticide risk assessment have greatly increased in recent years; however, issues concerning the ecological meaning of enzymatic responses have proved controversial. Ideally a good biomarker response should be modulated by the environmental contaminants alone and demonstrate a predictable behavior towards certain types of toxins. As these premises are rarely observed, the present study aims to outline research that has contributed to an understanding of the behavior of two widely used biomarkers, cholinesterase and glutathione-S-transferase, describing environmental and biotic factors that affect their response in freshwater invertebrates. Studies were performed in the main classes of aquatic invertebrates with these biomarkers and conclusions were reached concerning their behavior towards the main classes of pesticides. Links between biomarker responses and conventional endpoints were evaluated so that ecological relevance could be attributed to enzymatic responses. Toxicity of mixtures was investigated, and cases of synergism and antagonism were pointed out as factors changing the expected toxicity of aquatic systems and leading to misinterpretations of biomarker responses. Finally, the use of biomarkers as a tool for biomonitoring and in situ assays was investigated, with discussion of advantages and disadvantages of their use.

  7. Effects of stress pretreatment on the dynamics of blood cholinesterase activity after exposure to an organophosphorus pesticide in the rat.

    PubMed

    Gralewicz, Slawomir; Swiercz, Radoslaw; Lutz, Piotr; Wiaderna, Dorota; Wasowicz, Wojciech

    2010-01-01

    A single i.p. administration of 1.0 mg/kg of chlorphenvinphos (CVP), an organophosphorus pesticide, results in an acute stress response, evidenced by a marked (6-7 fold) rise in plasma corticosterone (CORT) concentration, and a diminished behavioural sensitivity to amphetamine (AMPH) three weeks postexposure. Surprisingly, in rats subjected to a single series of inescapable electric footshocks (60 10 msec triplets of 3.0 mA, 2 msec, square pulses during 20 min - IF ) two weeks prior to the CVP exposure, these effects are not observed. It has been assumed that the reduced effectiveness of CVP might be related to some persisting alterations in the functional state of the cholinergic system. The aim of the present work was to discover whether and in what way the IF pretreatment affects i) the cholinesterase activity in blood, and ii) the dynamics of the alterations in the cholinesterase (ChE) activity following the CVP exposure. The experiments were performed on 3 mo. old, male Wistar rats. In the first experiment, the blood samples were taken from the tail vein 15, 60 and 180 min after the IF. In the second experiment, the rats were pretreated with IF and 14 days later given 1.0 mg/kg of CVP i.p. Blood samples were taken 15 min, 60 min, 180 min, 24 h, 7 days, and 14 days after the CVP exposure. In the first experiment no differences in the ChE activity in plasma (pChE) and erythrocytes (rbcChE) were found between the shocked and control rats. In the second experiment, however, in rats pretreated with IF the rbcChE activity of was reduced by CVP less and pChE activity returned to normal faster than in rats not pretreated with IF. The results confirm that exposure to IF, a nonchemical stressor, induces some long-lasting adaptive changes which render the cholinergic system less susceptible to the harmful action of ChE inhibitors. It has been hypothesized that the changes consist in an increase of the antioxidant potential in blood and possibly other tissues. PMID

  8. Assessment of antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of pomegranate (Punica granatum) leaves.

    PubMed

    Bekir, Jalila; Mars, Mohamed; Souchard, Jean Pierre; Bouajila, Jalloul

    2013-05-01

    This study evaluated antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of extracts with different polarities (hexane, dichloromethane, ethyl acetate, ethanol and methanol) obtained from Punica granatum leaves. Total phenolics (8.8-127.3mg gallic acid equivalent/g dry weight), flavonoids (1.2-76.9mg quercetin equivalent/g dry weight), tannins (63.7-260.8mg catechin equivalent/kg dry weight) and anthocyanins (0.41-3.73mg cyanidin-3-glucoside equivalent/g dry weight) of different extracts were evaluated. The methanolic extract presented a good IC50 by DPPH and ABTS assays (5.62 and 1.31mg/l respectively). The strongest 5-lipoxygenase (5-LOX), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activities were obtained for the ethanol extract (IC50 values of 6.20, 14.83 and 2.65mg/l, respectively) and the best cytotoxic activity against MCF-7 cells was obtained for the methanol extract (IC50=31mg/l). These important biological activities showed that P. granatum leaves could be a potential source of the active molecules intended for applications in pharmaceutical industry, but only after additional in vivo experiments.

  9. Assessment of antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of pomegranate (Punica granatum) leaves.

    PubMed

    Bekir, Jalila; Mars, Mohamed; Souchard, Jean Pierre; Bouajila, Jalloul

    2013-05-01

    This study evaluated antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of extracts with different polarities (hexane, dichloromethane, ethyl acetate, ethanol and methanol) obtained from Punica granatum leaves. Total phenolics (8.8-127.3mg gallic acid equivalent/g dry weight), flavonoids (1.2-76.9mg quercetin equivalent/g dry weight), tannins (63.7-260.8mg catechin equivalent/kg dry weight) and anthocyanins (0.41-3.73mg cyanidin-3-glucoside equivalent/g dry weight) of different extracts were evaluated. The methanolic extract presented a good IC50 by DPPH and ABTS assays (5.62 and 1.31mg/l respectively). The strongest 5-lipoxygenase (5-LOX), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activities were obtained for the ethanol extract (IC50 values of 6.20, 14.83 and 2.65mg/l, respectively) and the best cytotoxic activity against MCF-7 cells was obtained for the methanol extract (IC50=31mg/l). These important biological activities showed that P. granatum leaves could be a potential source of the active molecules intended for applications in pharmaceutical industry, but only after additional in vivo experiments. PMID:23380204

  10. Altered quantities and in vivo activities of cholinesterase from Daphnia magna in sub-lethal exposure to organophosphorus insecticides.

    PubMed

    Liu, Hongcui; Yuan, Bingqiang; Li, Shaonan

    2012-06-01

    For investigating relationship between activity of cholinesterase (ChE) and ambient concentration of anticholinesterases, Daphnia magna had been exposed for 21 day to sub-lethal concentrations, i.e. 1/6 EC(50), 1/36 EC(50), and 1/216 EC(50), of either triazophos or chlorpyrifos. Samples were taken at different points of time for measuring total activity and immunoreactive content of ChE and actual concentrations of the anticholinesterases. A type of antigen formerly developed by immunizing mice with purified ChE was utilized in this study to establish an indirect non-competitive ELISA for measuring immunoreactive content of ChE in Daphnia. Studies showed that for apparent activity, i.e. activity that was scaled with total protein, the insecticides caused 5.2-6.9 percent inhibition and 17.0-17.7 percent inductions during the 21 d exposure, whereas for inherent activity, i.e. activity that was scaled with immunoreactive protein, no induction was detected during the exposure. Accompanied by up to 65.9 percent and 68.0 percent promotion in terms of the immunoreactive content, up to 42.8 percent and 44.6 percent inhibition in terms of the inherent activity was indicated, respectively, for triazophos and chlopyrifos. Judged by measured concentrations, the inherent activity recovered faster than the rate of dissipation of the anticholinesterases. Result of the study suggested that the inherent activity was more sensitive than the apparent one in predicting sub-lethal and/or long-term stress of anticholinesterases. It also suggested that apart from promotion in terms of content of the ChE, the Daphnia developed capacities to block bio-concentration of anticholinesterases, and these capacities would make it liable to underestimate ambient concentration of anticholinesterases along with the time of exposure.

  11. Elevated cholinesterase activity and increased urinary excretion of inorganic fluorides in the workers producing fluorine-containing plastic (polytetrafluoroethylene)

    SciTech Connect

    Baohui Xu |; Jiusun Zhang; Guaogeng Mao; Guifen Yang; Aini Chen; Aoyama, Kohji; Matsushita, Toshio; Ueda, Atsushi

    1992-07-01

    Fluoropolymers are widely used in thermal and electrical industries. Polytetrafluoroethylene (PTFE) plastic is a typical one. During its production, workers are occupationally exposed to many organic fluorides, especially tetrafluoroethylene, chlorodifluoromethane, PTFE and its thermal decomposition products. Of these compounds, it has been documented that following inhalation of combustion products of PTFE the focal hemorrhages, edema, fibrin deposition in lungs and renal infarcts were observed in rats. Odum and Green have demonstrated a marked damage to proximal tubule of kidney with no effects on the liver in rats exposed to 6000 ppm tetrafluoroethylene for 6 hr. The investigations of the hazards of these compounds to workers have been mainly focused on acute toxicity. There have been some reports that polymers and its pyrolysis caused polymer fume fever and pulmonary edema. In practice, workers engaged in PTFE manufacture are chronically exposed to the above-mentioned chemicals, but little was known about the hazards ascribed to these chemicals. To clarify the influences of the exposed chemicals on health in PTFE production we conducted a mass survey investigation in a PTFE production factory. As a result, in addition to the nephrotoxicity characterized by elevated ALP and NAG activities in urine, more interestingly, we have also found a reversible increase in cholinesterase (ChE) activity and enhanced urinary excretion of inorganic fluorides in workers engaged in PTFE production. We report here these findings and discuss their physiological significance. 18 refs., 4 tabs.

  12. Measurements of cholinesterase activity in the tropical freshwater cladoceran Pseudosida ramosa and its standardization as a biomarker.

    PubMed

    Freitas, Emanuela Cristina; Printes, Liane Biehl; Fernandes, Marisa Narciso; Rocha, Odete

    2014-03-01

    The activity of cholinesterases (ChE) has been recognized as a useful tool for assessing the toxicity in the environmental assessment programs. Nevertheless, the prior optimization of the experimental conditions for the appropriate measuring of the ChE activity enables us to get reliable results. Thus, the main objective of this study was to adapt and optimize a microplate assay for measuring the activity of ChE in the tropical cladoceran Pseudosida ramosa. The best readings for the reaction rates were obtained with buffers of pH 8.0 and molarity of 0.02M. The measurements of the reaction rates for the different substrate concentrations showed that the maximum reaction rate (32mODmin(-1)) was achieved by the final concentration of 2mM of substrate. In relation to the enzyme concentration, reaction rates were directly proportional to the protein concentration, which confirmed the linear kinetics for a maximum reaction rate. On the basis of the results of the assays for the effect of the number of individuals and homogenate dilution on the reaction rate of substrate hydrolysis and ChE activity, we recommend using of 30 individuals (3 days-old) in 250μL of buffer, 20 individuals (7 days-old) in 250μL of buffer and 15 individuals (both 14 and 21 days-old) in 300μL of buffer. The limits of quantitation obtained were 1.419mODmin(-1) (≤72h-old), 1.670mODmin(-1) (7 days-old), 0.943mODmin(-1) (14 days-old) and 0.797mODmin(-1) (21 days-old). In conclusion, it was possible to measure the ChE activity in P. ramosa with the methodology adapted, thus contributing to the implementation of a biochemical biomarker in freshwater toxicity assessments in tropical regions.

  13. Response and recovery of acetylcholinesterase activity in freshwater shrimp, Paratya australiensis (Decapoda: Atyidae) exposed to selected anti-cholinesterase insecticides.

    PubMed

    Kumar, A; Doan, H; Barnes, Mary; Chapman, J C; Kookana, R S

    2010-10-01

    The toxicity of carbaryl, chlorpyrifos, dimethoate and profenofos to the freshwater shrimp, Paratya australiensis was assessed by measuring acetylcholinesterase (AChE) inhibition after 96h exposures. Shrimp exposed to these pesticides exhibited significant AChE inhibition, with mortality in shrimp corresponding to 70-90% AChE inhibition. The sensitivity of P. australiensis to the four pesticides based on AChE inhibition can be given as chlorpyrifos > profenofos > carbaryl > dimethoate. Recovery of AChE activity was followed in shrimp after 96 h exposures to carbaryl, chlorpyrifos and dimethoate. Recovery after exposure to the carbamate pesticide carbaryl was more rapid than for the two organophosphorus pesticides, chlorpyrifos and dimethoate. The slow recovery of depressed AChE activity may mean that affected organisms in the natural system are unable to sustain physical activities such as searching for food or eluding predators. To investigate the ecological significance of AChE inhibition, chemotaxis behaviour was assessed in shrimp exposed to profenofos for 24h. Abnormal chemotaxis behaviour in the exposed shrimp was observed at concentrations representing 30-50% AChE inhibition. A clear relationship existed between the depression of AChE activity and observed chemotaxis responses, such as approaching and grasping the chemoattractant source. These results suggest that in vivo toxicity tests based on this specific biomarker are sensitive and present advantages over conventional acute tests based on mortality. Behavioural studies of test organisms conducted in conjunction with measurement of AChE inhibition will provide data to clarify the toxic effects caused by sublethal chemical concentrations of anti-cholinesterase compounds. PMID:20701973

  14. Modulation of histone deacetylase 6 (HDAC6) nuclear import and tubulin deacetylase activity through acetylation.

    PubMed

    Liu, Yuanjing; Peng, Lirong; Seto, Edward; Huang, Suming; Qiu, Yi

    2012-08-17

    The reversible acetylation of histones and non-histone proteins by histone acetyltransferases and deacetylases (HDACs) plays a critical role in many cellular processes in eukaryotic cells. HDAC6 is a unique histone deacetylase with two deacetylase domains and a C-terminal zinc finger domain. HDAC6 resides mainly in the cytoplasm and regulates many important biological processes, including cell migration and degradation of misfold proteins. HDAC6 has also been shown to localize in the nucleus to regulate transcription. However, how HDAC6 shuttles between the nucleus and cytoplasm is largely unknown. In addition, it is not clear how HDAC6 enzymatic activity is modulated. Here, we show that HDAC6 can be acetylated by p300 on five clusters of lysine residues. One cluster (site B) of acetylated lysine is in the N-terminal nuclear localization signal region. These lysine residues in site B were converted to glutamine to mimic acetylated lysines. The mutations significantly reduced HDAC6 tubulin deacetylase activity and further impaired cell motility, but had no effect on histone deacetylase activity. More interestingly, these mutations retained HDAC6 in the cytoplasm by blocking the interaction with the nuclear import protein importin-α. The retention of HDAC6 in the cytoplasm by acetylation eventually affects histone deacetylation. Thus, we conclude that acetylation is an important post-translational modification that regulates HDAC6 tubulin deacetylase activity and nuclear import.

  15. The HTLV-1-encoded protein HBZ directly inhibits the acetyl transferase activity of p300/CBP

    PubMed Central

    Wurm, Torsten; Wright, Diana G.; Polakowski, Nicholas; Mesnard, Jean-Michel; Lemasson, Isabelle

    2012-01-01

    The homologous cellular coactivators p300 and CBP contain intrinsic lysine acetyl transferase (termed HAT) activity. This activity is responsible for acetylation of several sites on the histones as well as modification of transcription factors. In a previous study, we found that HBZ, encoded by the Human T-cell Leukemia Virus type 1 (HTLV-1), binds to multiple domains of p300/CBP, including the HAT domain. In this study, we found that HBZ inhibits the HAT activity of p300/CBP through the bZIP domain of the viral protein. This effect correlated with a reduction of H3K18 acetylation, a specific target of p300/CBP, in cells expressing HBZ. Interestingly, lower levels of H3K18 acetylation were detected in HTLV-1 infected cells compared to non-infected cells. The inhibitory effect of HBZ was not limited to histones, as HBZ also inhibited acetylation of the NF-κB subunit, p65, and the tumor suppressor, p53. Recent studies reported that mutations in the HAT domain of p300/CBP that cause a defect in acetylation are found in certain types of leukemia. These observations suggest that inhibition of the HAT activity by HBZ is important for the development of adult T-cell leukemia associated with HTLV-1 infection. PMID:22434882

  16. Acetylation of glucokinase regulatory protein decreases glucose metabolism by suppressing glucokinase activity

    PubMed Central

    Park, Joo-Man; Kim, Tae-Hyun; Jo, Seong-Ho; Kim, Mi-Young; Ahn, Yong-Ho

    2015-01-01

    Glucokinase (GK), mainly expressed in the liver and pancreatic β-cells, is critical for maintaining glucose homeostasis. GK expression and kinase activity, respectively, are both modulated at the transcriptional and post-translational levels. Post-translationally, GK is regulated by binding the glucokinase regulatory protein (GKRP), resulting in GK retention in the nucleus and its inability to participate in cytosolic glycolysis. Although hepatic GKRP is known to be regulated by allosteric mechanisms, the precise details of modulation of GKRP activity, by post-translational modification, are not well known. Here, we demonstrate that GKRP is acetylated at Lys5 by the acetyltransferase p300. Acetylated GKRP is resistant to degradation by the ubiquitin-dependent proteasome pathway, suggesting that acetylation increases GKRP stability and binding to GK, further inhibiting GK nuclear export. Deacetylation of GKRP is effected by the NAD+-dependent, class III histone deacetylase SIRT2, which is inhibited by nicotinamide. Moreover, the livers of db/db obese, diabetic mice also show elevated GKRP acetylation, suggesting a broader, critical role in regulating blood glucose. Given that acetylated GKRP may affiliate with type-2 diabetes mellitus (T2DM), understanding the mechanism of GKRP acetylation in the liver could reveal novel targets within the GK-GKRP pathway, for treating T2DM and other metabolic pathologies. PMID:26620281

  17. Differences between male and female rhesus monkey erythrocyte acetylcholinesterase and plasma cholinesterase activity before and after exposure to sarin

    SciTech Connect

    Woodard, C.L.; Calamaio, C.A.; Kaminskis, A.; Anderson, D.R.; Harris, L.W.

    1993-05-13

    The female rhesus monkey has a menstrual cycle like the human. Additionally, several differences in enzyme levels between males and females and in the female during the menstrual cycle are present. Therefore we quantitated plasma cholinesterase (ChE/BuChE) and erythrocyte (RBC) acetylcholinesterase (AChE) activity before and after exposure to sarin (GB)(1 5 ug/kg, iv; a 0.75 LD50), in male and female rhesus (Macaca mulatta) monkeys. Twenty-eight-day preexposure baseline plasma ChE and RBC AChE values for six male and six female rhesus monkeys were compared for intra-animal, within sex and between sex differences. After these baseline values were obtained, the organophosphorus (OP) compound/Isopropyl methylphosphono-fluoridate (GB) was administered to atropinized monkeys to determine if there was a significant in vivo difference between the sexes in their response to this intoxication in regard to the rate of BuChE /AChE inhibition, pyridine-2-aldoxime methyl chloride (2-PAM) reactivation of the phosphonylated BuChE and the rate of aging of the phosphonylated:BuChE/AChE. In the pre-exposure portion of the protocol; the intra-animal and intra-group BuChE/AChE variations were found to be minimal; but there were significant differences between the male and female monkeys in both plasma BuChE and RBC AChE levels; although probably clinically insignificant in respect to an OP intoxication. No significant cyclic fluctuations were seen during the 28-day study in either sex.

  18. Aspirin inhibits glucose‑6‑phosphate dehydrogenase activity in HCT 116 cells through acetylation: Identification of aspirin-acetylated sites.

    PubMed

    Ai, Guoqiang; Dachineni, Rakesh; Kumar, D Ramesh; Alfonso, Lloyd F; Marimuthu, Srinivasan; Bhat, G Jayarama

    2016-08-01

    Glucose-6-phosphate dehydrogenase (G6PD) catalyzes the first reaction in the pentose phosphate pathway, and generates ribose sugars, which are required for nucleic acid synthesis, and nicotinamide adenine dinucleotide phosphate (NADPH), which is important for neutralization of oxidative stress. The expression of G6PD is elevated in several types of tumor, including colon, breast and lung cancer, and has been implicated in cancer cell growth. Our previous study demonstrated that exposure of HCT 116 human colorectal cancer cells to aspirin caused acetylation of G6PD, and this was associated with a decrease in its enzyme activity. In the present study, this observation was expanded to HT‑29 colorectal cancer cells, in order to compare aspirin‑mediated acetylation of G6PD and its activity between HCT 116 and HT‑29 cells. In addition, the present study aimed to determine the acetylation targets of aspirin on recombinant G6PD to provide an insight into the mechanisms of inhibition. The results demonstrated that the extent of G6PD acetylation was significantly higher in HCT 116 cells compared with in HT‑29 cells; accordingly, a greater reduction in G6PD enzyme activity was observed in the HCT 116 cells. Mass spectrometry analysis of aspirin‑acetylated G6PD (isoform a) revealed that aspirin acetylated a total of 14 lysine residues, which were dispersed throughout the length of the G6PD protein. One of the important amino acid targets of aspirin included lysine 235 (K235, in isoform a) and this corresponds to K205 in isoform b, which has previously been identified as being important for catalysis. Acetylation of G6PD at several sites, including K235 (K205 in isoform b), may mediate inhibition of G6PD activity, which may contribute to the ability of aspirin to exert anticancer effects through decreased synthesis of ribose sugars and NADPH. PMID:27356773

  19. Aspirin inhibits glucose‑6‑phosphate dehydrogenase activity in HCT 116 cells through acetylation: Identification of aspirin-acetylated sites.

    PubMed

    Ai, Guoqiang; Dachineni, Rakesh; Kumar, D Ramesh; Alfonso, Lloyd F; Marimuthu, Srinivasan; Bhat, G Jayarama

    2016-08-01

    Glucose-6-phosphate dehydrogenase (G6PD) catalyzes the first reaction in the pentose phosphate pathway, and generates ribose sugars, which are required for nucleic acid synthesis, and nicotinamide adenine dinucleotide phosphate (NADPH), which is important for neutralization of oxidative stress. The expression of G6PD is elevated in several types of tumor, including colon, breast and lung cancer, and has been implicated in cancer cell growth. Our previous study demonstrated that exposure of HCT 116 human colorectal cancer cells to aspirin caused acetylation of G6PD, and this was associated with a decrease in its enzyme activity. In the present study, this observation was expanded to HT‑29 colorectal cancer cells, in order to compare aspirin‑mediated acetylation of G6PD and its activity between HCT 116 and HT‑29 cells. In addition, the present study aimed to determine the acetylation targets of aspirin on recombinant G6PD to provide an insight into the mechanisms of inhibition. The results demonstrated that the extent of G6PD acetylation was significantly higher in HCT 116 cells compared with in HT‑29 cells; accordingly, a greater reduction in G6PD enzyme activity was observed in the HCT 116 cells. Mass spectrometry analysis of aspirin‑acetylated G6PD (isoform a) revealed that aspirin acetylated a total of 14 lysine residues, which were dispersed throughout the length of the G6PD protein. One of the important amino acid targets of aspirin included lysine 235 (K235, in isoform a) and this corresponds to K205 in isoform b, which has previously been identified as being important for catalysis. Acetylation of G6PD at several sites, including K235 (K205 in isoform b), may mediate inhibition of G6PD activity, which may contribute to the ability of aspirin to exert anticancer effects through decreased synthesis of ribose sugars and NADPH.

  20. Effect of acetylation on antioxidant and cytoprotective activity of polysaccharides isolated from pumpkin (Cucurbita pepo, lady godiva).

    PubMed

    Song, Yi; Yang, Yang; Zhang, Yuyu; Duan, Liusheng; Zhou, Chunli; Ni, Yuanying; Liao, Xiaojun; Li, Quanhong; Hu, Xiaosong

    2013-10-15

    Acetylation of pumpkin (Cucurbita pepo, lady godiva variety) polysaccharide using acetic anhydride with pyridines as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale. Furthermore, antioxidant activities and cytoprotective effects of pumpkin polysaccharide and its acetylated derivatives were investigated employing various established in vitro systems. Results showed that addition of pyridine as catalyst could increase the degree of substitution, whereas volume of acetic anhydride had little effect. The acetylated polysaccharides in DPPH scavenging radical activity assay, superoxide anion radical activity assay and reducing power assay exhibited higher antioxidant activity than that of unmodified polysaccharide. H2O2-induced oxidative damages on rat thymic lymphocyte were also prevented by pumpkin polysaccharide and its acetylated derivatives and the derivatives presented higher protective effects. On the whole, acetylated polysaccharide showed relevant antioxidant activity both in vitro and in a cell system.

  1. Application of brain cholinesterase reactivation to differentiate between organophosphorus and carbamate pesticide exposure in wild birds

    USGS Publications Warehouse

    Smith, M.R.; Thomas, N.J.; Hulse, C.

    1995-01-01

    Brain cholinesterase activity was measured to evaluate pesticide exposure in wild birds. Thermal reactivation of brain cholinesterase was used to differentiate between carbamate and organophosphorus pesticide exposure. Brain cholinesterase activity was compared with gas chromatography and mass spectrometry of stomach contents. Pesticides were identified and confirmed in 86 of 102 incidents of mortality from 29 states within the USA from 1986 through 1991. Thermal reactivation of cholinesterase activity was used to correctly predict carbamates in 22 incidents and organophosphates in 59 incidents. Agreement (P < 0.001) between predictions based on cholinesterase activities and GC/MS results was significant.

  2. Effect of temephos on cholinesterase activity in the earthworm Eisenia fetida (Oligochaeta, Lumbricidae).

    PubMed

    Hackenberger, Branimir K; Jarić-Perkusić, Davorka; Stepić, Sandra

    2008-10-01

    In this study, adult Eisenia fetida earthworms were exposed to the sub-lethal concentrations of temephos using the contact filter paper test procedure. Since temephos is an organophosphate pesticide, its effects on earthworms were determined by measuring ChE inhibition--a known biomarker of exposure. The ChE activity was measured after a short time of exposure--1 and 2 h. As expected, the lowest ChE activity (72.70% and 38.03% inhibition) was measured at the highest concentration of temephos (120 ng cm(-2)) applied. More interestingly, at the 0.12 ng cm(-2) concentration the ChE activity increased up to 36.28% of activity in the control in all three conducted experiments. Dose-response curves showed an inverted U-shape characteristic for hormesis. This hormetic-like effect could be important for health status of an earthworm.

  3. CORRELATIONS OF PESTICIDE-INDUCED CHOLINESTERASE INHIBITION AND MOTOR ACTIVITY CHANGES IN ADULT RATS.

    EPA Science Inventory

    The acute neurobehavioral effects of acetylcholinesterase-inhibiting pesticides are primarily due to overstimulation of the cholinergic system. Lowered motor activity levels represent a sensitive endpoint with which to monitor functional changes in laboratory animals exposed to ...

  4. The effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine, benzoylecgonine, ecgonine methyl ester, and norcocaine blood levels in pigs.

    PubMed

    Kambam, J; Mets, B; Hickman, R M; Janicki, P; James, M F; Fuller, B; Kirsch, R E

    1992-08-01

    We measured the blood levels of cocaine and its three major metabolites, benzoylecgonine, ecgonine methyl ester, and norcocaine, in three groups of male pigs weighing about 26 kg (25.75 +/- 0.25 kg) to determine the effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine metabolism. In addition, systemic elimination half-life, volume of distribution, and clearance of cocaine were calculated for the three groups. Group 1 pigs (n = 4) were pretreated with normal saline solution, group 2 pigs (n = 4) were pretreated with tetraisopropyl pyrophosphoramide, a specific plasma cholinesterase inhibitor, and group 3 pigs (n = 4) were pretreated with cimetidine, a hepatic microsomal enzyme inhibitor, all administered intramuscularly. Pigs were anesthetized with intravenous sodium thiopental; a carotid arterial cannula and an external jugular catheter were then inserted for the administration of cocaine and for blood sampling. Forty-five minutes later, when pigs were again completely awake, cocaine 3 mg/kg was given intravenously. Arterial blood samples were collected for the analysis of cocaine and cocaine metabolite levels just before and at 5, 10, 15, 30, 45, 60, 120, 180, and 1440 minutes after the administration of cocaine. Cocaine and cocaine metabolite blood levels were analyzed with high-pressure liquid chromatography methods and plasma cholinesterase activity was measured with a colorimetric method. The blood levels of cocaine and cocaine metabolites were significantly different among the three groups (p less than 0.05, analysis of variance). Statistically significant differences in half-life, volume of distribution and clearance were also seen among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Cohesin’s ATPase Activity Couples Cohesin Loading onto DNA with Smc3 Acetylation

    PubMed Central

    Ladurner, Rene; Bhaskara, Venugopal; Huis in ’t Veld, Pim J.; Davidson, Iain F.; Kreidl, Emanuel; Petzold, Georg; Peters, Jan-Michael

    2014-01-01

    Summary Background Cohesin mediates sister chromatid cohesion by topologically entrapping sister DNA molecules inside its ring structure. Cohesin is loaded onto DNA by the Scc2/NIPBL-Scc4/MAU2-loading complex in a manner that depends on the adenosine triphosphatase (ATPase) activity of cohesin’s Smc1 and Smc3 subunits. Subsequent cohesion establishment during DNA replication depends on Smc3 acetylation by Esco1 and Esco2 and on recruitment of sororin, which “locks” cohesin on DNA by inactivating the cohesin release factor Wapl. Results Human cohesin ATPase mutants associate transiently with DNA in a manner that depends on the loading complex but cannot be stabilized on chromatin by depletion of Wapl. These mutants cannot be acetylated, fail to interact with sororin, and do not mediate cohesion. The absence of Smc3 acetylation in the ATPase mutants is not a consequence of their transient association with DNA but is directly caused by their inability to hydrolyze ATP because acetylation of wild-type cohesin also depends on ATP hydrolysis. Conclusions Our data indicate that cohesion establishment involves the following steps. First, cohesin transiently associates with DNA in a manner that depends on the loading complex. Subsequently, ATP hydrolysis by cohesin leads to entrapment of DNA and converts Smc3 into a state that can be acetylated. Finally, Smc3 acetylation leads to recruitment of sororin, inhibition of Wapl, and stabilization of cohesin on DNA. Our finding that cohesin’s ATPase activity is required for both cohesin loading and Smc3 acetylation raises the possibility that cohesion establishment is directly coupled to the reaction in which cohesin entraps DNA. PMID:25220052

  6. Cholinesterase activity in black-crowned night-herons exposed to fenthion-treated water

    USGS Publications Warehouse

    Smith, G.J.; Spann, J.W.; Hill, E.F.

    1986-01-01

    Fenthion, (O,O-Dimethyl O-(3-methyl-4-(methylthio)phenyl) phosphorothioate), a widely used mosquito control agent, has caused wildlife mortality. To simulate a shallow wetland environment, an exposure chamber was used containing water treated with fenthion at 1 and 10 times the field application rate of 112 g active ingredient (AI)/ha. This system permitted an evaluation of exposure routes and the effects of fenthion in a representative species of wading bird, the black-crowned night-heron (Nycticorax nycticorax). The results suggested that herons received only a dermal exposure, and that their brain acetylcholinesterase activity was not significantly inhibited. In contrast, however, plasma butyrylcholinesterase activity was inhibited, suggesting the herons were exposed to the insecticide. The application rates and types of exposures were not life-threatening in this species.

  7. Cholinesterase inhibitors from botanicals

    PubMed Central

    Ahmed, Faiyaz; Ghalib, Raza Murad; Sasikala, P.; Ahmed, K. K. Mueen

    2013-01-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh), appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com) are also presented and the scope for future research is discussed. PMID:24347920

  8. Cholinesterase inhibitors from botanicals.

    PubMed

    Ahmed, Faiyaz; Ghalib, Raza Murad; Sasikala, P; Ahmed, K K Mueen

    2013-07-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh), appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com) are also presented and the scope for future research is discussed. PMID:24347920

  9. Labdane-type diterpenoids from Leonurus heterophyllus and their cholinesterase inhibitory activity.

    PubMed

    Hung, Tran Manh; Luan, Tran Cong; Vinh, Bui The; Cuong, To Dao; Min, Byung Sun

    2011-04-01

    In the course of screening plants used in natural medicines as memory enhancers, a 70% ethanol extract of the aerial parts of Leonurus heterophyllus showed significant AChE inhibitory activity. Bioassay-guided fractionation and repeated column chromatography led to the isolation of a new labdane-type diterpenoids (1), named leoheteronin F, and six known compounds (2-7). The chemical structures of isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data. The isolates 1-7 were investigated in vitro for their anticholinesterase activity using mouse cortex AChE enzyme. Leoheteronin A (5) and leopersin G (7), which possess a 15,16-epoxy group at the side chain, were found to be potent in the inhibition of AChE.

  10. Microwave assisted synthesis, cholinesterase enzymes inhibitory activities and molecular docking studies of new pyridopyrimidine derivatives.

    PubMed

    Basiri, Alireza; Murugaiyah, Vikneswaran; Osman, Hasnah; Kumar, Raju Suresh; Kia, Yalda; Ali, Mohamed Ashraf

    2013-06-01

    A series of hitherto unreported pyrido-pyrimidine-2-ones/pyrimidine-2-thiones were synthesized under microwave assisted solvent free reaction conditions in excellent yields and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Among the pyridopyrimidine derivatives, 7e and 7l displayed 2.5- and 1.5-fold higher enzyme inhibitory activities against AChE as compared to standard drug, galanthamine, with IC50 of 0.80 and 1.37 μM, respectively. Interestingly, all the compounds except 6k, 7j and 7k displayed higher inhibitory potential against BChE enzyme in comparison to standard with IC50 ranging from 1.18 to 18.90 μM. Molecular modeling simulations of 7e and 7l was performed using three-dimensional structure of Torpedo californica AChE (TcAChE) and human butyrylcholinesterase (hBChE) enzymes to disclose binding interaction and orientation of these molecule into the active site gorge of respective receptors.

  11. In vivo measurement of the acetylation state of sirtuin substrates as a proxy for sirtuin activity.

    PubMed

    Dominy, John; Puigserver, Pere; Cantó, Carles

    2013-01-01

    Evaluating the precise catalytic activity of sirtuin proteins in vivo is a challenging endeavor. Enzymological methods, including those employed in commercially available kits, require the isolation of immunopurified protein from cells or tissues, which can perturb regulatory protein-protein interactions as well as remove the enzyme from the reaction-altering effects of intracellular NAD(+), nicotinamide, and O-acetyl-ADP ribose concentrations. As such, the measurement of the steady state acetylation status of select sirtuin substrates in vivo remains an important tool for evaluating changes in sirtuin activity. Here, we describe how to perform the analysis of the acetylation status of key SIRT1 and SIRT3 targets in rodent tissues and cultured cells.

  12. Muscular cholinesterase activities and lipid peroxidation levels as biomarkers in several Mediterranean marine fish species and their relationship with ecological variables.

    PubMed

    Solé, Montserrat; Baena, Miguel; Arnau, Susana; Carrasson, Maite; Maynou, Francesc; Cartes, Joan E

    2010-02-01

    Muscular cholinesterase activities, as potential markers of neurotoxic exposure, and lipid peroxidation levels, indicative of oxidative stress damage, both currently used in early-warning pollution monitoring, were characterised in eighteen fish species of ecologic and/or economic importance. These species comprise five orders and eleven families of teleosts and two species of elasmobranchs, feed using different strategies (benthic, epibenthic, endobenthic and pelagic), belong to different trophic levels and express different swimming behaviour. Their habitat ranges from 50 to 60 m (shallow or continental shelf) and 600 to 850 m (middle continental slope). Sampling took place in front of the Barcelona coast (NW Mediterranean) during four seasonal cruises in 2007. In the summer sampling, another site potentially exposed to a different pollution load (Vilanova) was included for comparison. Species, seasonal and site differences were tested and discussed in relation to chemical analysis of the local sediment, systematic position, habitat depth, feeding strategy, trophic level and swimming activity. Greater inter species differences rather than seasonal or site trends were seen in accordance to little pollution fluctuations. Higher cholinesterase activities were recorded in suprabenthos feeders, regardless of depth habitat, whereas LP levels were similar in all species except for the shark Scyliorhinus canicula in which they were consistently elevated. This study confirms and broadens former observations carried out with a more reduced number of fish species (Solé et al., 2008a). PMID:20022635

  13. Abietane-type diterpenoids from the roots of Caryopteris mongolica and their cholinesterase inhibitory activities.

    PubMed

    Murata, Toshihiro; Ishikawa, Yoshinobu; Saruul, Erdenebileg; Selenge, Erdenechimeg; Sasaki, Kenroh; Umehara, Kaoru; Yoshizaki, Fumihiko; Batkhuu, Javzan

    2016-10-01

    Eleven abietane-type diterpenoids and two known abietanes were isolated from the roots of Caryopteris mongolica, and their structures were characterized. The absolute configurations at C-5 and C-10 were determined from the NMR data, including from the nuclear Overhauser effect and CD spectra, and the absolute configuration of C-16 in the hydroxypropyl group was determined via a modified Mosher's method. Furthermore, the previously unknown absolute configuration of the C-15 of cyrtophyllone B was determined to be in an R-configuration using X-ray crystallography. To estimate the preventive effects of the isolates for neurodegenerative disease development, their inhibitory activities against acetylcholinesterase (AChE) from human erythrocytes and butyrylcholinesterase (BChE) from horse serum were evaluated.

  14. Abietane-type diterpenoids from the roots of Caryopteris mongolica and their cholinesterase inhibitory activities.

    PubMed

    Murata, Toshihiro; Ishikawa, Yoshinobu; Saruul, Erdenebileg; Selenge, Erdenechimeg; Sasaki, Kenroh; Umehara, Kaoru; Yoshizaki, Fumihiko; Batkhuu, Javzan

    2016-10-01

    Eleven abietane-type diterpenoids and two known abietanes were isolated from the roots of Caryopteris mongolica, and their structures were characterized. The absolute configurations at C-5 and C-10 were determined from the NMR data, including from the nuclear Overhauser effect and CD spectra, and the absolute configuration of C-16 in the hydroxypropyl group was determined via a modified Mosher's method. Furthermore, the previously unknown absolute configuration of the C-15 of cyrtophyllone B was determined to be in an R-configuration using X-ray crystallography. To estimate the preventive effects of the isolates for neurodegenerative disease development, their inhibitory activities against acetylcholinesterase (AChE) from human erythrocytes and butyrylcholinesterase (BChE) from horse serum were evaluated. PMID:27298275

  15. Effects of motor patterns on water-soluble and membrane proteins and cholinesterase activity in subcellular fractions of rat brain tissue

    NASA Technical Reports Server (NTRS)

    Pevzner, L. Z.; Venkov, L.; Cheresharov, L.

    1980-01-01

    Albino rats were kept for a year under conditions of daily motor load or constant hypokinesia. An increase in motor activity results in a rise in the acetylcholinesterase activity determined in the synaptosomal and purified mitochondrial fractions while hypokinesia induces a pronounced decrease in this enzyme activity. The butyrylcholinesterase activity somewhat decreases in the synaptosomal fraction after hypokinesia but does not change under the motor load pattern. Motor load causes an increase in the amount of synaptosomal water-soluble proteins possessing an intermediate electrophoretic mobility and seem to correspond to the brain-specific protein 14-3-2. In the synaptosomal fraction the amount of membrane proteins with a low electrophoretic mobility and with the cholinesterase activity rises. Hypokinesia, on the contrary, decreases the amount of these membrane proteins.

  16. Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

    SciTech Connect

    Biswas, Arunima; Pasquel, Danielle; Tyagi, Rakesh Kumar; Mani, Sridhar

    2011-03-18

    Research highlights: {yields} Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. {yields} PXR undergoes dynamic deacetylation upon ligand-mediated activation. {yields} SIRT1 partially mediates PXR deacetylation. {yields} PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependent functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.

  17. Endo-N-acetyl-beta-D-glucosaminidase and peptide-N4-(N-acetyl-glucosaminyl) asparagine amidase activities during germination of Raphanus sativus.

    PubMed

    Berger, S; Menudier, A; Julien, R; Karamanos, Y

    1995-06-01

    Endo-N-acetyl-beta-D-glucosaminidase (ENGase, EC 3.2.1.96) and peptide-N4-(N-acetyl-beta-D-glucosaminyl) asparagine amidase (PNGase, EC 3.5.1.52) activities were monitored during germination and postgerminative development in Raphanus sativus. The PNGase activity was found in dry seeds and its level was constant during germination and postgermination. The ENGase activity was first detected about 18 hr after the start of imbibition (HAI) and displayed a maximum level at 36 HAI. After 36 HAI the production of both enzymes was constant until days 4-5. Both enzymes displayed substrate specificities corresponding to the potential glycoprotein substrates found in plants. They are in agreement (i) with the hypothesis that ENGase and PNGase are at the origin of the production of 'unconjugated N-glycans' and (ii) with the possibility that protein activity could be regulated by the removal of N-glycans.

  18. Romidepsin reduces histone deacetylase activity, induces acetylation of histones, inhibits proliferation, and activates apoptosis in immortalized epithelial endometriotic cells.

    PubMed

    Imesch, Patrick; Fink, Daniel; Fedier, André

    2010-12-01

    Romidepsin inhibited HDAC activity, produced acetylation of the histone proteins, up-regulated p21, and down-regulated cyclins B1 and D1, resulting in proliferation inhibition and apoptosis activation in 11z immortalized epithelial endometriotic cells. Our findings provide evidence that endometriotic cells are sensitive to the epigenetic effects of romidepsin and suggest that endometriosis may be therapeutically targeted by romidepsin.

  19. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  20. Acetylation of steroidogenic factor 1 protein regulates its transcriptional activity and recruits the coactivator GCN5.

    PubMed

    Jacob, A L; Lund, J; Martinez, P; Hedin, L

    2001-10-01

    Steroidogenic factor-1 (SF-1) is an orphan nuclear receptor that plays an essential role in the development of the hypothalamic-pituitary-gonadal axis in both sexes. SF-1 belongs to the hormone nuclear receptor superfamily and possesses an N-terminal DNA binding domain and a C-terminal ligand binding domain. Activation function domain 2 is located C-terminal of the ligand binding domain of SF-1 and is important for the transactivation of target genes. Coactivators with histone acetyltransferase activity such as cAMP response element-binding protein-binding protein and steroid receptor coactivator 1 interact and increase SF-1-mediated transcriptional activity. In this study we demonstrate that SF-1 is acetylated in vivo. Histone acetyltransferase GCN5 acetylates SF-1 in vitro. Moreover, we found that SF-1 recruited a novel coactivator GCN5, which can be a newly identified coactivator for SF-1. Acetylation of SF-1 stimulates its transcriptional activity. Inhibition of deacetylation by trichostatin A, a histone deacetylase inhibitor, increased SF-1-mediated transactivation and stabilized and induced the nuclear export of the SF-1 protein.

  1. Reversible lysine acetylation is involved in DNA replication initiation by regulating activities of initiator DnaA in Escherichia coli

    PubMed Central

    Zhang, Qiufen; Zhou, Aiping; Li, Shuxian; Ni, Jinjing; Tao, Jing; Lu, Jie; Wan, Baoshan; Li, Shuai; Zhang, Jian; Zhao, Shimin; Zhao, Guo-Ping; Shao, Feng; Yao, Yu-Feng

    2016-01-01

    The regulation of chromosomal replication is critical and the activation of DnaA by ATP binding is a key step in replication initiation. However, it remains unclear whether and how the process of ATP-binding to DnaA is regulated. Here, we show that DnaA can be acetylated, and its acetylation level varies with cell growth and correlates with DNA replication initiation frequencies in E. coli. Specifically, the conserved K178 in Walker A motif of DnaA can be acetylated and its acetylation level reaches the summit at the stationary phase, which prevents DnaA from binding to ATP or oriC and leads to inhibition of DNA replication initiation. The deacetylation process of DnaA is catalyzed by deacetylase CobB. The acetylation process of DnaA is mediated by acetyltransferase YfiQ, and nonenzymatically by acetyl-phosphate. These findings suggest that the reversible acetylation of DnaA ensures cells to respond promptly to environmental changes. Since Walker A motif is universally distributed across organisms, acetylation of Walker A motif may present a novel regulatory mechanism conserved from bacteria to eukaryotes. PMID:27484197

  2. Acetylation and carboxymethylation of the polysaccharide from Ganoderma atrum and their antioxidant and immunomodulating activities.

    PubMed

    Chen, Yi; Zhang, Hui; Wang, Yuanxing; Nie, Shaoping; Li, Chang; Xie, Mingyong

    2014-08-01

    A water-soluble polysaccharide extracted from Ganoderma atrum was chemically modified to obtain its acetyled and carboxymethylated derivatives. The results of chemical analysis, Fourier-transform infrared and (13)C nuclear magnetic resonance spectroscopy showed that these modifications were successful, although the molecular weight of these derivatives decreased due to slight degradation during the reaction. The antioxidant and immunomodulating activities of these derivatives were then investigated to determine the structure-bioactivity relationship. Results showed that the acetyled derivative with appropriate degree of substitution and lower molecular weight exhibited stronger antioxidant abilities on scavenging DPPH radical, and inhibitory effects in β-carotene-linoleic acid systems compared with the native polysaccharide. In addition, it also enhanced the macrophage phagocytosis capacity and tumor necrosis factor-α secretion, whereas the carboxymethylated derivative was shown to be slightly less effective. These results indicated that the type of substitution group and their degree of substitution play a decisive role in the bioactivities of the derivatives.

  3. Amino acid sequence of human cholinesterase. Annual report, 30 September 1984-30 September 1985

    SciTech Connect

    Lockridge, O.

    1985-10-01

    The active-site serine residue is located 198 amino acids from the N-terminal. The active-site peptide was isolated from three different genetic types of human serum cholinesterase: from usual, atypical, and atypical-silent genotypes. It was found that the amino acid sequence of the active-site peptide was identical in all three genotypes. Comparison of the complete sequences of cholinesterase from human serum and acetylcholinesterase from the electric organ of Torpedo californica shows an identity of 53%. Cholinesterase is of interest to the Department of Defense because cholinesterase protects against organophosphate poisons of the type used in chemical warfare. The structural results presented here will serve as the basis for cloning the gene for cholinesterase. The potential uses of large amounts of cholinesterase would be for cleaning up spills of organophosphates and possibly for detoxifying exposed personnel.

  4. Acetylation of Lysine92 Improves the Chaperone and Anti-apoptotic Activities of Human αB-Crystallin

    PubMed Central

    Nahomi, Rooban B.; Huang, Rong; Nandi, Sandip K.; Wang, Benlian; Padmanabha, Smitha; Santhoshkumar, Puttur; Filipek, Slawomir; Biswas, Ashis; Nagaraj, Ram H.

    2013-01-01

    αB-Crystallin is a chaperone and an anti-apoptotic protein that is highly expressed in many tissues, including the lens, retina, heart and kidney. In the human lens, several lysine residues in αB-crystallin are acetylated. We have previously shown that such acetylation is predominant at lysine92 (K92) and K166. We have investigated the effect of lysine acetylation on the structure and functions of αB-crystallin by the specific introduction of an Nε-acetyllysine (AcK) mimic at K92. The introduction of AcK slightly altered the secondary and tertiary structures of the protein. AcK introduction also resulted in an increase in the molar mass and hydrodynamic radius of the protein, and the protein became structurally more open and more stable than the native protein. The acetyl protein acquired higher surface hydrophobicity and exhibited 25-55% higher chaperone activity than the native protein. The acetyl protein had higher client protein binding per subunit of the protein and higher binding affinity relative to the native protein. The acetyl protein was at least 20% more effective in inhibiting chemically induced apoptosis than the native protein. Molecular modeling suggests that acetylation of K92 makes the ‘α-crystallin domain’ more hydrophobic. Together, our results reveal that the acetylation of a single lysine residue in αB-crystallin makes the protein structurally more stable and improves its chaperone and anti-apoptotic activities. Our findings suggest that lysine acetylation of αB-crystallin is an important chemical modification to enhance αB-crystallin’s protective functions in the eye. PMID:24128140

  5. SIRT3-dependent GOT2 acetylation status affects the malate-aspartate NADH shuttle activity and pancreatic tumor growth.

    PubMed

    Yang, Hui; Zhou, Lisha; Shi, Qian; Zhao, Yuzheng; Lin, Huaipeng; Zhang, Mengli; Zhao, Shimin; Yang, Yi; Ling, Zhi-Qiang; Guan, Kun-Liang; Xiong, Yue; Ye, Dan

    2015-04-15

    The malate-aspartate shuttle is indispensable for the net transfer of cytosolic NADH into mitochondria to maintain a high rate of glycolysis and to support rapid tumor cell growth. The malate-aspartate shuttle is operated by two pairs of enzymes that localize to the mitochondria and cytoplasm, glutamate oxaloacetate transaminases (GOT), and malate dehydrogenases (MDH). Here, we show that mitochondrial GOT2 is acetylated and that deacetylation depends on mitochondrial SIRT3. We have identified that acetylation occurs at three lysine residues, K159, K185, and K404 (3K), and enhances the association between GOT2 and MDH2. The GOT2 acetylation at these three residues promotes the net transfer of cytosolic NADH into mitochondria and changes the mitochondrial NADH/NAD(+) redox state to support ATP production. Additionally, GOT2 3K acetylation stimulates NADPH production to suppress ROS and to protect cells from oxidative damage. Moreover, GOT2 3K acetylation promotes pancreatic cell proliferation and tumor growth in vivo. Finally, we show that GOT2 K159 acetylation is increased in human pancreatic tumors, which correlates with reduced SIRT3 expression. Our study uncovers a previously unknown mechanism by which GOT2 acetylation stimulates the malate-aspartate NADH shuttle activity and oxidative protection. PMID:25755250

  6. SIRT3-dependent GOT2 acetylation status affects the malate–aspartate NADH shuttle activity and pancreatic tumor growth

    PubMed Central

    Yang, Hui; Zhou, Lisha; Shi, Qian; Zhao, Yuzheng; Lin, Huaipeng; Zhang, Mengli; Zhao, Shimin; Yang, Yi; Ling, Zhi-Qiang; Guan, Kun-Liang; Xiong, Yue; Ye, Dan

    2015-01-01

    The malate–aspartate shuttle is indispensable for the net transfer of cytosolic NADH into mitochondria to maintain a high rate of glycolysis and to support rapid tumor cell growth. The malate–aspartate shuttle is operated by two pairs of enzymes that localize to the mitochondria and cytoplasm, glutamate oxaloacetate transaminases (GOT), and malate dehydrogenases (MDH). Here, we show that mitochondrial GOT2 is acetylated and that deacetylation depends on mitochondrial SIRT3. We have identified that acetylation occurs at three lysine residues, K159, K185, and K404 (3K), and enhances the association between GOT2 and MDH2. The GOT2 acetylation at these three residues promotes the net transfer of cytosolic NADH into mitochondria and changes the mitochondrial NADH/NAD+ redox state to support ATP production. Additionally, GOT2 3K acetylation stimulates NADPH production to suppress ROS and to protect cells from oxidative damage. Moreover, GOT2 3K acetylation promotes pancreatic cell proliferation and tumor growth in vivo. Finally, we show that GOT2 K159 acetylation is increased in human pancreatic tumors, which correlates with reduced SIRT3 expression. Our study uncovers a previously unknown mechanism by which GOT2 acetylation stimulates the malate–aspartate NADH shuttle activity and oxidative protection. PMID:25755250

  7. HDAC3-dependent reversible lysine acetylation of cardiac myosin heavy chain isoforms modulates their enzymatic and motor activity.

    PubMed

    Samant, Sadhana A; Courson, David S; Sundaresan, Nagalingam R; Pillai, Vinodkumar B; Tan, Minjia; Zhao, Yingming; Shroff, Sanjeev G; Rock, Ronald S; Gupta, Mahesh P

    2011-02-18

    Reversible lysine acetylation is a widespread post-translational modification controlling the activity of proteins in different subcellular compartments. We previously demonstrated that a class II histone deacetylase (HDAC), HDAC4, and a histone acetyltransferase, PCAF, associate with cardiac sarcomeres, and a class I and II HDAC inhibitor, trichostatin A, enhances contractile activity of myofilaments. In this study, we show that a class I HDAC, HDAC3, is also present at cardiac sarcomeres. By immunohistochemical and electron microscopic analyses, we found that HDAC3 was localized to the A band of sarcomeres and was capable of deacetylating myosin heavy chain (MHC) isoforms. The motor domains of both cardiac α- and β-MHC isoforms were found to be reversibly acetylated. Biomechanical studies revealed that lysine acetylation significantly decreased the K(m) for the actin-activated ATPase activity of both α- and β-MHC isoforms. By an in vitro motility assay, we found that lysine acetylation increased the actin sliding velocity of α-myosin by 20% and β-myosin by 36%, compared to their respective non-acetylated isoforms. Moreover, myosin acetylation was found to be sensitive to cardiac stress. During induction of hypertrophy, myosin isoform acetylation increased progressively with duration of stress stimuli, independent of isoform shift, suggesting that lysine acetylation of myosin could be an early response of myofilaments to increase contractile performance of the heart. These studies provide the first evidence for localization of HDAC3 at myofilaments and uncover a novel mechanism modulating the motor activity of cardiac MHC isoforms.

  8. MRG15 activates the cdc2 promoter via histone acetylation in human cells

    SciTech Connect

    Pena, AndreAna N.; Tominaga, Kaoru; Pereira-Smith, Olivia M.

    2011-07-01

    Chromatin remodeling is required for transcriptional activation and repression. MRG15 (MORF4L1), a chromatin modulator, is a highly conserved protein and is present in complexes containing histone acetyltransferases (HATs) as well as histone deacetylases (HDACs). Loss of expression of MRG15 in mice and Drosophila results in embryonic lethality and fibroblast and neural stem/progenitor cells cultured from Mrg15 null mouse embryos exhibit marked proliferative defects when compared with wild type cells. To determine the role of MRG15 in cell cycle progression we performed chromatin immunoprecipitation with an antibody to MRG15 on normal human fibroblasts as they entered the cell cycle from a quiescent state, and analyzed various cell cycle gene promoters. The results demonstrated a 3-fold increase in MRG15 occupancy at the cdc2 promoter during S phase of the cell cycle and a concomitant increase in acetylated histone H4. H4 lysine 12 was acetylated at 24 h post-serum stimulation while there was no change in acetylation of lysine 16. HDAC1 and 2 were decreased at this promoter during cell cycle progression. Over-expression of MRG15 in HeLa cells activated a cdc2 promoter-reporter construct in a dose-dependent manner, whereas knockdown of MRG15 resulted in decreased promoter activity. In order to implicate HAT activity, we treated cells with the HAT inhibitor anacardic acid and determined that HAT inhibition results in loss of expression of cdc2 mRNA. Further, chromatin immunoprecipitation with Tip60 localizes the protein to the same 110 bp stretch of the cdc2 promoter pulled down by MRG15. Additionally, we determined that cotransfection of MRG15 with the known associated HAT Tip60 had a cooperative effect in activating the cdc2 promoter. These results suggest that MRG15 is acting in a HAT complex involving Tip60 to modify chromatin via acetylation of histone H4 at the cdc2 promoter to activate transcription.

  9. Three novel acetylation sites in the Foxp3 transcription factor regulate the suppressive activity of regulatory T cells

    PubMed Central

    Kwon, Hye-Sook; Lim, Hyung W.; Wu, Jessica; Schnoelzer, Martina; Verdin, Eric; Ott, Melanie

    2012-01-01

    The Foxp3 transcription factor is the master regulator of regulatory T cell (Treg) differentiation and function. Its activity is regulated by reversible acetylation. Using mass spectrometry of immunoprecipitated proteins, we identify three novel acetylation sites in murine Foxp3 (K31, K262, and K267) and the corresponding sites in human FoxP3 proteins. Newly raised modification-specific antibodies against acetylated K31 and K267 confirm acetylation of these residues in murine Tregs. Mutant Foxp3 proteins carrying arginine substitutions at the three acetylation sites (3KR) accumulate in T cells to higher levels than wildtype Foxp3 and exert better suppressive activity in co-culture experiments. Acetylation and stability of wildtype, but not mutant, Foxp3 is enhanced when cells are treated with Ex-527, an inhibitor of the NAD+-dependent deacetylase SIRT1. Treatment with Ex-527 promotes Foxp3 expression during induced Treg differentiation, enhances Foxp3 levels in natural Tregs, and prevents loss of Foxp3 expression in adoptively transferred Tregs in mice. Our data identify SIRT1 as a negative regulator of Treg function via deacetylation of three novel target sites in Foxp3. SIRT1 inhibitors strengthen the suppressive activity of Tregs and may be useful in enhancing Treg-based therapeutic approaches to autoimmune diseases or graft rejections. PMID:22312127

  10. NeuA sialic acid O-acetylesterase activity modulates O-acetylation of capsular polysaccharides in Group B Streptococcus

    PubMed Central

    Lewis, Amanda L.; Cao, Hongzhi; Patel, Silpa K.; Diaz, Sandra; Ryan, Wesley; Carlin, Aaron F.; Thon, Vireak; Lewis, Warren G.; Varki, Ajit; Chen, Xi; Nizet, Victor

    2008-01-01

    Group B Streptococcus (GBS) is a common cause of neonatal sepsis and meningitis. A major GBS virulence determinant is its sialic acid (Sia)-capped capsular polysaccharide (CPS). Recently, we discovered the presence and genetic basis of capsular Sia O-acetylation in GBS. We now characterize a GBS Sia O-acetylesterase that modulates the degree of GBS surface O-acetylation. The GBS Sia O-acetylesterase operates cooperatively with the GBS CMP-Sia synthetase, both part of a single polypeptide encoded by the neuA gene. NeuA de-O-acetylation of free 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac2) was enhanced by CTP and Mg2+, the substrate and co-factor respectively of the N-terminal GBS CMP-Sia synthetase domain. In contrast, the homologous bi-functional NeuA esterase from E. coli K1 did not display cofactor dependence. Further analyses showed that in vitro, GBS NeuA can operate via two alternate enzymatic pathways: de-O-acetylation of Neu5,9Ac2, followed by CMP-activation of Neu5Ac; or, activation of Neu5,9Ac2, then de-O-acetylation of CMP-Neu5,9Ac2. Consistent with in vitro esterase assays, genetic deletion of GBS neuA led to accumulation of intracellular O-acetylated Sias, and over-expression of GBS NeuA reduced O-acetylation of Sias on the bacterial surface. Site-directed mutagenesis of conserved asparagine residue 301 abolished esterase activity, but preserved CMP-Sia synthetase activity, as evidenced by hyper-O-acetylation of CPS Sias on GBS expressing only the N301A NeuA allele. These studies demonstrate a novel mechanism regulating the extent of capsular Sia O-acetylation in intact bacteria, and provide a genetic strategy for manipulating GBS O-acetylation, in order to explore the role of this modification in GBS pathogenesis and immunogenicity. PMID:17646166

  11. Acetylated Triterpene Glycosides and Their Biological Activity from Holothuroidea Reported in the Past Six Decades

    PubMed Central

    Bahrami, Yadollah; Franco, Christopher M. M.

    2016-01-01

    Sea cucumbers have been valued for many centuries as a tonic and functional food, dietary delicacies and important ingredients of traditional medicine in many Asian countries. An assortment of bioactive compounds has been described in sea cucumbers. The most important and abundant secondary metabolites from sea cucumbers are triterpene glycosides (saponins). Due to the wide range of their potential biological activities, these natural compounds have gained attention and this has led to their emergence as high value compounds with extended application in nutraceutical, cosmeceutical, medicinal and pharmaceutical products. They are characterized by bearing a wide spectrum of structures, such as sulfated, non-sulfated and acetylated glycosides. Over 700 triterpene glycosides have been reported from the Holothuroidea in which more than 145 are decorated with an acetoxy group having 38 different aglycones. The majority of sea cucumber triterpene glycosides are of the holostane type containing a C18 (20) lactone group and either Δ7(8) or Δ9(11) double bond in their genins. The acetoxy group is mainly connected to the C-16, C-22, C-23 and/or C-25 of their aglycone. Apparently, the presence of an acetoxy group, particularly at C-16 of the aglycone, plays a significant role in the bioactivity; including induction of caspase, apoptosis, cytotoxicity, anticancer, antifungal and antibacterial activities of these compounds. This manuscript highlights the structure of acetylated saponins, their biological activity, and their structure-activity relationships. PMID:27527190

  12. Acetylated Triterpene Glycosides and Their Biological Activity from Holothuroidea Reported in the Past Six Decades.

    PubMed

    Bahrami, Yadollah; Franco, Christopher M M

    2016-01-01

    Sea cucumbers have been valued for many centuries as a tonic and functional food, dietary delicacies and important ingredients of traditional medicine in many Asian countries. An assortment of bioactive compounds has been described in sea cucumbers. The most important and abundant secondary metabolites from sea cucumbers are triterpene glycosides (saponins). Due to the wide range of their potential biological activities, these natural compounds have gained attention and this has led to their emergence as high value compounds with extended application in nutraceutical, cosmeceutical, medicinal and pharmaceutical products. They are characterized by bearing a wide spectrum of structures, such as sulfated, non-sulfated and acetylated glycosides. Over 700 triterpene glycosides have been reported from the Holothuroidea in which more than 145 are decorated with an acetoxy group having 38 different aglycones. The majority of sea cucumber triterpene glycosides are of the holostane type containing a C18 (20) lactone group and either Δ(7(8)) or Δ(9(11)) double bond in their genins. The acetoxy group is mainly connected to the C-16, C-22, C-23 and/or C-25 of their aglycone. Apparently, the presence of an acetoxy group, particularly at C-16 of the aglycone, plays a significant role in the bioactivity; including induction of caspase, apoptosis, cytotoxicity, anticancer, antifungal and antibacterial activities of these compounds. This manuscript highlights the structure of acetylated saponins, their biological activity, and their structure-activity relationships. PMID:27527190

  13. Multitarget-directed tricyclic pyridazinones as G protein-coupled receptor ligands and cholinesterase inhibitors.

    PubMed

    Pau, Amedeo; Catto, Marco; Pinna, Giovanni; Frau, Simona; Murineddu, Gabriele; Asproni, Battistina; Curzu, Maria M; Pisani, Leonardo; Leonetti, Francesco; Loza, Maria Isabel; Brea, José; Pinna, Gérard A; Carotti, Angelo

    2015-06-01

    By following a multitarget ligand design approach, a library of 47 compounds was prepared, and they were tested as binders of selected G protein-coupled receptors (GPCRs) and inhibitors of acetyl and/or butyryl cholinesterase. The newly designed ligands feature pyridazinone-based tricyclic scaffolds connected through alkyl chains of variable length to proper amine moieties (e.g., substituted piperazines or piperidines) for GPCR and cholinesterase (ChE) molecular recognition. The compounds were tested at three different GPCRs, namely serotoninergic 5-HT1A, adrenergic α1A, and dopaminergic D2 receptors. Our main goal was the discovery of compounds that exhibit, in addition to ChE inhibition, antagonist activity at 5-HT1A because of its involvement in neuronal deficits typical of Alzheimer's and other neurodegenerative diseases. Ligands with nanomolar affinity for the tested GPCRs were discovered, but most of them behaved as dual antagonists of α1A and 5-HT1A receptors. Nevertheless, several compounds displaying this GPCR affinity profile also showed moderate to good inhibition of AChE and BChE, thus deserving further investigations to exploit the therapeutic potential of such unusual biological profiles.

  14. Releasing Activity Disengages Cohesin's Smc3/Scc1 Interface in a Process Blocked by Acetylation.

    PubMed

    Beckouët, Frederic; Srinivasan, Madhusudhan; Roig, Maurici Brunet; Chan, Kok-Lung; Scheinost, Johanna C; Batty, Paul; Hu, Bin; Petela, Naomi; Gligoris, Thomas; Smith, Alexandra C; Strmecki, Lana; Rowland, Benjamin D; Nasmyth, Kim

    2016-02-18

    Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesin's Scc1, Smc1, and Smc3 subunits is created during S and destroyed at anaphase through Scc1 cleavage by separase. Cohesin's association with chromosomes is controlled by opposing activities: loading by Scc2/4 complex and release by a separase-independent releasing activity as well as by cleavage. Coentrapment of sister DNAs at replication is accompanied by acetylation of Smc3 by Eco1, which blocks releasing activity and ensures that sisters remain connected. Because fusion of Smc3 to Scc1 prevents release and bypasses the requirement for Eco1, we suggested that release is mediated by disengagement of the Smc3/Scc1 interface. We show that mutations capable of bypassing Eco1 in Smc1, Smc3, Scc1, Wapl, Pds5, and Scc3 subunits reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from Smc3. This process involves interaction between Smc ATPase heads and is inhibited by Smc3 acetylation. PMID:26895425

  15. Acetylation of MnSOD directs enzymatic activity responding to cellular nutrient status or oxidative stress.

    PubMed

    Ozden, Ozkan; Park, Seong-Hoon; Kim, Hyun-Seok; Jiang, Haiyan; Coleman, Mitchell C; Spitz, Douglas R; Gius, David

    2011-02-01

    A fundamental observation in biology is that mitochondrial function, as measured by increased reactive oxygen species (ROS), changes significantly with age, suggesting a potential mechanistic link between the cellular processes governing longevity and mitochondrial metabolism homeostasis. In addition, it is well established that altered ROS levels are observed in multiple age-related illnesses including carcinogenesis, neurodegenerative, fatty liver, insulin resistance, and cardiac disease, to name just a few. Manganese superoxide dismutase (MnSOD) is the primary mitochondrial ROS scavenging enzyme that converts superoxide to hydrogen peroxide, which is subsequently converted to water by catalase and other peroxidases. It has recently been shown that MnSOD enzymatic activity is regulated by the reversible acetylation of specific, evolutionarily conserved lysine(s) in the protein. These results, suggest for the first time, that the mitochondria contain bidirectional post-translational signaling networks, similar to that observed in the cytoplasm and nucleus, and that changes in lysine acetylation alter MnSOD enzymatic activity. In addition, these new results demonstrate that the mitochondrial anti-aging or fidelity / sensing protein, SIRT3, responds to changes in mitochondrial nutrient and/or redox status to alter the enzymatic activity of specific downstream targets, including MnSOD that adjusts and/or maintains ROS levels as well as metabolic homeostatic poise. PMID:21386137

  16. Cholinesterase risk for Iowa farmers.

    PubMed

    Helmers, S; Dykstra, J; Kemp, B

    1990-02-01

    Exposure to organophosphate insecticides may pose a significant risk in rural populations. The study involved 71 Iowa farmers and 28 agribusiness workers who underwent serial measurements of serum cholinesterase levels prior to and following exposure to organophosphate containing pesticides.

  17. DEVELOPMENT OF REFERENCE RANGES FOR PLASMA TOTAL CHOLINESTERASE AND BRAIN ACETYLCHOLINESTERASE ACTIVITY IN FREE-RANGING CARNABY'S BLACK-COCKATOOS (CALYPTORHYNCHUS LATIROSTRIS).

    PubMed

    Vaughan-Higgins, Rebecca; Vitali, Simone; Reiss, Andrea; Besier, Shane; Hollingsworth, Tom; Smith, Gerard

    2016-07-01

    Published avian reference ranges for plasma cholinesterase (ChE) and brain acetylcholinesterase (AChE) are numerous. However, a consistently reported recommendation is the need for species- and laboratory-specific reference ranges because of variables, including assay methods, sample storage conditions, season, and bird sex, age, and physiologic status. We developed normal reference ranges for brain AChE and plasma total ChE (tChE) activity for Carnaby's Black-Cockatoos (Calyptorhynchus latirostris) using a standardized protocol (substrate acetylthiocholine at 25 C). We report reference ranges for brain AChE (19-41 μmol/min per g, mean 21±6.38) and plasma tChE (0.41-0.53 μmol/min per mL, mean 0.47±0.11) (n=15). This information will be of use in the ongoing field investigation of a paresis-paralysis syndrome in the endangered Carnaby's Black-Cockatoos, suspected to be associated with exposure to anticholinesterase compounds and add to the paucity of reference ranges for plasma tChE and brain AChE in Australian psittacine birds.

  18. Cholinesterase activity in the tissues of bivalves Noah's ark shell (Arca noae) and warty venus (Venus verrucosa): characterisation and in vitro sensitivity to organophosphorous pesticide trichlorfon.

    PubMed

    Perić, Lorena; Ribarić, Luka; Nerlović, Vedrana

    2013-08-01

    Cholinesterase (ChE, EC 3.1.1.7) activity was investigated in gills and adductor muscle of two bivalve species: Arca noae and Venus verrucosa. The properties of ChEs were investigated using acetylcholine iodide (ASCh), butyrylcholine iodide (BSCh) and propionylcholine iodide (PrSCh) as substrates and eserine, BW254c51 and iso-OMPA as specific inhibitors. The highest level of ChE activity in crude tissue extracts was detected with PrSCh followed by ASCh, while values obtained with BSCh were apparently low, except in A. noae adductor muscle. The enzyme activity in A. noae gills and V. verrucosa gills and adductor muscle was significantly inhibited by BW254c51, but not with iso-OMPA. ChE activity in adductor muscle of A. noae was significantly reduced by both diagnostic inhibitors. The effect of organophosphorous pesticide trichlorfon on ChE activity was investigated in vitro in both species as well as in the gills of mussels Mytilus galloprovincialis. The highest sensitivity of ChE to trichlorfon was observed in A. noae gills and adductor muscle (IC50 1.6×10(-7)M and 1.1×10(-7)M, respectively), followed by M. galloprovincialis gills (IC50 1.0×10(-6)M) and V. verrucosa gills and adductor muscle (IC50 1.7×10(-5)M and 0.9×10(-5)M, respectively). The results of this study suggest the potential of ChE activity measurement in the tissues of A. noae as effective biomarker of OP exposure in marine environment.

  19. Cholinesterase and glutathione S-transferase activities of three mollusc species from the NW Portuguese coast in relation to the 'Prestige' oil spill.

    PubMed

    Tim-Tim, Ana L S; Morgado, Fernando; Moreira, Susana; Rangel, Rui; Nogueira, António J A; Soares, Amadeu M V M; Guilhermino, Lúcia

    2009-12-01

    In November 2002, the tanker 'Prestige' released about 19,000 tonnes of a heavy fuel oil (no. 6) before sinking with about 58,000 tonnes of its cargo, 135 miles from Cabo Finisterra (Spain). A considerable part of the released fuel oil reached the Galician coast, causing a heavy black tide and an ecological disaster. Although the black tide did not reach the NW coast of Portugal, it is possible that some of the fuel oil or its components also arrived to this area directly through the sea water and/or indirectly through the food chain. Therefore, the aim of this study was to investigate possible changes in two widely used biomarkers, the activity of the enzymes cholinesterases (ChE) and glutathione S-transferases (GST), of three molluscs (Mytilus galloprovincialis, Nucella lapillus and Monodonta lineata) from wild populations of the NW Portuguese coast in relation to the 'Prestige' oil spill. Molluscs were collected seasonally before (autumn 2002) and after (winter 2002/2003), spring and summer 2003) the oil spill at several sites along the Portuguese NW coast. Enzymatic activities determined before the accident were compared with those determined at different times after the oil spill taking into consideration abiotic factors. Information from different parameters was integrated by Redundancy Analysis and Principal Response Curves (PRC). Results show that GST and ChE activities were influenced by abiotic factors. Despite this influence, the results of PRC analysis also suggest that some of the fuel oil reached the NW Portuguese coast changing the patterns of ChE and GST activities of local populations of rocky shore species. Furthermore, the present study highlights the need of long-term monitoring with wild populations to assess both historical and punctual effects of pollution in the marine environment.

  20. Histone acetylation influences the transcriptional activation of POX in Beta vulgaris L. and Beta maritima L. under salt stress.

    PubMed

    Yolcu, Seher; Ozdemir, Filiz; Güler, Aybüke; Bor, Melike

    2016-03-01

    Acetylation of histone proteins is a type of chromatin modification which facilitates the activation of genes. Recent studies brought up the importance of this reversible and rapid process for the regulation of gene expression especially in plant defense against a variety of environmental stresses. Deciphering the exact mechanisms of chromatin modifications under abiotic stress conditions is important for improving crop plants' performance and yield. In a previous study we compared the salt stress responses of Beta vulgaris (sugar beet) and Beta maritima (wild beet). In accordance with those results we suggested that chromatin remodeling can be an active process in the regulation of genes related to salt stress tolerance of these plants. Therefore we performed ChIP assay in control and salt stressed (250 and 500 mM NaCl) plants and compared the enrichment of acetylation in the associated chromatin sites. We found that the transcriptional activation of one peroxidase (POX) encoding gene was associated with the elevated levels of acetylation in H3K9 and H3K27 sites. The acetylation patterns were remarkably different between two species in which the highest acetylation levels were found at H3K9 and H3K27 in wild beet and sugar beet respectively. PMID:26773543

  1. Histone acetylation influences the transcriptional activation of POX in Beta vulgaris L. and Beta maritima L. under salt stress.

    PubMed

    Yolcu, Seher; Ozdemir, Filiz; Güler, Aybüke; Bor, Melike

    2016-03-01

    Acetylation of histone proteins is a type of chromatin modification which facilitates the activation of genes. Recent studies brought up the importance of this reversible and rapid process for the regulation of gene expression especially in plant defense against a variety of environmental stresses. Deciphering the exact mechanisms of chromatin modifications under abiotic stress conditions is important for improving crop plants' performance and yield. In a previous study we compared the salt stress responses of Beta vulgaris (sugar beet) and Beta maritima (wild beet). In accordance with those results we suggested that chromatin remodeling can be an active process in the regulation of genes related to salt stress tolerance of these plants. Therefore we performed ChIP assay in control and salt stressed (250 and 500 mM NaCl) plants and compared the enrichment of acetylation in the associated chromatin sites. We found that the transcriptional activation of one peroxidase (POX) encoding gene was associated with the elevated levels of acetylation in H3K9 and H3K27 sites. The acetylation patterns were remarkably different between two species in which the highest acetylation levels were found at H3K9 and H3K27 in wild beet and sugar beet respectively.

  2. [THE CHOLINESTERASE OF BLOOD SERUM IN WORKERS OF INDUSTRIAL ENTERPRISE].

    PubMed

    Radamishina, G G; Bakirov, A B; Gimranova, G G; Valeeva, O V

    2015-08-01

    The biochemical study of activity of serum cholinesterase in workers of industrial enterprise was carried out on the example of petrochemical industry. The indicators of average activity of enzyme and prevalence of indicators going beyond limits of reference values were analyzed depending on manufacturing-labor experience, profession and diseases established in workers. The main diseases, professional and labor experience groups were identified where activity of cholinesterase significantly changes. The impact of labor experience and profession on level of activity ofenzyme in blood serum is demonstrated. PMID:26596043

  3. Antistaphylococcal and biofilm inhibitory activities of acetyl-11-keto-β-boswellic acid from Boswellia serrata

    PubMed Central

    2011-01-01

    Background Boswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus Boswellia. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays. Results AKBA was found to be the most active compound showing an MIC range of 2-8 μg/ml against the entire gram positive bacterial pathogens tested. It exhibited concentration dependent killing of Staphylococcus aureus ATCC 29213 up to 8 × MIC and also demonstrated postantibiotic effect (PAE) of 4.8 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S. aureus and Staphylococcus epidermidis and also reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide and leakage of 260 and 280 nm absorbing material by AKBA treated cells of S aureus indicating that the antibacterial mode of action of AKBA probably occurred via disruption of microbial membrane structure. Conclusions This study supported the potential use of AKBA in treating S. aureus infections. AKBA can be further exploited to evolve potential lead compounds in the discovery of new anti-Gram-positive and anti-biofilm agents. PMID:21406118

  4. Sensitivity of brain cholinesterase activity to diazinon (BASUDIN 50EC) and fenobucarb (BASSA 50EC) insecticides in the air-breathing fish Channa striata (Bloch, 1793).

    PubMed

    Van Cong, Nguyen; Phuong, Nguyen Thanh; Bayley, Mark

    2006-05-01

    With the expansion of agricultural areas within the Mekong River Delta in Vietnam, a concurrent, dramatic increase has occurred in agrochemical usage. To date, little consideration has been given to the negative impacts of this agricultural activity on the aquatic resources of the region. Both acute toxicity and subacute effects on brain cholinesterase (ChE) of two of the most commonly used insecticides, diazinon and fenobucarb, on adult native snakehead (Channa striata) were evaluated in a static, nonrenewable system, the environmental parameters of which, such as dissolved oxygen, water temperature, and pH, fluctuated similarly to field conditions. Four levels of insecticides, from 0.008 to 0.52 mg/L (for diazinon) and from 0.11 to 9.35 mg/L (for fenobucarb), were tested to assess the effects on the brain ChE activity of the snakehead up to 30 and 10 d for diazinon and fenobucarb, respectively. Diazinon was highly toxic to this fish species, with a 96-h median lethal concentration (LC50) of only 0.79 mg/L, and it also caused long-term ChE inhibition, with activity still significantly inhibited by 30% after 30 d for the three highest concentrations. Fenobucarb was less toxic to this species, with a 96-h LC50 of 11.4 mg/L. Fenobucarb caused more rapid ChE inhibition but also rapid recovery. The results of the present study indicate an urgent need to regulate the usage of these pesticides in the Mekong River Delta. PMID:16704077

  5. Dynamic Competing Histone H4 K5K8 Acetylation and Butyrylation Are Hallmarks of Highly Active Gene Promoters

    PubMed Central

    Goudarzi, Afsaneh; Zhang, Di; Huang, He; Barral, Sophie; Kwon, Oh Kwang; Qi, Shankang; Tang, Zhanyun; Buchou, Thierry; Vitte, Anne-Laure; He, Tieming; Cheng, Zhongyi; Montellier, Emilie; Gaucher, Jonathan; Curtet, Sandrine; Debernardi, Alexandra; Charbonnier, Guillaume; Puthier, Denis; Petosa, Carlo; Panne, Daniel; Rousseaux, Sophie; Roeder, Robert G.; Zhao, Yingming; Khochbin, Saadi

    2016-01-01

    Summary Recently discovered histone lysine acylation marks increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters where acetylation guides the binding of Brdt, a bromodomain-containing protein, thereby mediating stage-specific gene expression programs and post-meiotic chromatin reorganization. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbor competing histone acetylation and butyrylation marks at H4 K5 and H4 K8. Despite acting as a direct stimulator of transcription, histone butyrylation competes with acetylation, especially at H4 K5, to prevent Brdt binding. Additionally, H4 K5K8 butyrylation also marks retarded histone removal during late spermatogenesis. Hence, alternating H4 acetylation and butyrylation, while sustaining direct gene activation and dynamic bromodomain binding, could impact the final male epigenome features. PMID:27105113

  6. Dynamic Competing Histone H4 K5K8 Acetylation and Butyrylation Are Hallmarks of Highly Active Gene Promoters.

    PubMed

    Goudarzi, Afsaneh; Zhang, Di; Huang, He; Barral, Sophie; Kwon, Oh Kwang; Qi, Shankang; Tang, Zhanyun; Buchou, Thierry; Vitte, Anne-Laure; He, Tieming; Cheng, Zhongyi; Montellier, Emilie; Gaucher, Jonathan; Curtet, Sandrine; Debernardi, Alexandra; Charbonnier, Guillaume; Puthier, Denis; Petosa, Carlo; Panne, Daniel; Rousseaux, Sophie; Roeder, Robert G; Zhao, Yingming; Khochbin, Saadi

    2016-04-21

    Recently discovered histone lysine acylation marks increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters where acetylation guides the binding of Brdt, a bromodomain-containing protein, thereby mediating stage-specific gene expression programs and post-meiotic chromatin reorganization. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbor competing histone acetylation and butyrylation marks at H4 K5 and H4 K8. Despite acting as a direct stimulator of transcription, histone butyrylation competes with acetylation, especially at H4 K5, to prevent Brdt binding. Additionally, H4 K5K8 butyrylation also marks retarded histone removal during late spermatogenesis. Hence, alternating H4 acetylation and butyrylation, while sustaining direct gene activation and dynamic bromodomain binding, could impact the final male epigenome features. PMID:27105113

  7. Design, Synthesis and Structure-Activity Relationship (SAR) Studies of 2,4-Disubstituted Pyrimidine Derivatives: Dual Activity as Cholinesterase and Aβ-Aggregation Inhibitors

    PubMed Central

    Mohamed, Tarek; Zhao, Xiaobei; Habib, Lila K.; Yang, Jerry; Rao, Praveen P. N.

    2011-01-01

    A novel class of 2,4-disubstituted pyrimidines (7a–u, 8a–f, 9a–e) that possess substituents with varying steric and electronic properties at the C-2 and C-4 positions, were designed, synthesized and evaluated as dual cholinesterase and amyloid-β (Aβ)-aggregation inhibitors. In vitro screening identified N-(naphth-1-ylmethyl)-2-(pyrrolidin-1-yl)pyrimidin-4-amine (9a) as the most potent AChE inhibitor (IC50 = 5.5 μM). Among this class of compounds, 2-(4-methylpiperidin-1-yl)-N-(naphth-1-ylmethyl)pyrimidin-4-amine (9e) was identified as the most potent and selective BuChE inhibitor (IC50 = 2.2 μM, Selectivity Index = 11.7) and was about 5.7-fold more potent compared to the commercial, approved reference drug galanthamine (BuChE IC50 = 12.6 μM). In addition, the selective AChE inhibitor N-benzyl-2-(4-methylpiperazin-1-yl)pyrimidin-4-amine (7d), exhibited good inhibition of hAChE-induced aggregation of Aβ1–40 fibrils (59% inhibition). Furthermore, molecular modeling studies indicate that a central pyrimidine ring serves as a suitable template to develop dual inhibitors of cholinesterase and AChE-induced Aβ aggregation thereby targeting multiple pathological routes in AD. PMID:21429752

  8. Insulin stimulates the dephosphorylation and activation of acetyl-CoA carboxylase

    SciTech Connect

    Witters, L.A.; Watts, T.D.; Daniels, D.L.; Evans, J.L. )

    1988-08-01

    The mechanism underlying the ability of insulin to acutely activate acetyl-CoA carboxylase has been examined in Fao Reuber hepatoma cells. Insulin promotes the rapid activation of AcCoACase, as measured in cell lysates, and this stimulation persists to the same degree after isolation of AcCoACase by avidin-Sepharose chromatography. The insulin-stimulated enzyme, as compared with control enzyme, exhibits an increase in both citrate-independent and -dependent activity and a decrease in the K{sub a} for citrate. Direct examination of the phosphorylation state of isolated {sup 32}P-labeled AcCoACase after insulin exposure reveals a marked decrease in total enzyme phosphorylation coincident with activation. The dephosphorylation due to insulin appears to be restricted to the phosphorylation sites previously shown to regulate AcCoACase activity. All of these effects of insulin are mimicked by a low molecular weight autocrine factor, tentatively identified as an oligosaccharide, present in conditioned medium of hepatoma cells. These data suggest that insulin may activate AcCoACase by inhibiting the activity of protein kinase(s) or stimulating the activity of protein phosphatase(s) that control the phosphorylation state of the enzyme.

  9. Silent cholinesterase gene: variations in the properties of serum enzyme in apparent homozygotes

    PubMed Central

    Rubinstein, H. M.; Dietz, A. A.; Hodges, L. K.; Lubrano, T.; Czebotar, V.

    1970-01-01

    The cholinesterase activity of the sera of 25 subjects diagnosed as homozygotes for the silent cholinesterase gene was studied by a sensitive enzymatic method employing several thiocholine esters and various inhibitors, and by disc electrophoretic, immunochemical, and chromatographic methods. (a) With one exception, the sera fell into two classes by all criteria. One class (type I, 16 cases) had no normal serum cholinesterase. The other class (type II, eight cases) had about 2% of apparently normal serum cholinesterase. The remaining serum was intermediate between the two classes in several respects. One explanation for these results is that there are several “silent” genes concerned; possibly these are allelic. (b) Normal sera and all silent sera contain small amounts of a cholinesterase activity labeled the residual cholinesterase. The enzyme(s) responsible has properties similar to those of acetylcholinesterase rather than serum cholinesterase. It is estimated that about 1% of the activity of normal serum against acetylthiocholine is due to this enzyme. The source of the residual cholinesterase is not yet known. Images PMID:4984470

  10. The carboxylesterase/cholinesterase gene family in invertebrate deuterostomes.

    PubMed

    Johnson, Glynis; Moore, Samuel W

    2012-06-01

    Carboxylesterase/cholinesterase family members are responsible for controlling the nerve impulse, detoxification and various developmental functions, and are a major target of pesticides and chemical warfare agents. Comparative structural analysis of these enzymes is thus important. The invertebrate deuterostomes (phyla Echinodermata and Hemichordata and subphyla Urochordata and Cephalochordata) lie in the transition zone between invertebrates and vertebrates, and are thus of interest to the study of evolution. Here we have investigated the carboxylesterase/cholinesterase gene family in the sequenced genomes of Strongylocentrotus purpuratus (Echinodermata), Saccoglossus kowalevskii (Hemichordata), Ciona intestinalis (Urochordata) and Branchiostoma floridae (Cephalochordata), using sequence analysis of the catalytic apparatus and oligomerisation domains, and phylogenetic analysis. All four genomes show blurring of structural boundaries between cholinesterases and carboxylesterases, with many intermediate enzymes. Non-enzymatic proteins are well represented. The Saccoglossus and Branchiostoma genomes show evidence of extensive gene duplication and retention. There is also evidence of domain shuffling, resulting in multidomain proteins consisting either of multiple carboxylesterase domains, or of carboxylesterase/cholinesterase domains linked to other domains, including RING finger, chitin-binding, immunoglobulin, fibronectin type 3, CUB, cysteine-rich-Frizzled, caspase activation and 7tm-1, amongst others. Such gene duplication and domain shuffling in the carboxylesterase/cholinesterase family appears to be unique to the invertebrate deuterostomes, and we hypothesise that these factors may have contributed to the evolution of the morphological complexity, particularly of the nervous system and neural crest, of the vertebrates. PMID:22210164

  11. The carboxylesterase/cholinesterase gene family in invertebrate deuterostomes.

    PubMed

    Johnson, Glynis; Moore, Samuel W

    2012-06-01

    Carboxylesterase/cholinesterase family members are responsible for controlling the nerve impulse, detoxification and various developmental functions, and are a major target of pesticides and chemical warfare agents. Comparative structural analysis of these enzymes is thus important. The invertebrate deuterostomes (phyla Echinodermata and Hemichordata and subphyla Urochordata and Cephalochordata) lie in the transition zone between invertebrates and vertebrates, and are thus of interest to the study of evolution. Here we have investigated the carboxylesterase/cholinesterase gene family in the sequenced genomes of Strongylocentrotus purpuratus (Echinodermata), Saccoglossus kowalevskii (Hemichordata), Ciona intestinalis (Urochordata) and Branchiostoma floridae (Cephalochordata), using sequence analysis of the catalytic apparatus and oligomerisation domains, and phylogenetic analysis. All four genomes show blurring of structural boundaries between cholinesterases and carboxylesterases, with many intermediate enzymes. Non-enzymatic proteins are well represented. The Saccoglossus and Branchiostoma genomes show evidence of extensive gene duplication and retention. There is also evidence of domain shuffling, resulting in multidomain proteins consisting either of multiple carboxylesterase domains, or of carboxylesterase/cholinesterase domains linked to other domains, including RING finger, chitin-binding, immunoglobulin, fibronectin type 3, CUB, cysteine-rich-Frizzled, caspase activation and 7tm-1, amongst others. Such gene duplication and domain shuffling in the carboxylesterase/cholinesterase family appears to be unique to the invertebrate deuterostomes, and we hypothesise that these factors may have contributed to the evolution of the morphological complexity, particularly of the nervous system and neural crest, of the vertebrates.

  12. Cholinesterase Inhibitors for Lewy Body Disorders: A Meta-Analysis

    PubMed Central

    Yasue, Ichiro; Iwata, Nakao

    2016-01-01

    Background: We performed a meta-analysis of cholinesterase inhibitors for patients with Lewy body disorders, such as Parkinson’s disease, Parkinson’s disease dementia, and dementia with Lewy bodies. Methods: The meta-analysis included only randomized controlled trials of cholinesterase inhibitors for Lewy body disorders. Results: Seventeen studies (n = 1798) were assessed. Cholinesterase inhibitors significantly improved cognitive function (standardized mean difference [SMD] = −0.53], behavioral disturbances (SMD = −0.28), activities of daily living (SMD = −0.28), and global function (SMD = −0.52) compared with control treatments. Changes in motor function were not significantly different from control treatments. Furthermore, the cholinesterase inhibitor group had a higher all-cause discontinuation (risk ratio [RR] = 1.48, number needed to harm [NNH] = 14), discontinuation due to adverse events (RR = 1.59, NNH = 20), at least one adverse event (RR = 1.13, NNH = 11), nausea (RR = 2.50, NNH = 13), and tremor (RR = 2.30, NNH = 20). Conclusions: Cholinesterase inhibitors appear beneficial for the treatment of Lewy body disorders without detrimental effects on motor function. However, a careful monitoring of treatment compliance and side effects is required. PMID:26221005

  13. Influence of acetylation degree and molecular weight of homogeneous chitosans on antibacterial and antifungal activities.

    PubMed

    Younes, Islem; Sellimi, Sabrine; Rinaudo, Marguerite; Jellouli, Kemel; Nasri, Moncef

    2014-08-18

    The results given in the literature are conflicting when considering the relationship between antimicrobial activity and chitosan characteristics. To be able to clarify, we prepared fifteen homogeneous chitosans with different acetylation degrees (DA) and molecular weights (MW) by reacetylation of a fully deacetylated chitin under homogeneous conditions. They were tested at different pH values for their antimicrobial activities against four Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella typhi), four Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Micrococcus luteus) and three fungi (Aspergillus niger, Fusarium oxysporum and Alternaria solani). Chitosans markedly inhibited growth of most bacteria and fungi tested, although the inhibitory effect depends on the type of microorganism and on the chitosan characteristics (DA and MW) with minimum inhibitory concentrations in the range of 0.001 to 0.1 w%. Considering chitosan efficiency on bacteria, our series of data clearly show that the lower DA and the lower pH give the larger efficiency. Antibacterial activity was further enhanced for Gram-negative bacteria with decreasing MW, whereas, opposite effect was observed with the Gram-positive. Concerning the antifungal activity, the influence of chitosan characteristics was dependent on the particular type of fungus. Fungal growth decreased with increasing MW for F. oxysporum and decreasing DA for A. solani, but no MW or DA dependences were observed with A. niger. PMID:24929684

  14. Inhibitory activity of synthesized acetylated Procyanidin B1 analogs against HeLa S3 cells proliferation.

    PubMed

    Okamoto, Syuhei; Ishihara, Sayaka; Okamoto, Taisuke; Doi, Syoma; Harui, Kota; Higashino, Yusuke; Kawasaki, Takashi; Nakajima, Noriyuki; Saito, Akiko

    2014-01-01

    Proanthocyanidins, also known as condensed tannins and/or oligomeric flavonoids, occur in many edible plants and have various interesting biological activities. Previously, we reported a synthetic method for the preparation of various procyanidins in pure form and described their biological activities. Here, we describe the synthesis of procyanidin B1 acetylated analogs and discuss their inhibition activities against HeLa S3 cell proliferation. Surprisingly, the lower-unit acetylated procyanidin B1 strongly inhibited the proliferation of HeLa S3 cells. This molecule showed much stronger inhibitory activity than did epigallocatechin-3-O-gallate (EGCG), green tea polyphenol, and dimeric compounds that included EGCG as a unit. This result suggests that the phenolic hydroxyl groups of the upper-units in flavan-3-ols are important for their inhibitory activity against cancer cell proliferation and that a hydrophobic lower unit dimer enhances this activity. PMID:24500007

  15. Activity of cholinesterases of blood and heart in rats of different sex and age during muscular loads and hypokinesia

    NASA Technical Reports Server (NTRS)

    Rozanova, V. D.; Antonova, G. A.

    1979-01-01

    The activity of acetylcholinesterase (Ache) and butyrilcholinesterase (Bche) in the blood and the heart of 3 and 13 month old control male rats is considerably lower than in female rats. In 25 month old rats, no sex differences in the Ache and Bche were revealed in the heart. In 3 and 13 month old male and female rats, under conditions of muscular exercises, the Ache and Bche activity is lower, and in hypokinetic male rats -- higher than that in respective control animals. In all the rats, irrespective of sex, age, and motor conditions, Ache and Bche activity tended to decrease from the sinoatrial node to the heart apex.

  16. Synthesis, structural studies and biological activity of new Cu(II) complexes with acetyl derivatives of 7-hydroxy-4-methylcoumarin.

    PubMed

    Klepka, Marcin T; Drzewiecka-Antonik, Aleksandra; Wolska, Anna; Rejmak, Paweł; Ostrowska, Kinga; Hejchman, Elżbieta; Kruszewska, Hanna; Czajkowska, Agnieszka; Młynarczuk-Biały, Izabela; Ferenc, Wiesława

    2015-04-01

    The new Cu(II) complexes with 6-acetyl-7-hydroxy-4-methylcoumarin (HL1) and 8-acetyl-7-hydroxy-4-methylcoumarin (HL2) have been obtained by the electrochemical method. The density functional theory calculations and X-ray absorption spectroscopy techniques have been used to geometrically describe a series of new compounds. The studies have been focused on the coordination mode of the hydroxy ligands to the metallic centre. The complexes, Cu(HL1)2 and Cu(HL2)2⋅0.5H2O, have flat square geometry with oxygen atoms in the first coordination sphere. Two bidentate anionic coumarins are bonded to the metal cation via the acetyl and deprotonated hydroxyl O atoms. Biological activity, including microbiological and cytotoxic, has been evaluated and found to be enhanced in comparison with the parent ligands. Moreover, the Cu(II) complex with 8-acetyl-7-hydroxy-4-methylcoumarin shows similar antifungal activity as commercially used fluconazole.

  17. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis. [quantitative structure-activity relationship, complete neglect of differential overlap

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of cationic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR-primeP(O)X, where R and R-prime are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrolysis rate constant.

  18. Keap1-Independent Regulation of Nrf2 Activity by Protein Acetylation and a BET Bromodomain Protein

    PubMed Central

    Chatterjee, Nirmalya; Tian, Min; Spirohn, Kerstin; Boutros, Michael; Bohmann, Dirk

    2016-01-01

    Mammalian BET proteins comprise a family of bromodomain-containing epigenetic regulators with complex functions in chromatin organization and gene regulation. We identified the sole member of the BET protein family in Drosophila, Fs(1)h, as an inhibitor of the stress responsive transcription factor CncC, the fly ortholog of Nrf2. Fs(1)h physically interacts with CncC in a manner that requires the function of its bromodomains and the acetylation of CncC. Treatment of cultured Drosophila cells or adult flies with fs(1)h RNAi or with the BET protein inhibitor JQ1 de-represses CncC transcriptional activity and engages protective gene expression programs. The mechanism by which Fs(1)h inhibits CncC function is distinct from the canonical mechanism that stimulates Nrf2 function by abrogating Keap1-dependent proteasomal degradation. Consistent with the independent modes of CncC regulation by Keap1 and Fs(1)h, combinations of drugs that can specifically target these pathways cause a strong synergistic and specific activation of protective CncC- dependent gene expression and boosts oxidative stress resistance. This synergism might be exploitable for the design of combinatorial therapies to target diseases associated with oxidative stress or inflammation. PMID:27233051

  19. Keap1-Independent Regulation of Nrf2 Activity by Protein Acetylation and a BET Bromodomain Protein.

    PubMed

    Chatterjee, Nirmalya; Tian, Min; Spirohn, Kerstin; Boutros, Michael; Bohmann, Dirk

    2016-05-01

    Mammalian BET proteins comprise a family of bromodomain-containing epigenetic regulators with complex functions in chromatin organization and gene regulation. We identified the sole member of the BET protein family in Drosophila, Fs(1)h, as an inhibitor of the stress responsive transcription factor CncC, the fly ortholog of Nrf2. Fs(1)h physically interacts with CncC in a manner that requires the function of its bromodomains and the acetylation of CncC. Treatment of cultured Drosophila cells or adult flies with fs(1)h RNAi or with the BET protein inhibitor JQ1 de-represses CncC transcriptional activity and engages protective gene expression programs. The mechanism by which Fs(1)h inhibits CncC function is distinct from the canonical mechanism that stimulates Nrf2 function by abrogating Keap1-dependent proteasomal degradation. Consistent with the independent modes of CncC regulation by Keap1 and Fs(1)h, combinations of drugs that can specifically target these pathways cause a strong synergistic and specific activation of protective CncC- dependent gene expression and boosts oxidative stress resistance. This synergism might be exploitable for the design of combinatorial therapies to target diseases associated with oxidative stress or inflammation. PMID:27233051

  20. The energetics of the acetylation switch in p53-mediated transcriptional activation.

    PubMed

    Eichenbaum, Kenneth D; Rodríguez, Yoel; Mezei, Mihaly; Osman, Roman

    2010-02-01

    Targeted therapeutic intervention in receptor-ligand interactions of p53-mediated tumor suppression can impact progression of disease, aging, and variation in genetic expression. Here, we conducted a number of molecular simulations, based on structures of p53 in complex with its transcriptional coactivating CBP bromodomain, determined by NMR spectroscopy, to investigate the energetics of the binding complex. Building on the observation that acetylation of K382 in p53 serves as the essential triggering switch for a specific interaction with CBP, we assessed the differential effect of acetylation on binding from simulations of an octapeptide derived from p53 with acetylated and nonacetylated K382 (residues 379-386). Cluster analysis of the simulations shows that acetylation of the free peptide does not significantly change the population of the preferred conformation of the peptide in solution for binding to CBP. Conversion of the acetylated K382 to nonacetylated form with free energy perturbation (FEP) simulations of the p53 CBP complex and the free peptide showed that the relative contribution of the acetyl group to binding is 4.8 kcal/mol. An analysis of residue contributions to the binding energy using an MM-GBSA approach agrees with the FEP results and sheds additional light on the origin of selectivity in p53 binding to the CBP bromodomain.

  1. PPARα Activation Induces Nε-Lys-Acetylation of Rat Liver Peroxisomal Multifunctional Enzyme Type 1

    PubMed Central

    Contreras, Miguel A.; Alzate, Oscar; Singh, Avtar K.

    2013-01-01

    Peroxisomes are ubiquitous subcellular organelles that participate in metabolic and disease processes, with few of its proteins undergoing posttranslational modifications. As the role of lysine-acetylation has expanded into the cellular intermediary metabolism, we used a combination of differential centrifugation, organelle isolation by linear density gradient centrifugation, western blot analysis, and peptide fingerprinting and amino acid sequencing by mass spectrometry to investigate protein acetylation in control and ciprofibrate-treated rat liver peroxisomes. Organelle protein samples isolated by density gradient centrifugation from PPARα-agonist treated rat liver screened with an anti-Nε-acetyl lysine antibody revealed a single protein band of 75 kDa. Immunoprecipitation with this antibody resulted in the precipitation of a protein from the protein pool of ciprofibrate-induced peroxisomes, but not from the protein pool of non-induced peroxisomes. Peptide mass fingerprinting analysis identified the protein as the peroxisomal multifunctional enzyme type 1. In addition, mass spectrometry-based amino acid sequencing resulted in the identification of unique peptides containing 4 acetylated-Lys residues (K155, K173, K190, and K583). This is the first report that demonstrates posttranslational acetylation of a peroxisomal enzyme in PPARα-dependent proliferation of peroxisomes in rat liver. PMID:24092543

  2. Salicylanilide diethyl phosphates as cholinesterases inhibitors.

    PubMed

    Krátký, Martin; Štěpánková, Šárka; Vorčáková, Katarína; Vinšová, Jarmila

    2015-02-01

    Based on the presence of dialkyl phosphate moiety, we evaluated twenty-seven salicylanilide diethyl phosphates (diethyl [2-(phenylcarbamoyl)phenyl] phosphates) for the inhibition of acetylcholinesterase (AChE) from electric eel (Electrophorus electricus L.) and butyrylcholinesterase (BChE) from equine serum. Ellman's spectrophotometric method was used. The inhibitory activity (expressed as IC50 values) was compared with that of the established drugs galantamine and rivastigmine. Salicylanilide diethyl phosphates showed significant activity against both cholinesterases with IC50 values from 0.903 to 86.3 μM. IC50s for BChE were comparatively lower than those obtained for AChE. All of the investigated compounds showed higher inhibition of AChE than rivastigmine, and six of them inhibited BChE more effectively than both rivastigmine and galantamine. In general, derivatives of 4-chlorosalicylic acid showed enhanced activity when compared to derivatives of 5-halogenated salicylic acids, especially against BChE. The most effective inhibitor of AChE was O-{5-chloro-2-[(3-bromophenyl)carbamoyl]phenyl} O,O-diethyl phosphate with IC50 of 35.4 μM, which is also one of the most potent inhibitors of BChE. O-{5-Chloro-2-[(3,4-dichlorophenyl)carbamoyl]phenyl} O,O-diethyl phosphate exhibited in vitro the strongest inhibition of BChE (0.90 μM). Salicylanilide diethyl phosphates act as pseudo-irreversible cholinesterases inhibitors. PMID:25462625

  3. Comparative brain cholinesterase-inhibiting activity of Glycyrrhiza glabra, Myristica fragrans, ascorbic acid, and metrifonate in mice.

    PubMed

    Dhingra, Dinesh; Parle, Milind; Kulkarni, S K

    2006-01-01

    The central cholinergic pathways play a prominent role in the learning and memory processes. Acetylcholinesterase is an enzyme that inactivates acetylcholine. The present study was undertaken to estimate the acetylcholinesterase- inhibiting activity of extracts of Glycyrrhiza glabra, Myristica fragrans seeds, and ascorbic acid and compare these values with a standard acetylcholinesterase-inhibiting drug, metrifonate. Aqueous extract of G. glabra (150 mg/kg p.o. for 7 successive days), n-hexane extract of M. fragrans seeds (5 mg/kg p.o. for 3 successive days), ascorbic acid (60 mg/kg i.p. for 3 successive days), and metrifonate (50 mg/kg i.p.) were administered to young male Swiss albino mice. Acetylcholinesterase enzyme was estimated in brains of mice. G. glabra, M. fragrans, ascorbic acid, and metrifonate significantly decreased acetylcholinesterase activity as compared with their respective vehicle-treated control groups.

  4. Brain regional acetylcholinesterase activity and muscarinic acetylcholine receptors in rats after repeated administration of cholinesterase inhibitors and its withdrawal

    SciTech Connect

    Kobayashi, Haruo . E-mail: hk1664@iwate-u.ac.jp; Suzuki, Tadahiko; Sakamoto, Maki; Hashimoto, Wataru; Kashiwada, Keiko; Sato, Itaru; Akahori, Fumiaki; Satoh, Tetsuo

    2007-03-15

    Activity of acetylcholinesterase (AChE) and specific binding of [{sup 3}H]quinuclidinyl benzilate (QNB), [{sup 3}H]pirenzepine (PZP) and [{sup 3}H]AF-DX 384 to muscarinic acetylcholine receptor (mAChR) preparations in the striatum, hippocampus and cortex of rats were determined 1, 6 and 11 days after the last treatment with an organophosphate DDVP, a carbamate propoxur or a muscarinic agonist oxotremorine as a reference for 7 and 14 days. AChE activity was markedly decreased in the three regions 1 day after the treatment with DDVP for 7 and 14 days with a gradual recovery 6 to 11 days, and much less decreased 1, 6 and 11 days after the treatment with propoxur for 7 days but not for 14 days in the hippocampus and cortex. The binding of [{sup 3}H]-QNB, PZP and AF-DX 384 in the three regions was generally decreased by the treatment with DDVP for 7 and 14 days. Such down-regulations were generally restored 6 or 11 days after the treatment for 7 but not for 14 days. The down-regulation or up-regulation as measured by [{sup 3}H]-QNB, PZP and AF-DX 384 was observed 1, 6 or 11 days after treatment with propoxur for 7 days and/or 14 days. Repeated treatment with oxotremorine produced similar effects except AChE activity to DDVP. These results suggest that repeated inhibition of AChE activity may usually cause down-regulation of mAChRs with some exception in the hippocampus when a reversible antiChE propoxur is injected.

  5. New cholinesterase inhibitors for Alzheimer's disease: Structure Activity Studies (SARs) and molecular docking of isoquinolone and azepanone derivatives.

    PubMed

    Bacalhau, Patrícia; San Juan, Amor A; Marques, Carolina S; Peixoto, Daniela; Goth, Albertino; Guarda, Cátia; Silva, Mara; Arantes, Sílvia; Caldeira, A Teresa; Martins, Rosário; Burke, Anthony J

    2016-08-01

    A library of isoquinolinone and azepanone derivatives were screened for both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. The strategy adopted included (a) in vitro biological assays, against eel AChE (EeAChE) and equine serum BuChE (EqBuChE) in order to determine the compounds IC50 and their dose-response activity, consolidated by (b) molecular docking studies to evaluate the docking poses and interatomic interactions in the case of the hit compounds, validated by STD-NMR studies. Compound (1f) was identified as one of these hits with an IC50 of 89.5μM for EeAChE and 153.8μM for EqBuChE, (2a) was identified as a second hit with an IC50 of 108.4μM (EeAChE) and 277.8μM (EqBuChE). In order to gain insights into the binding mode and principle active site interactions of these molecules, (R)-(1f) along with 3 other analogues (also as the R-enantiomer) were docked into both RhAChE and hBuChE models. Galantamine was used as the benchmark. The docking study was validated by performing an STD-NMR study of (1f) with EeAChE using galantamine as the benchmark. PMID:27231829

  6. Unusual Extra Space at the Active Site and High Activity for Acetylated Hydroxyproline of Prolyl Aminopeptidase from Serratia marcescens

    PubMed Central

    Nakajima, Yoshitaka; Ito, Kiyoshi; Sakata, Makoto; Xu, Yue; Nakashima, Kanako; Matsubara, Futoshi; Hatakeyama, Susumi; Yoshimoto, Tadashi

    2006-01-01

    The prolyl aminopeptidase complexes of Ala-TBODA [2-alanyl-5-tert-butyl-(1, 3, 4)-oxadiazole] and Sar-TBODA [2-sarcosyl-5-tert-butyl-(1, 3, 4)-oxadiazole] were analyzed by X-ray crystallography at 2.4 Å resolution. Frames of alanine and sarcosine residues were well superimposed on each other in the pyrrolidine ring of proline residue, suggesting that Ala and Sar are recognized as parts of this ring of proline residue by the presence of a hydrophobic proline pocket at the active site. Interestingly, there was an unusual extra space at the bottom of the hydrophobic pocket where proline residue is fixed in the prolyl aminopeptidase. Moreover, 4-acetyloxyproline-βNA (4-acetyloxyproline β-naphthylamide) was a better substrate than Pro-βNA. Computer docking simulation well supports the idea that the 4-acetyloxyl group of the substrate fitted into that space. Alanine scanning mutagenesis of Phe139, Tyr149, Tyr150, Phe236, and Cys271, consisting of the hydrophobic pocket, revealed that all of these five residues are involved significantly in the formation of the hydrophobic proline pocket for the substrate. Tyr149 and Cys271 may be important for the extra space and may orient the acetyl derivative of hydroxyproline to a preferable position for hydrolysis. These findings imply that the efficient degradation of collagen fragment may be achieved through an acetylation process by the bacteria. PMID:16452443

  7. Alterations in the cholinesterase and adenosine deaminase activities and inflammation biomarker levels in patients with multiple sclerosis.

    PubMed

    Polachini, C R N; Spanevello, R M; Casali, E A; Zanini, D; Pereira, L B; Martins, C C; Baldissareli, J; Cardoso, A M; Duarte, M F; da Costa, P; Prado, A L C; Schetinger, M R C; Morsch, V M

    2014-04-25

    Multiple sclerosis (MS) is one of the main chronic inflammatory diseases of the CNS that cause functional disability in young adults. It has unknown etiology characterized by the infiltration of lymphocytes and macrophages into the brain. The aim of this study was to evaluate the acetylcholinesterase (AChE) activity in lymphocytes and whole blood, as well as butyrylcholinesterase (BChE) and adenosine deaminase (ADA) activities in serum. We also checked the levels of nucleotides, nucleosides, biomarkers of inflammation such as cytokines (interleukin (IL)-1, IL-6, interferon (IFN)-γ, tumor necrosis factor-alpha (TNF-α) and IL-10) and C-reactive protein (CRP) in serum from 29 patients with the relapsing-remitting form of MS (RRMS) and 29 healthy subjects as the control group. Results showed that AChE in lymphocytes and whole blood as well as BChE, and ADA activities in serum were significantly increased in RRMS patients when compared to the control group (P<0.05). In addition, we observed a decrease in ATP levels and a significant increase in the levels of ADP, AMP, adenosine and inosine in serum from RRMS patients in relation to the healthy subjects (P<0.05). Results also demonstrated an increase in the IFN-γ, TNF-α, IL-1, IL-6 and CRP (P<0.05) and a significant decrease in the IL-10 (P<0.0001) in RRMS patients when compared to control. Our results suggest that alterations in the biomarkers of inflammation and hydrolysis of nucleotides and nucleosides may contribute to the understanding of the neurological dysfunction of RRMS patients.

  8. A third type of serum cholinesterase deficiency in Eskimos.

    PubMed Central

    Scott, E M; Wright, R C

    1976-01-01

    A new type of serum cholinesterase deficiency with less than 10% of the normal activity was found in an Alaskan Eskimo. The new type of deficiency appeared to be allelic with two types previously described in this population. Images Fig. 2 PMID:1266852

  9. Relationship Between Brain and Plasma Carbaryl Levels and Cholinesterase Inhibition

    EPA Science Inventory

    Carbaryl is a N-methylcarbamate pesticide and, like others in this class, is a reversible inhibitor of cholinesterase (ChE) enzymes. Although studied for many years, there is a surprising lack of information relating tissue levels of carbaryl with ChE activity in the same animals...

  10. Investigation of the Roles of Allosteric Domain Arginine, Aspartate, and Glutamate Residues of Rhizobium etli Pyruvate Carboxylase in Relation to Its Activation by Acetyl CoA.

    PubMed

    Sirithanakorn, Chaiyos; Jitrapakdee, Sarawut; Attwood, Paul V

    2016-08-01

    The mechanism of allosteric activation of pyruvate carboxylase by acetyl CoA is not fully understood. Here we have examined the roles of residues near the acetyl CoA binding site in the allosteric activation of Rhizobium etli pyruvate carboxylase using site-directed mutagenesis. Arg429 was found to be especially important for acetyl CoA binding as substitution with serine resulted in a 100-fold increase in the Ka of acetyl CoA activation and a large decrease in the cooperativity of this activation. Asp420 and Arg424, which do not make direct contact with bound acetyl CoA, were nonetheless found to affect acetyl CoA binding when mutated, probably through changed interactions with another acetyl CoA binding residue, Arg427. Thermodynamic activation parameters for the pyruvate carboxylation reaction were determined from modified Arrhenius plots and showed that acetyl CoA acts to decrease the activation free energy of the reaction by both increasing the activation entropy and decreasing the activation enthalpy. Most importantly, mutations of Asp420, Arg424, and Arg429 enhanced the activity of the enzyme in the absence of acetyl CoA. A main focus of this work was the detailed investigation of how this increase in activity occurred in the R424S mutant. This mutation decreased the activation enthalpy of the pyruvate carboxylation reaction by an amount consistent with removal of a single hydrogen bond. It is postulated that Arg424 forms a hydrogen bonding interaction with another residue that stabilizes the asymmetrical conformation of the R. etli pyruvate carboxylase tetramer, constraining its interconversion to the symmetrical conformer that is required for catalysis. PMID:27379711

  11. Novel series of tacrine-tianeptine hybrids: Synthesis, cholinesterase inhibitory activity, S100B secretion and a molecular modeling approach.

    PubMed

    Ceschi, Marco Antonio; da Costa, Jessie Sobieski; Lopes, João Paulo Bizarro; Câmara, Viktor Saraiva; Campo, Leandra Franciscato; Borges, Antonio César de Amorim; Gonçalves, Carlos Alberto Saraiva; de Souza, Daniela Fraga; Konrath, Eduardo Luis; Karl, Ana Luiza Martins; Guedes, Isabella Alvim; Dardenne, Laurent Emmanuel

    2016-10-01

    Tianeptine was linked to various 9-aminoalkylamino-1,2,3,4-tetrahydroacridines using EDC·HCl/HOBt to afford a series of tacrine-tianeptine hybrids. The hybrids were tested for their ability to inhibit AChE and BuChE and IC50 values in the nanomolar concentration scale were obtained. AChE molecular modeling studies of these hybrids indicated that tacrine moiety interacts in the bottom of the gorge with the catalytic active site (CAS) while tianeptine binds to peripheral anionic site (PAS). Furthermore, the compounds 2g and 2e were able to reduce the in vitro basal secretion of S100B, suggesting its therapeutic action in some cases or stages of Alzheimer's disease.

  12. Novel series of tacrine-tianeptine hybrids: Synthesis, cholinesterase inhibitory activity, S100B secretion and a molecular modeling approach.

    PubMed

    Ceschi, Marco Antonio; da Costa, Jessie Sobieski; Lopes, João Paulo Bizarro; Câmara, Viktor Saraiva; Campo, Leandra Franciscato; Borges, Antonio César de Amorim; Gonçalves, Carlos Alberto Saraiva; de Souza, Daniela Fraga; Konrath, Eduardo Luis; Karl, Ana Luiza Martins; Guedes, Isabella Alvim; Dardenne, Laurent Emmanuel

    2016-10-01

    Tianeptine was linked to various 9-aminoalkylamino-1,2,3,4-tetrahydroacridines using EDC·HCl/HOBt to afford a series of tacrine-tianeptine hybrids. The hybrids were tested for their ability to inhibit AChE and BuChE and IC50 values in the nanomolar concentration scale were obtained. AChE molecular modeling studies of these hybrids indicated that tacrine moiety interacts in the bottom of the gorge with the catalytic active site (CAS) while tianeptine binds to peripheral anionic site (PAS). Furthermore, the compounds 2g and 2e were able to reduce the in vitro basal secretion of S100B, suggesting its therapeutic action in some cases or stages of Alzheimer's disease. PMID:27392529

  13. Species-specific patterns of swimming escape performance and cholinesterase activity in a guild of aquatic insects exposed to endosulfan.

    PubMed

    Trekels, Hendrik; Van de Meutter, Frank; Stoks, Robby

    2012-04-01

    Next to imposing direct lethal effects, pollutants may also indirectly impose mortality by making prey organisms more vulnerable to predation. We report that four water boatmen species differed strongly in direct endosulfan-imposed mortality, and only the species that suffered highest mortality, Sigara iactans, also showed a reduction in escape swimming speed. While head AChE activity was inhibited in all four species, body ChE was only inhibited in S. iactans where it covaried with escape swimming speed, indicating a mechanistic link between body ChE and swimming speed. Our study underscores the need for risk assessment to consider sublethal pollutant effects, which may considerably affect survival rates under natural conditions, also when testing concentrations of a pesticide that cause direct mortality. Such sublethal effects may generate discrepancies between laboratory and field studies and should be considered when designing safety factors for toxicants where the risk assessment is solely based on LC50 values.

  14. Synthesis, characterization, antibacterial activity and quantum chemical studies of N'-Acetyl propane sulfonic acid hydrazide

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Alyar, Hamit; Ozdemir, Ummuhan Ozmen; Sahin, Omer; Kaya, Kerem; Ozbek, Neslihan; Gunduzalp, Ayla Balaban

    2015-08-01

    A new N'-Acetyl propane sulfonic acid hydrazide, C3H7sbnd SO2sbnd NHsbnd NHsbnd COCH3 (Apsh, an sulfon amide compound) has been synthesized for the first time. The structure of Apsh was investigated using elemental analysis, spectral (IR, 1H/13C NMR) measurements. In addition, molecular structure of the Apsh was determined by single crystal X-ray diffraction technique and found that the compound crystallizes in monoclinic, space group P 21/c. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The structure of Apsh is optimized using Density Functional Theory (DFT) method. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The theoretical IR frequencies are found to be in good agreement with the experimental IR frequencies. Nonlinear optical (NLO) behaviour of Apsh is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The antibacterial activities of synthesized compound were studied against Gram positive bacteria: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 23212, Staphylococcus epidermidis ATCC 34384, Gram negative bacteria: Eschericha coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70063 by using microdilution method (as MICs) and disc diffusion method.

  15. Soraphen A, an inhibitor of acetyl CoA carboxylase activity, interferes with fatty acid elongation

    PubMed Central

    Jump, Donald B.; Torres-Gonzalez, Moises; Olson, L. Karl

    2010-01-01

    Acetyl CoA carboxylase (ACC1 & ACC2) generates malonyl CoA, a substrate for de novo lipogenesis (DNL) and an inhibitor of mitochondrial fatty acid β-oxidation (FAO). Malonyl CoA is also a substrate for microsomal fatty acid elongation, an important pathway for saturated (SFA), mono- (MUFA) and polyunsaturated fatty acid (PUFA) synthesis. Despite the interest in ACC as a target for obesity and cancer therapy, little attention has been given to the role ACC plays in long chain fatty acid synthesis. This report examines the effect of pharmacological inhibition of ACC on DNL & palmitate (16:0) and linoleate (18:2,n-6) metabolism in HepG2 and LnCap cells. The ACC inhibitor, soraphen A, lowers cellular malonyl CoA, attenuates DNL and the formation of fatty acid elongation products derived from exogenous fatty acids, i.e., 16:0 & 18:2,n-6; IC50 ~ 5 nM. Elevated expression of fatty acid elongases (Elovl5, Elovl6) or desaturases (FADS1, FADS2) failed to override the soraphen A effect on SFA, MUFA or PUFA synthesis. Inhibition of fatty acid elongation leads to the accumulation of 16- and 18-carbon unsaturated fatty acids derived from 16:0 and 18:2,n-6, respectively. Pharmacological inhibition of ACC activity will not only attenuate DNL and induce FAO, but will also attenuate the synthesis of very long chain saturated, mono- and polyunsaturated fatty acids. PMID:21184748

  16. 15-O-Acetyl-3-O-benzoylcharaciol and helioscopinolide A, two diterpenes isolated from Euphorbia helioscopia suppress microglia activation.

    PubMed

    Wang, Hao; Liu, Yu; Zhang, Jingling; Xu, Jing; Cui, Chun-Ai; Guo, Yuanqiang; Jin, Da-Qing

    2016-01-26

    Microglia activation plays an important role in the pathogenesis of various neurodegenerative diseases by producing neurotoxic factors. In the present study, we found that two diterpenes isolated from Euphorbia helioscopia, 15-O-Acetyl-3-O-benzoylcharaciol and helioscopinolide A suppressed NO and PGE2 production by inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. The diterpenes also inhibited the production of ROS and proinflammatory cytokines including interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, the mechanism involved the NF-κB but not Akt and mitogen-activated protein kinase (MAPK) pathway. Moreover, the two diterpenes also attenuate microglia activation-mediated neuronal death. These results suggest that 15-O-Acetyl-3-O-benzoylcharaciol and helioscopinolide A may provide potential therapeutic strategy for various neuroinflammatory diseases.

  17. Chemotactic activity from rabbit peritoneal neutrophils. Lack of identity with N-acetyl-DL-phenylalanine beta-napthyl esterase.

    PubMed

    Tsung, P K; Showell, H J; Kegeles, S W; Becker, E L

    1976-08-12

    The chemotactic and N-acetyl-DL-phenylalanine beta-naphthyl esterase activities of rabbit peritoneal neutrophils are separable from each other by both DEAE cellulose and Sephadex G-100 column chromatography. Partially purified esterase obtained from DEAE-cellulose chromatography had molecular weight of 70 000. However, the partially purified fraction contained chemotactic activities with major activity in molecular weight of 28000 and minor activities in the molecular weights of 45000, 21900, 14500 and 10500. Esterase activity is inhibited by 10(-7) M p-nitrophenylethyl-5-chloropentylphosphonate but chemotactic activity is not.

  18. Enhancement of acetyl xylan esterase activity on cellulose acetate through fusion to a family 3 cellulose binding module.

    PubMed

    Mai-Gisondi, Galina; Turunen, Ossi; Pastinen, Ossi; Pahimanolis, Nikolaos; Master, Emma R

    2015-11-01

    The current study investigates the potential to increase the activity of a family 1 carbohydrate esterase on cellulose acetate through fusion to a family 3 carbohydrate binding module (CBM). Specifically, CtCBM3 from Clostridium thermocellum was fused to the carboxyl terminus of the acetyl xylan esterase (AnAXE) from Aspergillus nidulans, and active forms of both AnAXE and AnAXE-CtCBM3 were produced in Pichia pastoris. CtCBM3 fusion had negligible impact on the thermostability or regioselectivity of AnAXE; activities towards acetylated corncob xylan, 4-methylumbelliferyl acetate, p-nitrophenyl acetate, and cellobiose octaacetate were also unchanged. By contrast, the activity of AnAXE-CtCBM3 on cellulose acetate increased by two to four times over 24 h, with greater differences observed at earlier time points. Binding studies using microcrystalline cellulose (Avicel) and a commercial source of cellulose acetate confirmed functional production of the CtCBM3 domain; affinity gel electrophoresis using acetylated xylan also verified the selectivity of CtCBM3 binding to cellulose. Notably, gains in enzyme activity on cellulose acetate appeared to exceed gains in substrate binding, suggesting that fusion to CtCBM3 increases functional associations between the enzyme and insoluble, high molecular weight cellulosic substrates.

  19. Enhanced activity of acetyl CoA synthetase adsorbed on smart microgel: an implication for precursor biosynthesis.

    PubMed

    Dubey, Nidhi Chandrama; Tripathi, Bijay Prakash; Müller, Martin; Stamm, Manfred; Ionov, Leonid

    2015-01-28

    Acetyl coenzyme A (acetyl CoA) is an essential precursor molecule for synthesis of metabolites such as the polyketide-based drugs (tetracycline, mitharamycin, Zocor, etc.) fats, lipids, and cholesterol. Acetyl CoA synthetase (Acs) is one of the enzymes that catalyzes acetyl CoA synthesis, and this enzyme is essentially employed for continuous supply of the acetyl CoA for the production of these metabolites. To achieve reusable and a more robust entity of the enzyme, we carried out the immobilization of Acs on poly(N-isopropylacrylamide)-poly(ethylenimine) (PNIPAm-PEI) microgels via adsorption. Cationic PNIPAm-PEI microgel was synthesized by one-step graft copolymerization of NIPAm and N,N-methylene bis-acrylamide (MBA) from PEI. Adsorption studies of Acs on microgel indicated high binding of enzymes, with a maximum binding capacity of 286 μg/mg of microgel for Acs was achieved. The immobilized enzymes showed improved biocatalytic efficiency over free enzymes, beside this, the reaction parameters and circular dichroism (CD) spectroscopy studies indicated no significant changes in the enzyme structure after immobilization. This thoroughly characterized enzyme bioconjugate was further immobilized on an ultrathin membrane to assess the same reaction in flow through condition. Bioconjugate was covalently immobilized on a thin layer of preformed microgel support upon polyethylene terephthalate (PET) track etched membrane. The prepared membrane was used in a dead end filtration device to monitor the bioconversion efficiency and operational stability of cross-linked bioconjugate. The membrane reactor showed consistent operational stability and maintained >70% of initial activity after 7 consecutive operation cycles. PMID:25561344

  20. Exposure of nonbreeding migratory shorebirds to cholinesterase-inhibiting contaminants in the western hemisphere

    USGS Publications Warehouse

    Strum, K.M.; Hooper, M.J.; Johnson, K.A.; Lanctot, Richard B.; Zaccagnini, M.E.; Sandercock, B.K.

    2010-01-01

    Migratory shorebirds frequently forage and roost in agricultural habitats, where they may be exposed to cholinesterase-inhibiting pesticides. Exposure to organophosphorus and carbamate compounds, common anti-cholinesterases, can cause sublethal effects, even death. To evaluate exposure of migratory shorebirds to organophosphorus and carbamates, we sampled birds stopping over during migration in North America and wintering in South America. We compared plasma cholinesterase activities and body masses of individuals captured at sites with no known sources of organophosphorus or carbamates to those captured in agricultural areas where agrochemicals were recommended for control of crop pests. In South America, plasma acetylcholinesterase and butyrylcholinesterase activity in Buff-breasted Sandpipers was lower at agricultural sites than at reference sites, indicating exposure to organophosphorus and carbamates. Results of plasma cholinesterase reactivation assays and foot-wash analyses were inconclusive. A meta-analysis of six species revealed no widespread effect of agricultural chemicals on cholinesterase activity. however, four of six species were negative for acetylcholinesterase and one of six for butyrylcholinesterase, indicating negative effects of pesticides on cholinesterase activity in a subset of shorebirds. Exposure to cholinesterase inhibitors can decrease body mass, but comparisons between treatments and hemispheres suggest that agrochemicals did not affect migratory shorebirds' body mass. Our study, one of the first to estimate of shorebirds' exposure to cholinesterase-inhibiting pesticides, suggests that shorebirds are being exposed to cholinesterase- inhibiting pesticides at specific sites in the winter range but not at migratory stopover sites. future research should examine potential behavioral effects of exposure and identify other potential sitesand levels of exposure. ?? The Cooper Ornithological Society 2010.

  1. [Cholinesterase inhibitor poisoning: a complicated medical challenge].

    PubMed

    Lavon, Ophir; Sagi, Ram

    2013-07-01

    Exposure to insecticides, mainly cholinesterase inhibitors, is a global problem with substantial morbidity and mortality. Risk of intoxication is increased in rural areas where there is high availability and proximity of insecticides to families and children. Neglected storage and inadequate practice lead to dangerous exposure. Strict regulations and appropriate safety measures are needed for the prevention of exposure to insecticides. Broad toxicological knowledge is necessary in order to treat organophosphate and carbamate poisoned patients. Diagnosis is not trivial, since the identity of the poison is not always apparent. Multiple exposures including organic solvents are possible. The clinical presenting can be confusing. Measurement of cholinesterase activity is mandatory in establishing the diagnosis. Prompt treatment with proper antidotes and respiratory support is indicated. Early administration of anticonvulsants may mitigate central neurologic complications. Monitoring neurologic and cardiac function is advised for rapid identification of complications and prognosis evaluation. Meticulous preparedness of health care providers for insecticide poisoning is needed from the pre-hospital phase to emergency departments and the different hospital wards.

  2. Determinants within the C-terminal domain of Streptomyces lividans acetyl-CoA synthetase that block acetylation of its active site lysine in vitro by the protein acetyltransferase (Pat) enzyme.

    PubMed

    Tucker, Alex C; Escalante-Semerena, Jorge C

    2014-01-01

    Reversible lysine acetylation (RLA) is a widespread regulatory mechanism that modulates the function of proteins involved in diverse cellular processes. A strong case has been made for RLA control exerted by homologues of the Salmonella enterica protein acetyltransferase (SePat) enzyme on the broadly distributed AMP-forming CoA ligase (a.k.a. acyl-CoA synthetases) family of metabolic enzymes, with acetyl-CoA synthetase (Acs) being the paradigm in the field. Here we investigate why the Acs homologue in Streptomyces lividans (SlAcs) is poorly acetylated in vitro by the S. lividans protein acetyltransferase (SlPat) enzyme. Chimeras of S. enterica Acs (SeAcs) and S. lividans Acs (SlAcs) constructed during the course of this work were acetylated by SlPatA in vitro, retained most of their activity, and were under RLA control in a heterologous host. We identified SeAcs residues N- and C-terminal to the target lysine that when introduced into SlAcs, rendered the latter under RLA control. These results lend further support to the idea that Pat enzymes interact with extensive surfaces of their substrates. Finally, we suggest that acetylation of SlAcs depends on factors or conditions other than those present in our in vitro system. We also discuss possible explanations why SlAcs is not controlled by RLA as defined in other bacterial species.

  3. The Structure- and Metal-dependent Activity of Escherichia coli PgaB Provides Insight into the Partial De-N-acetylation of Poly-β-1,6-N-acetyl-d-glucosamine*

    PubMed Central

    Little, Dustin J.; Poloczek, Joanna; Whitney, John C.; Robinson, Howard; Nitz, Mark; Howell, P. Lynne

    2012-01-01

    Exopolysaccharides are required for the development and integrity of biofilms produced by a wide variety of bacteria. In Escherichia coli, partial de-N-acetylation of the exopolysaccharide poly-β-1,6-N-acetyl-d-glucosamine (PNAG) by the periplasmic protein PgaB is required for polysaccharide intercellular adhesin-dependent biofilm formation. To understand the molecular basis for PNAG de-N-acetylation, the structure of PgaB in complex with Ni2+ and Fe3+ have been determined to 1.9 and 2.1 Å resolution, respectively, and its activity on β-1,6-GlcNAc oligomers has been characterized. The structure of PgaB reveals two (β/α)x barrel domains: a metal-binding de-N-acetylase that is a member of the family 4 carbohydrate esterases (CE4s) and a domain structurally similar to glycoside hydrolases. PgaB displays de-N-acetylase activity on β-1,6-GlcNAc oligomers but not on the β-1,4-(GlcNAc)4 oligomer chitotetraose and is the first CE4 member to exhibit this substrate specificity. De-N-acetylation occurs in a length-dependent manor, and specificity is observed for the position of de-N-acetylation. A key aspartic acid involved in de-N-acetylation, normally seen in other CE4s, is missing in PgaB, suggesting that the activity of PgaB is attenuated to maintain the low levels of de-N-acetylation of PNAG observed in vivo. The metal dependence of PgaB is different from most CE4s, because PgaB shows increased rates of de-N-acetylation with Co2+ and Ni2+ under aerobic conditions, and Co2+, Ni2+ and Fe2+ under anaerobic conditions, but decreased activity with Zn2+. The work presented herein will guide inhibitor design to combat biofilm formation by E. coli and potentially a wide range of medically relevant bacteria producing polysaccharide intercellular adhesin-dependent biofilms. PMID:22810235

  4. N-Acetyl-β-D-glucosaminidase activity in feral Carcinus maenas exposed to cadmium.

    PubMed

    Mesquita, Sofia Raquel; Ergen, Şeyda Fikirdeşici; Rodrigues, Aurélie Pinto; Oliva-Teles, M Teresa; Delerue-Matos, Cristina; Guimarães, Laura

    2015-02-01

    Cadmium is a priority hazardous substance, persistent in the aquatic environment, with the capacity to interfere with crustacean moulting. Moulting is a vital process dictating crustacean growth, reproduction and metamorphosis. However, for many organisms, moult disruption is difficult to evaluate in the short term, what limits its inclusion in monitoring programmes. N-acetyl-β-D-glucosaminidase (NAGase) is an enzyme acting in the final steps of the endocrine-regulated moulting cascade, allowing for the cast off of the old exoskeleton, with potential interest as a biomarker of moult disruption. This study investigated responses to waterborne cadmium of NAGase activity of Carcinus maenas originating from estuaries with different histories of anthropogenic contamination: a low impacted and a moderately polluted one. Crabs from both sites were individually exposed for seven days to cadmium concentrations ranging from 1.3 to 2000 μg/L. At the end of the assays, NAGase activity was assessed in the epidermis and digestive gland. Detoxification, antioxidant, energy production, and oxidative stress biomarkers implicated in cadmium metabolism and tolerance were also assessed to better understand differential NAGase responses: activity of glutathione S-transferases (GST), glutathione peroxidase (GPx) glutathione reductase (GR), levels of total glutathiones (TG), lipid peroxidation (LPO), lactate dehydrogenase (LDH), and NADP(+)-dependent isocitrate dehydrogenase (IDH). Animals from the moderately polluted estuary had lower NAGase activity both in the epidermis and digestive gland than in the low impacted site. NAGase activity in the epidermis and digestive gland of C. maenas from both estuaries was sensitive to cadmium exposure suggesting its usefulness for inclusion in monitoring programmes. However, in the digestive gland NAGase inhibition was found in crabs from the less impacted site but not in those from the moderately contaminated one. Altered glutathione levels were

  5. Active transgenes in zebrafish are enriched in acetylated histone H4 and dynamically associate with RNA Pol II and splicing complexes.

    PubMed

    Collas, P; Liang, M R; Vincent, M; Aleström, P

    1999-04-01

    We have investigated the functional organization of active and silent integrated luciferase transgenes in zebrafish, with the aim of accounting for the variegation of transgene expression in this species. We demonstrate the enrichment of transcriptionally active transgenes in acetylated histone H4 and the dynamic association of the transgenes with splicing factor SC35 and RNA Pol II. Analysis of interphase nuclei and extended chromatin fibers by immunofluorescence and in situ hybridization reveals a co-localization of transgenes with acetylated H4 in luciferase-expressing animals only. Enrichment of expressed transgenes in acetylated H4 is further demonstrated by their co-precipitation from chromatin using anti-acetylated H4 antibodies. Little correlation exists, however, between the level of histone acetylation and the degree of transgene expression. In transgene-expressing zebrafish, most transgenes co-localize with Pol II and SC35, whereas no such association occurs in non-expressing individuals. Inhibition of Pol II abolishes transgene expression and disrupts association of transgenes with SC35, although inactivated transgenes remains enriched in acetylated histones. Exposure of embryos to the histone deacetylation inhibitor TSA induces expression of most silent transgenes. Chromatin containing activated transgenes becomes enriched in acetylated histones and the transgenes recruit SC35 and Pol II. The results demonstrate a correlation between H4 acetylation and transgene activity, and argue that active transgenes dynamically recruit splicing factors and Pol II. The data also suggest that dissociation of splicing factors from transgenes upon Pol II inhibition is not a consequence of changes in H4 acetylation. PMID:10198286

  6. Acetylated analogues of the microtubule-stabilizing agent discodermolide: preparation and biological activity.

    PubMed

    Gunasekera, S P; Longley, R E; Isbrucker, R A

    2001-02-01

    A series of eight discodermolide acetates have been prepared using natural (+)-discodermolide and evaluated for in vitro cytotoxicity against the cultured murine P-388 leukemia cells. The acetylated analogues showed a significant variation of cytotoxicity and suggested the importance of C-11 and C-17 hydroxyl groups for potency. The preparation and structure elucidation of the new analogues are described.

  7. Dehydrozingerone based 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles: Synthesis, characterization and anticancer activity

    NASA Astrophysics Data System (ADS)

    Ratković, Zoran; Muškinja, Jovana; Burmudžija, Adrijana; Ranković, Branislav; Kosanić, Marijana; Bogdanović, Goran A.; Marković, Bojana Simović; Nikolić, Aleksandar; Arsenijević, Nebojša; Đorđevic, Snežana; Vukićević, Rastko D.

    2016-04-01

    A small series of 1-acetyl-5-aryl-4,5-dihydro-1H-pyrazoles (aryl = 4-hydroxy-3-methoxyphenyl and 4-alkoxy-3-methoxyphenyl) was prepared, starting from 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, dehydrozingerone, and its alkyl derivatives. Their in vitro cytotoxic activity against some cancer cell lines was tested, showing significant anticancer activity. All the new compounds were well characterized by IR, 1H, 13C NMR and ESI-MS spectroscopy and physical data, whereas structures of two of them were determined by single crystal X-ray analysis.

  8. Acetyl chloride

    Integrated Risk Information System (IRIS)

    Acetyl chloride ; CASRN 75 - 36 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  9. Histone Deacetylase 3 (HDAC3)-dependent Reversible Lysine Acetylation of Cardiac Myosin Heavy Chain Isoforms Modulates Their Enzymatic and Motor Activity.

    PubMed

    Samant, Sadhana A; Pillai, Vinodkumar B; Sundaresan, Nagalingam R; Shroff, Sanjeev G; Gupta, Mahesh P

    2015-06-19

    Reversible lysine acetylation is a widespread post-translational modification controlling the activity of proteins in different subcellular compartments. We previously demonstrated that a class II histone deacetylase (HDAC), HDAC4, and a histone acetyltransferase, p300/CREB-binding protein-associated factor, associate with cardiac sarcomeres and that a class I and II HDAC inhibitor, trichostatin A, enhances contractile activity of myofilaments. In this study we show that a class I HDAC, HDAC3, is also present at cardiac sarcomeres. By immunohistochemical and electron microscopic analyses, we found that HDAC3 was localized to A-band of sarcomeres and capable of deacetylating myosin heavy chain (MHC) isoforms. The motor domains of both cardiac α- and β-MHC isoforms were found to be reversibly acetylated. Biomechanical studies revealed that lysine acetylation significantly decreased the Km for the actin-activated ATPase activity of MHC isoforms. By in vitro motility assay, we found that lysine acetylation increased the actin-sliding velocity of α-myosin by 20% and β-myosin by 36% compared with their respective non-acetylated isoforms. Moreover, myosin acetylation was found to be sensitive to cardiac stress. During induction of hypertrophy, myosin isoform acetylation increased progressively with duration of stress stimuli independently of isoform shift, suggesting that lysine acetylation of myosin could be an early response of myofilaments to increase contractile performance of the heart. These studies provide the first evidence for localization of HDAC3 at myofilaments and uncover a novel mechanism modulating the motor activity of cardiac MHC isoforms.

  10. The distribution of cholinesterases in the cat carotid body.

    PubMed

    Biscoe, T J; Silver, A

    1966-03-01

    1. The distribution of acetyl- and butyrylcholinesterase in the carotid body of the cat has been examined histochemically. Studies were made on normal carotid bodies and on carotid bodies from cats in which certain nerves had been cut some time previously. The nerves sectioned were the sinus nerve, the post-ganglionic sympathetic branch of the superior cervical ganglion or the preganglionic cervical sympathetic trunk.2. It was confirmed that more butyrylcholinesterase than acetylcholinesterase is present. Both enzymes are found in three sites: (i) as strands, (ii) as plexuses, (iii) inside a few cells.3. The distribution is unaffected by cutting the sinus nerve or preganglionic cervical sympathetic nerves. Disorganization and depletion of the cholinesterases in the strands and plexuses occurs when the post-ganglionic branch of the superior cervical ganglion is cut. The cholinesterase in cells is unaffected.4. In carotid bodies in which vessels were filled with red blood cells or in which the vascular bed was injected with carmine-gelatine, it was seen that strands and plexuses are associated with blood vessels, and with blood vessels and cells respectively.5. It is suggested that a cholinergic pathway controlling carotid body blood vessels runs in the post-ganglionic cervical sympathetic.

  11. Acetate Activation in Methanosaeta thermophila: Characterization of the Key Enzymes Pyrophosphatase and Acetyl-CoA Synthetase

    PubMed Central

    Berger, Stefanie; Welte, Cornelia; Deppenmeier, Uwe

    2012-01-01

    The thermophilic methanogen Methanosaeta thermophila uses acetate as sole substrate for methanogenesis. It was proposed that the acetate activation reaction that is needed to feed acetate into the methanogenic pathway requires the hydrolysis of two ATP, whereas the acetate activation reaction in Methanosarcina sp. is known to require only one ATP. As these organisms live at the thermodynamic limit that sustains life, the acetate activation reaction in Mt. thermophila seems too costly and was thus reevaluated. It was found that of the putative acetate activation enzymes one gene encoding an AMP-forming acetyl-CoA synthetase was highly expressed. The corresponding enzyme was purified and characterized in detail. It catalyzed the ATP-dependent formation of acetyl-CoA, AMP, and pyrophosphate (PPi) and was only moderately inhibited by PPi. The breakdown of PPi was performed by a soluble pyrophosphatase. This enzyme was also purified and characterized. The pyrophosphatase hydrolyzed the major part of PPi (KM = 0.27 ± 0.05 mM) that was produced in the acetate activation reaction. Activity was not inhibited by nucleotides or PPi. However, it cannot be excluded that other PPi-dependent enzymes take advantage of the remaining PPi and contribute to the energy balance of the cell. PMID:22927778

  12. NAT10 regulates p53 activation through acetylating p53 at K120 and ubiquitinating Mdm2.

    PubMed

    Liu, Xiaofeng; Tan, Yuqin; Zhang, Chunfeng; Zhang, Ying; Zhang, Liangliang; Ren, Pengwei; Deng, Hongkui; Luo, Jianyuan; Ke, Yang; Du, Xiaojuan

    2016-03-01

    As a genome guardian, p53 maintains genome stability by arresting cells for damage repair or inducing cell apoptosis to eliminate the damaged cells in stress response. Several nucleolar proteins stabilize p53 by interfering Mdm2-p53 interaction upon cellular stress, while other mechanisms by which nucleolar proteins activate p53 remain to be determined. Here, we identify NAT10 as a novel regulator for p53 activation. NAT10 acetylates p53 at K120 and stabilizes p53 by counteracting Mdm2 action. In addition, NAT10 promotes Mdm2 degradation with its intrinsic E3 ligase activity. After DNA damage, NAT10 translocates to nucleoplasm and activates p53-mediated cell cycle control and apoptosis. Finally, NAT10 inhibits cell proliferation and expression of NAT10 decreases in human colorectal carcinomas. Thus, our data demonstrate that NAT10 plays a critical role in p53 activation via acetylating p53 and counteracting Mdm2 action, providing a novel pathway by which nucleolar protein activates p53 as a cellular stress sensor. PMID:26882543

  13. [Insect cholinesterases and irreversible inhibitors. Statistical treatment of the data].

    PubMed

    Moralev, S N

    2010-01-01

    The data on sensitivity of cholinesterases (ChE) of different insects to reversible inhibitors, as well as the data on physico-chemical parameters of amino acids constituting their active centers, were treated by factor analysis and juxtaposed. It is shown that both these characteristics are related to taxonomical belonging of insects. It is revealed the "material substrate" of the factors determining inhibitor action specificity, which are specific sites in ChE active center.

  14. Synthesis of 1-acyl-2-(3H)acetyl-SN-glycero-3-phosphocholine, a structural analog of platelet activating factor, by vascular endothelial cells

    SciTech Connect

    Mueller, H.W.; Nollert, M.U.; Eskin, S.G. )

    1991-05-15

    Human umbilical vein endothelial cells (HUVECS) were challenged with thrombin in the presence of (3H)acetate to stimulate the production of radiolabeled platelet activating factor (PAF, 1-O-alkyl-2-(3H)acetyl-sn-glycero-3-phosphocholine, 1-O-alkyl-2-(3H)acetyl-GPC). The 3H-product was isolated by thin-layer chromatography, and 1-radyl-2(3H),3- diacetylglycerols were prepared by phospholipase C digestion and subsequent acetylation at the sn-3 position. When the 1-radyl-2(3H),3-diacetylglycerols were analyzed by zonal thin-layer chromatography, 96-97% of the radiolabeled derivative migrated with 1-acyl-2,3-diacetylglycerol standard. Only minor amounts (3-4%) of 1-alkyl-2(3H),3-diacetylglycerol were observed, demonstrating that the predominant acetylated product synthesized by thrombin-stimulated HUVECS was 1-acyl-2-(3H)acetyl-GPC. This relative abundance of 1-acyl-2-(3H)-acetyl-GPC was not significantly affected by thrombin dose, incubation time, or cell passage, and was also observed in HUVECS challenged with ionophore A23187. In addition, the acetylated product from ionophore A23187- or bradykinin-stimulated bovine aortic endothelial cells contained 90% 1-acyl-2-(3H)acetyl-GPC, suggesting that the synthesis of the 1-acyl PAF analog is not unique to HUVECS. These findings demonstrate that PAF is a minor synthetic component of HUVECS and bovine aortic endothelial cells. In light of the integral role which the vascular endothelial cell plays in the regulation of thrombosis, these findings also suggest that the production of 1-acyl-2-acetyl-GPC may be biologically important.

  15. Prognostic Factors in Cholinesterase Inhibitor Poisoning

    PubMed Central

    Sun, In O; Yoon, Hyun Ju; Lee, Kwang Young

    2015-01-01

    Background Organophosphates and carbamates are insecticides that are associated with high human mortality. The purpose of this study is to investigate the prognostic factors affecting survival in patients with cholinesterase inhibitor (CI) poisoning. Material/Methods This study included 92 patients with CI poisoning in the period from January 2005 to August 2013. We divided these patients into 2 groups (survivors vs. non-survivors), compared their clinical characteristics, and analyzed the predictors of survival. Results The mean age of the included patients was 56 years (range, 16–88). The patients included 57 (62%) men and 35 (38%) women. When we compared clinical characteristics between the survivor group (n=81, 88%) and non-survivor group (n=11, 12%), there were no differences in renal function, pancreatic enzymes, or serum cholinesterase level, except for serum bicarbonate level and APACHE II score. The serum bicarbonate level was lower in non-survivors than in survivors (12.45±2.84 vs. 18.36±4.73, P<0.01). The serum APACHE II score was higher in non-survivors than in survivors (24.36±5.22 vs. 12.07±6.67, P<0.01). The development of pneumonia during hospitalization was higher in non-survivors than in survivors (n=9, 82% vs. n=31, 38%, P<0.01). In multiple logistic regression analysis, serum bicarbonate concentration, APACHE II score, and pneumonia during hospitalization were the important prognostic factors in patients with CI poisoning. Conclusions Serum bicarbonate and APACHE II score are useful prognostic factors in patients with CI poisoning. Furthermore, pneumonia during hospitalization was also important in predicting prognosis in patients with CI poisoning. Therefore, prevention and active treatment of pneumonia is important in the management of patients with CI poisoning. PMID:26411989

  16. Melatonin inhibits TPA-induced oral cancer cell migration by suppressing matrix metalloproteinase-9 activation through the histone acetylation

    PubMed Central

    Yeh, Chia-Ming; Lin, Chiao-Wen; Yang, Jia-Sin; Yang, Wei-En; Su, Shih-Chi; Yang, Shun-Fa

    2016-01-01

    Melatonin exerts antimetastatic effects on liver and breast cancer and also inhibits matrix metalloproteinase (MMP) activity. However, the detailed impacts and underlying mechanisms of melatonin on oral cancer cell metastasis are still unclear. This study showed that melatonin attenuated the 12-O-tetradecanoylphorbol-13-acetate-induced migration of oral cancer cell lines, HSC-3 and OECM-1. Zymography, quantitative real-time PCR, and Western blotting analyses revealed that melatonin lessened MMP-9 enzyme activity as well as the expression of MMP-9 mRNA and protein. Furthermore, melatonin suppressed the phosphorylation of the ERK1/2 signalling pathway, which dampened MMP-9 gene transcription by affecting the expression of transcriptional coactivators, such as CREB-binding protein (CREBBP) and E1A binding protein p300 (EP300), and decreasing histone acetylation in HSC-3 and OECM-1 cells. Examinations on clinical samples exhibited that MMP-9, CREBBP, and EP300 were significantly increased in oral cancer tissues. Moreover, the relative level of CREBBP was positively correlated with the expression of MMP-9 and EP300. In conclusion, we demonstrated that melatonin inhibits the motility of HSC-3 and OECM-1 cells in vitro through a molecular mechanism that involves attenuation of MMP-9 expression and activity mediated by decreased histone acetylation. PMID:26980735

  17. Releasing Activity Disengages Cohesin’s Smc3/Scc1 Interface in a Process Blocked by Acetylation

    PubMed Central

    Beckouët, Frederic; Srinivasan, Madhusudhan; Roig, Maurici Brunet; Chan, Kok-Lung; Scheinost, Johanna C.; Batty, Paul; Hu, Bin; Petela, Naomi; Gligoris, Thomas; Smith, Alexandra C.; Strmecki, Lana; Rowland, Benjamin D.; Nasmyth, Kim

    2016-01-01

    Summary Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesin’s Scc1, Smc1, and Smc3 subunits is created during S and destroyed at anaphase through Scc1 cleavage by separase. Cohesin’s association with chromosomes is controlled by opposing activities: loading by Scc2/4 complex and release by a separase-independent releasing activity as well as by cleavage. Coentrapment of sister DNAs at replication is accompanied by acetylation of Smc3 by Eco1, which blocks releasing activity and ensures that sisters remain connected. Because fusion of Smc3 to Scc1 prevents release and bypasses the requirement for Eco1, we suggested that release is mediated by disengagement of the Smc3/Scc1 interface. We show that mutations capable of bypassing Eco1 in Smc1, Smc3, Scc1, Wapl, Pds5, and Scc3 subunits reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from Smc3. This process involves interaction between Smc ATPase heads and is inhibited by Smc3 acetylation. PMID:26895425

  18. Melatonin inhibits TPA-induced oral cancer cell migration by suppressing matrix metalloproteinase-9 activation through the histone acetylation.

    PubMed

    Yeh, Chia-Ming; Lin, Chiao-Wen; Yang, Jia-Sin; Yang, Wei-En; Su, Shih-Chi; Yang, Shun-Fa

    2016-04-19

    Melatonin exerts antimetastatic effects on liver and breast cancer and also inhibits matrix metalloproteinase (MMP) activity. However, the detailed impacts and underlying mechanisms of melatonin on oral cancer cell metastasis are still unclear. This study showed that melatonin attenuated the 12-O-tetradecanoylphorbol-13-acetate-induced migration of oral cancer cell lines, HSC-3 and OECM-1. Zymography, quantitative real-time PCR, and Western blotting analyses revealed that melatonin lessened MMP-9 enzyme activity as well as the expression of MMP-9 mRNA and protein. Furthermore, melatonin suppressed the phosphorylation of the ERK1/2 signalling pathway, which dampened MMP-9 gene transcription by affecting the expression of transcriptional coactivators, such as CREB-binding protein (CREBBP) and E1A binding protein p300 (EP300), and decreasing histone acetylation in HSC-3 and OECM-1 cells. Examinations on clinical samples exhibited that MMP-9, CREBBP, and EP300 were significantly increased in oral cancer tissues. Moreover, the relative level of CREBBP was positively correlated with the expression of MMP-9 and EP300. In conclusion, we demonstrated that melatonin inhibits the motility of HSC-3 and OECM-1 cells in vitro through a molecular mechanism that involves attenuation of MMP-9 expression and activity mediated by decreased histone acetylation. PMID:26980735

  19. Citrullination-acetylation interplay guides E2F-1 activity during the inflammatory response.

    PubMed

    Ghari, Fatemeh; Quirke, Anne-Marie; Munro, Shonagh; Kawalkowska, Joanna; Picaud, Sarah; McGouran, Joanna; Subramanian, Venkataraman; Muth, Aaron; Williams, Richard; Kessler, Benedikt; Thompson, Paul R; Fillipakopoulos, Panagis; Knapp, Stefan; Venables, Patrick J; La Thangue, Nicholas B

    2016-02-01

    Peptidyl arginine deiminase 4 (PAD4) is a nuclear enzyme that converts arginine residues to citrulline. Although increasingly implicated in inflammatory disease and cancer, the mechanism of action of PAD4 and its functionally relevant pathways remains unclear. E2F transcription factors are a family of master regulators that coordinate gene expression during cellular proliferation and diverse cell fates. We show that E2F-1 is citrullinated by PAD4 in inflammatory cells. Citrullination of E2F-1 assists its chromatin association, specifically to cytokine genes in granulocyte cells. Mechanistically, citrullination augments binding of the BET (bromodomain and extra-terminal domain) family bromodomain reader BRD4 (bromodomain-containing protein 4) to an acetylated domain in E2F-1, and PAD4 and BRD4 coexist with E2F-1 on cytokine gene promoters. Accordingly, the combined inhibition of PAD4 and BRD4 disrupts the chromatin-bound complex and suppresses cytokine gene expression. In the murine collagen-induced arthritis model, chromatin-bound E2F-1 in inflammatory cells and consequent cytokine expression are diminished upon small-molecule inhibition of PAD4 and BRD4, and the combined treatment is clinically efficacious in preventing disease progression. Our results shed light on a new transcription-based mechanism that mediates the inflammatory effect of PAD4 and establish the interplay between citrullination and acetylation in the control of E2F-1 as a regulatory interface for driving inflammatory gene expression. PMID:26989780

  20. Citrullination-acetylation interplay guides E2F-1 activity during the inflammatory response

    PubMed Central

    Ghari, Fatemeh; Quirke, Anne-Marie; Munro, Shonagh; Kawalkowska, Joanna; Picaud, Sarah; McGouran, Joanna; Subramanian, Venkataraman; Muth, Aaron; Williams, Richard; Kessler, Benedikt; Thompson, Paul R.; Fillipakopoulos, Panagis; Knapp, Stefan; Venables, Patrick J.; La Thangue, Nicholas B.

    2016-01-01

    Peptidyl arginine deiminase 4 (PAD4) is a nuclear enzyme that converts arginine residues to citrulline. Although increasingly implicated in inflammatory disease and cancer, the mechanism of action of PAD4 and its functionally relevant pathways remains unclear. E2F transcription factors are a family of master regulators that coordinate gene expression during cellular proliferation and diverse cell fates. We show that E2F-1 is citrullinated by PAD4 in inflammatory cells. Citrullination of E2F-1 assists its chromatin association, specifically to cytokine genes in granulocyte cells. Mechanistically, citrullination augments binding of the BET (bromodomain and extra-terminal domain) family bromodomain reader BRD4 (bromodomain-containing protein 4) to an acetylated domain in E2F-1, and PAD4 and BRD4 coexist with E2F-1 on cytokine gene promoters. Accordingly, the combined inhibition of PAD4 and BRD4 disrupts the chromatin-bound complex and suppresses cytokine gene expression. In the murine collagen-induced arthritis model, chromatin-bound E2F-1 in inflammatory cells and consequent cytokine expression are diminished upon small-molecule inhibition of PAD4 and BRD4, and the combined treatment is clinically efficacious in preventing disease progression. Our results shed light on a new transcription-based mechanism that mediates the inflammatory effect of PAD4 and establish the interplay between citrullination and acetylation in the control of E2F-1 as a regulatory interface for driving inflammatory gene expression. PMID:26989780

  1. Endo-N-acetyl-beta-D-glucosaminidase activity in rat liver. Studies on substrate specificity, enzyme inhibition, subcellular localization and partial purification.

    PubMed

    Lisman, J J; van der Wal, C J; Overdijk, B

    1985-07-15

    Endo-N-acetyl-beta-D-glucosaminidase (EC 3.2.1.96, endoglucosaminidase) has been partially purified (520-fold with respect to the cytoplasmic activity) by using concanavalin A-Sepharose, CM-Sephadex and Bio-Gel P-150 chromatography. From the influence of exogenous glycopeptides on the endoglucosaminidase activity it can be concluded that this activity consists of one enzyme hydrolysing both N-acetyl-lactosaminic-type and oligomannosidic-type substrates. Glycoproteins present in the homogenate inhibit the endoglucosaminidase activity. On re-examination of the subcellular distribution of endoglucosaminidase (after removal of inhibiting glycoproteins from the respective subcellular fractions), its cytoplasmic localization was confirmed. PMID:3929770

  2. Endo-N-acetyl-beta-D-glucosaminidase activity in rat liver. Studies on substrate specificity, enzyme inhibition, subcellular localization and partial purification.

    PubMed Central

    Lisman, J J; van der Wal, C J; Overdijk, B

    1985-01-01

    Endo-N-acetyl-beta-D-glucosaminidase (EC 3.2.1.96, endoglucosaminidase) has been partially purified (520-fold with respect to the cytoplasmic activity) by using concanavalin A-Sepharose, CM-Sephadex and Bio-Gel P-150 chromatography. From the influence of exogenous glycopeptides on the endoglucosaminidase activity it can be concluded that this activity consists of one enzyme hydrolysing both N-acetyl-lactosaminic-type and oligomannosidic-type substrates. Glycoproteins present in the homogenate inhibit the endoglucosaminidase activity. On re-examination of the subcellular distribution of endoglucosaminidase (after removal of inhibiting glycoproteins from the respective subcellular fractions), its cytoplasmic localization was confirmed. PMID:3929770

  3. sup. alpha. N-acetyl derivatives of. beta. -endorphin-(1-31) and -(1-27) regulate the supraspinal antinociceptive activity of different opioids in mice

    SciTech Connect

    Garzon, J.; Sanchez-Blazquez, P. )

    1991-01-01

    {sup {alpha}}N-acetyl human {beta}-endorphin(1-31) injected icv to mice antagonized the analgesic activity of {beta}-endorphin-(1-31) and morphine whereas the analgesia evoked by DADLE and DAGO was enhanced by this treatment. The modulatory activity of {sup {alpha}}N-acetyl {beta}-endorphin-(1-31) was exhibited at remarkable low doses (fmols) reaching a maximum that persisted even though the dose was increased 100,000 times. The regulatory effect of a single dose of the acetylated neuropeptide lasted for 24h. The activity of {sup {alpha}}N-acetyl human {beta}-endorphin(1-31) was partially retained by the shorter peptide {sup {alpha}}N-acetyl human {beta}-endorphin-(1-27) and to a lesser extent by {beta}-endorphin-(1-27), {beta}-endorphin-(1-31) lacked this regulatory activity on opioid analgesia. Acetylated {beta}-endorphin-(1-31) displayed a biphasic curve when competing with 5 pM ({sup 125}I)-Tyr{sup 27} human {beta}-endorphin-(1-31) specific binding, the first step was abolished with an apparent IC{sub 50} of 0.35 nM, and the rest with an IC{sub 50} of 200 nM. It is suggested that {sup {alpha}}N-acetyl {beta}-endorphin-(1-31) changed the efficiency of the opioid analgesics by acting upon a specific substrate that is functionally coupled to the opioid receptor, presumably the guanine nucleotide binding regulatory proteins G{sub i}/G{sub 0}.

  4. [Levels of plasma cholinesterase in Colombian working-class populations].

    PubMed

    Carmona-Fonseca, Jaime

    2003-12-01

    Levels of plasma cholinesterase in Colombian working-class populations Reference values for plasma cholinesterase (EC 3.1.1.8) are not available for Colombian populations. A representative sample of a working-class population was used to establish these values to provide reference data for use by the social security system. Two working-class populations were sampled from the Aburrá Valley (Aburrá) and eastern Antioquia (Oriente). Cholinesterase activity was measured in 827 workers, with ages spanning 18-49 years, 415 from Aburrá and 412 people from Oriente. Three methods were used to measure cholinesterase: Michel, EQM and Monotest The average values by Michel and EQM were not statistically different between regions (Michel: Aburrá, 1.11, and East, 1.13 deltas pH/hora; EQM: Aburrá, 2.55, and Oriente, 2.48 U/ml). By the Monotest, the enzyme average was statistically higher in Aburra than in Oriente (5,743 and 5,459 U/L respectively; p = 0 .012). By region and technique, men had significantly higher enzymatic levels than women. Within both regions and sexes, no statistically significant difference among the three aged groups was noted. Our obtained Colombian values differed significantly from foreign reference values: Michel and Monotest levels were higher and EQM levels were lower. For making clinical and epidemiologic decisions in Colombia related to these data, the values obtained for the Colombian populations are preferred over values derived from external sources. PMID:14968922

  5. Thanatos-associated protein 7 associates with template activating factor-Ibeta and inhibits histone acetylation to repress transcription.

    PubMed

    Macfarlan, Todd; Parker, J Brandon; Nagata, Kyosuke; Chakravarti, Debabrata

    2006-02-01

    The posttranslational modifications of histones on chromatin or a lack thereof is critical in transcriptional regulation. Emerging studies indicate a role for histone-binding proteins in transcriptional activation and repression. We have previously identified template-activating factor-Ibeta (TAF-Ibeta, also called PHAPII, SET, and I(2)(pp2A)) as a component of a cellular complex called inhibitor of acetyltransferases (INHAT) that masks histone acetylation in vitro and blocks histone acetyltransferase (HAT)-dependent transcription in living cells. TAF-Ibeta has also been shown to associate with transcription factors, including nuclear receptors, to regulate their activities. To identify novel interactors of TAF-Ibeta, we employed a yeast two-hybrid screen and identified a previously uncharacterized human protein called thanatos-associated protein-7 (THAP7), a member of a large family of THAP domain-containing putative DNA-binding proteins. In this study we demonstrate that THAP7 associates with TAF-Ibeta in vitro and map their association domains to a C-terminal predicted coiled-coil motif on THAP7 and the central region of TAF-Ibeta. Similarly, stably transfected THAP7 associates with endogenous TAF-Ibeta in intact cells. Like TAF-Ibeta, THAP7 associates with histone H3 and histone H4 and inhibits histone acetylation. The histone-interacting domain of THAP7 is sufficient for this activity in vitro. Promoter-targeted THAP7 can also recruit TAF-Ibeta and silencing mediator of retinoid and thyroid receptors/nuclear hormone receptor corepressor (NCoR) proteins to promoters, and knockdown of TAF-Ibeta by small interfering RNA relieves THAP7-mediated repression, indicating that, like nuclear hormone receptors, THAP7 may represent a novel class of transcription factor that uses TAF-Ibeta as a corepressor to maintain histones in a hypoacetylated, repressed state. PMID:16195249

  6. Changes in N-acetyl-B-D-glucosaminidase and B-glucuronidase activities in milk during bovine mastitis.

    PubMed

    Nagahata, H; Saito, S; Noda, H

    1987-01-01

    To determine the N-acetyl-B-D-glucosaminidase (NAGase) and B-glucuronidase (B-Gase) activities in mastitic milk, basic enzyme assay conditions, distribution of NAGase and B-Gase, comparison of their activities with California Mastitis Test scores, and the effects of the milking process on their enzyme activities were examined. The mean NAGase and B-Gase activities in milk macrophages were about threefold higher than those of milk and blood polymorphonuclear cells. Very little NAGase activity appeared to be associated with blood mononuclear cells, whereas a relatively higher B-Gase activity was observed. California Mastitis Test scores of each group (1 to 5) appeared to be well correlated (r = 0.86 for NAGase and 0.92 for B-Gase) with the levels of NAGase and B-Gase activity. The milking process was least effective in the normal milk, but some variations of enzyme activities during milking in mastitic milk were found. Changes in NAGase and B-Gase activities in quarter milk were well monitored during the course of clinical mastitis. PMID:3567747

  7. A cholinesterase genes server (ESTHER): a database of cholinesterase-related sequences for multiple alignments, phylogenetic relationships, mutations and structural data retrieval.

    PubMed Central

    Cousin, X; Hotelier, T; Liévin, P; Toutant, J P; Chatonnet, A

    1996-01-01

    We have built a database of sequences phylogenetically related to cholinesterases (ESTHER) for esterases, alpha/beta hydrolase enzymes and relatives). These sequences define a homogeneous group of enzymes (carboxylesterases, lipases and hormone-sensitive lipases) with some related proteins devoid of enzymatic activity. The purpose of ESTHER is to help comparison and alignment of any new sequence appearing in the field, to favour mutation analysis of structure-function relationships and to allow structural data recovery. ESTHER is a World Wide Web server with the URL http://www.montpellier.inra.fr:70/cholinesterase. PMID:8594562

  8. A cholinesterase genes server (ESTHER): a database of cholinesterase-related sequences for multiple alignments, phylogenetic relationships, mutations and structural data retrieval.

    PubMed

    Cousin, X; Hotelier, T; Liévin, P; Toutant, J P; Chatonnet, A

    1996-01-01

    We have built a database of sequences phylogenetically related to cholinesterases (ESTHER) for esterases, alpha/beta hydrolase enzymes and relatives). These sequences define a homogeneous group of enzymes (carboxylesterases, lipases and hormone-sensitive lipases) with some related proteins devoid of enzymatic activity. The purpose of ESTHER is to help comparison and alignment of any new sequence appearing in the field, to favour mutation analysis of structure-function relationships and to allow structural data recovery. ESTHER is a World Wide Web server with the URL http://www.montpellier.inra.fr:70/cholinesterase.

  9. [Activity of protective proteins in wheat plants treated with chitooligosaccharides with different degrees of acetylation and infection with Bipolaris sorokiniana].

    PubMed

    Iarullina, L G; Kasimova, R I; Akhatova, A R

    2014-01-01

    The influence of chitooligosaccharides (COS) with different degrees of acetylation (DA) on the production of hydrogen peroxide (H2O2) and changes in the level of gene expression of pathogenesis-related (PR) proteins (oxalate oxidase AJ556991.1, peroxidase TC 151917, chitinase AV029935L, proteinase inhibitor EU293132.1) in the roots of the wheat Triticum aestivum L. inoculated with root rot pathogen Bipolaris sorokiniana (Sacc.) Shoenaker was investigated. Differences were detected in plant responses to infection. These differences were due to the pretreatment of COS seeds with differing DA. Our results demonstrated that COS with a DA over 65% more effectively induced accumulation of H2O2 and increased the transcriptional activity of genes of PR-proteins as compared to COS with a DA of 30%. These data suggest an important role for DA in the manifestation of eliciting properties of COS, also in the presence of H2O2.

  10. Assessment of Serum Cholinesterase in Rural Punjabi Sprayers Exposed to a Mixture of Pesticides

    PubMed Central

    Dhalla, Amar Santosh; Sharma, Suman

    2013-01-01

    Serum cholinesterase (SChE) activity is considered as a biomarker and is also taken as an exposure index to assess the low level, chronic residue exposures among sprayers. Thus, cholinesterase activity was studied in the professional rural Punjabi sprayers of Bathinda district in Punjab. This study was made to estimate the irregularities in the level of cholinesterase according to multiple pesticides used by sprayers, exposure periods, age, and body mass index (BMI) of the sprayers. The data generated was statistically analyzed by applying Student's ‘t’ test and one-way analysis of variance. A positive correlation was found between SChE activity and years of exposure and a significant reduction in SChE activity was observed in younger population. Again, a positive correlation was seen between BMI and SChE inhibition. PMID:24082509

  11. 21 CFR 862.3240 - Cholinesterase test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... to measure cholinesterase (an enzyme that catalyzes the hydrolysis of acetylcholine to choline) in... obtained by this device are used in the diagnosis and treatment of cholinesterase inhibition disorders...

  12. 21 CFR 862.3240 - Cholinesterase test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... to measure cholinesterase (an enzyme that catalyzes the hydrolysis of acetylcholine to choline) in... obtained by this device are used in the diagnosis and treatment of cholinesterase inhibition disorders...

  13. 21 CFR 862.3240 - Cholinesterase test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... to measure cholinesterase (an enzyme that catalyzes the hydrolysis of acetylcholine to choline) in... obtained by this device are used in the diagnosis and treatment of cholinesterase inhibition disorders...

  14. Inhibition of sulfur mustard-increased protease activity by niacinamide, N-acetyl-L-cysteine or dexamethasone

    SciTech Connect

    Cowan, F.M.; Broomfield, C.A.; Smith, W.J.

    1991-03-11

    The pathologic mechanism of sulfur mustard-induced skin vesication is as yet undefined. Papirmeister et al. have postulated a biochemical mechanism for sulfur mustard-induced cutaneous injury involving sequelae of DNA alkylation, metabolic disruption resulting in NAD+ depletion and activation of protease. The authors have utilized a chromogenic peptide substrate assay to establish that human peripheral blood lymphocytes exposed 24 hr previously to sulfur mustard exhibited an increase in proteolytic activity. Doses of compounds known to alter the biochemical events associated with sulfur mustard exposure or reduce protease activity were tested in this system for their ability to block the sulfur mustard-induced protease activity. Treatment with niacinamide 1 hr after or with N-acetyl-L-cysteine or dexamethasone 24 hr prior to sulfur mustard exposure resulted in a decrease of 39%, 33% and 42% respectively of sulfur mustard-increased protease activity. These data suggest that therapeutic intervention into the biochemical pathways that culminate in protease activation might serve as an approach to treatment of sulfur mustard-induced pathology.

  15. Protease inhibitors and indoleamines selectively inhibit cholinesterases in the histopathologic structures of Alzheimer disease.

    PubMed Central

    Wright, C I; Guela, C; Mesulam, M M

    1993-01-01

    Neurofibrillary tangles and amyloid plaques express acetylcholinesterase and butyrylcholinesterase activity in Alzheimer disease. We previously reported that traditional acetylcholinesterase inhibitors such as BW284C51, tacrine, and physostigmine were more potent inhibitors of the acetylcholinesterase in normal axons and cell bodies than of the acetylcholinesterase in plaques and tangles. We now report that the reverse pattern is seen with indoleamines (such as serotonin and its precursor 5-hydroxytryptophan), carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal axons and cell bodies. This shift in enzymatic affinity may lead to the abnormal protein processing that is thought to play a major role in the pathogenesis of Alzheimer disease. The availability of pharmacological and dietary means for altering brain indoleamines raises therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer disease. Images PMID:8421706

  16. Histone acetylation: truth of consequences?

    PubMed

    Choi, Jennifer K; Howe, Leann J

    2009-02-01

    Eukaryotic DNA is packaged into a nucleoprotein structure known as chromatin, which is comprised of DNA, histones, and nonhistone proteins. Chromatin structure is highly dynamic, and can shift from a transcriptionally inactive state to an active form in response to intra- and extracellular signals. A major factor in chromatin architecture is the covalent modification of histones through the addition of chemical moieties, such as acetyl, methyl, ubiquitin, and phosphate groups. The acetylation of the amino-terminal tails of histones is a process that is highly conserved in eukaryotes, and was one of the earliest histone modifications characterized. Since its identification in 1964, a large body of evidence has accumulated demonstrating that histone acetylation plays an important role in transcription. Despite our ever-growing understanding of the nuclear processes involved in nucleosome acetylation, however, the exact biochemical mechanisms underlying the downstream effects of histone acetylation have yet to be fully elucidated. To date, histone acetylation has been proposed to function in 2 nonmutually exclusive manners: by directly altering chromatin structure, and by acting as a molecular tag for the recruitment of chromatin-modifying complexes. Here, we discuss recent research focusing on these 2 potential roles of histone acetylation and clarify what we actually know about the function of this modification.

  17. Community shifts of actively growing lake bacteria after N-acetyl-glucosamine addition: improving the BrdU-FACS method

    PubMed Central

    Tada, Yuya; Grossart, Hans-Peter

    2014-01-01

    In aquatic environments, community dynamics of bacteria, especially actively growing bacteria (AGB), are tightly linked with dissolved organic matter (DOM) quantity and quality. We analyzed the community dynamics of DNA-synthesizing and accordingly AGB by linking an improved bromodeoxyuridine immunocytochemistry approach with fluorescence-activated cell sorting (BrdU-FACS). FACS-sorted cells of even oligotrophic ecosystems in winter were characterized by 16S rRNA gene analysis. In incubation experiments, we examined community shifts of AGB in response to the addition of N-acetyl-glucosamine (NAG), one of the most abundant aminosugars in aquatic systems. Our improved BrdU-FACS analysis revealed that AGB winter communities of oligotrophic Lake Stechlin (northeastern Germany) substantially differ from those of total bacteria and consist of Alpha-, Beta-, Gamma-, Deltaproteobacteria, Actinobacteria, Candidatus OP10 and Chloroflexi. AGB populations with different BrdU-fluorescence intensities and cell sizes represented different phylotypes suggesting that single-cell growth potential varies at the taxon level. NAG incubation experiments demonstrated that a variety of widespread taxa related to Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Planctomycetes, Spirochaetes, Verrucomicrobia and Chloroflexi actively grow in the presence of NAG. The BrdU-FACS approach enables detailed phylogenetic studies of AGB and, thus, to identify those phylotypes which are potential key players in aquatic DOM cycling. PMID:23985742

  18. Activity of the response regulator CiaR in mutants of Streptococcus pneumoniae R6 altered in acetyl phosphate production

    PubMed Central

    Marx, Patrick; Meiers, Marina; Brückner, Reinhold

    2015-01-01

    The two-component regulatory system (TCS) CiaRH of Streptococcus pneumoniae is implicated in competence, ß-lactam resistance, maintenance of cell integrity, bacteriocin production, host colonization, and virulence. Depending on the growth conditions, CiaR can be highly active in the absence of its cognate kinase CiaH, although phosphorylation of CiaR is required for DNA binding and gene regulation. To test the possibility that acetyl phosphate (AcP) could be the alternative phosphodonor, genes involved in pyruvate metabolism were disrupted to alter cellular levels of acetyl phosphate. Inactivating the genes of pyruvate oxidase SpxB, phosphotransacetylase Pta, and acetate kinase AckA, resulted in very low AcP levels and in strongly reduced CiaR-mediated gene expression in CiaH-deficient strains. Therefore, alternative phosphorylation of CiaR appears to proceed via AcP. The AcP effect on CiaR is not detected in strains with CiaH. Attempts to obtain elevated AcP by preventing its degradation by acetate kinase AckA, were not successful in CiaH-deficient strains with a functional SpxB, the most important enzyme for AcP production in S. pneumoniae. The ciaH-spxB-ackA mutant producing intermediate amounts of AcP could be constructed and showed a promoter activation, which was much higher than expected. Since activation was dependent on AcP, it can apparently be used more efficiently for CiaR phosphorylation in the absence of AckA. Therefore, high AcP levels in the absence of CiaH and AckA may cause extreme overexpression of the CiaR regulon leading to synthetic lethality. AckA is also involved in a regulatory response, which is mediated by CiaH. Addition of acetate to the growth medium switch CiaH from kinase to phosphatase. This switch is lost in the absence of AckA indicating metabolism of acetate is required, which starts with the production of AcP by AckA. Therefore, AckA plays a special regulatory role in the control of the CiaRH TCS. PMID:25642214

  19. Rosemary tea consumption results to anxiolytic- and anti-depressant-like behavior of adult male mice and inhibits all cerebral area and liver cholinesterase activity; phytochemical investigation and in silico studies.

    PubMed

    Ferlemi, Anastasia-Varvara; Katsikoudi, Antigoni; Kontogianni, Vassiliki G; Kellici, Tahsin F; Iatrou, Grigoris; Lamari, Fotini N; Tzakos, Andreas G; Margarity, Marigoula

    2015-07-25

    Our aim was to investigate the possible effects of regular drinking of Rosmarinus officinalis L. leaf infusion on behavior and on AChE activity of mice. Rosemary tea (2% w/w) phytochemical profile was investigated through LC/DAD/ESI-MS(n). Adult male mice were randomly divided into two groups: "Rosemary-treated" that received orally the rosemary tea for 4weeks and "control" that received drinking water. The effects of regular drinking of rosemary tea on behavioral parameters were assessed by passive avoidance, elevated plus maze and forced swimming tests. Moreover, its effects on cerebral and liver cholinesterase (ChE) isoforms activity were examined colorimetricaly. Phytochemical analysis revealed the presence of diterpenes, flavonoids and hydroxycinnamic derivatives in rosemary tea; the major compounds were quantitatively determined. Its consumption rigorously affected anxiety/fear and depression-like behavior of mice, though memory/learning was unaffected. ChE isoforms activity was significantly decreased in brain and liver of "rosemary treated" mice. In order to explain the tissue ChE inhibition, principal component analysis, pharmacophore alignment and molecular docking were used to explore a possible relationship between main identified compounds of rosemary tea, i.e. rosmarinic acid, luteolin-7-O-glucuronide, caffeic acid and known AChE inhibitors. Results revealed potential common pharmacophores of the phenolic components with the inhibitors. Our findings suggest that rosemary tea administration exerts anxiolytic and antidepressant effects on mice and inhibits ChE activity; its main phytochemicals may function in a similar way as inhibitors.

  20. AMPK activation represses the human gene promoter of the cardiac isoform of acetyl-CoA carboxylase: Role of nuclear respiratory factor-1

    SciTech Connect

    Adam, Tasneem; Opie, Lionel H.; Essop, M. Faadiel

    2010-07-30

    Research highlights: {yields} AMPK inhibits acetyl-CoA carboxylase beta gene promoter activity. {yields} Nuclear respiratory factor-1 inhibits acetyl-CoA carboxylase beta promoter activity. {yields} AMPK regulates acetyl-CoA carboxylase beta at transcriptional level. -- Abstract: The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC{beta}) produces malonyl-CoA, a potent inhibitor of carnitine palmitoyltransferase-1. AMPK inhibits ACC{beta} activity, lowering malonyl-CoA levels and promoting mitochondrial fatty acid {beta}-oxidation. Previously, AMPK increased promoter binding of nuclear respiratory factor-1 (NRF-1), a pivotal transcriptional modulator controlling gene expression of mitochondrial proteins. We therefore hypothesized that NRF-1 inhibits myocardial ACC{beta} promoter activity via AMPK activation. A human ACC{beta} promoter-luciferase construct was transiently transfected into neonatal cardiomyocytes {+-} a NRF-1 expression construct. NRF-1 overexpression decreased ACC{beta} gene promoter activity by 71 {+-} 4.6% (p < 0.001 vs. control). Transfections with 5'-end serial promoter deletions revealed that NRF-1-mediated repression of ACC{beta} was abolished with a pPII{beta}-18/+65-Luc deletion construct. AMPK activation dose-dependently reduced ACC{beta} promoter activity, while NRF-1 addition did not further decrease it. We also investigated NRF-1 inhibition in the presence of upstream stimulatory factor 1 (USF1), a known transactivator of the human ACC{beta} gene promoter. Here NRF-1 blunted USF1-dependent induction of ACC{beta} promoter activity by 58 {+-} 7.5% (p < 0.001 vs. control), reversed with a dominant negative NRF-1 construct. NRF-1 also suppressed endogenous USF1 transcriptional activity by 55 {+-} 6.2% (p < 0.001 vs. control). This study demonstrates that NRF-1 is a novel transcriptional inhibitor of the human ACC{beta} gene promoter in the mammalian heart. Our data extends AMPK regulation of ACC{beta} to the transcriptional level.

  1. Acetylation-deacetylation of the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) regulates its transcriptional activity and nucleocytoplasmic localization.

    PubMed

    Kawai, Yumiko; Garduño, Lakisha; Theodore, Melanie; Yang, Jianqi; Arinze, Ifeanyi J

    2011-03-01

    Activation of Nrf2 by covalent modifications that release it from its inhibitor protein Keap1 has been extensively documented. In contrast, covalent modifications that may regulate its action after its release from Keap1 have received little attention. Here we show that CREB-binding protein induced acetylation of Nrf2, increased binding of Nrf2 to its cognate response element in a target gene promoter, and increased Nrf2-dependent transcription from target gene promoters. Heterologous sirtuin 1 (SIRT1) decreased acetylation of Nrf2 as well as Nrf2-dependent gene transcription, and its effects were overridden by dominant negative SIRT1 (SIRT1-H355A). The SIRT1-selective inhibitors EX-527 and nicotinamide stimulated Nrf2-dependent gene transcription, whereas resveratrol, a putative activator of SIRT1, was inhibitory, mimicking the effect of SIRT1. Mutating lysine to alanine or to arginine at Lys(588) and Lys(591) of Nrf2 resulted in decreased Nrf2-dependent gene transcription and abrogated the transcription-activating effect of CREB-binding protein. Furthermore, SIRT1 had no effect on transcription induced by these mutants, indicating that these sites are acetylation sites. Microscope imaging of GFP-Nrf2 in HepG2 cells as well as immunoblotting for Nrf2 showed that acetylation conditions resulted in increased nuclear localization of Nrf2, whereas deacetylation conditions enhanced its cytoplasmic rather than its nuclear localization. We posit that Nrf2 in the nucleus undergoes acetylation, resulting in binding, with basic-region leucine zipper protein(s), to the antioxidant response element and consequently in gene transcription, whereas deacetylation disengages it from the antioxidant response element, thereby resulting in transcriptional termination and subsequently in its nuclear export. PMID:21196497

  2. Microbial transformation of acetyl-11-keto-β-boswellic acid and their inhibitory activity on LPS-induced NO production.

    PubMed

    Sun, Yan; Liu, Dan; Xi, Ronggang; Wang, Xiaobo; Wang, Yan; Hou, Jie; Zhang, Baojing; Wang, Changyuan; Liu, Kexin; Ma, Xiaochi

    2013-03-01

    The capabilities of 20 strains of fungi to transform acetyl-11-keto-β-boswellic (AKBA) were screened. And biotransformation of AKBA by Cunninghamella blakesleana AS 3.970 afforded five metabolites (1-5), while two metabolites (6, 7) were isolated from biotransformation of Cunninghamella elegans AS 3.1207. The chemical structures of these metabolites were identified by spectral methods including 2D NMR and their structures were elucidated as 7β-hydroxy-3-acety-11-keto-β-boswellic acid (1), 21β-dihydroxy-3-acety-11-keto-β-boswellic acid (2), 7β,22α-dihydroxy-3-acety-11-keto-β-boswellic acid (3), 7β,16α-dihydroxy-3-acety-11-keto-β-boswellic acid (4), 7β,15α-dihydroxy-3-acety-11-keto-β-boswellic acid (5); 7β,15α,21β-trihydroxy-3-acety-11-keto-β-boswellic acid (6) and 15α,21β-dihydroxy-3-acety-11-keto-β-boswellic acid (7). All these products are previously unknown. Their primary structure-activity relationships (SAR) of inhibition activity on LPS-induced NO production in RAW 264.7 macrophage cells were evaluated.

  3. Antimicrobial and demelanizing activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl esters.

    PubMed

    Heleno, Sandrina A; Ferreira, Isabel C F R; Esteves, Ana P; Ćirić, Ana; Glamočlija, Jasmina; Martins, Anabela; Soković, Marina; Queiroz, Maria João R P

    2013-08-01

    Mushroom extracts or isolated compounds may be useful in the search of new potent antimicrobial agents. Herein, it is described the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, two compounds identified in the medicinal mushroom Ganoderma lucidum. Their antimicrobial and demelanizing activities were evaluated and compared to the parent acids and G. lucidum extract. p-Hydroxybenzoic and cinnamic acids, as also their protected glucuronide derivatives revealed high antimicrobial (antibacterial and antifungal) activity, even better than the one showed by commercial standards. Despite the variation in the order of parent acids and the protected glucuronide derivatives, their antimicrobial activity was always higher than the one revealed by the extract. Nevertheless, the extract was the only one with demelanizing activity against Aspergillus niger. The acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds.

  4. Reactive oxygen species scavenger N-acetyl cysteine reduces methamphetamine-induced hyperthermia without affecting motor activity in mice

    PubMed Central

    Sanchez-Alavez, Manuel; Bortell, Nikki; Galmozzi, Andrea; Conti, Bruno; Marcondes, Maria Cecilia G.

    2014-01-01

    Hyperthermia is a potentially lethal side effect of Methamphetamine (Meth) abuse, which involves the participation of peripheral thermogenic sites such as the Brown Adipose Tissue (BAT). In a previous study we found that the anti-oxidant N-acetyl cysteine (NAC) can prevent the high increase in temperature in a mouse model of Meth-hyperthermia. Here, we have further explored the ability of NAC to modulate Meth-induced hyperthermia in correlation with changes in BAT. We found that NAC treatment in controls causes hypothermia, and, when administered prior or upon the onset of Meth-induced hyperthermia, can ameliorate the temperature increase and preserve mitochondrial numbers and integrity, without affecting locomotor activity. This was different from Dantrolene, which decreased motor activity without affecting temperature. The effects of NAC were seen in spite of its inability to recover the decrease of mitochondrial superoxide induced in BAT by Meth. In addition, NAC did not prevent the Meth-induced decrease of BAT glutathione. Treatment with S-adenosyl-L-methionine, which improves glutathione activity, had an effect in ameliorating Meth-induced hyperthermia, but also modulated motor activity. This suggests a role for the remaining glutathione for controlling temperature. However, the mechanism by which NAC operates is independent of glutathione levels in BAT and specific to temperature. Our results show that, in spite of the absence of a clear mechanism of action, NAC is a pharmacological tool to examine the dissociation between Meth-induced hyperthermia and motor activity, and a drug of potential utility in treating the hyperthermia associated with Meth-abuse. PMID:26346736

  5. Structural Diversity Within the Mononuclear and Binuclear Active Sites of N-Acetyl-D-Glucosamine-6-Phosphate Deacetylase

    SciTech Connect

    Hall,R.; Brown, S.; Fedorov, A.; Fedorov, E.; Xu, C.; Babbitt, P.; Almo, S.; Raushel, F.

    2007-01-01

    NagA catalyzes the hydrolysis of N-acetyl-D-glucosamine-6-phosphate to D-glucosamine-6-phosphate and acetate. X-ray crystal structures of NagA from Escherichia coli were determined to establish the number and ligation scheme for the binding of zinc to the active site and to elucidate the molecular interactions between the protein and substrate. The three-dimensional structures of the apo-NagA, Zn-NagA, and the D273N mutant enzyme in the presence of a tight-binding N-methylhydroxyphosphinyl-D-glucosamine-6-phosphate inhibitor were determined. The structure of the Zn-NagA confirms that this enzyme binds a single divalent cation at the beta-position in the active site via ligation to Glu-131, His-195, and His-216. A water molecule completes the ligation shell, which is also in position to be hydrogen bonded to Asp-273. In the structure of NagA bound to the tight binding inhibitor that mimics the tetrahedral intermediate, the methyl phosphonate moiety has displaced the hydrolytic water molecule and is directly coordinated to the zinc within the active site. The side chain of Asp-273 is positioned to activate the hydrolytic water molecule via general base catalysis and to deliver this proton to the amino group upon cleavage of the amide bond of the substrate. His-143 is positioned to help polarize the carbonyl group of the substrate in conjunction with Lewis acid catalysis by the bound zinc. The inhibitor is bound in the {alpha}-configuration at the anomeric carbon through a hydrogen bonding interaction of the hydroxyl group at C-1 with the side chain of His-251. The phosphate group of the inhibitor attached to the hydroxyl at C-6 is ion paired with Arg-227 from the adjacent subunit. NagA from Thermotoga maritima was shown to require a single divalent cation for full catalytic activity.

  6. The Effect of Substituent, Degree of Acetylation and Positioning of the Cationic Charge on the Antibacterial Activity of Quaternary Chitosan Derivatives

    PubMed Central

    Sahariah, Priyanka; Gaware, Vivek S.; Lieder, Ramona; Jónsdóttir, Sigríður; Hjálmarsdóttir, Martha Á.; Sigurjonsson, Olafur E.; Másson, Már

    2014-01-01

    A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone (C-0, C-2 and C-6) with the aid of 3,6-di-O-tert-butyldimethylsilyl protection of the chitosan backbone, thus allowing full (100%) substitution of the free amino groups. All of the derivatives were characterized using 1H-NMR, 1H-1H COSY and FT-IR spectroscopy, while molecular weight was determined by GPC. Antibacterial activity was investigated against Gram positive S. aureus and Gram negative E. coli. The relationship between structure and activity/toxicity was defined, considering the effect of the cationic group’s structure and its distance from the polymer backbone, as well as the degree of acetylation within a molecular weight range of 7–23 kDa for the final compounds. The N,N,N-trimethyl chitosan with 100% quaternization showed the highest antibacterial activity with moderate cytotoxicity, while increasing the spacer length reduced the activity. Trimethylammoniumyl quaternary ammonium moieties contributed more to activity than 1-pyridiniumyl moieties. In general, no trend in the antibacterial activity of the compounds with increasing molecular weight or degree of acetylation up to 34% was observed. PMID:25196937

  7. TESTING FOR DEPARTURES FROM ADDITIVITY FOR A 2:1 MIXTURE OF CHLORPYRIFOS AND CARBARYL ON CHOLINESTERASE ACTIVITY IN BRAIN, PLASMA, AND RED BLOOD CELLS OF LONG EVANS RATS.

    EPA Science Inventory

    Detecting and characterizing interactions among chemicals is an important environmental issue. This study was conducted to test for the existence of a significant departure from additivity for a mixture of two cholinesterase (ChE)-inhibiting pesticides: chlorpyrifos (CPF), an org...

  8. Acetyl-L-Carnitine Prevents Methamphetamine-Induced Structural Damage on Endothelial Cells via ILK-Related MMP-9 Activity.

    PubMed

    Fernandes, S; Salta, S; Bravo, J; Silva, A P; Summavielle, T

    2016-01-01

    Methamphetamine (METH) is a potent psychostimulant highly used worldwide. Recent studies evidenced the involvement of METH in the breakdown of the blood-brain-barrier (BBB) integrity leading to compromised function. The involvement of the matrix metalloproteinases (MMPs) in the degradation of the neurovascular matrix components and tight junctions (TJs) is one of the most recent findings in METH-induced toxicity. As BBB dysfunction is a pathological feature of many neurological conditions, unveiling new protective agents in this field is of major relevance. Acetyl-L-carnitine (ALC) has been described to protect the BBB function in different paradigms, but the mechanisms underling its action remain mostly unknown. Here, the immortalized bEnd.3 cell line was used to evaluate the neuroprotective features of ALC in METH-induced damage. Cells were exposed to ranging concentrations of METH, and the protective effect of ALC 1 mM was assessed 24 h after treatment. F-actin rearrangement, TJ expression and distribution, and MMPs activity were evaluated. Integrin-linked kinase (ILK) knockdown cells were used to assess role of ALC in ILK mediated METH-triggered MMPs' activity. Our results show that METH led to disruption of the actin filaments concomitant with claudin-5 translocation to the cytoplasm. These events were mediated by MMP-9 activation in association with ILK overexpression. Pretreatment with ALC prevented METH-induced activation of MMP-9, preserving claudin-5 location and the structural arrangement of the actin filaments. The present results support the potential of ALC in preserving BBB integrity, highlighting ILK as a new target for the ALC therapeutic use.

  9. Comparison of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase activities for evaluation of microangiopathy in diabetes mellitus.

    PubMed

    Shimojo, N; Kitahashi, S; Naka, K; Fujii, A; Okuda, K; Tanaka, S; Fujii, S

    1987-03-01

    The activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) were measured in 207 diabetic patients and 57 healthy controls, and the relationship of these enzymes to different stages of diabetic microangiopathy was studied. Diabetics with clinical proteinuria had higher urinary NAG and AAP (17.7 +/- 1.9 and 42.8 +/- 4.9 U/g creatinine, mean +/- SE, respectively) than healthy controls (1.8 +/- 0.1 and 10.0 +/- 0.4) or diabetics without proteinuria. Among diabetics without proteinuria, NAG excretion in those with retinopathy was slightly higher than in those without (6.4 +/- 0.5 v 5.4 +/- 0.4), and AAP in those with retinopathy was significantly higher than in those without (23.0 +/- 1.5 v 17.4 +/- 0.8, P less than 0.01). Urinary albumin measured by radioimmunoassay and lysozyme in diabetics with retinopathy but without proteinuria was higher than those without retinopathy (P less than 0.001 and P less than 0.01). The increase in albumin was the greatest in diabetics with long duration of the disease (greater than or equal to 8 years); however, NAG and AAP increased more significantly in those with high hemoglobin A1c than in patients with long duration.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2881186

  10. Semi-synthetic preparation of 1-O-(1'-/sup 14/C)hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) using plant cell cultures

    SciTech Connect

    Weber, N.; Mangold, H.K.

    1985-04-01

    Incubation of photomixotrophic cell suspension cultures of rape (Brassica napus) and heterotrophic cell suspension cultures of soya (Glycine max) with 1-O-(1'-/sup 14/C)hexadecyl-sn-glycerol or rac-1-O-(1'-/sup 14/C)hexadecylglycerol leads in high yield (up to 78%) to labeled 1-O-hexadecyl-2-acyl-sn-glycero-3-phosphocholines. Alkaline hydrolysis of the choline glycerophospholipids yields pure 1-O-(1'-/sup 14/C)hexadecyl-sn-glycero-3-phosphocholine. 1-O-(1'-14C)Hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) is obtained by acetylating the lyso compound. The semi-synthetic preparation described leads to labeled platelet activating factor in an overall yield of 50-60% without loss of specific activity.

  11. Neurogenin 3 Recruits CBP Co-activator to Facilitate Histone H3/H4 Acetylation in the Target Gene INSM1

    PubMed Central

    Breslin, Mary B.; Wang, Hong-Wei; Pierce, Amy; Aucoin, Rebecca; Lan, Michael S.

    2007-01-01

    INSM1 is a downstream target gene of ngn3. A promoter construct containing the −426/+40bp region transiently co-transfected into NIH-3T3 cells with a ngn3 expression plasmid resulted in a 12 fold increase in promoter activity. The ngn3/E47 heterodimer selectively binds and activates the E-box3 of the INSM1 promoter. The endogenous ngn3 and CBP co-activator occupy the INSM1 promoter, resulting in hyper-acetylation of histone H3/H4 chromatin in a human neuroblastoma cell line, IMR-32. Additionally, adenoviral ngn3 can induce endogenous INSM-1 expression in PANC-1 cells through the recruitment of CBP to the INSM1 promoter and increase the acetylation of the INSM1 promoter region. PMID:17300785

  12. Acetylation regulates Jun protein turnover in Drosophila.

    PubMed

    Zhang, Daoyong; Suganuma, Tamaki; Workman, Jerry L

    2013-11-01

    C-Jun is a major transcription factor belonging to the activating protein 1 (AP-1) family. Phosphorylation has been shown to be critical for c-Jun activation and stability. Here, we report that Jra, the Drosophila Jun protein, is acetylated in vivo. We demonstrate that the acetylation of Jra leads to its rapid degradation in response to osmotic stress. Intriguingly, we also found that Jra phosphorylation antagonized its acetylation, indicating the opposite roles of acetylation and phosphorylation in Jra degradation process under osmotic stress. Our results provide new insights into how c-Jun proteins are precisely regulated by the interplay of different posttranslational modifications.

  13. Brain cholinesterases: III. Future perspectives of AD research and clinical practice.

    PubMed

    Shen, Z-X

    2004-01-01

    Alzheimer's disease (AD) is initially and primarily associated with the degeneration and alteration in the metabolism of cholinesterases (ChEs). The use of ChEs inhibitors to treat Alzheimer's condition, on the basis of the cholinergic hypothesis of the disease, is, therefore, without grounds. Most disturbing is the fact that the currently available anti-ChEs are designed to inhibit normal ChEs in the brain and throughout the body, but not the abnormal ones. Based on the acetylcholinesterase (AChE) deficiency theory, treatment should be designed to protect the cranial ChEs system from alteration and/or to help that system fight against degeneration through restoring its homeostatic action for brain structure and function instead. The overlap in the clinical, biochemical, molecular-cellular, and pathological alterations seen in patients with AD and individuals with many other brain disorders, which has bewildered many investigators, may now be explained by the shared underlying mismetabolism of brain ChEs. The abnormal metabolism of ChEs existing in asymptomatic subjects may indicate that the system is "at risk" and deserves serious attention. Future perspectives of ChEs research in vivo and in vitro in connection with AD and clinical diagnosis, prevention and treatment are proposed. Several potentially useful therapeutic and preventive means and pharmacological agents in this regard are identified and discussed, such as physical and intellectual stimulation, and a class of drugs including vitamin E, R-(-)-deprenyl (deprenyl, selegiline), acetyl L-carnitine, cytidine diphosphocholine (CDP-choline), centrophenoxine, L-phenylalanine, naloxone, galactose, and lithium, that have been proven to be able to stimulate AChE activity. Their working mechanisms may be through directly changing the configuration of AChE molecules and/or correcting micro- and overall environmental biological conditions for ChEs.

  14. Extracellular production of Streptomyces lividans acetyl xylan esterase A in Escherichia coli for rapid detection of activity.

    PubMed

    Nisole, Audrey; Lussier, François-Xavier; Morley, Krista L; Shareck, François; Kazlauskas, Romas J; Dupont, Claude; Pelletier, Joelle N

    2006-04-01

    Acetyl xylan esterase A (AxeA) from Streptomyces lividans belongs to a large family of industrially relevant polysaccharide esterases. AxeA and its truncated form containing only the catalytically competent domain, AxeA(tr), catalyze both the deacetylation of xylan and the N-deacetylation of chitosan. This broad substrate specificity lends additional interest to their characterization and production. Here, we report three systems for extracellular production of AxeA(tr): secretion from the native host S. lividans with the native signal peptide, extracellular production in Escherichia coli with the native signal peptide, and in E. coli with the OmpA signal peptide. Over five to seven days of a shake flask culture, the native host S. lividans with the native signal peptide secreted AxeA(tr) into the extracellular medium in high yield (388 mg/L) with specific activity of 19 U/mg corresponding to a total of 7000 U/L. Over one day of shake flask culture, E. coli with the native secretion signal peptide produced 84-fold less in the extracellular medium (4.6 mg/L), but the specific activity was higher (100 U/mg) corresponding to a total of 460 U/L. A similar E. coli culture using the OmpA signal peptide, produced 10mg/L with a specific activity of 68 U/mg, corresponding to a total of 680 U/L. In 96-well microtiter plates, extracellular production with E. coli gave approximately 30 and approximately 86 microg/mL in S. lividans. Expression in S. lividans with the native signal peptide is best for high level production, while expression in E. coli using the OmpA secretion signal peptide is best for high-throughput expression and screening of variants in microtiter plate format.

  15. Protein acetylation in metabolism - metabolites and cofactors.

    PubMed

    Menzies, Keir J; Zhang, Hongbo; Katsyuba, Elena; Auwerx, Johan

    2016-01-01

    Reversible acetylation was initially described as an epigenetic mechanism regulating DNA accessibility. Since then, this process has emerged as a controller of histone and nonhistone acetylation that integrates key physiological processes such as metabolism, circadian rhythm and cell cycle, along with gene regulation in various organisms. The widespread and reversible nature of acetylation also revitalized interest in the mechanisms that regulate lysine acetyltransferases (KATs) and deacetylases (KDACs) in health and disease. Changes in protein or histone acetylation are especially relevant for many common diseases including obesity, diabetes mellitus, neurodegenerative diseases and cancer, as well as for some rare diseases such as mitochondrial diseases and lipodystrophies. In this Review, we examine the role of reversible acetylation in metabolic control and how changes in levels of metabolites or cofactors, including nicotinamide adenine dinucleotide, nicotinamide, coenzyme A, acetyl coenzyme A, zinc and butyrate and/or β-hydroxybutyrate, directly alter KAT or KDAC activity to link energy status to adaptive cellular and organismal homeostasis.

  16. Cholinesterase inhibitors from the roots of Harpagophytum procumbens.

    PubMed

    Bae, Yoon Ho; Cuong, To Dao; Hung, Tran Manh; Kim, Jeong Ah; Woo, Mi Hee; Byeon, Jeong Su; Choi, Jae Sue; Min, Byung Sun

    2014-01-01

    Inhibition of cholinesterase has been proposed to be a therapeutic target for the treatment of Alzheimer's diseases. In our preliminary screening study on the acetylcholinesterase (AChE) inhibitory activity, an ethyl acetate soluble fraction of the roots of Harpagophytum procumbens (Pedaliaceae) was found to inhibit AChE activity at the concentration of 100 μg/mL. Ten compounds (1-10) were isolated from the active fraction and evaluated for their inhibitory effect on AChE and butyrylcholinesterase (BChE). Among the isolates, verbascosides (5, 6, and 8) containing a caffeoyl and a 3,4-dihydroxyphenethyl groups in their structures, showed effective AChE inhibitory activity and also possessed BChE inhibitory activity. The findings suggest that verbascoside derivatives may be partially related to the anti-Alzheimer effect of this medicinal plant. PMID:24374905

  17. Cholinesterase inhibitors from the roots of Harpagophytum procumbens.

    PubMed

    Bae, Yoon Ho; Cuong, To Dao; Hung, Tran Manh; Kim, Jeong Ah; Woo, Mi Hee; Byeon, Jeong Su; Choi, Jae Sue; Min, Byung Sun

    2014-01-01

    Inhibition of cholinesterase has been proposed to be a therapeutic target for the treatment of Alzheimer's diseases. In our preliminary screening study on the acetylcholinesterase (AChE) inhibitory activity, an ethyl acetate soluble fraction of the roots of Harpagophytum procumbens (Pedaliaceae) was found to inhibit AChE activity at the concentration of 100 μg/mL. Ten compounds (1-10) were isolated from the active fraction and evaluated for their inhibitory effect on AChE and butyrylcholinesterase (BChE). Among the isolates, verbascosides (5, 6, and 8) containing a caffeoyl and a 3,4-dihydroxyphenethyl groups in their structures, showed effective AChE inhibitory activity and also possessed BChE inhibitory activity. The findings suggest that verbascoside derivatives may be partially related to the anti-Alzheimer effect of this medicinal plant.

  18. Species- and concentration-dependent differences of acetyl- and butyrylcholinesterase sensitivity to physostigmine and neostigmine.

    PubMed

    Bitzinger, Diane I; Gruber, Michael; Tümmler, Simon; Michels, Bernhard; Bundscherer, Anika; Hopf, Susanne; Trabold, Benedikt; Graf, Bernhard M; Zausig, York A

    2016-10-01

    Previous and more recent studies show that cholinesterase inhibitors (ChE-Is) are an important possibility for therapeutic intervention in Alzheimer's Disease, sepsis and other inflammatory syndromes. ChE-Is maintain high levels of acetylcholine (ACh) determining beneficial effects on the disease process. Despite numerous efforts to identify the appropriate choice of agents and dose of ChE-Is, a common protocol regarding concentration- and species-dependent differences in inhibitory potency (IC 50) of clinical relevant ChE-Is is still not available. To evaluate the in vitro sensitivity of Acetyl- and Butyrylcholinesterase (AChE, BChE), we compared the concentration-response effects of physostigmine and neostigmine on cholinesterases in whole blood from rat and human. A spectrophotometrical test system based on in vitro Ellman's reagent has been used to determine the kinetic properties of clinical relevant ChE-Is. In vitro, the enzyme activity of human AChE and BChE was inhibited in a concentration-dependent manner until a residual activity of 4-6% for AChE and 20-30% for BChE (IC 50 human AChE: 0.117 ± 0.007 μM physostigmine, 0.062 ± 0.003 μM neostigmine; IC 50 human BChE: 0.373 ± 0.089 μM neostigmine; 0.059 ± 0.012 μM physostigmine). The inhibition curve of rat BChE in contrast showed no concentration-dependency for physostigmine and neostigmine (87% residual activity even at high inhibitor concentrations). Rat AChE was inhibited in a concentration-dependent manner until a residual activity of 53%. The results suggest that cholinesterases from human and rat show marked species- and inhibitor-dependent differences in sensitivity to physostigmine and neostigmine. Knowledge of such differences may be critical in assessing the possible therapeutic effects of ChE-Is in both species and may guide researchers in the optimal design of future experiments regarding the application of ChE-Is. PMID:26772968

  19. Cholinesterases in neural development: new findings and toxicologic implications.

    PubMed Central

    Brimijoin, S; Koenigsberger, C

    1999-01-01

    Developing animals are more sensitive than adults to acute cholinergic toxicity from anticholinesterases, including organophosphorus pesticides, when administered in a laboratory setting. It is also possible that these agents adversely affect the process of neural development itself, leading to permanent deficits in the architecture of the central and peripheral nervous systems. Recent observations indicate that organophosphorus exposure can affect DNA synthesis and cell survival in neonatal rat brain. New evidence that acetylcholinesterase may have a direct role in neuronal differentiation provides additional grounds for interest in the developmental toxicity of anticholinesterases. For example, correlative anatomic studies show that transient bursts of acetylcholinesterase expression often coincide with periods of axonal outgrowth in maturing avian, rodent, and primate brain. Some selective cholinesterase inhibitors effectively suppress neurite outgrowth in model systems like differentiating neuroblastoma cells and explanted sensory ganglia. When enzyme expression is altered by genetic engineering, acetylcholinesterase levels on the outer surface of transfected neurons correlate with ability to extend neurites. Certain of these "morphogenic" effects may depend on protein-protein interactions rather than catalytic acetylcholinesterase activity. Nonetheless, it remains possible that some pesticides interfere with important developmental functions of the cholinesterase enzyme family. Images Figure 1 Figure 3 PMID:10229707

  20. In vitro antioxidant and inhibitory activity of water decoctions of carob tree (Ceratonia siliqua L.) on cholinesterases, α-amylase and α-glucosidase.

    PubMed

    Custódio, Luísa; Patarra, João; Alberício, Fernando; Neng, Nuno Rosa; Nogueira, José Manuel Florêncio; Romano, Anabela

    2015-01-01

    This work reports the in vitro inhibitory activity of water decoctions of leaves, germ flour, pulp, locust bean gum and stem bark of carob tree on α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase. The antioxidant activity and the chemical characterisation of the extracts made by spectrophotometric assays and by high-performance liquid chromatography are also reported. Leaves and stem bark decoctions strongly inhibited all the enzymes tested, had significant antioxidant activity and the highest total phenolics content. The major compounds were identified as gallic acid in the leaves and gentisic acid in the stem bark.

  1. In vitro antioxidant and inhibitory activity of water decoctions of carob tree (Ceratonia siliqua L.) on cholinesterases, α-amylase and α-glucosidase.

    PubMed

    Custódio, Luísa; Patarra, João; Alberício, Fernando; Neng, Nuno Rosa; Nogueira, José Manuel Florêncio; Romano, Anabela

    2015-01-01

    This work reports the in vitro inhibitory activity of water decoctions of leaves, germ flour, pulp, locust bean gum and stem bark of carob tree on α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase. The antioxidant activity and the chemical characterisation of the extracts made by spectrophotometric assays and by high-performance liquid chromatography are also reported. Leaves and stem bark decoctions strongly inhibited all the enzymes tested, had significant antioxidant activity and the highest total phenolics content. The major compounds were identified as gallic acid in the leaves and gentisic acid in the stem bark. PMID:25582851

  2. Crystal Structure of the Extracellular Cholinesterase-Like Domain from Neuroligin-2

    SciTech Connect

    Koehnke,J.; Jin, X.; Budreck, E.; Posy, S.; Scheiffele, P.; Hnoig, B.; Shapiro, L.

    2008-01-01

    Neuroligins (NLs) are catalytically inactive members of a family of cholinesterase-like transmembrane proteins that mediate cell adhesion at neuronal synapses. Postsynaptic neuroligins engage in Ca2+-dependent transsynaptic interactions via their extracellular cholinesterase domain with presynaptic neurexins (NRXs). These interactions may be regulated by two short splice insertions (termed A and B) in the NL cholinesterase domain. Here, we present the 3.3- Angstroms crystal structure of the ectodomain from NL2 containing splice insertion A (NL2A). The overall structure of NL2A resembles that of cholinesterases, but several structural features are unique to the NL proteins. First, structural elements surrounding the esterase active-site region differ significantly between active esterases and NL2A. On the opposite surface of the NL2A molecule, the positions of the A and B splice insertions identify a candidate NRX interaction site of the NL protein. Finally, sequence comparisons of NL isoforms allow for mapping the location of residues of previously identified mutations in NL3 and NL4 found in patients with autism spectrum disorders. Overall, the NL2 structure promises to provide a valuable model for dissecting NL isoform- and synapse-specific functions.

  3. Time-resolved luminescence biosensor for continuous activity detection of protein acetylation-related enzymes based on DNA-sensitized terbium(III) probes.

    PubMed

    Han, Yitao; Li, Hao; Hu, Yufang; Li, Pei; Wang, Huixia; Nie, Zhou; Yao, Shouzhuo

    2015-09-15

    Protein acetylation of histone is an essential post-translational modification (PTM) mechanism in epigenetic gene regulation, and its status is reversibly controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Herein, we have developed a sensitive and label-free time-resolved luminescence (TRL) biosensor for continuous detection of enzymatic activity of HATs and HDACs, respectively, based on acetylation-mediated peptide/DNA interaction and Tb(3+)/DNA luminescent probes. Using guanine (G)-rich DNA-sensitized Tb(3+) luminescence as the output signal, the polycationic substrate peptides interact with DNA with high affinity and subsequently replace Tb(3+), eliminating the luminescent signal. HAT-catalyzed acetylation remarkably reduces the positive charge of the peptides and diminishes the peptide/DNA interaction, resulting in the signal on detection via recovery of DNA-sensitized Tb(3+) luminescence. With this TRL sensor, HAT (p300) can be sensitively detected with a wide linear range from 0.2 to 100 nM and a low detection limit of 0.05 nM. The proposed sensor was further used to continuously monitor the HAT activity in real time. Additionally, the TRL biosensor was successfully applied to evaluating HAT inhibition by two specific inhibitors, anacardic acid and C464, and satisfactory Z'-factors above 0.73 were obtained. Moreover, this sensor is feasible to continuously monitor the HDAC (Sirt1)-catalyzed deacetylation with a linear range from 0.5 to 500 nM and a detection limit of 0.5 nM. The proposed sensor is a convenient, sensitive, and mix-and-read assay, presenting a promising platform for protein acetylation-targeted epigenetic research and drug discovery.

  4. Use of cholinesterase activity as a biomarker of pesticide exposure used on Costa Rican banana plantations in the native tropical fish Astyanax aeneus (Günther, 1860).

    PubMed

    Mena, F; Azzopardi, M; Pfennig, S; Ruepert, C; Tedengren, M; Castillo, L E; Gunnarsson, J S

    2014-01-01

    In Costa Rica, thousands of tones of agricultural pesticides have been used for decades and their use is continuously increasing due to intensive and expanding production of coffee, pineapple, rice, ornamental plants and bananas. The objective of this study was to evaluate whether choline esterase (ChE) activity could be used as a biomarker of exposure to pesticides in the Costa Rican native fish Astyanax aeneus (characidae). Three methods used in order to evaluate the ChE biomarker were as follows: Laboratory studies where A. aeneus was exposed to organophosphate pesticide (ethoprophos); In situ 48 hr exposure assessment using caging experiments with fish exposed upstream and downstream of banana plantations and ChE activity estimation of in fish captured directly at sites with different degrees of pesticide exposure. Results from the laboratory studies showed that ChE activity in both brain and muscle tissue was significantly lower in fish exposed to ethoprophos than in controls. Fish from the caging experiments showed no difference in ChE activity neither in brain nor in muscle tissue between the four tested sites and was attributed to the short duration of the exposure. Asignificant difference in ChE activity was determined in muscle of fish captured from Laguna Madre de Dios compared to fish from Canal Batán. Although our laboratory results revealed that ChE activity in A. aeneus was highly responsive to ethoprophos, results from field experiments were less conclusive and showed that the captured fish showed large variability in ChE activity and that more research is needed before ChE activity can be used as reliable biomarker of pesticide exposure. PMID:24579519

  5. Use of cholinesterase activity as a biomarker of pesticide exposure used on Costa Rican banana plantations in the native tropical fish Astyanax aeneus (Günther, 1860).

    PubMed

    Mena, F; Azzopardi, M; Pfennig, S; Ruepert, C; Tedengren, M; Castillo, L E; Gunnarsson, J S

    2014-01-01

    In Costa Rica, thousands of tones of agricultural pesticides have been used for decades and their use is continuously increasing due to intensive and expanding production of coffee, pineapple, rice, ornamental plants and bananas. The objective of this study was to evaluate whether choline esterase (ChE) activity could be used as a biomarker of exposure to pesticides in the Costa Rican native fish Astyanax aeneus (characidae). Three methods used in order to evaluate the ChE biomarker were as follows: Laboratory studies where A. aeneus was exposed to organophosphate pesticide (ethoprophos); In situ 48 hr exposure assessment using caging experiments with fish exposed upstream and downstream of banana plantations and ChE activity estimation of in fish captured directly at sites with different degrees of pesticide exposure. Results from the laboratory studies showed that ChE activity in both brain and muscle tissue was significantly lower in fish exposed to ethoprophos than in controls. Fish from the caging experiments showed no difference in ChE activity neither in brain nor in muscle tissue between the four tested sites and was attributed to the short duration of the exposure. Asignificant difference in ChE activity was determined in muscle of fish captured from Laguna Madre de Dios compared to fish from Canal Batán. Although our laboratory results revealed that ChE activity in A. aeneus was highly responsive to ethoprophos, results from field experiments were less conclusive and showed that the captured fish showed large variability in ChE activity and that more research is needed before ChE activity can be used as reliable biomarker of pesticide exposure.

  6. Comparative aspects of the purification and properties of cholinesterases

    PubMed Central

    Augustinsson, Klas-Bertil

    1971-01-01

    Recent years have seen great progress in the purification and characterization of cholinesterases. Investigation has indicated the existence of two principal groups: a fairly homogeneous group of acetylcholinesterases and a group of enzymes that utilize butyrylcholine, propionycholine, or benzoylcholine as substrates and that differ widely in their properties. This paper reviews the different types of cholinesterase and their sources, the importance of a proper choice of substrate in cholinesterase studies, methods for the purification of cholinesterases, and some of the properties of these enzymes. PMID:4938026

  7. Activity of cholinesterases, pyruvate kinase and adenosine deaminase in rats experimentally infected by Fasciola hepatica: Influences of these enzymes on inflammatory response and pathological findings.

    PubMed

    Baldissera, Matheus D; Bottari, Nathieli B; Mendes, Ricardo E; Schwertz, Claiton I; Lucca, Neuber J; Dalenogare, Diessica; Bochi, Guilherme V; Moresco, Rafael N; Morsch, Vera M; Schetinger, Maria R C; Rech, Virginia C; Jaques, Jeandre A; Da Silva, Aleksandro S

    2015-11-01

    The aim of this study was to investigate acetylcholinesterase (AChE) in total blood and liver tissue; butyrylcholinesterase (BChE) in serum and liver tissue; adenosine deaminase (ADA) in serum and liver tissue; and pyruvate kinase (PK) in liver tissue of rats experimentally infected by Fasciola hepatica. Animals were divided into two groups with 12 animals each, as follows: group A (uninfected) and group B (infected). Samples were collected at 20 (A1 and B1;n=6 each) and 150 (A2 and B2; n=6 each) days post-infection (PI). Infected animals showed an increase in AChE activity in whole blood and a decrease in AChE activity in liver homogenates (P<0.05) at 20 and 150 days PI. BChE and PK activities were decreased (P<0.05) in serum and liver homogenates of infected animals at 150 days PI. ADA activity was decreased in serum at 20 and 150 days PI, while in liver homogenates it was only decreased at 150 days PI (P<0.05). Aspartate aminotransferase and alanine aminotransferase activities in serum were increased (P<0.05), while concentrations of total protein and albumin were decreased (P<0.05) when compared to control. The histological analysis revealed fibrous perihepatitis and necrosis. Therefore, we conclude that the liver fluke is associated with cholinergic and purinergic dysfunctions, which in turn may influence the pathogenesis of the disease.

  8. Fatal Intoxication with Acetyl Fentanyl.

    PubMed

    Cunningham, Susan M; Haikal, Nabila A; Kraner, James C

    2016-01-01

    Among the new psychoactive substances encountered in forensic investigations is the opioid, acetyl fentanyl. The death of a 28-year-old man from recreational use of this compound is reported. The decedent was found in the bathroom of his residence with a tourniquet secured around his arm and a syringe nearby. Postmortem examination findings included marked pulmonary and cerebral edema and needle track marks. Toxicological analysis revealed acetyl fentanyl in subclavian blood, liver, vitreous fluid, and urine at concentrations of 235 ng/mL, 2400 ng/g, 131 ng/mL, and 234 ng/mL, respectively. Acetyl fentanyl was also detected in the accompanying syringe. Death was attributed to recreational acetyl fentanyl abuse, likely through intravenous administration. The blood acetyl fentanyl concentration is considerably higher than typically found in fatal fentanyl intoxications. Analysis of this case underscores the need for consideration of a wide range of compounds with potential opioid-agonist activity when investigating apparent recreational drug-related deaths. PMID:26389815

  9. Lead-induced effects on learning/memory and fear/anxiety are correlated with disturbances in specific cholinesterase isoform activity and redox imbalance in adult brain.

    PubMed

    Ferlemi, Anastasia-Varvara; Avgoustatos, Dionisis; Kokkosis, Alexandros G; Protonotarios, Vasilis; Constantinou, Caterina; Margarity, Marigoula

    2014-05-28

    The aim of the present study was to investigate whether the underlying mechanism of lead (Pb)-induced effects on learning/memory and fear/anxiety behavior involves changes either on AChE G4 (most abundant in brain) or on G1 isoform activity, and/or to a putative local disruption of oxidant/antioxidant balance. Adult male mice were randomly divided into two groups (18 animals/group): a vehicle group [500ppm (mg/L) CH3COONa/day for 4weeks in their drinking water] and a Pb-treated group [500ppm Pb(CH3COO)2/day for 4weeks in their drinking water]. At the end of the treatment period, mice were subjected to the behavioral tasks. Learning/memory was tested by step-through passive avoidance test, whereas fear/anxiety was studied using the elevated plus-maze and thigmotaxis tests. Pb levels in mice brain were determined using atomic absorption spectrometry. AChE activity was determined colorimetrically, and GSH and MDA levels fluorometrically in whole brain minus cerebellum, cerebral cortex, midbrain, hippocampus, striatum and cerebellum. The possible correlations between learning/memory or fear/anxiety behavior with the AChE activity and/or the lipid peroxidation levels and GSH content were also examined. Pb consumption caused significant deficits on mice learning/memory ability and increased anxiety. The consumption of the Pb solution inhibited the activity of the two AChE isoforms in all brain regions tested. Moreover, Pb exposure increased lipid peroxidation and decreased GSH levels in all brain regions examined. Spearman correlation analysis revealed that the coefficients between the particular behaviors, AChE activity and redox balance were brain region- and AChE isoform-specific. PMID:24768645

  10. From arylamine N-acetyltransferase to folate-dependent acetyl CoA hydrolase: impact of folic acid on the activity of (HUMAN)NAT1 and its homologue (MOUSE)NAT2.

    PubMed

    Laurieri, Nicola; Dairou, Julien; Egleton, James E; Stanley, Lesley A; Russell, Angela J; Dupret, Jean-Marie; Sim, Edith; Rodrigues-Lima, Fernando

    2014-01-01

    Acetyl Coenzyme A-dependent N-, O- and N,O-acetylation of aromatic amines and hydrazines by arylamine N-acetyltransferases is well characterised. Here, we describe experiments demonstrating that human arylamine N-acetyltransferase Type 1 and its murine homologue (Type 2) can also catalyse the direct hydrolysis of acetyl Coenzyme A in the presence of folate. This folate-dependent activity is exclusive to these two isoforms; no acetyl Coenzyme A hydrolysis was found when murine arylamine N-acetyltransferase Type 1 or recombinant bacterial arylamine N-acetyltransferases were incubated with folate. Proton nuclear magnetic resonance spectroscopy allowed chemical modifications occurring during the catalytic reaction to be analysed in real time, revealing that the disappearance of acetyl CH3 from acetyl Coenzyme A occurred concomitantly with the appearance of a CH3 peak corresponding to that of free acetate and suggesting that folate is not acetylated during the reaction. We propose that folate is a cofactor for this reaction and suggest it as an endogenous function of this widespread enzyme. Furthermore, in silico docking of folate within the active site of human arylamine N-acetyltransferase Type 1 suggests that folate may bind at the enzyme's active site, and facilitate acetyl Coenzyme A hydrolysis. The evidence presented in this paper adds to our growing understanding of the endogenous roles of human arylamine N-acetyltransferase Type 1 and its mouse homologue and expands the catalytic repertoire of these enzymes, demonstrating that they are by no means just xenobiotic metabolising enzymes but probably also play an important role in cellular metabolism. These data, together with the characterisation of a naphthoquinone inhibitor of folate-dependent acetyl Coenzyme A hydrolysis by human arylamine N-acetyltransferase Type 1/murine arylamine N-acetyltransferase Type 2, open up a range of future avenues of exploration, both for elucidating the developmental role of these

  11. Blood cholinesterase in rats fed an insect resistance apple clone containing a natural cholinesterase inhibitor.

    PubMed

    Stoewsand, G S; Anderson, J L; Brown, S K

    1994-01-01

    A crab apple clone (Malus brevipes 1021), highly resistant to the apple maggot, is being used in breeding programs developing commercial apple cultivars. This study has discovered that this crab apple contains a natural cholinesterase (ChE) inhibitor that caused a 17.5% in vitro inhibition of rat blood ChE activity. This crab apple also showed a relatively high total (titratable) acidity of 1.28%. The commercial, nonresistant, apple cultivar McIntosh was capable of causing a 7.9% inhibition of blood ChE in vitro. The total acidity in McIntosh was 0.45%. A 4-wk feeding study compared 2 groups of 5-wk-old Fischer 344 male rats fed diets containing 45% of either M. brevipes or McIntosh freeze-dried apples to a third (control) group of rats fed a semipurified diet. In vivo blood ChE activities were similar in all groups of rats, as well as hemoglobin, hematocrit, and red blood cell counts. The liver mixed-function oxidase activity through aminopyrine N-demethylase in the rats fed the apple diets was higher than the controls, but p-nitroanisole O-demethylase activity was induced only in the animals fed the maggot-resistant crab apple. Lowered growth with concomitant lowered food intake, in the otherwise healthy rats fed the maggot-resistant crab apple diet, was attributed to the less palatable, highly acidic fruit. This study indicates that the natural ChE inhibitor in the insect-resistant apple M. brevipes is apparently detoxified upon ingestion.

  12. Kinetic analysis of interactions of amodiaquine with human cholinesterases and organophosphorus compounds.

    PubMed

    Bierwisch, Anne; Wille, Timo; Thiermann, Horst; Worek, Franz

    2016-03-30

    Standard therapy of poisoning by organophosphorus compounds (OP) is a combined administration of an anti-muscarinic drug (e.g. atropine) and an oxime as reactivator of inhibited acetylcholinesterase (AChE). Limited efficacy of clinically used oximes against a variety of OPs was shown in numerous studies, calling for research on novel reactivators of OP-inhibited AChE. Recently, reactivation of OP-inhibited AChE by the antimalarial drug amodiaquine was reported. In the present study, amodiaquine and its interactions with human cholinesterases in presence or absence of OP nerve agents was investigated in vitro. Thereby, reversible inhibition of human cholinesterases by amodiaquine (AChE ≫ BChE) was observed. Additionally, a mixed competitive-non-competitive inhibition type of amodiaquine with human AChE was determined. Slow and partial reactivation of sarin-, cyclosarin- and VX-inhibited cholinesterases by amodiaquine was recorded, amodiaquine failed to reactivate tabun-inhibited human cholinesterases. Amodiaquine, being a potent, reversible AChE inhibitor, was tested for its potential benefit as a pretreatment to prevent complete irreversible AChE inhibition by the nerve agent soman. Hereby, amodiaquine failed to prevent phosphonylation and resulted only in a slight increase of AChE activity after removal of amodiaquine and soman. At present the molecular mechanism of amodiaquine-induced reactivation of OP-inhibited AChE is not known, nevertheless amodiaquine could be considered as a template for the design of more potent non-oxime reactivators. PMID:26851641

  13. Plasma cholinesterase activity as a biomarker for quantifying exposure of green sturgeon to carbaryl following applications to control burrowing shrimp in Washington State.

    PubMed

    Troiano, Alexandra T; Grue, Christian E

    2016-08-01

    Willapa Bay (Washington State, USA) has been 1 of the rare intertidal locations where large-scale pesticide applications occur. Until recently, carbaryl was applied to control burrowing shrimp that decrease commercial oyster productivity. The bay is a critical habitat for green sturgeon (Acipenser medirostris), an anadromous species listed as threatened under the US Endangered Species Act. However, the hazard that carbaryl poses is unknown. Surrogate seawater-acclimated white sturgeon (A. transmontanus) were exposed to 0 μg L(-1) , 30 μg L(-1) , 100 μg L(-1) , 300 μg L(-1) , 1000 μg L(-1) , and 3000 μg L(-1) carbaryl for 6 h, and brain acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE) activities were measured. Enzyme recovery was measured in an additional cohort exposed to 1000 μg L(-1) carbaryl for 6 h. Activity of AChE was reduced (p ≤ 0.001) at concentrations ≥ 100 μg L(-1) with recovery in the 1000 μg L(-1) cohort by 72 h. Surprisingly, BChE activity was greater than controls at concentrations ≥ 300 μg L(-1) (p > 0.05), a finding confirmed in additional fish exposed to 3000 μg L(-1) for 6 h (+30%, p < 0.001) with apparent recovery by 48 h. Plasma samples were collected from free-living green sturgeon before and 4 d to 5 d after application of carbaryl in Willapa Bay. Activity of BChE after application was reduced 28% (p < 0.001), indicating exposure to the pesticide. However, the lack of congruence between BChE and AChE activity in captive white sturgeon exposed to carbaryl indicates that further studies are needed to better understand the risk carbaryl exposure poses to green sturgeon. Environ Toxicol Chem 2016;35:2003-2015. © 2015 SETAC.

  14. Plasma cholinesterase activity as a biomarker for quantifying exposure of green sturgeon to carbaryl following applications to control burrowing shrimp in Washington State.

    PubMed

    Troiano, Alexandra T; Grue, Christian E

    2016-08-01

    Willapa Bay (Washington State, USA) has been 1 of the rare intertidal locations where large-scale pesticide applications occur. Until recently, carbaryl was applied to control burrowing shrimp that decrease commercial oyster productivity. The bay is a critical habitat for green sturgeon (Acipenser medirostris), an anadromous species listed as threatened under the US Endangered Species Act. However, the hazard that carbaryl poses is unknown. Surrogate seawater-acclimated white sturgeon (A. transmontanus) were exposed to 0 μg L(-1) , 30 μg L(-1) , 100 μg L(-1) , 300 μg L(-1) , 1000 μg L(-1) , and 3000 μg L(-1) carbaryl for 6 h, and brain acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE) activities were measured. Enzyme recovery was measured in an additional cohort exposed to 1000 μg L(-1) carbaryl for 6 h. Activity of AChE was reduced (p ≤ 0.001) at concentrations ≥ 100 μg L(-1) with recovery in the 1000 μg L(-1) cohort by 72 h. Surprisingly, BChE activity was greater than controls at concentrations ≥ 300 μg L(-1) (p > 0.05), a finding confirmed in additional fish exposed to 3000 μg L(-1) for 6 h (+30%, p < 0.001) with apparent recovery by 48 h. Plasma samples were collected from free-living green sturgeon before and 4 d to 5 d after application of carbaryl in Willapa Bay. Activity of BChE after application was reduced 28% (p < 0.001), indicating exposure to the pesticide. However, the lack of congruence between BChE and AChE activity in captive white sturgeon exposed to carbaryl indicates that further studies are needed to better understand the risk carbaryl exposure poses to green sturgeon. Environ Toxicol Chem 2016;35:2003-2015. © 2015 SETAC. PMID:26678014

  15. The relationship between the level of cholinesterase in plasma and the action of suxamethonium in animals

    PubMed Central

    Hobbiger, F.; Peck, A. W.

    1970-01-01

    1. The neuromuscular blocking action of suxamethonium, given by intravenous injection, and the effect upon it of iso-OMPA (tetraisopropyl pyrophosphoramide) in doses which produced marked selective inhibition of cholinesterase in blood were studied in anaesthetized rats and cats, and in mice. 2. In cats experiments were also carried out in which suxamethonium was given by intravenous infusion until an effect which remained constant with time was achieved. From the degree of neuromuscular block (under equilibrium conditions) obtained with different infusion rates the infusion rate for 50% reduction in twitch tension of the indirectly stimulated soleus and gastrocnemius muscles (IR50) was calculated. The effect on it of raising the suxamethonium hydrolysing capacity of blood and of selectively reducing the level of cholinesterase in blood by various doses of iso-OMPA was then investigated. 3. At relevant stages of each experiment cholinesterase activity in blood was determined with butyrylcholine or benzoylcholine and where appropriate with suxamethonium as substrate. 4. The results obtained show that in rats and cats the effectiveness of suxamethonium is unrelated to the level of cholinesterase activity in blood and that raising the suxamethonium hydrolysing capacity in the blood up to 22-fold (in cats) only reduces the IR50 by a factor of 1·6. 5. The enhancement of the effectiveness of suxamethonium in the three species (2- to 3-fold in rats, 2- to 4-fold in mice and 7- to 8-fold in cats under the conditions used for comparison) which follows the administration of iso-OMPA is attributable to inhibition of cholinesterase in the tissues. 6. It is concluded that the results obtained clearly indicate that the species studied do not give information as regards suxamethonium and its metabolism which is applicable to man. ImagesFIG. 2FIG. 6 PMID:4322043

  16. Gulf War illness: Effects of repeated stress and pyridostigmine treatment on blood-brain barrier permeability and cholinesterase activity in rat brain.

    PubMed

    Amourette, Christine; Lamproglou, Ioannis; Barbier, Laure; Fauquette, William; Zoppe, Amélie; Viret, Roselyne; Diserbo, Michel

    2009-11-01

    After the first Persian Gulf War, many soldiers have complained of a variety of symptoms designated as "Gulf War Illness". Among several factors, implication of pyridostigmine (PB) in late cognitive dysfunction is highly likely. As a hypothesis to explain these behavioural disorders is a potentiation of the operational stress effects by pyridostigmine. We have previously described that repeated stress combined to pyridostigmine treatment induces learning dysfunction linked to genomic cerebral modifications [Barbier L, Diserbo M, Lamproglou I, Amourette C, Peinnequin A, Fauquette W. Repeated stress in combination with pyridostigmine: part II-changes in selected cerebral genes expression. Behav Brain Res 2009;197:292-300; Lamproglou I, Barbier L, Diserbo M, Fauvelle F, Fauquette W, Amourette C. Repeated stress in combination with pyridostigmine: part I-long-term behavioural consequences. Behav Brain Res 2009;197:301-10]. In the present study, using the same experimental model, we attempted to determine if such modifications are linked to a central passage of pyridostigmine under stress. Indeed it is known that exposure to stress can disrupt blood-brain barrier (BBB) and thereby increase the neurotoxicity induced by chemicals in many cerebral areas. Adult rats were subjected to repeated stress based on a modification of the pole climbing avoidance technique and treated daily by PB (1.5mg/kg/day, oral in water), for two 5-day periods separated by 2-day rest. Just after the last stress session, (3)H-pyridostigmine was administered as a tracer to evaluate BBB breakdown. In brain micro-punches and brain coronal cryosections, we failed to detect any radioactivity in animals chronically stressed and treated by pyridostigmine. Accordingly, no change of ChE activity was noted in any brain area studied. It thus appears that, in our experimental model, pyridostigmine induces effects on central nervous system, but these effects do not seem to be mediated by a central passage of

  17. N-acetyl cysteine, L-cysteine, and beta-mercaptoethanol augment selenium-glutathione peroxidase activity in glucose-6-phosphate dehydrogenase-deficient human erythrocytes.

    PubMed

    Alicigüzel, Y; Aslan, M

    2004-09-01

    In glucose-6-phosphate dehydrogenase (G6PD)-deficient erythrocytes, failure to maintain normal levels of reduced glutathione (GSH) due to decreased NADPH regeneration in the hexose monophosphate pathway results in acute hemolytic anemia following exposure to oxidative insults, such as ingestion of Vicia fava beans or use of certain drugs. GSH is a source of protection against oxidative attack, used by the selenium-dependent glutathione peroxidase (Se-GSH-Px)/reductase (GR) system to detoxify hydrogen peroxide and organic peroxides, provided that sufficient GSH is made available. In this study, Se-GSH-Px activity was analyzed in G6PD-deficient patients in the presence of reducing agents such as N-Acetyl cysteine, L-cysteine, and beta-mercaptoethanol. Se-GSH-Px activity was decreased in G6PD-deficient red blood cells (RBCs). N-Acetyl cysteine, L-cysteine, and beta-mercaptoethanol increased Se-GSH-Px activity in G6PD-deficient human erythrocytes, indicating that other reducing agents can be utilized to complement Se-GSH-Px activity in G6PD deficiency. Based on the increased susceptibility of G6PD-deficient patients to oxidative stress, the reported increase in Se-GSH-Px activity can facilitate the detoxification of reactive oxygen species. PMID:15598086

  18. Structure-Based Design and Optimization of Multitarget-Directed 2H-Chromen-2-one Derivatives as Potent Inhibitors of Monoamine Oxidase B and Cholinesterases.

    PubMed

    Farina, Roberta; Pisani, Leonardo; Catto, Marco; Nicolotti, Orazio; Gadaleta, Domenico; Denora, Nunzio; Soto-Otero, Ramon; Mendez-Alvarez, Estefania; Passos, Carolina S; Muncipinto, Giovanni; Altomare, Cosimo D; Nurisso, Alessandra; Carrupt, Pierre-Alain; Carotti, Angelo

    2015-07-23

    The multifactorial nature of Alzheimer's disease calls for the development of multitarget agents addressing key pathogenic processes. To this end, by following a docking-assisted hybridization strategy, a number of aminocoumarins were designed, prepared, and tested as monoamine oxidases (MAOs) and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibitors. Highly flexible N-benzyl-N-alkyloxy coumarins 2-12 showed good inhibitory activities at MAO-B, AChE, and BChE but low selectivity. More rigid inhibitors, bearing meta- and para-xylyl linkers, displayed good inhibitory activities and high MAO-B selectivity. Compounds 21, 24, 37, and 39, the last two featuring an improved hydrophilic/lipophilic balance, exhibited excellent activity profiles with nanomolar inhibitory potency toward hMAO-B, high hMAO-B over hMAO-A selectivity and submicromolar potency at hAChE. Cell-based assays of BBB permeation, neurotoxicity, and neuroprotection supported the potential of compound 37 as a BBB-permeant neuroprotective agent against H2O2-induced oxidative stress with poor interaction as P-gp substrate and very low cytotoxicity.

  19. SPOTing Acetyl-Lysine Dependent Interactions.

    PubMed

    Picaud, Sarah; Filippakopoulos, Panagis

    2015-08-17

    Post translational modifications have been recognized as chemical signals that create docking sites for evolutionary conserved effector modules, allowing for signal integration within large networks of interactions. Lysine acetylation in particular has attracted attention as a regulatory modification, affecting chromatin structure and linking to transcriptional activation. Advances in peptide array technologies have facilitated the study of acetyl-lysine-containing linear motifs interacting with the evolutionary conserved bromodomain module, which specifically recognizes and binds to acetylated sequences in histones and other proteins. Here we summarize recent work employing SPOT peptide technology to identify acetyl-lysine dependent interactions and document the protocols adapted in our lab, as well as our efforts to characterize such bromodomain-histone interactions. Our results highlight the versatility of SPOT methods and establish an affordable tool for rapid access to potential protein/modified-peptide interactions involving lysine acetylation.

  20. SPOTing Acetyl-Lysine Dependent Interactions

    PubMed Central

    Picaud, Sarah; Filippakopoulos, Panagis

    2015-01-01

    Post translational modifications have been recognized as chemical signals that create docking sites for evolutionary conserved effector modules, allowing for signal integration within large networks of interactions. Lysine acetylation in particular has attracted attention as a regulatory modification, affecting chromatin structure and linking to transcriptional activation. Advances in peptide array technologies have facilitated the study of acetyl-lysine-containing linear motifs interacting with the evolutionary conserved bromodomain module, which specifically recognizes and binds to acetylated sequences in histones and other proteins. Here we summarize recent work employing SPOT peptide technology to identify acetyl-lysine dependent interactions and document the protocols adapted in our lab, as well as our efforts to characterize such bromodomain-histone interactions. Our results highlight the versatility of SPOT methods and establish an affordable tool for rapid access to potential protein/modified-peptide interactions involving lysine acetylation. PMID:27600229

  1. SPOTing Acetyl-Lysine Dependent Interactions

    PubMed Central

    Picaud, Sarah; Filippakopoulos, Panagis

    2015-01-01

    Post translational modifications have been recognized as chemical signals that create docking sites for evolutionary conserved effector modules, allowing for signal integration within large networks of interactions. Lysine acetylation in particular has attracted attention as a regulatory modification, affecting chromatin structure and linking to transcriptional activation. Advances in peptide array technologies have facilitated the study of acetyl-lysine-containing linear motifs interacting with the evolutionary conserved bromodomain module, which specifically recognizes and binds to acetylated sequences in histones and other proteins. Here we summarize recent work employing SPOT peptide technology to identify acetyl-lysine dependent interactions and document the protocols adapted in our lab, as well as our efforts to characterize such bromodomain-histone interactions. Our results highlight the versatility of SPOT methods and establish an affordable tool for rapid access to potential protein/modified-peptide interactions involving lysine acetylation.

  2. Serial cholinesterase estimation in carbamate poisoning.

    PubMed

    Pinakini, K S; Kumar, T S Mohan

    2006-07-01

    Poisoning is one of the most important causes of morbidity and mortality in developing countries like India. Anticholinesterase compounds like organophosphates (OP) and carbamates account for the majority of these poisoning cases because of their easy availability and agricultural use. Carbamates are as popular as OPs as insecticides that often go undiagnosed. A fatal case of carbofuran poisoning is presented where serial cholinesterase estimation played a major role in the diagnosis of the same. The pertinent medical literature on carbofuran poisoning is reviewed. The establishment of poison information center in each state is needed for proper diagnosis and management of poisoning cases.

  3. Capsaicin, nonivamide and trans-pellitorine decrease free fatty acid uptake without TRPV1 activation and increase acetyl-coenzyme A synthetase activity in Caco-2 cells.

    PubMed

    Rohm, Barbara; Riedel, Annett; Ley, Jakob P; Widder, Sabine; Krammer, Gerhard E; Somoza, Veronika

    2015-01-01

    Red pepper and its major pungent component, capsaicin, have been associated with hypolipidemic effects in rats, although mechanistic studies on the effects of capsaicin and/or structurally related compounds on lipid metabolism are scarce. In this work, the effects of capsaicin and its structural analog nonivamide, the aliphatic alkamide trans-pellitorine and vanillin as the basic structural element of all vanilloids on the mechanisms of intestinal fatty acid uptake in differentiated intestinal Caco-2 cells were studied. Capsaicin and nonivamide were found to reduce fatty acid uptake, with IC₅₀ values of 0.49 μM and 1.08 μM, respectively. trans-Pellitorine was shown to reduce fatty acid uptake by 14.0±2.14% at 100 μM, whereas vanillin was not effective, indicating a pivotal role of the alkyl chain with the acid amide group in fatty acid uptake by Caco-2 cells. This effect was associated neither with the activation of the transient receptor potential cation channel subfamily V member 1 (TRPV1) or the epithelial sodium channel (ENaC) nor with effects on paracellular transport or glucose uptake. However, acetyl-coenzyme A synthetase activity increased (p<0.05) in the presence of 10 μM capsaicin, nonivamide or trans-pellitorine, pointing to an increased fatty acid biosynthesis that might counteract the decreased fatty acid uptake.

  4. Anti-inflammatory effect of 2-methoxy-4-vinylphenol via the suppression of NF-κB and MAPK activation, and acetylation of histone H3.

    PubMed

    Jeong, Jin Boo; Hong, Se Chul; Jeong, Hyung Jin; Koo, Jin Suk

    2011-12-01

    Although inflammation acts as host defense mechanism against infection or injury and is primarily a self limiting process, inadequate resolution of inflammatory responses leads to various chronic disorders. This work aimed to elucidate the anti-inflammatory effects of 2-methoxy-4-vinylphenol (2M4VP) isolated from pine needles in LPS-stimulated RAW264.7 cells. Some key pro-inflammatory mediators including nitric oxide (NO), prostaglandins (PGE(2)), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA and western blot. In addition, suppression of NF-κB and MAPK activation, and histone acetylation was studied by western blot analysis and immunostaining. 2M4VP dosedependently inhibited NO and PGE(2) production and also blocked LPS-induced iNOS and COX-2 expression. In addition, 2M4VP potently inhibited the translocation of NF-κB p65 into the nucleus by IκB degradation following IκB-α phosphorylation and the phosphorylation of MAPKs such as p38, ERK1/2, and JNK. Also, 2M4VP inhibited hyper-acetylation of histone H3 (Lys9/Lys14) induced by LPS. Taken together, our results suggest that 2M4VP, a naturally occurring phenolic compound, exert potent anti-inflammatory effects by inhibiting LPS-induced NO, PGE(2), iNOS, and COX-2 in RAW264.7 cells. These effects are mediated by suppression of NF-κB and MAPK activation and histone acetylation.

  5. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    NASA Astrophysics Data System (ADS)

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  6. Accumulation of fatty acids in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoAcarboxylase, temperature, and co-immobilization with Azospirillum brasilense [corrected].

    PubMed

    Leyva, Luis A; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  7. Acetyl-L-carnitine increases mitochondrial protein acetylation in the aged rat heart.

    PubMed

    Kerner, Janos; Yohannes, Elizabeth; Lee, Kwangwon; Virmani, Ashraf; Koverech, Aleardo; Cavazza, Claudio; Chance, Mark R; Hoppel, Charles

    2015-01-01

    Previously we showed that in vivo treatment of elderly Fisher 344 rats with acetylcarnitine abolished the age-associated defect in respiratory chain complex III in interfibrillar mitochondria and improved the functional recovery of the ischemic/reperfused heart. Herein, we explored mitochondrial protein acetylation as a possible mechanism for acetylcarnitine's effect. In vivo treatment of elderly rats with acetylcarnitine restored cardiac acetylcarnitine content and increased mitochondrial protein lysine acetylation and increased the number of lysine-acetylated proteins in cardiac subsarcolemmal and interfibrillar mitochondria. Enzymes of the tricarboxylic acid cycle, mitochondrial β-oxidation, and ATP synthase of the respiratory chain showed the greatest acetylation. Acetylation of isocitrate dehydrogenase, long-chain acyl-CoA dehydrogenase, complex V, and aspartate aminotransferase was accompanied by decreased catalytic activity. Several proteins were found to be acetylated only after treatment with acetylcarnitine, suggesting that exogenous acetylcarnitine served as the acetyl-donor. Two-dimensional fluorescence difference gel electrophoresis analysis revealed that acetylcarnitine treatment also induced changes in mitochondrial protein amount; a two-fold or greater increase/decrease in abundance was observed for thirty one proteins. Collectively, our data provide evidence for the first time that in the aged rat heart in vivo administration of acetylcarnitine provides acetyl groups for protein acetylation and affects the amount of mitochondrial proteins. PMID:25660059

  8. Acetylation Reader Proteins: Linking Acetylation Signaling to Genome Maintenance and Cancer

    PubMed Central

    Miller, Kyle M.

    2016-01-01

    Chromatin-based DNA damage response (DDR) pathways are fundamental for preventing genome and epigenome instability, which are prevalent in cancer. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) catalyze the addition and removal of acetyl groups on lysine residues, a post-translational modification important for the DDR. Acetylation can alter chromatin structure as well as function by providing binding signals for reader proteins containing acetyl-lysine recognition domains, including the bromodomain (BRD). Acetylation dynamics occur upon DNA damage in part to regulate chromatin and BRD protein interactions that mediate key DDR activities. In cancer, DDR and acetylation pathways are often mutated or abnormally expressed. DNA damaging agents and drugs targeting epigenetic regulators, including HATs, HDACs, and BRD proteins, are used or are being developed to treat cancer. Here, we discuss how histone acetylation pathways, with a focus on acetylation reader proteins, promote genome stability and the DDR. We analyze how acetylation signaling impacts the DDR in the context of cancer and its treatments. Understanding the relationship between epigenetic regulators, the DDR, and chromatin is integral for obtaining a mechanistic understanding of genome and epigenome maintenance pathways, information that can be leveraged for targeting acetylation signaling, and/or the DDR to treat diseases, including cancer. PMID:27631103

  9. Acetylation Reader Proteins: Linking Acetylation Signaling to Genome Maintenance and Cancer.

    PubMed

    Gong, Fade; Chiu, Li-Ya; Miller, Kyle M

    2016-09-01

    Chromatin-based DNA damage response (DDR) pathways are fundamental for preventing genome and epigenome instability, which are prevalent in cancer. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) catalyze the addition and removal of acetyl groups on lysine residues, a post-translational modification important for the DDR. Acetylation can alter chromatin structure as well as function by providing binding signals for reader proteins containing acetyl-lysine recognition domains, including the bromodomain (BRD). Acetylation dynamics occur upon DNA damage in part to regulate chromatin and BRD protein interactions that mediate key DDR activities. In cancer, DDR and acetylation pathways are often mutated or abnormally expressed. DNA damaging agents and drugs targeting epigenetic regulators, including HATs, HDACs, and BRD proteins, are used or are being developed to treat cancer. Here, we discuss how histone acetylation pathways, with a focus on acetylation reader proteins, promote genome stability and the DDR. We analyze how acetylation signaling impacts the DDR in the context of cancer and its treatments. Understanding the relationship between epigenetic regulators, the DDR, and chromatin is integral for obtaining a mechanistic understanding of genome and epigenome maintenance pathways, information that can be leveraged for targeting acetylation signaling, and/or the DDR to treat diseases, including cancer.

  10. Inhibition of cholinesterases by stereoisomers of Huperzine-A

    SciTech Connect

    Saxena, A.; Qian, N.; Kovach, I.M.; Ashani, Y.; Kozikowski, A.P.

    1993-05-13

    Huperzine-A, a potential drug for the treatment of Alzheimer's disease and possible pretreament for nerve agent toxicity, has recently been characterized as a reversible inhibitor of cholinesterases (Ashani et al., BBRC, 184:719-726, 1992). Long-term incubation of purified cholinesterases with Huperzine-A did not show any chemical modification of Huperzine-A. The dissociation constant, K(I), for fetal bovine serum acetylcholinesterase (FBS AChE) was approximately 20 nM, for Torpedo AChE was 215 nM, and for horse serum butyrylcholinesterase (BChE) was 40 micrometers M. Inhibition studies with the two stereoisomers of Huperzine-A have shown that naturally occurring (-)-Huperzine-A inhibited FBS AChE 35-fold more potently than (+)-Huperzine-A, with K(I) values of 6.2 nM and 210 nM, respectively. These results are in agreement with those reported previously using crude preparations of rat cortical AChE (McKinney et al., Eur. J. Pharmacol., 203, 303-305, 1991). (-)-Huperzine-A, on the other hand, was 80-fold more potent than (+)-Huperzine-A in inhibiting Torpedo AChE, with K(I), values of 0.25 micrometers M and 22 micrometer M, respectively. No significant differences in K(I) were observed for the two stereoisomers of Huperzine-A with horse serum BChE, indicating the lack of stereoselectivity of this compound for BChE. Molecular modeling studies involving docking of each of the two stereoisomers of Huperzine-A into the active-site gorge of Torpedo AChE also revealed that (-)-Huperzine-A gave a better fit than (+)-Huperzine-A.

  11. Sodium butyrate up-regulates cathelicidin gene expression via activator protein-1 and histone acetylation at the promoter region in a human lung epithelial cell line, EBC-1.

    PubMed

    Kida, Yutaka; Shimizu, Takashi; Kuwano, Koichi

    2006-05-01

    The antimicrobial protein cathelicidin is considered to play an important role in the defense mechanisms against bacterial infection. Recent studies show that sodium butyrate induces cathelicidin gene expression in human colonic, gastric and hepatic cells. However, little is known about the precise regulatory mechanisms underlying sodium butyrate-induced cathelicidin gene expression. In this study, we examined the regulatory mechanisms involved in sodium butyrate-induced cathelicidin gene expression using a human lung epithelial cell line, EBC-1. Our results indicate that sodium butyrate induces both cathelicidin mRNA and protein expression. Moreover, deletion or mutation of a putative activator protein-1 (AP-1) binding site in the cathelicidin gene promoter abrogated the response to sodium butyrate stimulation. Three different mitogen-activated protein (MAP) kinase inhibitors suppressed sodium butyrate-induced transactivation of the cathelicidin promoter. Electrophoretic mobility shift assays (EMSA) showed that nuclear extracts prepared from sodium butyrate-stimulated EBC-1 cells generated specific binding to probe including a putative AP-1 binding site in the cathelicidin gene promoter. Furthermore, chromatin immunoprecipitation (ChIP) assays demonstrated that sodium butyrate augmented histone acetylation of the cathelicidin promoter in EBC-1 cells. Therefore, these results indicate that AP-1 and histone acetylation of the cathelicidin promoter play a critical role in the regulation of inducible cathelicidin gene expression in EBC-1 cells stimulated with sodium butyrate.

  12. Characterization of Cholinesterases in Plasma of Three Portuguese Native Bird Species: Application to Biomonitoring

    PubMed Central

    Santos, Cátia S. A.; Monteiro, Marta S.; Soares, Amadeu M. V. M.; Loureiro, Susana

    2012-01-01

    Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of the three species studied the main cholinesterase form present is butyrylcholinesterase (BChE). Plasma BChE activity in non-exposed individuals was 0.48±0.11 SD U/ml, 0.39±0.12 SD U/ml, 0.15±0.04 SD U/ml in the northern gannet, white stork and grey heron, respectively. These results are crucial for the further use of plasma BChE activity in these bird species as a contamination bioindicator of anti-cholinesterase agents in both wetland and marine environments. Our findings also underscore the importance of plasma ChE characterization before its use as a biomarker in biomonitoring studies with birds. PMID:22470503

  13. Histone deacetylase 3 indirectly modulates tubulin acetylation.

    PubMed

    Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

    2015-12-15

    Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3-silencing mediator of retinoic and thyroid receptors (SMRT)-deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation.

  14. Cholinesterase Newfoundland: a new succinylcholine-sensitive variant of cholinesterase at locus 1.

    PubMed Central

    Simpson, N E; Elliott, C R

    1981-01-01

    A family from Newfoundland was found to have a new rare variant for plasma cholinesterase (E.C.3.1.1.8) recognized by a high-percentage inhibition by dibucaine (DN), particularly when succinyldithiocholine was used as substrate (DNSDTC) but also somewhat high when benzoylcholine was substrate (DNBZCH). The family data demonstrated that the variant is determined by an allele of the usual and atypical alleles at locus 1, and the new allele is designated CHE1*NFLD. The proband who was heterozygous for the Newfoundland and atypical alleles had shown sensitivity to succinylcholine. It is postulated that cholinesterase Newfoundland (NFLD) has a reduced affinity for succinylcholine. Samples selected for high DNs with a benzoylcholine from 200 Canadian Caucasians and 70 Newfoundlanders did not have the variant, and, therefore, it is assumed that the remainder of the samples did not have the variant. PMID:7246542

  15. Stable Suppression of Lactate Dehydrogenase Activity during Anoxia in the Foot Muscle of Littorina littorea and the Potential Role of Acetylation as a Novel Posttranslational Regulatory Mechanism.

    PubMed

    Shahriari, Ali; Dawson, Neal J; Bell, Ryan A V; Storey, Kenneth B

    2013-01-01

    The intertidal marine snail, Littorina littorea, has evolved to withstand extended bouts of oxygen deprivation brought about by changing tides or other potentially harmful environmental conditions. Survival is dependent on a strong suppression of its metabolic rate and a drastic reorganization of its cellular biochemistry in order to maintain energy balance under fixed fuel reserves. Lactate dehydrogenase (LDH) is a crucial enzyme of anaerobic metabolism as it is typically responsible for the regeneration of NAD(+), which allows for the continued functioning of glycolysis in the absence of oxygen. This study compared the kinetic and structural characteristics of the D-lactate specific LDH (E.C. 1.1.1.28) from foot muscle of aerobic control versus 24 h anoxia-exposed L. littorea. Anoxic LDH displayed a near 50% decrease in V max (pyruvate-reducing direction) as compared to control LDH. These kinetic differences suggest that there may be a stable modification and regulation of LDH during anoxia, and indeed, subsequent dot-blot analyses identified anoxic LDH as being significantly less acetylated than the corresponding control enzyme. Therefore, acetylation may be the regulatory mechanism that is responsible for the suppression of LDH activity during anoxia, which could allow for the production of alternative glycolytic end products that in turn would increase the ATP yield under fixed fuel reserves. PMID:24233354

  16. Stable Suppression of Lactate Dehydrogenase Activity during Anoxia in the Foot Muscle of Littorina littorea and the Potential Role of Acetylation as a Novel Posttranslational Regulatory Mechanism

    PubMed Central

    Shahriari, Ali; Dawson, Neal J.; Bell, Ryan A. V.; Storey, Kenneth B.

    2013-01-01

    The intertidal marine snail, Littorina littorea, has evolved to withstand extended bouts of oxygen deprivation brought about by changing tides or other potentially harmful environmental conditions. Survival is dependent on a strong suppression of its metabolic rate and a drastic reorganization of its cellular biochemistry in order to maintain energy balance under fixed fuel reserves. Lactate dehydrogenase (LDH) is a crucial enzyme of anaerobic metabolism as it is typically responsible for the regeneration of NAD+, which allows for the continued functioning of glycolysis in the absence of oxygen. This study compared the kinetic and structural characteristics of the D-lactate specific LDH (E.C. 1.1.1.28) from foot muscle of aerobic control versus 24 h anoxia-exposed L. littorea. Anoxic LDH displayed a near 50% decrease in Vmax (pyruvate-reducing direction) as compared to control LDH. These kinetic differences suggest that there may be a stable modification and regulation of LDH during anoxia, and indeed, subsequent dot-blot analyses identified anoxic LDH as being significantly less acetylated than the corresponding control enzyme. Therefore, acetylation may be the regulatory mechanism that is responsible for the suppression of LDH activity during anoxia, which could allow for the production of alternative glycolytic end products that in turn would increase the ATP yield under fixed fuel reserves. PMID:24233354

  17. A Monoclonal Antibody to O-Acetyl-GD2 Ganglioside and Not to GD2 Shows Potent Anti-Tumor Activity without Peripheral Nervous System Cross-Reactivity

    PubMed Central

    Cochonneau, Denis; Chaumette, Tanguy; Clemenceau, Béatrice; Leprieur, Stéphanie; Bougras, Gwenola; Supiot, Stéphane; Mussini, Jean-Marie; Barbet, Jacques; Saba, Julie; Paris, François; Aubry, Jacques; Birklé, Stéphane

    2011-01-01

    Background Monoclonal antibodies (mAb) against GD2 ganglioside have been shown to be effective for the treatment of neuroblastoma. Beneficial actions are, however, associated with generalized pain due to the binding of anti- GD2 mAbs to peripheral nerve fibers followed by complement activation. Neuroblastoma cells that express GD2 also express its O-acetyl derivative, O-acetyl- GD2 ganglioside (OAcGD2). Hence, we investigated the distribution of OAcGD2 in human tissues using mAb 8B6 to study the cross-reactivity of mAb 8B6 with human tissues. Methodology/Principal Findings The distribution of OAcGD2 was performed in normal and malignant tissues using an immunoperoxydase technique. Anti-tumor properties of mAb 8B6 were studied in vitro and in vivo in a transplanted tumor model in mice. We found that OAcGD2 is not expressed by peripheral nerve fibers. Furthermore, we demonstrated that mAb 8B6 was very effective in the in vitro and in vivo suppression of the growth of tumor cells. Importantly, mAb 8B6 anti-tumor efficacy was comparable to that of mAb 14G2a specific to GD2. Conclusion/Significance Development of therapeutic antibodies specific to OAcGD2 may offer treatment options with reduced adverse side effects, thereby allowing dose escalation of antibodies. PMID:21966461

  18. Acetylation modulates the STAT signaling code.

    PubMed

    Wieczorek, Martin; Ginter, Torsten; Brand, Peter; Heinzel, Thorsten; Krämer, Oliver H

    2012-12-01

    A fascinating question of modern biology is how a limited number of signaling pathways generate biological diversity and crosstalk phenomena in vivo. Well-defined posttranslational modification patterns dictate the functions and interactions of proteins. The signal transducers and activators of transcription (STATs) are physiologically important cytokine-induced transcription factors. They are targeted by a multitude of posttranslational modifications that control and modulate signaling responses and gene expression. Beyond phosphorylation of serine and tyrosine residues, lysine acetylation has recently emerged as a critical modification regulating STAT functions. Interestingly, acetylation can determine STAT signaling codes by various molecular mechanisms, including the modulation of other posttranslational modifications. Here, we provide an overview on the acetylation of STATs and how this protein modification shapes cellular cytokine responses. We summarize recent advances in understanding the impact of STAT acetylation on cell growth, apoptosis, innate immunity, inflammation, and tumorigenesis. Furthermore, we discuss how STAT acetylation can be targeted by small molecules and we consider the possibility that additional molecules controlling STAT signaling are regulated by acetylation. Our review also summarizes evolutionary aspects and we show similarities between the acetylation-dependent control of STATs and other important molecules. We propose the concept that, similar to the 'histone code', distinct posttranslational modifications and their crosstalk orchestrate the functions and interactions of STAT proteins. PMID:22795479

  19. Circadian rhythm transcription factor CLOCK regulates the transcriptional activity of the glucocorticoid receptor by acetylating its hinge region lysine cluster: potential physiological implications

    PubMed Central

    Nader, Nancy; Chrousos, George P.; Kino, Tomoshige

    2009-01-01

    Glucocorticoids, end products of the hypothalamic-pituitary-adrenal axis, influence functions of virtually all organs and tissues through the glucocorticoid receptor (GR). Circulating levels of glucocorticoids fluctuate naturally in a circadian fashion and regulate the transcriptional activity of GR in target tissues. The basic helix-loop-helix protein CLOCK, a histone acetyltransferase (HAT), and its heterodimer partner BMAL1 are self-oscillating transcription factors that generate circadian rhythms in both the central nervous system and periphery. We found that CLOCK/BMAL1 repressed GR-induced transcriptional activity in a HAT-activity- dependent fashion. In serum-shock-synchronized cells, transactivational activity of GR, accessed by mRNA expression of an endogenous-responsive gene, fluctuated spontaneously in a circadian fashion in reverse phase with CLOCK/BMAL1 mRNA expression. CLOCK and GR interacted with each other physically, and CLOCK suppressed binding of GR to its DNA recognition sequences by acetylating multiple lysine residues located in its hinge region. These findings indicate that CLOCK/BMAL1 functions as a reverse-phase negative regulator of glucocorticoid action in target tissues, possibly by antagonizing biological actions of diurnally fluctuating circulating glucocorticoids. Further, these results suggest that a peripheral target tissue circadian rhythm indirectly influences the functions of every organ and tissue inside the body through modulation of the ubiquitous and diverse actions of glucocorticoids.—Nader, N., Chrousos, G. P., Kino, T. Circadian rhythm transcription factor CLOCK regulates the transcriptional activity of the glucocorticoid receptor by acetylating its hinge region lysine cluster: potential physiological implications. PMID:19141540

  20. SIRT2 inhibition exacerbates neuroinflammation and blood-brain barrier disruption in experimental traumatic brain injury by enhancing NF-κB p65 acetylation and activation.

    PubMed

    Yuan, Fang; Xu, Zhi-Ming; Lu, Li-Yan; Nie, Hui; Ding, Jun; Ying, Wei-Hai; Tian, Heng-Li

    2016-02-01

    Sirtuin 2 (SIRT2) is a member of the sirtuin family of NAD(+) -dependent protein deacetylases. In recent years, SIRT2 inhibition has emerged as a promising treatment for neurodegenerative diseases. However, to date, there is no evidence of a specific role for SIRT2 in traumatic brain injury (TBI). We investigated the effects of SIRT2 inhibition on experimental TBI using the controlled cortical impact (CCI) injury model. Adult male mice underwent CCI or sham surgery. A selective brain-permeable SIRT2 inhibitor, AK-7, was administrated 30 min before injury. The volume of the brain edema lesion and the water content of the brain were significantly increased in mice treated with AK-7 (20 mg/kg), compared with the vehicle group, following TBI (p < 0.05 at 1 day and p < 0.05 at 3 days, respectively). Concomitantly, AK-7 administration greatly worsened neurobehavioral deficits on days 3 and 7 after CCI. Furthermore, blood-brain barrier disruption and matrix metalloproteinases (MMP)-9 activity increased following SIRT2 inhibition. AK-7 treatment increased TBI-induced microglial activation both in vivo and in vitro, accompanied by a large increase in the expression and release of inflammatory cytokines. Mechanistically, SIRT2 inhibition increased both K310 acetylation and nuclear translocation of NF-κB p65, leading to enhanced NF-κB activation and up-regulation of its target genes, including aquaporin 4 (AQP4), MMP-9, and pro-inflammatory cytokines. Together, these data demonstrate that SIRT2 inhibition exacerbates TBI by increasing NF-κB p65 acetylation and activation. Our findings provide additional evidence of an anti-inflammatory effect of SIRT2. SIRT2 is a member of the sirtuin family of NAD+-dependent protein deacetylases. Our study suggests that the SIRT2 inhibitor AK-7 exacerbates traumatic brain injury (TBI) via a potential mechanism involving increased acetylation and nuclear translocation of NF-κB p65, resulting in up-regulation of NF-κB target genes

  1. Clinical observation and comparison of the effectiveness of several oxime cholinesterase reactivators.

    PubMed

    Xue, S Z; Ding, X J; Ding, Y

    1985-01-01

    After passing toxicity and experimental therapeutic tests, four oxime cholinesterase reactivators [PAM (pyridine aldoxime methiodide), PAC (pralidoxime, pyridine aldoxime methylchloride), TMB4 (trimedoxime), and DMO4 (obidoxime, Toxogonin, LüH6)] were compared in clinical trials. All of them proved capable of restoring erythrocyte cholinesterase activity and relieving symptoms and signs of organophosphate insecticide poisoning. Mildly and moderately poisoned patients can be treated by several injections of any one of these drugs alone, but severe cases need the synergistic action of atropine, as well as treatments for two to three consecutive days. Although response to treatment is stronger with TMB4 and DMO4, they are not recommended for routine treatment because of their dangerous adverse side effects.

  2. Clinical observation and comparison of the effectiveness of several oxime cholinesterase reactivators.

    PubMed

    Xue, S Z; Ding, X J; Ding, Y

    1985-01-01

    After passing toxicity and experimental therapeutic tests, four oxime cholinesterase reactivators [PAM (pyridine aldoxime methiodide), PAC (pralidoxime, pyridine aldoxime methylchloride), TMB4 (trimedoxime), and DMO4 (obidoxime, Toxogonin, LüH6)] were compared in clinical trials. All of them proved capable of restoring erythrocyte cholinesterase activity and relieving symptoms and signs of organophosphate insecticide poisoning. Mildly and moderately poisoned patients can be treated by several injections of any one of these drugs alone, but severe cases need the synergistic action of atropine, as well as treatments for two to three consecutive days. Although response to treatment is stronger with TMB4 and DMO4, they are not recommended for routine treatment because of their dangerous adverse side effects. PMID:3914075

  3. CHOLINESTERASE INHIBITION AND HYPOTHERMIA FOLLOWING EXPOSURE TO BINARY MIXTURES OF ANTICHOLINESTERASE AGENTS: LACK OF EVIDENCE FOR CAUSE-AND-EFFECT

    EPA Science Inventory

    Dose-additivity has been the default assumption in risk assessments of pesticides with a common mechanism of action but it has been suspected that there could be non-additive effects. Inhibition of plasma cholinesterase (ChE) activity and hypothermia were used as benchmarks of e...

  4. RELATIONSHIPS BETWEEN TISSUE LEVELS OF CARBARYL, A PROTOTYPICAL CARBAMATE PESTICIDE, AND CHOLINESTERASE INHIBITION IN LONG EVANS RATS.

    EPA Science Inventory

    As part of an effort to link pharmacokinetics with biochemical and physiological endpoints, the relationships between cholinesterase (ChE) activity and tissue levels of a prototypical N-methyl carbamate pesticide were examined. In a dose-response study, carbaryl (0, 3, 7.5, 15, 3...

  5. Histone acetylation and globin gene switching.

    PubMed Central

    Hebbes, T R; Thorne, A W; Clayton, A L; Crane-Robinson, C

    1992-01-01

    An affinity-purified antibody that recognises the epitope epsilon-acetyl lysine has been used to fractionate chicken erythrocyte mononucleosomes obtained from 5 and 15 day embryos. The antibody bound chromatin was enriched in multiply acetylated forms of the core histones H3, H4 and H2B, but not in ubiquitinated H2A. The DNA of these modified nucleosomes was probed with genomic sequences from the embryonic beta rho gene (active at 5 days) and from the adult beta A gene (active at 15 days). Both genes were found to be highly enriched in the acetylated nucleosomes fractionated from both 5 day and from 15 day erythrocytes. We conclude that globin switching is not linked to a change in acetylation status of the genes and that a 'poised' gene carries histones acetylated to a similar level as a transcriptionally active gene. Core histone acetylation is not therefore a direct consequence of the transcriptional process and might operate at the level of the globin locus as a general enabling step for transcription. Images PMID:1549462

  6. Identification of a frameshift mutation responsible for the silent phenotype of human serum cholinesterase, Gly 117 (GGT----GGAG).

    PubMed Central

    Nogueira, C P; McGuire, M C; Graeser, C; Bartels, C F; Arpagaus, M; Van der Spek, A F; Lightstone, H; Lockridge, O; La Du, B N

    1990-01-01

    A frameshift mutation that causes a silent phenotype for human serum cholinesterase was identified in the DNA of seven individuals of two unrelated families. The mutation, identified using the polymerase chain reaction, causes a shift in the reading frame from Gly 117, where GGT (Gly)----GGAG (Gly+ 1 base) to a new stop codon created at position 129. This alteration is upstream of the active site (Ser 198), and, if any protein were made, it would represent only 22% of the mature enzyme found in normal serum. Results of analysis of the enzymatic activities in serum agreed with the genotypes inferred from the nucleotide sequence. Rocket immunoelectrophoresis using alpha-naphthyl acetate to detect enzymatic activity showed an absence of cross-reactive material, as expected. One additional individual with a silent phenotype did not show the same frameshift mutation. This was not unexpected, since there must be considerable molecular heterogeneity involved in causes for the silent cholinesterase phenotype. This is the first report of a molecular mechanism underlying the silent phenotype for serum cholinesterase. The analytical approach used was similar to the one we recently employed to identify the mutation that causes the atypical cholinesterase variant. Images Figure 3 Figure 5 Figure 6 PMID:2339692

  7. Glutamine Assimilation and Feedback Regulation of L-acetyl-N-glutamate Kinase Activity in Chlorella variabilis NC64A Results in Changes in Arginine Pools.

    PubMed

    Minaeva, Ekaterina; Forchhammer, Karl; Ermilova, Elena

    2015-11-01

    Glutamine is a metabolite of central importance in nitrogen metabolism of microorganisms and plants. The Chlorella PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine/arginine biosynthesis pathway, N-acetyl-L-glutamate kinase (NAGK) that leads to arginine formation. We provide evidence that glutamine promotes effective growth of C. variabilis strain NC64A. The present study shows that externally supplied glutamine directly influences the internal pool of arginine in NC64A. Glutamine synthetase (GS) catalyzes the ATP-dependent conversion of glutamate and ammonium to glutamine. The results of this study demonstrate that glutamine acts as a negative effector of GS activity. These data emphasize the importance of glutamine-dependent coupling of metabolism and signaling as components of an efficient pathway allowing the maintenance of metabolic homeostasis and sustaining growth of Chlorella.

  8. Glutamine Assimilation and Feedback Regulation of L-acetyl-N-glutamate Kinase Activity in Chlorella variabilis NC64A Results in Changes in Arginine Pools.

    PubMed

    Minaeva, Ekaterina; Forchhammer, Karl; Ermilova, Elena

    2015-11-01

    Glutamine is a metabolite of central importance in nitrogen metabolism of microorganisms and plants. The Chlorella PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine/arginine biosynthesis pathway, N-acetyl-L-glutamate kinase (NAGK) that leads to arginine formation. We provide evidence that glutamine promotes effective growth of C. variabilis strain NC64A. The present study shows that externally supplied glutamine directly influences the internal pool of arginine in NC64A. Glutamine synthetase (GS) catalyzes the ATP-dependent conversion of glutamate and ammonium to glutamine. The results of this study demonstrate that glutamine acts as a negative effector of GS activity. These data emphasize the importance of glutamine-dependent coupling of metabolism and signaling as components of an efficient pathway allowing the maintenance of metabolic homeostasis and sustaining growth of Chlorella. PMID:26356535

  9. Transcriptional activation of the enterocyte differentiation marker intestinal alkaline phosphatase is associated with changes in the acetylation state of histone H3 at a specific site within its promoter region in vitro.

    PubMed

    Hinnebusch, Brian F; Henderson, J Welles; Siddique, Aleem; Malo, Madhu S; Zhang, Wenying; Abedrapo, Mario A; Hodin, Richard A

    2003-02-01

    Enterocyte differentiation is thought to occur through the transcriptional regulation of a small subset of specific genes. A recent growing body of evidence indicates that post-translational modifications of chromatin proteins (histones) play an important role in the control of gene transcription. Previous work has demonstrated that one such modification, histone acetylation, occurs in an in vitro model of enterocyte differentiation, butyrate-treated HT-29 cells. In the present work, we sought to determine if the epigenetic signal of histone acetylation occurs in an identifiable pattern in association with the transcriptional activation of the enterocyte differentiation marker gene intestinal alkaline phosphatase (IAP). HT-29 cells were maintained under standard culture conditions and differentiated with sodium butyrate. The chromatin immunoprecipitation (ChIP) assay was used to compare the acetylation state of histones associated with specific regions of the IAP promoter in the two cell populations (undifferentiated vs. differentiated). Chromatin was extracted from cells and cleaved by sonication or enzymatic digestion to obtain fragments of approximately 200 to 600 base-pairs, as confirmed by polymerase chain reaction using primers designed to amplify the IAP segments of interest. The ChIP assay selects DNA sequences that are associated with acetylated histones by immunoprecipitation. Unbound segments represent DNA sequences whose histones are not acetylated. After immunoprecipitation, sequences were detected by radiolabeled polymerase chain reaction, and the relative intensity of the bands was quantified by densitometry. The relative acetylation state of histones at specific sites was determined by comparing the ratios of bound/unbound segments. We determined that in a segment of the IAP promoter between -378 and -303 base-pairs upstream from the transcriptional start site, the acetylation state of histone H3 increased twofold in the differentiated, IAP

  10. A novel and highly sensitive acetyl-cholinesterase biosensor modified with hollow gold nanospheres.

    PubMed

    Sun, Xia; Zhai, Chen; Wang, Xiangyou

    2013-03-01

    In this work, a highly sensitive acetylcholinesterase (AChE) inhibition-based amperometric biosensor has been developed. Firstly, a glassy carbon electrode (GCE) was modified with chitosan (Chits). Then, hollow gold nanospheres (HGNs) were absorbed onto the surface of chitosan based on the strong affinity through electrostatic adsorption. After that, L-cysteine (L-cys) was assembled on HGNs through Au-S bond. The hollow gold nanospheres were prepared by using Co nanoparticles as sacrificial templates and characterized by scanning electron microscopy, transmission electron microscopy and ultraviolet spectra, respectively. Finally, AChE was immobilized with covalent binding via -COOH groups of L-cysteine onto the modified GCE. The AChE biosensor fabrication process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy methods with the use of ferricyanide as an electrochemical redox indicator. Under optimum conditions, the inhibition rates of pesticides were proportional to their concentrations in the range of 0.1-150 and 0.1-200 μg L(-1) for chlorpyrifos and carbofuran, respectively, the detection limits were 0.06 μg L(-1) for chlorpyrifos and 0.08 μg L(-1) for carbofuran. Moreover, the biosensor exhibited a good stability and reproducibility and was suitable for trace detection of pesticide residues in vegetables and fruits.

  11. Physical location of the site for N-acetyl-L-glutamate, the allosteric activator of carbamoyl phosphate synthetase, in the 20-kilodalton COOH-terminal domain.

    PubMed

    Rodriguez-Aparicio, L B; Guadalajara, A M; Rubio, V

    1989-04-01

    Mammalian liver mitochondrial carbamoyl phosphate synthetase, a polypeptide of 160 kDa, is activated allosterically by N-acetyl-L-glutamate. The analogue of this activator N-(chloroacetyl)-L-[14C]glutamate has been found to serve as a photoaffinity label for this enzyme. The specificity was demonstrated by the drastic reduction in the radioactivity bound to the protein when (a) an excess of unlabeled acetylglutamate was present during the irradiation and (b) the enzyme was replaced by pyruvate kinase, an enzyme that is not affected by acetylglutamate. The labeling was due to the photoactivation of the chloroacetyl group since there was no labeling under equal conditions with acetyl[14C]glutamate. To localize the binding site, limited proteolysis was used. Trypsin cleaves carbamoyl phosphate synthetase into complementary NH2- and COOH-terminal fragments of about 140 and 20 kDa, respectively [Powers-Lee, S. G., & Corina, K. (1986) J. Biol. Chem. 261, 15349-15352], but only the latter was found to be labeled. Similarly, of the various fragments generated by elastase, only two, of 20 and 120 kDa, contain the COOH terminus [see Powers-Lee and Corina (1986) above] and were found to be labeled. Thus, the binding site for acetylglutamate is within 20 kDa from the COOH terminus. This excludes the possibility that the acetylglutamate binding site evolved from an ancestral substrate site for glutamine: this substrate binds to the small subunit of the Escherichia coli enzyme, which is homologous to the NH2-terminal domain of the rat liver enzyme. Exhaustive tryptic digestion of photolabeled carbamoyl phosphate synthetase yielded a single radioactive peak, suggesting that the labeling is restricted to a single minimal tryptic peptide. PMID:2742825

  12. Imaging opiate receptors by positron tomography (PET): Evaluation by displacement of 3-Acetyl-6-Deoxy-6-Beta-/sup 18/F-flouronaltrexone with active and inactive naloxone

    SciTech Connect

    Larson, S.M.; Channing, M.A.; Rice, K.R.; Pert, C.B.; Eckelman, W.C.; Burke, T.R.; Bennett, J.M.; Carson, R.E.; Di Chiro, G.

    1985-05-01

    We recently reported the development of a new radiopharmaceutical for in vivo PET imaging of opiate receptors, 3-acetyl-6-deoxy-6-Beta-/sup 18/F-fluoronaltrexone: 3-acetylcyclofoxy, or /sup 18/F-ACF. These studies involved displacement of /sup 18/F-ACF from sites of uptake in the baboon sub-cortical gray matter, and provided strong proof of the opiate receptor specificity of the tracer. We now report on the anatomic localization of /sup 18/F-ACF in the sub-cortical grapy matter of baboon, and the kinetics of uptake and displacement of the tracer. /sup 18/F-ACF was prepared from the known 3-acetyl-6-alpha-naltrexol via the triflate, using /sup 18/F produced by neutron bombardment of /sup 6/Li/sub 2/CO/sub 3/. Anesthetized baboons were imaged after injection of /sup 18/F-ACF (sp.ac.=20Ci/mmol), using the NIH NEUROPET, a high resolution PET scanner. After bolus injection, the initial distribution to brain was rapid with peak uptake at 6 minutes post-injection. Clearance from opiate receptor rich regions of thalamus and basal ganglia was gradual, but after injection of active (but not after inactive), naloxone, clearance from these regions more than doubled. In non-opiate rich regions, (e.g. cerebellum), the predominant component of clearance was equally rapid with or without the active naloxone. Displacement studies of positron labelled ligands provide a powerful tool for non-invasive study of opiate receptor in living primates.

  13. Antibodies specific to acetylated histones document the existence of deposition- and transcription-related histone acetylation in Tetrahymena

    PubMed Central

    1989-01-01

    In this study, we have constructed synthetic peptides which are identical to hyperacetylated amino termini of two Tetrahymena core histones (tetra-acetylated H4 and penta-acetylated hv1) and used them to generate polyclonal antibodies specific for acetylated forms (mono-, di-, tri-, etc.) of these histones. Neither of these antisera recognizes histone that is unacetylated. Immunoblotting analyses demonstrate that both transcription-related and deposition-related acetate groups on H4 are recognized by both antisera. In addition, the antiserum raised against penta-acetylated hv1 also recognizes acetylated forms of this variant. Immunofluorescent analyses with both antisera demonstrate that, as expected, histone acetylation is specific to macronuclei (or new macronuclei) at all stages of the life cycle except when micronuclei undergo periods of rapid replication and chromatin assembly. During this time micronuclear staining is also detected. Our results also suggest that transcription-related acetylation begins selectively in new macronuclei immediately after the second postzygotic division. Acetylated histone is not observed in new micronuclei during stages corresponding to anlagen development and, therefore, histone acetylation can be distributed asymmetrically in development. Equally striking is the rapid turnover of acetylated histone in parental macronuclei during the time of their inactivation and elimination from the cell. Taken together, these data lend strong support to the idea that modulation of histone acetylation plays an important role in gene activation and in chromatin assembly. PMID:2654136

  14. Determination of Acetylation of the Gli Transcription Factors.

    PubMed

    Coni, Sonia; Di Magno, Laura; Canettieri, Gianluca

    2015-01-01

    The Gli transcription factors (Gli1, Gli2, and Gli3) are the final effectors of the Hedgehog (Hh) signaling and play a key role in development and cancer. The activity of the Gli proteins is finely regulated by covalent modifications, such as phosphorylation, ubiquitination, and acetylation. Both Gli1 and Gli2 are acetylated at a conserved lysine, and this modification causes the inhibition of their transcriptional activity. Thus, the acetylation status of these proteins represents a useful marker to monitor Hh activation in pathophysiological conditions. Herein we describe the techniques utilized to detect in vitro and intracellular acetylation of the Gli transcription factors. PMID:26179046

  15. Isolation and characterization of full-length cDNA clones coding for cholinesterase from fetal human tissues

    SciTech Connect

    Prody, C.A.; Zevin-Sonkin, D.; Gnatt, A.; Goldberg, O.; Soreq, H.

    1987-06-01

    To study the primary structure and regulation of human cholinesterases, oligodeoxynucleotide probes were prepared according to a consensus peptide sequence present in the active site of both human serum pseudocholinesterase and Torpedo electric organ true acetylcholinesterase. Using these probes, the authors isolated several cDNA clones from lambdagt10 libraries of fetal brain and liver origins. These include 2.4-kilobase cDNA clones that code for a polypeptide containing a putative signal peptide and the N-terminal, active site, and C-terminal peptides of human BtChoEase, suggesting that they code either for BtChoEase itself or for a very similar but distinct fetal form of cholinesterase. In RNA blots of poly(A)/sup +/ RNA from the cholinesterase-producing fetal brain and liver, these cDNAs hybridized with a single 2.5-kilobase band. Blot hybridization to human genomic DNA revealed that these fetal BtChoEase cDNA clones hybridize with DNA fragments of the total length of 17.5 kilobases, and signal intensities indicated that these sequences are not present in many copies. Both the cDNA-encoded protein and its nucleotide sequence display striking homology to parallel sequences published for Torpedo AcChoEase. These finding demonstrate extensive homologies between the fetal BtChoEase encoded by these clones and other cholinesterases of various forms and species.

  16. Apoptosis induced by penta-acetyl geniposide in C6 glioma cells is associated with JNK activation and Fas ligand induction

    SciTech Connect

    Peng, C.-H.; Tseng, T.-H.; Huang, C.-N.; Hsu, S.-P.; Wang, C.-J. . E-mail: wcj@csmu.edu.tw

    2005-01-15

    In our previous study, penta-acetyl geniposide ((AC){sub 5}GP) is suggested to induce tumor cell apoptosis through the specific activation of PKC{delta}. However, the downstream signal pathway of PKC{delta} has not yet been investigated. It was shown that JNK may play an important role in the regulation of apoptosis and could be a possible downstream signal of PKC{delta} isoforms. In the present study, we investigate whether JNK is involved in (AC){sub 5}GP induced apoptosis. The result reveals that (AC){sub 5}GP induces JNK activation and c-Jun phosphorylation thus stimulating the expression of Fas-L and Fas. Using SP600125 to block JNK activation shows that (AC){sub 5}GP-mediated apoptosis and related proteins expression are attenuated. Furthermore, we find that the (AC){sub 5}GP induces apoptosis through the activation of JNK/Jun/Fas L/Fas/caspase 8/caspase 3, a mitochondria-independent pathway. The JNK pathway is suggested to be the downstream signal of PKC{delta}, since rottlerin impedes (AC){sub 5}GP-induced JNK activation. Therefore, (AC){sub 5}GP mediates cell death via activation of PKC{delta}/JNK/FasL cascade signaling.

  17. Structural, Kinetic and Proteomic Characterization of Acetyl Phosphate-Dependent Bacterial Protein Acetylation

    PubMed Central

    Sahu, Alexandria; Sorensen, Dylan; Minasov, George; Lima, Bruno P.; Scholle, Michael; Mrksich, Milan; Anderson, Wayne F.; Gibson, Bradford W.; Schilling, Birgit; Wolfe, Alan J.

    2014-01-01

    The emerging view of Nε-lysine acetylation in eukaryotes is of a relatively abundant post-translational modification (PTM) that has a major impact on the function, structure, stability and/or location of thousands of proteins involved in diverse cellular processes. This PTM is typically considered to arise by the donation of the acetyl group from acetyl-coenzyme A (acCoA) to the ε-amino group of a lysine residue that is reversibly catalyzed by lysine acetyltransferases and deacetylases. Here, we provide genetic, mass spectrometric, biochemical and structural evidence that Nε-lysine acetylation is an equally abundant and important PTM in bacteria. Applying a recently developed, label-free and global mass spectrometric approach to an isogenic set of mutants, we detected acetylation of thousands of lysine residues on hundreds of Escherichia coli proteins that participate in diverse and often essential cellular processes, including translation, transcription and central metabolism. Many of these acetylations were regulated in an acetyl phosphate (acP)-dependent manner, providing compelling evidence for a recently reported mechanism of bacterial Nε-lysine acetylation. These mass spectrometric data, coupled with observations made by crystallography, biochemistry, and additional mass spectrometry showed that this acP-dependent acetylation is both non-enzymatic and specific, with specificity determined by the accessibility, reactivity and three-dimensional microenvironment of the target lysine. Crystallographic evidence shows acP can bind to proteins in active sites and cofactor binding sites, but also potentially anywhere molecules with a phosphate moiety could bind. Finally, we provide evidence that acP-dependent acetylation can impact the function of critical enzymes, including glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, and RNA polymerase. PMID:24756028

  18. Cloning, Purification and Characterization of Acetyl Xylane Esterase from Anoxybacillus flavithermus DSM 2641(T) with Activity on Low Molecular-Weight Acetates.

    PubMed

    Eminoğlu, Ayşenur; Ülker, Serdar; Sandallı, Cemal

    2015-08-01

    Family 4 carbohydrate esterases (CE-4) have deacetylate different forms of acetylated poly/oligosaccharides in nature. This family is recognized with a specific polysaccharide deacetylase domain assigned as NodB homology domain in their secondary structure. Most family 4 carbohydrate esterases have been structurally and biochemically characterized. However, this is the first study about the enzymological function of pdaB-like CE4s from thermophilic bacterium Anoxybacillus flavithermus DSM 2641(T). A. flavithermus WK1 genome harbors five putative CE4 family genes. One of them is 762 bp long and encodes a protein of 253 amino acids in length and it was used as reference sequence in this study. It was described as acetyl xylane esterase (AXE) in genome project and this AfAXE gene was amplified without signal sequence and cloned. The recombinant protein was expressed in E. coli BL21 (DE3), purified by nickel affinity chromatography and its purity was visualized on SDS-PAGE. The activity of the recombinant enzyme was shown by zymogram analysis with α-naphtyl acetate as a substrate. The enzyme was characterized spectrophotometrically using chromogenic p-nitrophenyl acetate. Optimum temperature and pH were determined as 50 °C and 7.5, respectively. Km and Vmax were determined as 0.43 mM and 3333.33 U/mg, respectively under optimum conditions. To our knowledge this is the first enzymological characterization of a pdaB-like family 4 carbohydrate esterase from the members of Anoxybacillus genus.

  19. Protein acetylation in metabolism - metabolites and cofactors.

    PubMed

    Menzies, Keir J; Zhang, Hongbo; Katsyuba, Elena; Auwerx, Johan

    2016-01-01

    Reversible acetylation was initially described as an epigenetic mechanism regulating DNA accessibility. Since then, this process has emerged as a controller of histone and nonhistone acetylation that integrates key physiological processes such as metabolism, circadian rhythm and cell cycle, along with gene regulation in various organisms. The widespread and reversible nature of acetylation also revitalized interest in the mechanisms that regulate lysine acetyltransferases (KATs) and deacetylases (KDACs) in health and disease. Changes in protein or histone acetylation are especially relevant for many common diseases including obesity, diabetes mellitus, neurodegenerative diseases and cancer, as well as for some rare diseases such as mitochondrial diseases and lipodystrophies. In this Review, we examine the role of reversible acetylation in metabolic control and how changes in levels of metabolites or cofactors, including nicotinamide adenine dinucleotide, nicotinamide, coenzyme A, acetyl coenzyme A, zinc and butyrate and/or β-hydroxybutyrate, directly alter KAT or KDAC activity to link energy status to adaptive cellular and organismal homeostasis. PMID:26503676

  20. Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

    PubMed

    Rodríguez, Yeray A; Gutiérrez, Margarita; Ramírez, David; Alzate-Morales, Jans; Bernal, Cristian C; Güiza, Fausto M; Romero Bohórquez, Arnold R

    2016-10-01

    New N-allyl/propargyl 4-substituted 1,2,3,4-tetrahydroquinolines derivatives were efficiently synthesized using acid-catalyzed three components cationic imino Diels-Alder reaction (70-95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl-cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl-cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl-cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets.

  1. Biting deterrence and insecticidal activity of hydrazide–hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles against Aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Hydrazones are important compounds for drug design and they have also good insecticidal activity. In this study, A series of hydrazide–hydrazones (1-10) and 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles (11-20) were investigated for their biting deterrent and insecticidal act...

  2. Inflammatory stimuli induce inhibitory S-nitrosylation of the deacetylase SIRT1 to increase acetylation and activation of p53 and p65.

    PubMed

    Shinozaki, Shohei; Chang, Kyungho; Sakai, Michihiro; Shimizu, Nobuyuki; Yamada, Marina; Tanaka, Tomokazu; Nakazawa, Harumasa; Ichinose, Fumito; Yamada, Yoshitsugu; Ishigami, Akihito; Ito, Hideki; Ouchi, Yasuyoshi; Starr, Marlene E; Saito, Hiroshi; Shimokado, Kentaro; Stamler, Jonathan S; Kaneki, Masao

    2014-01-01

    Inflammation increases the abundance of inducible nitric oxide synthase (iNOS), leading to enhanced production of nitric oxide (NO), which can modify proteins by S-nitrosylation. Enhanced NO production increases the activities of the transcription factors p53 and nuclear factor κB (NF-κB) in several models of disease-associated inflammation. S-nitrosylation inhibits the activity of the protein deacetylase SIRT1. SIRT1 limits apoptosis and inflammation by deacetylating p53 and p65 (also known as RelA), a subunit of NF-κB. We showed in multiple cultured mammalian cell lines that NO donors or inflammatory stimuli induced S-nitrosylation of SIRT1 within CXXC motifs, which inhibited SIRT1 by disrupting its ability to bind zinc. Inhibition of SIRT1 reduced deacetylation and promoted activation of p53 and p65, leading to apoptosis and increased expression of proinflammatory genes. In rodent models of systemic inflammation, Parkinson's disease, or aging-related muscular atrophy, S-nitrosylation of SIRT1 correlated with increased acetylation of p53 and p65 and activation of p53 and NF-κB target genes, suggesting that S-nitrosylation of SIRT1 may represent a proinflammatory switch common to many diseases and aging. PMID:25389371

  3. Inflammatory stimuli induce inhibitory S-nitrosylation of the deacetylase SIRT1 to increase acetylation and activation of p53 and p65

    PubMed Central

    Shinozaki, Shohei; Chang, Kyungho; Sakai, Michihiro; Shimizu, Nobuyuki; Yamada, Marina; Tanaka, Tomokazu; Nakazawa, Harumasa; Ichinose, Fumito; Yamada, Yoshitsugu; Ishigami, Akihito; Ito, Hideki; Ouchi, Yasuyoshi; Starr, Marlene E.; Saito, Hiroshi; Shimokado, Kentaro; Stamler, Jonathan S.; Kaneki, Masao

    2015-01-01

    Inflammation increases the abundance of inducible nitric oxide synthase (iNOS), leading to enhanced production of nitric oxide (NO), which can modify proteins by S-nitrosylation. Enhanced NO production increases the activities of the transcription factors p53 and nuclear factor κB (NF-κB) in several models of disease-associated inflammation. S-Nitrosylation inhibits the activity of the protein deacetylase SIRT1. SIRT1 limits apoptosis and inflammation by deacetylating p53 and p65 (also known as RelA), a subunit of NF-κB. We showed in multiple cultured mammalian cell lines that NO donors or inflammatory stimuli induced S-nitrosylation of SIRT1 within CXXC motifs, which inhibited SIRT1 by disrupting its ability to bind zinc. Inhibition of SIRT1 reduced deacetylation and promoted activation of p53 and p65, leading to apoptosis and increased expression of proinflammatory genes. In rodent models of systemic inflammation, Parkinson’s disease, or aging-related muscular atrophy, S-nitrosylation of SIRT1 correlated with increased acetylation of p53 and p65 and activation of p53 and NF-κB target genes, suggesting that S-nitrosylation of SIRT1 may represent a proinflammatory switch common to many diseases and aging. PMID:25389371

  4. Acetyl-CoA synthetase is activated as part of the PDH-bypass in the oleaginous green alga Chlorella desiccata

    PubMed Central

    Avidan, Omri; Pick, Uri

    2015-01-01

    In a recent study, it has been shown that biosynthesis of triacylglycerol (TAG) in the oleaginous green alga Chlorella desiccata is preceded by a large increase in acetyl-coenzyme A (Ac-CoA) levels and by upregulation of plastidic pyruvate dehydrogenase (ptPDH). It was proposed that the capacity to accumulate high TAG critically depends on enhanced production of Ac-CoA. In this study, two alternative Ac-CoA producers—plastidic Ac-CoA synthase (ptACS) and ATP citrate lyase (ACL)—are shown to be upregulated prior to TAG accumulation under nitrogen deprivation in the oleaginous species C. desiccata, but not in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Measurements of endogenous acetate production and of radiolabelled acetate incorporation into lipids are consistent with the upregulation of ptACS, but suggest that its contribution to the overall TAG biosynthesis is negligible. Induction of ACS and production of endogenous acetate are correlated with activation of alcohol dehydrogenase, suggesting that the upregulation of ptACS is associated with activation of PDH-bypass in C. desiccata. It is proposed that activation of the PDH-bypass in C. desiccata is needed to enable a high rate of lipid biosynthesis under nitrogen deprivation by controlling the level of pyruvate reaching ptPHD and/or mtPDH. This may be an important parameter for massive TAG accumulation in microalgae. PMID:26357883

  5. Acetyl-CoA synthetase is activated as part of the PDH-bypass in the oleaginous green alga Chlorella desiccata.

    PubMed

    Avidan, Omri; Pick, Uri

    2015-12-01

    In a recent study, it has been shown that biosynthesis of triacylglycerol (TAG) in the oleaginous green alga Chlorella desiccata is preceded by a large increase in acetyl-coenzyme A (Ac-CoA) levels and by upregulation of plastidic pyruvate dehydrogenase (ptPDH). It was proposed that the capacity to accumulate high TAG critically depends on enhanced production of Ac-CoA. In this study, two alternative Ac-CoA producers-plastidic Ac-CoA synthase (ptACS) and ATP citrate lyase (ACL)-are shown to be upregulated prior to TAG accumulation under nitrogen deprivation in the oleaginous species C. desiccata, but not in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Measurements of endogenous acetate production and of radiolabelled acetate incorporation into lipids are consistent with the upregulation of ptACS, but suggest that its contribution to the overall TAG biosynthesis is negligible. Induction of ACS and production of endogenous acetate are correlated with activation of alcohol dehydrogenase, suggesting that the upregulation of ptACS is associated with activation of PDH-bypass in C. desiccata. It is proposed that activation of the PDH-bypass in C. desiccata is needed to enable a high rate of lipid biosynthesis under nitrogen deprivation by controlling the level of pyruvate reaching ptPHD and/or mtPDH. This may be an important parameter for massive TAG accumulation in microalgae.

  6. 2-Methoxy-6-acetyl-7-methyljuglone (MAM), a natural naphthoquinone, induces NO-dependent apoptosis and necroptosis by H2O2-dependent JNK activation in cancer cells.

    PubMed

    Sun, Wen; Bao, Jiaolin; Lin, Wei; Gao, Hongwei; Zhao, Wenwen; Zhang, Qingwen; Leung, Chung-Hang; Ma, Dik-Lung; Lu, Jinjian; Chen, Xiuping

    2016-03-01

    Redox signaling plays a fundamental role in maintaining cell physiological activities. A deregulation of this balance through oxidative stress or nitrosative stress has been implicated in cancer. Here, we reported that 2-methoxy-6-acetyl-7-methyl juglone (MAM), a natural naphthoquinone isolated from Polygonum cuspidatum Sieb. et Zucc, caused hydrogen peroxide (H2O2) dependent activation of JNK and induced the expression of inducible nitric oxide synthase (iNOS), thereby leading to nitric oxide (NO) generation in multiple cancer cells. Nitrosative stress induced necroptosis in A549 lung cancer cells, but resulted in caspase-dependent intrinsic apoptosis in B16-F10 melanoma and MCF7 breast cancer cells. In addition, a decrease in GSH/GSSG levels accompanied with increased ROS production was observed. Reversal of ROS generation and cell death in GSH pretreated cells indicated the involvement of GSH depletion in MAM mediated cytotoxicity. In summary, a natural product MAM induced NO-dependent multiple forms of cell death in cancer cells mediated by H2O2-dependent JNK activation in cancer cells. GSH depletion might play an initial role in MAM-induced cytotoxicity. PMID:26802903

  7. Purification and studies on characteristics of cholinesterases from Daphnia magna *

    PubMed Central

    Yang, Yan-xia; Niu, Li-zhi; Li, Shao-nan

    2013-01-01

    Due to their significant value in both economy and ecology, Daphnia had long been employed to investigate in vivo response of cholinesterase (ChE) in anticholinesterase exposures, whereas the type constitution and property of the enzyme remained unclear. A type of ChE was purified from Daphnia magna using a three-step procedure, i.e., Triton X-100 extraction, ammonium sulfate precipitation, and diethylaminoethyl (DEAE)-Sepharose™-Fast-Flow chromatography. According to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), molecular mass of the purified ChE was estimated to be 84 kDa. Based on substrate studies, the purified enzyme preferred butyrylthiocholine iodide (BTCh) [with maximum velocity (V max)/Michaelis constant (K m)=8.428 L/(min·mg protein)] to acetylthiocholine iodide (ATCh) [with V max/K m=5.346 L/(min·mg protein)] as its substrate. Activity of the purified enzyme was suppressed by high concentrations of either ATCh or BTCh. Inhibitor studies showed that the purified enzyme was more sensitive towards inhibition by tetraisopropylpyrophosphoramide (iso-OMPA) than by 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284C51). Result of the study suggested that the purified ChE was more like a type of pseudocholinesterase, and it also suggested that Daphnia magna contained multiple types of ChE in their bodies. PMID:23549850

  8. Effects of two oxadiazolidinones on cholinesterases and acetylcholine receptors

    SciTech Connect

    Bakry, N.; Lockyer, S.; Sherby, S.; Eldefrawi, A.; Eldefrawi, M.

    1986-03-05

    Inhibition of acetylcholinesterase (AChE) and butyryl cholinesterase (BuChE) by 3-(2,3-dihydro-2,2-dimethyl-benzofuran-'7-yl)-5-methoxy-1,3,4-oxadiazol-2(/sup 3/H)-one (DBOX) and 3-(2-methoxyphenyl)-5-methoxy-1,3,4-oxadiazol-2(/sup 3/H)-one (MPOX) was measured by the Ellmann spectrophotometric method. Inhibition was quasi first order and irreversible. DBOX was 2-3 orders of magnitude more potent than MPOX. Housefly brain AChE and horse serum BuChE were more sensitive than AChEs of red blood cells or eel and Torpedo electric organs. It is suggested that the nonesteratic oxadiazolidinones are activated to carbanillates on the surface of the enzyme and produce a carbanillated enzyme which ages rapidly. Carbamate anticholinesterases protected AChE against carbanillation as they did against phosphorylation. At higher concentrations, the two oxadiazolidinones also affected binding of (/sup 125/I) ..cap alpha.. bungarotoxin and (/sup 3/H)perhydrohistrionicotoxin to Torpedo nicotinic acetylcholine receptors, but did not affect binding of (/sup 3/H)quinuclidinyl benzilate to rat brain muscarinic receptors.

  9. Cholinesterase inhibitors affect brain potentials in amnestic mild cognitive impairment

    PubMed Central

    Irimajiri, Rie; Michalewski, Henry J; Golob, Edward J; Starr, Arnold

    2007-01-01

    Amnestic mild cognitive impairment (MCI) is an isolated episodic memory disorder that has a high likelihood of progressing to Alzheimer’s disease. Auditory sensory cortical responses (P50, N100) have been shown to be increased in amplitude in MCI compared to older controls. We tested whether (1) cortical potentials to other sensory modalities (somatosensory and visual) were also affected in MCI and (2) cholinesterase inhibitors (ChEIs), one of the therapies used in this disorder, modulated sensory cortical potentials in MCI. Somatosensory cortical potentials to median nerve stimulation and visual cortical potentials to reversing checkerboard stimulation were recorded from 15 older controls and 15 amnestic MCI subjects (single domain). Results were analyzed as a function of diagnosis (Control, MCI) and ChEIs treatment (Treated MCI, Untreated MCI). Somatosensory and visual potentials did not differ significantly in amplitude in MCI subjects compared to controls. When ChEIs use was considered, somatosensory potentials (N20, P50) but not visual potentials (N70, P100, N150) were of larger amplitude in untreated MCI subjects compared to treated MCI subjects. Three individual MCI subjects showed increased N20 amplitude while off ChEIs compared to while on ChEIs. An enhancement of N20 somatosensory cortical activity occurs in amnestic single domain MCI and is sensitive to modulation by ChEIs. PMID:17320833

  10. N-acetyl-L-cysteine increases MnSOD activity and enhances the recruitment of quiescent human fibroblasts to the proliferation cycle during wound healing.

    PubMed

    Mao, Gaowei; Goswami, Monali; Kalen, Amanda L; Goswami, Prabhat C; Sarsour, Ehab H

    2016-01-01

    The rebuilding of the connective tissue during wound healing requires the recruitment of fibroblasts to the wound area as well as reentry of quiescent fibroblasts to the proliferative cycle. Whether this process can be modulated by a small molecular weight thiol antioxidant N-acetyl-L-cysteine (NAC) was tested in normal human skin fibroblasts (NHFs) using a uni-directional wound healing assay. NAC treated cells demonstrated a decreased migration rate but increased number of proliferating cells recruited into the wound area post wounding. Fifteen day quiescent control and NAC treated NHFs were re-plated at a lower density and cell numbers counted at different days post-plating. Interestingly, NAC treated cells exhibited increased cellular proliferation indicated by both decreased cell population doubling time and increased S phase cells. NAC treated cells demonstrated decreased steady state levels of reactive oxygen species as well as increased protein and activity levels of manganese superoxide dismutase (MnSOD). NAC treatment failed to induce proliferation in quiescent cells lacking MnSOD expression. These results demonstrate that NAC enhanced the recruitment of quiescent NHFs into proliferation cycle during wound healing. Our results also suggest that the wound healing properties of NAC might be due to its ability to induce and enhance MnSOD expression and activity. Altogether, these findings suggest NAC might be potentially developed as a dietary intervention to improve tissue injury in animals and humans.

  11. Cholinesterase-inhibiting and genotoxic effects of acute carbofuran intoxication in man: a case report.

    PubMed

    Zeljezic, Davor; Vrdoljak, Ana Lucic; Kopjar, Nevenka; Radic, Bozica; Milkovic Kraus, Sanja

    2008-10-01

    Carbofuran belongs to the group of N-methylcarbamate insecticides used for the control of soil-dwelling and foliar-feeding insects in various crops; its consumption totals approximately 20,000 tonnes per year. Although the neurological effects on human beings have been well documented, little is known on its impact on the genome. A 38-year-old, healthy male worker employed in a carbofuran production facility accidentally inhaled the dust of the active ingredient carbofuran. Thirty minutes later, he experienced weakness, fatigue, perspiration, breathing difficulties, cephalalgia, disorientation, abdominal pain and vomiting. Blood samples were taken to measure cholinesterase activity, and to perform the alkaline comet assay and micronucleus assay combined with pancentromeric probes. Analyses were repeated 72 hr after intoxication and compared with the results obtained from regular monitoring conducted 10 days prior to the accident. Cholinesterase activity showed the highest correlation with the number of apoptotic cells, comet assay tail length, and number of long-tailed nuclei, suggesting that these are the genomic end-points primarily affected by carbofuran intake. Only a weak correlation was detected for the total number of micronuclei, centromere-containing micronuclei and nuclear buds. Since those end-points increased significantly 72 hr after the accident, they could be considered as late biomarkers of the effects of carbofuran intoxication. The results of this report suggest that, in the interests of higher standards in risk assessment and health hazard protection, periodical medical examination of carbamate-exposed populations should include genotoxicity testing in addition to the assessment of cholinesterase activity.

  12. Cholinesterase inhibition and acetylcholine accumulation following intracerebral administration of paraoxon in rats

    SciTech Connect

    Ray, A.; Liu, J.; Karanth, S.; Gao, Y.; Brimijoin, S.; Pope, C.

    2009-05-01

    We evaluated the inhibition of striatal cholinesterase activity following intracerebral administration of paraoxon assaying activity either in tissue homogenates ex vivo or by substrate hydrolysis in situ. Artificial cerebrospinal fluid (aCSF) or paraoxon in aCSF was infused unilaterally (0.5 {mu}l/min for 2 h) and ipsilateral and contralateral striata were harvested for ChE assay ex vivo. High paraoxon concentrations were needed to inhibit ipsilateral striatal cholinesterase activity (no inhibition at < 0.1 mM; 27% at 0.1 mM; 79% at 1 mM paraoxon). With 3 mM paraoxon infusion, substantial ChE inhibition was also noted in contralateral striatum. ChE histochemistry generally confirmed these concentration- and side-dependent effects. Microdialysates collected for up to 4 h after paraoxon infusion inhibited ChE activity when added to striatal homogenate, suggesting prolonged efflux of paraoxon. Since paraoxon efflux could complicate acetylcholine analysis, we evaluated the effects of paraoxon (0, 0.03, 0.1, 1, 10 or 100 {mu}M, 1.5 {mu}l/min for 45 min) administered by reverse dialysis through a microdialysis probe. ChE activity was then monitored in situ by perfusing the colorimetric substrate acetylthiocholine through the same probe and measuring product (thiocholine) in dialysates. Concentration-dependent inhibition was noted but reached a plateau of about 70% at 1 {mu}M and higher concentrations. Striatal acetylcholine was below the detection limit at all times with 0.1 {mu}M paraoxon but was transiently elevated (0.5-1.5 h) with 10 {mu}M paraoxon. In vivo paraoxon (0.4 mg/kg, sc) in adult rats elicited about 90% striatal ChE inhibition measured ex vivo, but only about 10% inhibition measured in situ. Histochemical analyses revealed intense AChE and glial fibrillary acidic protein staining near the cannula track, suggesting proliferation of inflammatory cells/glia. The findings suggest that ex vivo and in situ cholinesterase assays can provide very different views

  13. Survey of the human acetylator polymorphism in spontaneous disorders.

    PubMed Central

    Evans, D A

    1984-01-01

    There is ample evidence that the human acetylator phenotypes are associated with drug induced phenomena. It is principally the slow acetylators who exhibit toxic adverse effects because of their relative inability to detoxify the original drug compounds. In rare instances, however, it is the rapid acetylators who are at a disadvantage. In the matter of association of spontaneous disease with either acetylator phenotype, there are two groups of disorders to consider. First, disorders in which carcinogenic amines are known to be an aetiological factor. This is because these amines are substrates for the polymorphic N-acetyltransferase activity and hence there is a possible rational basis for searching for an association. Secondly, other disorders where searches for associations are based more on hunches. In the first group there is a definite statistical association between cancer of the bladder and the slow acetylator phenotype. In prevalence studies the slow phenotype is 39% more associated with bladder cancer than is the rapid phenotype. On the basis of the evidence now available it is not possible to say whether this association is because slow acetylators develop the disease more frequently or whether they survive longer. In the second group the relevant studies show (1) a greatly increased prevalence of slow acetylators in Gilbert's disease; (2) a confirmed association between the rapid acetylator phenotype and diabetes; (3) a possible association between the rapid acetylator phenotype and breast cancer; (4) a possible association between the slow acetylator phenotype and leprosy in Chinese patients; (5) an earlier age of onset of thyrotoxicosis (Graves' disease) in slow acetylators than in rapid acetylators; (6) no evidence of an association between either phenotype and spontaneous systemic lupus erythematosus. PMID:6387123

  14. N-acetyl-L-cysteine protects against cadmium-induced neuronal apoptosis by inhibiting ROS-dependent activation of Akt/mTOR pathway in mouse brain

    PubMed Central

    Chen, Sujuan; Ren, Qian; Zhang, Jinfei; Ye, Yangjing; Zhang, Zhen; Xu, Yijiao; Guo, Min; Ji, Haiyan; Xu, Chong; Gu, Chenjian; Gao, Wei; Huang, Shile; Chen, Long

    2014-01-01

    Aims This study explores the neuroprotective effects and mechanisms of N-acetyl-L-cysteine (NAC) in mice exposed to cadmium (Cd). Methods NAC (150 mg/kg) was intraperitoneally administered to mice exposed to Cd (10-50 mg/L) in drinking water for 6 weeks. The changes of cell damage and death, reactive oxygen species (ROS), antioxidant enzymes, as well as Akt/mammalian target of rapamycin (mTOR) signaling pathway in brain neurons were assessed. To verify the role of mTOR activation in Cd-induced neurotoxicity, mice also received a subacute regimen of intraperitoneally administered Cd (1 mg/kg) with/without rapamycin (7.5 mg/kg) for 11 days. Results Chronic exposure of mice to Cd induced brain damage or neuronal cell death, due to ROS induction. Co-administration of NAC significantly reduced Cd levels in the plasma and brain of the animals. NAC prevented Cd-induced ROS and significantly attenuated Cd-induced brain damage or neuronal cell death. The protective effect of NAC was mediated, at least partially, by elevating the activities of Cu/Zn-superoxide dismutase, catalase and glutathione peroxidase, as well as the level of glutathione in the brain. Furthermore, Cd-induced activation of Akt/mTOR pathway in the brain was also inhibited by NAC. Rapamycin in vitro and in vivo protected against Cd-induced neurotoxicity. Conclusions NAC protects against Cd-induced neuronal apoptosis in mouse brain partially by inhibiting ROS-dependent activation of Akt/mTOR pathway. The findings highlight that NAC may be exploited for prevention and treatment of Cd-induced neurodegenerative diseases. PMID:24299490

  15. Cholinesterase inhibition in meadow voles Microtus pennsylvanicus following field applications of Orthene

    USGS Publications Warehouse

    Jett, D.A.

    1986-01-01

    Brain acetylcholinesterase activity in field-caught meadow voles (Microtus pennsylvanicus) was depressed after a field-spray of Orthene (acephate: acetylphosphoramidothioic acid O,S-dimethyl ester) by as much as 32% in 1982 and 38% in 1983. Short-term recovery was demonstrated and occurred in a time-dependent fashion in 1982. Plasma cholinesterase levels were move variable but also were depressed. Residues were detected in vegetation samples and in the gastrointestinal tracts of exposed voles. Residues in vegetation were diluted or absent 7 to 8 d following the treatment.

  16. Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene

    USGS Publications Warehouse

    Niethammer, K.R.; Baskett, T.S.

    1983-01-01

    Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached normal 10 days after treatment. ChE inhibition for dickcissels and red-winged blackbirds differed significantly (p<0.05); maximum inhibition for the former species was 74%, and for the latter, 40%. These differences could not be explained by the diets of the two species, as they were similar.

  17. In-silico identification of the binding mode of synthesized adamantyl derivatives inside cholinesterase enzymes

    PubMed Central

    Al-Aboudi, Amal; Al-Qawasmeh, Raed A; Shahwan, Alaa; Mahmood, Uzma; Khalid, Asaad; Ul-Haq, Zaheer

    2015-01-01

    Aim: To investigate the binding mode of synthesized adamantly derivatives inside of cholinesterase enzymes using molecular docking simulations. Methods: A series of hybrid compounds containing adamantane and hydrazide moieties was designed and synthesized. Their inhibitory activities against acetylcholinesterase (AChE) and (butyrylcholinesterase) BChE were assessed in vitro. The binding mode of the compounds inside cholinesterase enzymes was investigated using Surflex-Dock package of Sybyl7.3 software. Results: A total of 26 adamantyl derivatives were synthesized. Among them, adamantane-1-carboxylic acid hydrazide had an almost equal inhibitory activity towards both enzymes, whereas 10 other compounds exhibited moderate inhibitory activity against BChE. The molecular docking studies demonstrated that hydrophobic interactions between the compounds and their surrounding residues in the active site played predominant roles, while hydrophilic interactions were also found. When the compounds were docked inside each enzyme, they exhibited stronger interactions with BChE over AChE, possibly due to the larger active site of BChE. The binding affinities of the compounds for BChE and AChE estimated were in agreement with the experimental data. Conclusion: The new adamantly derivatives selectively inhibit BChE with respect to AChE, thus making them good candidates for testing the hypothesis that BChE inhibitors would be more efficient and better tolerated than AChE inhibitors in the treatment of Alzheimer's disease. PMID:25937631

  18. Atorvastatin acts synergistically with N-acetyl cysteine to provide therapeutic advantage against Fas-activated erythrocyte apoptosis during chronic arsenic exposure in rats

    SciTech Connect

    Biswas, Debabrata; Sen, Gargi; Sarkar, Avik; Biswas, Tuli

    2011-01-01

    Arsenic is an environmental toxicant that reduces the lifespan of circulating erythrocytes during chronic exposure. Our previous studies had indicated involvement of hypercholesterolemia and reactive oxygen species (ROS) in arsenic-induced apoptotic death of erythrocytes. In this study, we have shown an effective recovery from arsenic-induced death signaling in erythrocytes in response to treatment with atorvastatin (ATV) and N-acetyl cysteine (NAC) in rats. Our results emphasized on the importance of cholesterol in the promotion of ROS-mediated Fas signaling in red cells. Arsenic-induced activation of caspase 3 was associated with phosphatidylserine exposure on the cell surface and microvesiculation of erythrocyte membrane. Administration of NAC in combination with ATV, proved to be more effective than either of the drugs alone towards the rectification of arsenic-mediated disorganization of membrane structural integrity, and this could be linked with decreased ROS accumulation through reduced glutathione (GSH) repletion along with cholesterol depletion. Moreover, activation of caspase 3 was capable of promoting aggregation of band 3 with subsequent binding of autologous IgG and opsonization by C3b that led to phagocytosis of the exposed cells by the macrophages. NAC-ATV treatment successfully amended these events and restored lifespan of erythrocytes from the exposed animals almost to the control level. This work helped us to identify intracellular membrane cholesterol enrichment and GSH depletion as the key regulatory points in arsenic-mediated erythrocyte destruction and suggested a therapeutic strategy against Fas-activated cell death related to enhanced cholesterol and accumulation of ROS.

  19. Antidiabetic effect, antioxidant activity, and toxicity of 3',4'-Di-O-acetyl-cis-khellactone in Streptozotocin-induced diabetic rats.

    PubMed

    Domínguez-Mendoza, Elix Alberto; Cornejo-Garrido, Jorge; Burgueño-Tapia, Eleuterio; Ordaz-Pichardo, Cynthia

    2016-08-15

    Pyranocoumarins are compounds with an important pharmacological profile, such as anti-inflammatory, antioxidant, cytotoxic, antiviral, antibacterial, and hypoglycemic effects. These molecules have a widespread presence as secondary metabolites in medicinal plants used to treat Diabetes Mellitus (DM). The aim of this work was to evaluate antidiabetic activity in Streptozotocin (STZ)-induced diabetic rats and the antioxidant effects of 3',4'-Di-O-acetyl-cis-khellactone (DOAcK), as well as its toxic potential. We obtained DOAcK with an enantiomeric excess of 70% by chemical synthesis. Our results showed that this compound exerts an important antidiabetic effect: blood glucose decreased in groups treated with DOAcK by 60.9% at dose of 15mg/kg (p<0.05) compared with the diabetic control group, and demonstrated a statistically significant increase in weight gain (45.7±9.7 in the group treated with DOAcK vs. -23.0±33.1 in the group with diabetes). In a biochemical profile, DOAcK did not modify lipid metabolism and did not cause damage at the renal level. DOAcK administration increased the activities of Catalase (CAT), Glutathione Peroxidase (GPx), and Super Oxide Dismutase (SOD) to levels near those of the healthy group. Histopathological analysis exhibited morphology similar to that of the healthy group and the group treated with DOAcK. DOAcK is not mutagenic by Ames test for Salmonella typhimurium strains TA98, TA100, or TA102, and is not genotoxic by Micronucleus assay; median lethal dose (LD50) >2000mg/kg and, at this dose, no signs of toxicity or death were reported after 14days of observation. These results indicate that DOAcK can improve glucose metabolism, which may be due to the increased antioxidant activity of CAT, GPx and SOD. In addition, DOAcK is not toxic in the studies tested. PMID:27397496

  20. N-acetylaspartate catabolism determines cytosolic acetyl-CoA levels and histone acetylation in brown adipocytes

    PubMed Central

    Prokesch, A.; Pelzmann, H. J.; Pessentheiner, A. R.; Huber, K.; Madreiter-Sokolowski, C. T.; Drougard, A.; Schittmayer, M.; Kolb, D.; Magnes, C.; Trausinger, G.; Graier, W. F.; Birner-Gruenberger, R.; Pospisilik, J. A.; Bogner-Strauss, J. G.

    2016-01-01

    Histone acetylation depends on the abundance of nucleo-cytoplasmic acetyl-CoA. Here, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. N-acetylaspartate (NAA) is a highly abundant brain metabolite catabolized by aspartoacylase yielding aspartate and acetate. The latter can be further used for acetyl-CoA production. Prior to this work, the presence of NAA has not been described in adipocytes. Here, we show that accumulation of NAA decreases the brown adipocyte phenotype. We increased intracellular NAA concentrations in brown adipocytes via media supplementation or knock-down of aspartoacylase and measured reduced lipolysis, thermogenic gene expression, and oxygen consumption. Combinations of approaches to increase intracellular NAA levels showed additive effects on lipolysis and gene repression, nearly abolishing the expression of Ucp1, Cidea, Prdm16, and Ppara. Transcriptome analyses of aspartoacylase knock-down cells indicate deficiencies in acetyl-CoA and lipid metabolism. Concordantly, cytoplasmic acetyl-CoA levels and global histone H3 acetylation were decreased. Further, activating histone marks (H3K27ac and H3K9ac) in promoters/enhancers of brown marker genes showed reduced acetylation status. Taken together, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. Thereby, we mechanistically connect the NAA pathway to the epigenomic regulation of gene expression, modulating the phenotype of brown adipocytes. PMID:27045997

  1. 21 CFR 862.3240 - Cholinesterase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cholinesterase test system. 862.3240 Section 862.3240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems §...

  2. Synthesis and Some Reactions of 1-aryl-4-acetyl-5-methyl-1,2,3-triazole Derivatives with Anticonvulsant Activity.

    PubMed

    Nassar, Ekhlass M; Abdelrazek, Fathy M; Ayyad, Rezk R; El-Farargy, Ahmed F

    2016-01-01

    The triazoles 3a-d underwent condensation reactions with 4-(piperidin-1-yl)-benzaldehyde to afford the chalcones 5a-d. Chalcone derivatives 5a-d were reacted with 2,3-diaminomaleonitrile, thiourea and hydrazine hydrate to afford the novel diazepine-dicarbonitrile derivatives 7a-d, the pyrimidine-2-thiol derivatives 9a-d and hydrazino-pyrimidines 10a-d respectively. Structures of the prepared compounds were elucidated by physical and spectral data like FT-IR, (1)H NMR, (13)C NMR, and mass spectroscopy. Some of the synthesized compounds were screened for their anticonvulsant activity and SAR. PMID:26776225

  3. Evidence that NiNi acetyl-CoA synthase is active and that the CuNi enzyme is not.

    PubMed

    Seravalli, Javier; Xiao, Yuming; Gu, Weiwei; Cramer, Stephen P; Antholine, William E; Krymov, Vladimir; Gerfen, Gary J; Ragsdale, Stephen W

    2004-04-01

    The bifunctional CO dehydrogenase/acetyl-CoA synthase (CODH/ACS) plays a central role in the Wood-Ljungdahl pathway of autotrophic CO(2) fixation. One structure of the Moorella thermoacetica enzyme revealed that the active site of ACS (the A-cluster) consists of a [4Fe-4S] cluster bridged to a binuclear CuNi center with Cu at the proximal metal site (M(p)) and Ni at the distal metal site (M(d)). In another structure of the same enzyme, Ni or Zn was present at M(p). On the basis of a positive correlation between ACS activity and Cu content, we had proposed that the Cu-containing enzyme is active [Seravalli, J., et al. (2003) Proc. Natl. Acad. Sci. U.S.A. 100, 3689-3694]. Here we have reexamined this proposal. Enzyme preparations with a wider range of Ni (1.6-2.8) and Cu (0.2-1.1) stoichiometries per dimer were studied to reexamine the correlation, if any, between the Ni and Cu content and ACS activity. In addition, the effects of o-phenanthroline (which removes Ni but not Cu) and neocuproine (which removes Cu but not Ni) on ACS activity were determined. EXAFS results indicate that these chelators selectively remove M(p). Multifrequency EPR spectra (3-130 GHz) of the paramagnetic NiFeC state of the A-cluster were examined to investigate the electronic state of this proposed intermediate in the ACS reaction mechanism. The combined results strongly indicate that the CuNi enzyme is inactive, that the NiNi enzyme is active, and that the NiNi enzyme is responsible for the NiFeC EPR signal. The results also support an electronic structure of the NiFeC-eliciting species as a [4Fe-4S](2+) (net S = 0) cluster bridged to a Ni(1+) (S = (1)/(2)) at M(p) that is bridged to planar four-coordinate Ni(2+) (S = 0) at M(d), with the spin predominantly on the Ni(1+). Furthermore, these studies suggest that M(p) is inserted during cell growth. The apparent vulnerability of the proximal metal site in the A-cluster to substitution with different metals appears to underlie the

  4. Role of hMOF-dependent histone H4 lysine 16 acetylation in the maintenance of TMS1/ASC gene activity1

    PubMed Central

    Kapoor-Vazirani, Priya; Kagey, Jacob D.; Powell, Doris R.; Vertino, Paula M.

    2008-01-01

    Epigenetic silencing of tumor suppressor genes in human cancers is associated with aberrant methylation of promoter region CpG islands and local alterations in histone modifications. However, the mechanisms that drive these events remain unclear. Here, we establish an important role for histone H4 lysine 16 acetylation (H4K16Ac) and the histone acetyltransferase hMOF in the regulation of TMS1/ASC, a proapoptotic gene that undergoes epigenetic silencing in human cancers. In the unmethylated and active state, the TMS1 CpG island is spanned by positioned nucleosomes and marked by histone H3K4 methylation. H4K16Ac was uniquely localized to two sharp peaks that flanked the unmethylated CpG island and corresponded to strongly positioned nucleosomes. Aberrant methylation and silencing of TMS1 was accompanied by loss of the H4K16Ac peaks, loss of nucleosome positioning, hypomethylation of H3K4 and hypermethylation of H3K9. In addition, a single peak of histone H4 lysine 20 trimethylation was observed near the transcription start site. Downregulation of hMOF or another component of the MSL complex resulted in a gene-specific decrease in H4K16Ac, loss of nucleosome positioning and silencing of TMS1. Gene silencing induced by H4K16 deacetylation occurred independently of changes in histone methylation and DNA methylation and was reversed upon hMOF re-expression. These results indicate that the selective marking of nucleosomes flanking the CpG island by hMOF is required to maintain TMS1 gene activity, and suggest that the loss of H4K16Ac, mobilization of nucleosomes and transcriptional downregulation may be important events in the epigenetic silencing of certain tumor suppressor genes in cancer. PMID:18701507

  5. Differential Complement Activation Pathways Promote C3b Deposition on Native and Acetylated LDL thereby Inducing Lipoprotein Binding to the Complement Receptor 1

    PubMed Central

    Klop, Boudewijn; van der Pol, Pieter; van Bruggen, Robin; Wang, Yanan; de Vries, Marijke A.; van Santen, Selvetta; O'Flynn, Joseph; van de Geijn, Gert-Jan M.; Njo, Tjin L.; Janssen, Hans W.; de Man, Peter; Jukema, J. Wouter; Rabelink, Ton J.; Rensen, Patrick C. N.; van Kooten, Cees; Cabezas, Manuel Castro

    2014-01-01

    Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1. PMID:25349208

  6. Dual effects of N-acetyl-L-cysteine dependent on NQO1 activity: Suppressive or promotive of 9,10-phenanthrenequinone-induced toxicity

    SciTech Connect

    Toyooka, Tatsushi; Shinmen, Takuya; Aarts, Jac M.M.J.G.; Ibuki, Yuko

    2012-11-01

    A typical antioxidant, N-acetyl-L-cysteine (NAC) generally protects cells from oxidative damage induced by reactive oxygen species (ROS). 9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, produces ROS in redox cycling following two-electron reduction by NAD(P)H:quinone oxidoreductase 1 (NQO1), which has been considered as a cause of its cyto- and genotoxicity. In this study, we show that NAC unexpectedly augments the toxicity of 9,10-PQ in cells with low NQO1 activity. In four human skin cell lines, the expression and the activity of NQO1 were lower than in human adenocarcinoma cell lines, A549 and MCF7. In the skin cells, the cytotoxicity of 9,10-PQ was significantly enhanced by addition of NAC. The formation of DNA double strand breaks accompanying phosphorylation of histone H2AX, was also remarkably augmented. On the other hand, the cyto- and genotoxicity were suppressed by addition of NAC in the adenocarcinoma cells. Two contrasting experiments: overexpression of NQO1 in CHO-K1 cells which originally expressed low NQO1 levels, and knock‐down of NQO1 in the adenocarcinoma cell line A549 by transfection of RNAi, also showed that NAC suppressed 9,10-PQ-induced toxicity in cell lines expressing high NQO1 activity and enhanced it in cell lines with low NQO1 activity. The results suggested that dual effects of NAC on the cyto- and genotoxicity of 9,10-PQ were dependent on tissue-specific NQO1 activity. -- Highlights: ► NAC augmented the cytotoxicity of 9,10-PQ in skin cell lines. ► 9,10-PQ-induced DSBs accompanying γ-H2AX were also augmented by NAC. ► NAC suppressed the cyto- and genotoxicity of 9,10-PQ in adenocarcinoma cell lines. ► The dual effects of NAC on toxicity of 9,10-PQ were dependent on NQO1 activity.

  7. Histone deacetylase 3 indirectly modulates tubulin acetylation

    PubMed Central

    Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

    2015-01-01

    Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3–silencing mediator of retinoic and thyroid receptors (SMRT)–deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. PMID:26450925

  8. Influence of cholinesterase inhibitors, donepezil and rivastigmine on the acquisition, expression, and reinstatement of morphine-induced conditioned place preference in rats.

    PubMed

    Gawel, Kinga; Labuz, Krzysztof; Jenda, Malgorzata; Silberring, Jerzy; Kotlinska, Jolanta H

    2014-07-15

    The influence of systemic administration of cholinesterase inhibitors, donepezil and rivastigmine on the acquisition, expression, and reinstatement of morphine-induced conditioned place preference (CPP) was examined in rats. Additionally, this study aimed to compare the effects of donepezil, which selectively inhibits acetylcholinesterase, and rivastigmine, which inhibits both acetylcholinesterase and butyrylcholinesterase on morphine reward. Morphine-induced CPP (unbiased method) was induced by four injections of morphine (5 mg/kg, i.p.). Donepezil (0.5, 1, and 3 mg/kg, i.p.) or rivastigmine (0.03, 0.5, and 1 mg/kg, i.p.) were given 20 min before morphine during conditioning phase and 20 min before the expression or reinstatement of morphine-induced CPP. Our results indicated that both inhibitors of cholinesterase attenuated the acquisition and expression of morphine CPP. The results were more significant after rivastigmine due to a broader inhibitory spectrum of this drug. Moreover, donepezil (1 mg/kg) and rivastigmine (0.5 mg/kg) attenuated the morphine CPP reinstated by priming injection of 5mg/kg morphine. These properties of both cholinesterase inhibitors were reversed by mecamylamine (3 mg/kg, i.p.), a nicotinic acetylcholine receptor antagonist but not scopolamine (0.5 mg/kg, i.p.), a muscarinic acetylcholine receptor antagonist. All effects of cholinesterase inhibitors were observed at the doses that had no effects on locomotor activity of animals. Our results suggest beneficial role of cholinesterase inhibitors in reduction of morphine reward and morphine-induced seeking behavior. Finally, we found that the efficacy of cholinesterase inhibitors in attenuating reinstatement of morphine CPP provoked by priming injection may be due to stimulation of nicotinic acetylcholine receptors.

  9. Synthesis and in vitro evaluation of novel rhodanine derivatives as potential cholinesterase inhibitors.

    PubMed

    Krátký, Martin; Štěpánková, Šárka; Vorčáková, Katarína; Vinšová, Jarmila

    2016-10-01

    Based on a broad spectrum of biological activities of rhodanines, we synthesized aromatic amides and esters of 2-(4-oxo-2-thioxothiazolidin-3-yl)acetic acid (rhodanine-3-acetic acid) via carbodiimide- or PCl3-mediated coupling. Both esters and amides were investigated for their in vitro inhibitory potency and selectivity against acetylcholinesterase (AChE) from electric eel and butyrylcholinesterase (BChE) from equine serum using Ellman's spectrophotometric method. The derivatives exhibited mostly a moderate activity against both cholinesterases. IC50 values for AChE were in a closer concentration range of 24.05-86.85μM when compared to BChE inhibition (7.92-227.19μM). The esters caused the more efficient inhibition of AChE than amides and parent acid. The esterification and amidation of the rhodanine-3-acetic acid increased inhibition of BChE, even up to 26 times. Derivatives of 4-nitroaniline/phenol showed the activity superior to other substituents (H, Cl, CH3, OCH3, CF3). Rhodanines produced a balanced inhibition of both cholinesterases. Seven derivatives produced the more potent inhibition of AChE than rivastigmine, a clinically used drug; additional three compounds were comparable. Two amides exceeded inhibitory potency of rivastigmine towards BChE. Importantly, this is the first evidence that rhodanine-based compounds are able to inhibit BChE.

  10. Synthesis, cholinesterase inhibition and molecular modelling studies of coumarin linked thiourea derivatives.

    PubMed

    Saeed, Aamer; Zaib, Sumera; Ashraf, Saba; Iftikhar, Javeria; Muddassar, Muhammad; Zhang, Kam Y J; Iqbal, Jamshed

    2015-12-01

    Alzheimer's disease is among the most widespread neurodegenerative disorder. Cholinesterases (ChEs) play an indispensable role in the control of cholinergic transmission and thus the acetylcholine level in the brain is enhanced by inhibition of ChEs. Coumarin linked thiourea derivatives were designed, synthesized and evaluated biologically in order to determine their inhibitory activity against acetylcholinesterases (AChE) and butyrylcholinesterases (BChE). The synthesized derivatives of coumarin linked thiourea compounds showed potential inhibitory activity against AChE and BChE. Among all the synthesized compounds, 1-(2-Oxo-2H-chromene-3-carbonyl)-3-(3-chlorophenyl)thiourea (2e) was the most potent inhibitor against AChE with an IC50 value of 0.04±0.01μM, while 1-(2-Oxo-2H-chromene-3-carbonyl)-3-(2-methoxyphenyl)thiourea (2b) showed the most potent inhibitory activity with an IC50 value of 0.06±0.02μM against BChE. Molecular docking simulations were performed using the homology models of both cholinesterases in order to explore the probable binding modes of inhibitors. Results showed that the novel synthesized coumarin linked thiourea derivatives are potential candidates to develop for potent and efficacious acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors.

  11. Synthesis and in vitro evaluation of novel rhodanine derivatives as potential cholinesterase inhibitors.

    PubMed

    Krátký, Martin; Štěpánková, Šárka; Vorčáková, Katarína; Vinšová, Jarmila

    2016-10-01

    Based on a broad spectrum of biological activities of rhodanines, we synthesized aromatic amides and esters of 2-(4-oxo-2-thioxothiazolidin-3-yl)acetic acid (rhodanine-3-acetic acid) via carbodiimide- or PCl3-mediated coupling. Both esters and amides were investigated for their in vitro inhibitory potency and selectivity against acetylcholinesterase (AChE) from electric eel and butyrylcholinesterase (BChE) from equine serum using Ellman's spectrophotometric method. The derivatives exhibited mostly a moderate activity against both cholinesterases. IC50 values for AChE were in a closer concentration range of 24.05-86.85μM when compared to BChE inhibition (7.92-227.19μM). The esters caused the more efficient inhibition of AChE than amides and parent acid. The esterification and amidation of the rhodanine-3-acetic acid increased inhibition of BChE, even up to 26 times. Derivatives of 4-nitroaniline/phenol showed the activity superior to other substituents (H, Cl, CH3, OCH3, CF3). Rhodanines produced a balanced inhibition of both cholinesterases. Seven derivatives produced the more potent inhibition of AChE than rivastigmine, a clinically used drug; additional three compounds were comparable. Two amides exceeded inhibitory potency of rivastigmine towards BChE. Importantly, this is the first evidence that rhodanine-based compounds are able to inhibit BChE. PMID:27428597

  12. Variation of Cholinesterase-Based Biosensor Sensitivity to Inhibition by Organophosphate Due To Ionizing Radiation

    PubMed Central

    Pohanka, Miroslav; Koch, Miroslav

    2009-01-01

    A cholinesterase based biosensor was constructed in order to assess the effects of ionizing radiation on exposed AChE. Although the primary objective of the experiment was to investigate the effect of ionizing radiation on the activity of the biosensor, no changes in cholinesterase activity were observed. Current provided by oxidation of thiocholine previously created from acetylthiocholine by enzyme catalyzed reaction was in a range 395–455 nA. No significant influence of radiation on AChE activity was found, despite the current variation. However, a surprising phenomenon was observed when a model organophosphate paraoxon was assayed. Irradiated biosensors seem to be more susceptible to the inhibitory effects of paraoxon. Control biosensors provided a 94 ± 5 nA current after exposure to 1 ppm paraoxon. The biosensors irradiated by a 5 kGy radiation dose and exposed to paraoxon provided a current of 49 ± 6 nA. Irradiation by doses ranging from 5 mGy to 100 kGy were investigated and the mentioned effect was confirmed at doses above 50 Gy. After the first promising experiments, biosensors irradiated by 5 kGy were used for calibration on paraoxon and compared with the control biosensors. Limits of detection 2.5 and 3.8 ppb were achieved for irradiated and non-irradiated biosensors respectively. The overall impact of this effect is discussed. PMID:22346715

  13. Pro-2-PAM Therapy for Central and Peripheral Cholinesterases

    PubMed Central

    DeMar, James C.; Clarkson, Edward D.; Ratcliffe, Ruthie H.; Campbell, Amy J.; Thangavelu, Sonia G.; Herdman, Christine A.; Leader, Haim; Schulz, Susan M.; Marek, Elizabeth; Medynets, Marie A.; Ku, Theresa C.; Evans, Sarah A.; Khan, Farhat A.; Owens, Roberta R.; Nambiar, Madhusoodana P.; Gordon, Richard K.

    2010-01-01

    Novel therapeutics to overcome the toxic effects of organophosphorus (OP) chemical agents are needed due to the documented use of OPs in warfare (e.g. 1980–1988 Iran/Iraq war) and terrorism (e.g. 1995 Tokyo subway attacks). Standard OP exposure therapy in the United States consists of atropine sulfate (to block muscarinic receptors), the acetylcholinesterase (AChE) reactivator (oxime) pralidoxime chloride (2-PAM), and a benzodiazepine anticonvulsant to ameliorate seizures. A major disadvantage is that quaternary nitrogen charged oximes, including 2-PAM, do not cross the blood brain barrier (BBB) to treat brain AChE. Therefore, we have synthesized and evaluated pro-2-PAM (a lipid permeable 2-PAM derivative) that can enter the brain and reactivate CNS AChE, preventing seizures in guinea pigs after exposure to OPs. The protective effects of the pro-2-PAM after OP exposure were shown using a) surgically-implanted radiotelemetry probes for electroencephalogram (EEG) b) neurohistopathology of brain, c) cholinesterase activities in the PNS and CNS, and d) survivability. The PNS oxime 2-PAM was ineffective at reducing seizures/status epilepticus (SE) in diisopropyl-fluorophosphate (DFP)-exposed animals. In contrast, pro-2-PAM significantly suppressed and then eliminated seizure activity. In OP-exposed guinea pigs, there was a significant reduction in neurological damage with pro-2-PAM, but not 2-PAM. Distinct regional areas of the brains showed significantly higher AChE activity 1.5 h after OP exposure in pro-2-PAM treated animals compared to the 2-PAM treated ones. However, blood and diaphragm showed similar AChE activities in animals treated with either oxime, as both 2-PAM and pro 2-PAM are PNS active oximes. In conclusion, pro-2-PAM can cross the BBB, is rapidly metabolized inside the brain to 2-PAM, and protects against OP-induced SE through restoration of brain AChE activity. Pro-2-PAM represents the first non-invasive means of administering a CNS therapeutic for

  14. Risk Factors for Nursing Home Placement in Alzheimer's Disease: A Longitudinal Study of Cognition, ADL, Service Utilization, and Cholinesterase Inhibitor Treatment

    ERIC Educational Resources Information Center

    Wattmo, Carina; Wallin, Asa K.; Londos, Elisabet; Minthon, Lennart

    2011-01-01

    Purpose of the Study: To identify risk factors for early nursing home placement (NHP) in Alzheimer's disease (AD), focusing on the impact of longitudinal change in cognition, activities of daily living (ADL), service utilization, and cholinesterase inhibitor treatment (ChEI). Design and Methods: In an open, 3-year, prospective, multicenter study…

  15. Cholinesterase Inhibition and Depression of the Photic After Discharge of Flash Evoked Potentials Following Acute or Repeated Exposures to a Mixture of Carbaryl and Propoxur

    EPA Science Inventory

    While information exists regarding inhibition of cholinesterase (ChE) activity, little is known about neurophysiological changes produced by a mixture of N-methyl carbamate pesticides. Previously, we reported that acute treatment with propoxur or carbaryl decreased the duration o...

  16. DEPRESSION OF THE PHOTIC AFTER DISCHARGE OF FLASH EVOKED POTENTIALS BY PHYSOSTIGMINE, CARBARYL AND PROPOXUR AND THE RELATIONSHIP TO INHIBITION OF BRAIN CHOLINESTERASE

    EPA Science Inventory

    The effects of N-methyl carbamate pesticides on the photic after discharge (PhAD) of flash evoked potentials (FEPs) and the relationship between inhibition of brain cholinesterase (ChE) activity and the PhAD were evaluated. FEPs were recorded in Long Evans rats treated with physo...

  17. Acetylated histone H4 is reduced in human gastric adenomas and carcinomas.

    PubMed

    Ono, S; Oue, N; Kuniyasu, H; Suzuki, T; Ito, R; Matsusaki, K; Ishikawa, T; Tahara, E; Yasui, W

    2002-09-01

    Acetylation of core histones is closely linked to transcriptional activation of various genes. The acetylation levels of nucleosomal histones can be modified through a balance of histone acetyltransferases and deacetylases. To elucidate the role of histone acetylation in human gastric carcinogenesis, we studied the status of histone H4 acetylation in gastric carcinoma tissues and corresponding non-neoplastic mucosa. The status of histone acetylation was assessed by examining the expression of acetylated histone H4 through Western blotting and immunohistochemistry using an anti-acetylated histone H4 antibody. The levels of acetylated histone H4 expression were obviously reduced in 72% (13/18) of gastric carcinomas in comparison with non-neoplastic mucosa by Western blotting. In immunohistochemistry, acetylated histone H4 was clearly detected in the nuclei of both non-neoplastic epithelial and stromal cells, whereas the levels of acetylated histone H4 were heterogeneous or reduced in 66% (38/57) of gastric carcinomas and 46% (6/13) of gastric adenomas. Reduced expression of acetylated histone H4 was also observed in some areas of intestinal metaplasia adjacent to carcinomas. Reduction in the expression of acetylated histone H4 was significantly correlated with advanced stage, depth of tumor invasion and lymph node metastasis. These results suggest that low levels of histone acetylation may be closely associated with the development and progression of gastric carcinomas, possibly through alteration of gene expression.

  18. Synthesis and biological activity of hydrazide hydrazones and their corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various new 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles (11-20) were prepared by the reaction of aryl substituted hydrazones of 4-fluorobenzoic acid hydrazide (1-10) with acetic anhydride. The structures of the newly synthesized compounds 11-20, were confirmed by UV, IR and 1H NMR spec...

  19. Human AP-endonuclease (APE1/Ref-1) and its acetylation regulate YB-1/p300 recruitment and RNA polymerase II loading in the drug induced activation of multidrug resistance gene MDR1

    PubMed Central

    Sengupta, Shiladitya; Mantha, Anil K.; Mitra, Sankar; Bhakat, Kishor K.

    2010-01-01

    Overexpression of human AP-endonuclease (APE1/Ref-1), a key enzyme in the DNA base excision repair (BER) pathway, is often associated with tumor cell resistance to various anticancer drugs. In this study, we examined the molecular basis of transcriptional regulatory (non repair) function of APE1 in promoting resistance to certain types of drugs. We have recently shown that APE1 stably interacts with Y-box-binding protein 1 (YB-1), and acts as its coactivator for the expression of multidrug resistance gene MDR1, thereby causing drug-resistance. Here we show for the first time that APE1 is stably associated with the basic transcription factor RNA polymerase II (RNA pol II) and the coactivator p300 on the endogenous MDR1 promoter. APE1’s depletion significantly reduces YB-1/p300 recruitment to the promoter, resulting in reduced RNA pol II loading. Drug-induced APE1 acetylation which is mediated by p300 enhances formation of acetylated APE1 (AcAPE1)/YB-1/p300 complex on the MDR1 promoter. Enhanced recruitment of this complex increases MDR1 promoter dependent luciferase activity and its endogenous expression. Using APE1 downregulated cells and cells overexpressing wild type APE1 or its nonacetylable mutant we have demonstrated that the loss of APE1’s acetylation impaired MDR1 activation and sensitizes the cells to cisplatin or etoposide. We have thus established the basis for APE1’s acetylation-dependent regulatory function in inducing MDR1-mediated drug resistance. PMID:20856196

  20. Structural analysis of the asparagine-linked oligosaccharides of cholinesterases. N-linked carbohydrates of cholinesterases

    SciTech Connect

    Saxena, A.; Doctor, B.P.

    1995-12-31

    Cholinesterases are serine esterases that hydrolyse choline esters faster than other substrates. They are highly glycosylated proteins with up to 24% of their molecular weight constituted of carbohydrates. Here we report the results of our studies on the glycosylation of fetal bovine serum acetylcholinesterase (FBS AChE) and horse serum butyrylcholinesterase (Eq BChE). Analysis of the monosaccharide content of the two enzymes indicated that Eq BChE contained 520 nmoles of monosaccharide/mg protein, as compared to 1290 nmoles/mg protein for Eq BChE. Both enzymes contained mannose, galactose, N-acetylglucosamine and sialic acid. Fucose was present in Eq BChE only. The structures of the two major oligosaccharides from FBS AChE and one major oligosaccharide from Eq BChE were determined and found to be very similar except that one of the oligosaccharides from FBS AChE contained a galactose alphal-3 galactose betal-4-determinant which has been identified as a potentially immunogenic determinant.

  1. Effects of Agricultural Management Policies on the Exposure of Black-Winged Stilts (Himantopus himantopus) Chicks to Cholinesterase-Inhibiting Pesticides in Rice Fields.

    PubMed

    Toral, Gregorio M; Baouab, Riad E; Martinez-Haro, Mónica; Sánchez-Barbudo, Inés S; Broggi, Juli; Martínez-de la Puente, Josue; Viana, Duarte; Mateo, Rafael; Figuerola, Jordi

    2015-01-01

    Levels of exposure to pesticides in rice fields can be significant depending on the environmental policies practiced. The aim of European Union integrated management policy is to reduce pesticide use and impact on environment. Rice fields provide an alternative breeding habitat for many waterbirds that are exposed to the pesticides used and therefore can be valuable indicators of their risk for wildlife. To evaluate integrated management success we examined exposure of Black-winged Stilts (Himantopus himantopus) to cholinesterase-inhibiting pesticides in rice fields under different types of management by measuring plasma cholinesterase activity. Cholinesterase activity was lower in birds sampled in (a) 2008 after a period of intense pesticide application, than in (b) 2005-2007 and 2011 in rice fields subject to integrated management in Doñana (SW Spain) and (c) in control natural wetlands in Spain and Morocco. During 2009 and 2010, cholinesterase activity was lower in rice fields in Doñana than in rice fields in Larache and Sidi Allal Tazi (NW Morocco). Our results suggest that integrated management successfully reduced the exposure of Black-winged Stilts to pesticides in most of the years. Care should be taken to implement mosquito and pest crop controls on time and with environmentally friendly products in order to reduce its impact on wildlife. PMID:25970170

  2. Effects of Agricultural Management Policies on the Exposure of Black-Winged Stilts (Himantopus himantopus) Chicks to Cholinesterase-Inhibiting Pesticides in Rice Fields

    PubMed Central

    Toral, Gregorio M.; Baouab, Riad E.; Martinez-Haro, Mónica; Sánchez-Barbudo, Inés S.; Broggi, Juli; Martínez-de la Puente, Josue; Viana, Duarte; Mateo, Rafael; Figuerola, Jordi

    2015-01-01

    Levels of exposure to pesticides in rice fields can be significant depending on the environmental policies practiced. The aim of European Union integrated management policy is to reduce pesticide use and impact on environment. Rice fields provide an alternative breeding habitat for many waterbirds that are exposed to the pesticides used and therefore can be valuable indicators of their risk for wildlife. To evaluate integrated management success we examined exposure of Black-winged Stilts (Himantopus himantopus) to cholinesterase-inhibiting pesticides in rice fields under different types of management by measuring plasma cholinesterase activity. Cholinesterase activity was lower in birds sampled in (a) 2008 after a period of intense pesticide application, than in (b) 2005-2007 and 2011 in rice fields subject to integrated management in Doñana (SW Spain) and (c) in control natural wetlands in Spain and Morocco. During 2009 and 2010, cholinesterase activity was lower in rice fields in Doñana than in rice fields in Larache and Sidi Allal Tazi (NW Morocco). Our results suggest that integrated management successfully reduced the exposure of Black-winged Stilts to pesticides in most of the years. Care should be taken to implement mosquito and pest crop controls on time and with environmentally friendly products in order to reduce its impact on wildlife. PMID:25970170

  3. Effects of Agricultural Management Policies on the Exposure of Black-Winged Stilts (Himantopus himantopus) Chicks to Cholinesterase-Inhibiting Pesticides in Rice Fields.

    PubMed

    Toral, Gregorio M; Baouab, Riad E; Martinez-Haro, Mónica; Sánchez-Barbudo, Inés S; Broggi, Juli; Martínez-de la Puente, Josue; Viana, Duarte; Mateo, Rafael; Figuerola, Jordi

    2015-01-01

    Levels of exposure to pesticides in rice fields can be significant depending on the environmental policies practiced. The aim of European Union integrated management policy is to reduce pesticide use and impact on environment. Rice fields provide an alternative breeding habitat for many waterbirds that are exposed to the pesticides used and therefore can be valuable indicators of their risk for wildlife. To evaluate integrated management success we examined exposure of Black-winged Stilts (Himantopus himantopus) to cholinesterase-inhibiting pesticides in rice fields under different types of management by measuring plasma cholinesterase activity. Cholinesterase activity was lower in birds sampled in (a) 2008 after a period of intense pesticide application, than in (b) 2005-2007 and 2011 in rice fields subject to integrated management in Doñana (SW Spain) and (c) in control natural wetlands in Spain and Morocco. During 2009 and 2010, cholinesterase activity was lower in rice fields in Doñana than in rice fields in Larache and Sidi Allal Tazi (NW Morocco). Our results suggest that integrated management successfully reduced the exposure of Black-winged Stilts to pesticides in most of the years. Care should be taken to implement mosquito and pest crop controls on time and with environmentally friendly products in order to reduce its impact on wildlife.

  4. [Pesticide detection in Costarican vegetables based on the inhibition of serum and erythrocytic human cholinesterases].

    PubMed

    Nevermann, Karl Schosinsky; Guzmán, Eugenia Quintana

    2004-12-01

    A simple and low cost method able to detect the presence of pesticides, organophosphates and carbamates based on the inhibition of serum and erythrocytic cholinesterases, was used in lettuce (Lactuca sativa), cilantro (Coriandum santivum) and celery (Apium graveolens) obtained from the Ferias del Agricultor from Valle Central of Costa Rica. The percentage inhibition of cholinesterases is related to the presence of plaguicide in the vegetable. Thirteen percent of the analyzed samples were positive for plaguicides using serum cholinesterase and 33% for erythrocytic cholinesterase. Washing and cooking the vegetables does not eliminate the presence of plaguicides but they lower slightly the concentration. Statistical evidence (p = 0.0001) indicates that erythrocytic cholinesterase has higher analytical sensitivity than serum cholinesterase. It is very important to establish the degree of contamination with pesticides in these agricultural products because they are exposed to direct contamination by fumigation, soil contamination and irrigation water, and are products that are often consumed without adequate cooking and washing.

  5. Effect of acute and chronic cholinesterase inhibition on biogenic amines in rat brain.

    PubMed

    Soininen, H; Unni, L; Shillcutt, S

    1990-12-01

    The effects of five cholinesterase inhibitors on forebrain monoamine and their metabolite levels, and on forebrain and plasma cholinesterase (ChE) activity in rat were studied in acute and chronic conditions. Acute tetrahydroaminoacridine (THA) dosing caused lower brain (68%) and higher plasma (90%) ChE inhibition than the other drugs studied and increased levels of brain dihydroxyphenylacetic acid (DOPAC) (236%), homovanillic acid (HVA) (197%) and 5-hydroxyindoleacetic acid (5-HIAA) (130%). Acute physostigmine (PHY) administration caused a 215% increase in brain DOPAC content. Despite high brain ChE inhibition induced by metrifonate (MTF), dichlorvos (DDVP) or naled no changes in brain noradrenaline (NA), dopamine (DA) or serotonin (5-HT) occurred due to treatment with the study drugs in the acute study. In the chronic 10-day study THA or PHY caused no substantial ChE inhibition in brain when measured 18 hours after the last dose, whereas MTF induced 74% ChE inhibition. Long-term treatment with THA or MTF caused no changes in monoamine levels, but PHY treatment resulted in slightly increased 5-HT values. These results suggest that MTF, DDVP and naled seem to act solely by cholinergic mechanisms. However, the central neuropharmacological mechanism of action of THA and PHY may involve changes in cholinergic as well as dopaminergic and serotoninergic systems. PMID:1711162

  6. The structure-function relationships in Drosophila neurotactin show that cholinesterasic domains may have adhesive properties.

    PubMed Central

    Darboux, I; Barthalay, Y; Piovant, M; Hipeau-Jacquotte, R

    1996-01-01

    Neurotactin (Nrt), a Drosophila transmembrane glycoprotein which is expressed in neuronal and epithelial tissues during embryonic and larval stages, exhibits heterophilic adhesive properties. The extracellular domain is composed of a catalytically inactive cholinesterase-like domain. A three-dimensional model deduced from the crystal structure of Torpedo acetylcholinesterase (AChE) has been constructed for Nrt and suggests that its extracellular domain is composed of two sub-domains organized around a gorge: an N-terminal region, whose three-dimensional structure is almost identical to that of Torpedo AChE, and a less conserved C-terminal region. By using truncated Nrt molecules and a homotypic cell aggregation assay which involves a soluble ligand activity, it has been possible to show that the adhesive function is localized in the N-terminal region of the extracellular domain comprised between His347 and His482. The C-terminal region of the protein can be removed without impairing Nrt adhesive properties, suggesting that the two sub-domains are structurally independent. Chimeric molecules in which the Nrt cholinesterase-like domain has been replaced by homologous domains from Drosophila AChE, Torpedo AChE or Drosophila glutactin (Glt), share similar adhesive properties. These properties may require the presence of Nrt cytoplasmic and transmembrane domains since authentic Drosophila AChE does not behave as an adhesive molecule when transfected in S2 cells. Images PMID:8890157

  7. Chemical and molecular aspects on interactions of galanthamine and its derivatives with cholinesterases.

    PubMed

    Gulcan, Hayrettin O; Orhan, Ilkay E; Sener, Bilge

    2015-01-01

    Dual action of galanthamine as potent cholinesterase inhibitor and nicotinic modulator has attracted a great attention to be used in the treatment of AD. Consequently, galanthamine, a natural alkaloid isolated from a Galanthus species (snowdrop, Amaryllidaceae), has become an attractive model compound for synthesis of its novel derivatives to discover new drug candidates. Numerous studies have been done to elucidate interactions between galanthamine and its different derivatives and the enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using in vitro and in silico experimental models. The in vitro studies revealed that galanthamine inhibits AChE in strong, competitive, long-acting, and reversible manner as well as BChE, although its selectivity towards AChE is much higher than BChE. The in silico studies carried out by employing molecular docking experiments as well as molecular dynamics simulations pointed out to existence of strong interactions of galanthamine with the active gorge of AChE, mostly of Torpedo californica (the Pasific electric ray) origin. In this review, we evaluate the mainstays of cholinesterase inhibitory action of galanthamine and its various derivatives from the point of view of chemical and molecular aspects. PMID:25483718

  8. Chemical and molecular aspects on interactions of galanthamine and its derivatives with cholinesterases.

    PubMed

    Gulcan, Hayrettin O; Orhan, Ilkay E; Sener, Bilge

    2015-01-01

    Dual action of galanthamine as potent cholinesterase inhibitor and nicotinic modulator has attracted a great attention to be used in the treatment of AD. Consequently, galanthamine, a natural alkaloid isolated from a Galanthus species (snowdrop, Amaryllidaceae), has become an attractive model compound for synthesis of its novel derivatives to discover new drug candidates. Numerous studies have been done to elucidate interactions between galanthamine and its different derivatives and the enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using in vitro and in silico experimental models. The in vitro studies revealed that galanthamine inhibits AChE in strong, competitive, long-acting, and reversible manner as well as BChE, although its selectivity towards AChE is much higher than BChE. The in silico studies carried out by employing molecular docking experiments as well as molecular dynamics simulations pointed out to existence of strong interactions of galanthamine with the active gorge of AChE, mostly of Torpedo californica (the Pasific electric ray) origin. In this review, we evaluate the mainstays of cholinesterase inhibitory action of galanthamine and its various derivatives from the point of view of chemical and molecular aspects.

  9. Gypsogenin derivatives: an unexpected class of inhibitors of cholinesterases.

    PubMed

    Heller, Lucie; Schwarz, Stefan; Weber, Björn A; Csuk, René

    2014-10-01

    Gypsogenin (1) was obtained by acidic hydrolysis from its saponin. While the parent compound 1 acted as a selective inhibitor for butyrylcholinesterase (from equus) possessing a moderate mixed-type inhibition of the enzyme, Ki values as low as 2.67 ± 0.59 μM were determined for (3β,4α) 3-O-acetyl-olean-12-ene-23,28-dinitrile (11) and acetylcholinesterase (AChE, from electric eel). Thus, 11 possesses one-fifth of the inhibitory activity of the "gold standard" galantamine hydrobromide; this compound is one of the first pentacyclic triterpenoids described as a potent AChE-selective inhibitor. PMID:25042600

  10. Mechanistic insights into the regulation of metabolic enzymes by acetylation

    PubMed Central

    2012-01-01

    The activity of metabolic enzymes is controlled by three principle levels: the amount of enzyme, the catalytic activity, and the accessibility of substrates. Reversible lysine acetylation is emerging as a major regulatory mechanism in metabolism that is involved in all three levels of controlling metabolic enzymes and is altered frequently in human diseases. Acetylation rivals other common posttranslational modifications in cell regulation not only in the number of substrates it modifies, but also the variety of regulatory mechanisms it facilitates. PMID:22826120

  11. [The reversible inhibition of cholinesterases from different biological sources by phosphonium betaines].

    PubMed

    Zhuzhovskiĭ, Iu G; Kuznetsova, L P; Sochilina, E E; Dmitrieva, E N; Gololobov, Iu G; Bykovskaia, E Iu

    1996-01-01

    The action of some phosphonium betains on cholinesterases from different biological sources has been studied. It has been shown, that all studied betains are reversible inhibitors of cholinesterase hydrolysis of acetyltiocholine. Inhibiting action of these compounds on acetylcholinesterases is about ten times weaker that of the majority of known phosphonium salts, while their action on butyrylcholinesterases has no peculiarities. There were found certain differences for each betain compounds in their action on cholinesterases from different biological sources. These results may be used for detail classification of cholinesterases and allow to extend knowledge in comparative enzymology. PMID:8967277

  12. Plasma and brain cholinesterase in methomyl-intoxicated free-ranging pigeons (Columba livia f. domestica).

    PubMed

    Villar, David; Balvin, Dubel; Giraldo, Carlos; Motas, Miguel; Olivera, Marta

    2010-03-01

    A mortality event caused by exposure to the carbamate insecticide methomyl was diagnosed in several hundred pigeons fed treated corn kernels in a city park. A cholinesterase inhibitor insecticide was initially suspected based on clinical signs and a significant inhibition (P < 0.05) of brain cholinesterase (ChE) activity compared with normal values for the species. However, brain ChE activity was within the normal range in birds subsequently submitted in an advanced stage of autolysis. Two groups of 10 healthy pigeons were allocated into a control group and an experimental group, which was offered corn samples retrieved from the incident site. Within minutes of ingesting the contaminated corn, the birds became immobile, had transient wing fluttering, and developed profuse salivation immediately followed by death. Plasma ChE activity at death had declined by more than 95% of preexposure levels (0.04 +/- 0.02 vs. 1.56 +/- 0.23 micromol/min per milliliter). Brain activity in the sagittal brain sections that were immediately frozen after death was inhibited by > or =50% of control birds (13.5 +/- 2.2 vs. 27.5 +/- 1.8 micromol/min per gram). However, the sagittal sections left for 1.5 days at ambient temperature of 25 degrees C had normal or higher activity, an effect that was attributed to a combination of spontaneous reactivation and dehydration. After incubation of both plasma and brain homogenates for 1 hr at 37 degrees C, ChE activity recovered by 2- and 1.46-fold, respectively. An organophosphorus and carbamate screen conducted by 2 independent laboratories identified and quantified methomyl in treated kernels at 400 ppm. These results indicate that spontaneous reactivation and dehydration can mask previous reductions in ChE activity.

  13. Altered acetylation and succinylation profiles in Corynebacterium glutamicum in response to conditions inducing glutamate overproduction.

    PubMed

    Mizuno, Yuta; Nagano-Shoji, Megumi; Kubo, Shosei; Kawamura, Yumi; Yoshida, Ayako; Kawasaki, Hisashi; Nishiyama, Makoto; Yoshida, Minoru; Kosono, Saori

    2016-02-01

    The bacterium Corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as L-glutamate. During L-glutamate fermentation, C. glutamicum changes the flux of central carbon metabolism to favor L-glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. Here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in C. glutamicum; acetylation decreased, whereas succinylation increased. A label-free semi-quantitative proteomic analysis identified 604 acetylated proteins with 1328 unique acetylation sites and 288 succinylated proteins with 651 unique succinylation sites. Acetylation and succinylation targeted enzymes in central carbon metabolic pathways that are directly related to glutamate production, including the 2-oxoglutarate dehydrogenase complex (ODHC), a key enzyme regulating glutamate overproduction. Structural mapping revealed that several critical lysine residues in the ODHC components were susceptible to acetylation and succinylation. Furthermore, induction of glutamate production was associated with changes in the extent of acetylation and succinylation of lysine, suggesting that these modifications may affect the activity of enzymes involved in glutamate production. Deletion of phosphotransacetylase decreased the extent of protein acetylation in nonproducing condition, suggesting that acetyl phosphate-dependent acetylation is active in C. glutamicum. However, no effect was observed on the profiles of acetylation and succinylation in glutamate-producing condition upon disruption of acetyl phosphate metabolism or deacetylase homologs. It was considered likely that the reduced acetylation in glutamate-producing condition may reflect metabolic states where the flux through acid-producing pathways is very low, and substrates for acetylation do not accumulate in the cell. Succinylation would occur more

  14. Dysregulated miR-34a-SIRT1-acetyl p65 axis is a potential mediator of immune activation in the colon during chronic SIV infection of rhesus macaques

    PubMed Central

    Mohan, Mahesh; Kumar, Vinay; Lackner, Andrew A.; Alvarez, Xavier

    2014-01-01

    Persistent gastrointestinal (GI) inflammation, a hallmark of progressive HIV/SIV infection causes disruption of the GI epithelial barrier, microbial translocation and generalized immune activation/inflammation driving AIDS progression. Apart from protein regulators, recent studies strongly suggest critical roles for microRNAs (miRNAs) in regulating and managing certain aspects of the inflammatory process. To examine their immunoregulatory role, we profiled miRNA expression in colon from 12 chronic SIV-infected and 4 control macaques. After applying multiple comparisons correction, 10 (3-up and 7-down) miRNAs showed differential expression. Most notably, miR-34a showed significant upregulation in both epithelial and lamina propria leukocyte (LPL) compartments. Intense γH2AX expression in colonic epithelium and LPL confirmed the contribution of DNA damage response in driving miR-34a upregulation. SIRT1 mRNA and protein decreased significantly in both colonic epithelium and LPL. Luciferase reporter assays validated rhesus macaque SIRT1 as a direct miR-34a target. Decreased SIRT1 expression was associated with constitutively enhanced expression of the transcriptionally active form of the p65 (acetylated on lysine 310) subunit of NFκB exclusively in the LPL compartment. The intensity and number of acetylated-p65+ cells was markedly elevated in LPLs of chronically SIV-infected macaques compared to uninfected controls and localized to increased numbers of IgA+ and IgG+ plasma cells. These findings provide new insights into the potential role of the miR-34a-SIRT1-p65 axis in causing hyperactivation of the intestinal B cell system. Our results point to a possible mechanism where the normal immunosuppressive function of SIRT1 is inhibited by elevated miR-34a expression resulting in constitutive activation of acetylated-p65 (lysine 310). PMID:25452565

  15. In the absence of cellular poly (A) binding protein, the glycolytic enzyme GAPDH translocated to the cell nucleus and activated the GAPDH mediated apoptotic pathway by enhancing acetylation and serine 46 phosphorylation of p53.

    PubMed

    Thangima Zannat, Mst; Bhattacharjee, Rumpa B; Bag, Jnanankur

    2011-06-01

    The cytoplasmic poly (A) binding protein (PABP) interacts with 3' poly (A) tract of eukaryotic mRNA and is important for both translation and stability of mRNA. Previously, we have shown that depletion of PABP by siRNA prevents protein synthesis and consequently leads to cell death through apoptosis. In the present investigation, we studied the mechanism of cell apoptosis. We show that in the absence of PABP, the glycolytic enzyme GAPDH translocated to the cell nucleus and activated the GAPDH mediated apoptotic pathway by enhancing acetylation and serine 46 phosphorylation of p53. As a result, p53 translocated to the mitochondria to initiate Bax mediated apoptosis.

  16. Nagstatin, a new inhibitor of N-acetyl-beta-D-glucosaminidase, produced by Streptomyces amakusaensis MG846-fF3. Taxonomy, production, isolation, physico-chemical properties and biological activities.

    PubMed

    Aoyagi, T; Suda, H; Uotani, K; Kojima, F; Aoyama, T; Horiguchi, K; Hamada, M; Takeuchi, T

    1992-09-01

    Nagstatin, a new inhibitor of N-acetyl-beta-D-glucosaminidase (NAG-ase) was discovered in the fermentation broth of Streptomyces amakusaensis MG846-fF3. It was purified by chromatography on Dowex 50W, Avicel and Sephadex LH-20 followed by the treatment of active carbon and then isolated as colorless powder. Nagstatin has the molecular formula of C12H17N3O6. It is competitive with the substrate, and the inhibition constant (Ki) was 1.7 x 10(-8) M. PMID:1429224

  17. The Arabidopsis thaliana ortholog of a purported maize cholinesterase gene encodes a GDSL-lipase.

    PubMed

    Muralidharan, Mrinalini; Buss, Kristina; Larrimore, Katherine E; Segerson, Nicholas A; Kannan, Latha; Mor, Tsafrir S

    2013-04-01

    Acetylcholinesterase is an enzyme that is intimately associated with regulation of synaptic transmission in the cholinergic nervous system and in neuromuscular junctions of animals. However the presence of cholinesterase activity has been described also in non-metazoan organisms such as slime molds, fungi and plants. More recently, a gene purportedly encoding for acetylcholinesterase was cloned from maize. We have cloned the Arabidopsis thaliana homolog of the Zea mays gene, At3g26430, and studied its biochemical properties. Our results indicate that the protein encoded by the gene exhibited lipase activity with preference to long chain substrates but did not hydrolyze choline esters. The At3g26430 protein belongs to the SGNH clan of serine hydrolases, and more specifically to the GDS(L) lipase family. PMID:23430565

  18. Action of the herbicide butachlor on cholinesterases in the freshwater snail Pila globosa (Swainson).

    PubMed

    Rajyalakshmi, T; Srinivas, T; Swamy, K V; Prasad, N S; Mohan, P M

    1996-11-01

    Butachlor action on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activates in central nervous tissue of the snail Pila globosa was assayed following the method of ELLMAN et al1, in vitro by adding butachlor directly (10-100 mu moles), to tissue homogenates and in in vivo by exposing the snails to sub-lethal concentration (26.6 ppm) and taking out the tissue for experimentation at different intervals (3, 6, 12, 24 and 48 h) of exposure. The enzyme activities decreased in a dose-dependent manner in vitro, and up to 12-24 h in vivo after which they showed recovery towards the control. The inhibition of cholinesterases by butachlor in vitro indicates a direct action of the herbicide on these enzymes. Presumably butachlor exercises its neurotoxic effects through cholinergic impairment in a way similar to that of organophosphates and carbamates.

  19. 9-O-Acetylation of sialic acids is catalysed by CASD1 via a covalent acetyl-enzyme intermediate.

    PubMed

    Baumann, Anna-Maria T; Bakkers, Mark J G; Buettner, Falk F R; Hartmann, Maike; Grove, Melanie; Langereis, Martijn A; de Groot, Raoul J; Mühlenhoff, Martina

    2015-01-01

    Sialic acids, terminal sugars of glycoproteins and glycolipids, play important roles in development, cellular recognition processes and host-pathogen interactions. A common modification of sialic acids is 9-O-acetylation, which has been implicated in sialoglycan recognition, ganglioside biology, and the survival and drug resistance of acute lymphoblastic leukaemia cells. Despite many functional implications, the molecular basis of 9-O-acetylation has remained elusive thus far. Following cellular approaches, including selective gene knockout by CRISPR/Cas genome editing, we here show that CASD1--a previously identified human candidate gene--is essential for sialic acid 9-O-acetylation. In vitro assays with the purified N-terminal luminal domain of CASD1 demonstrate transfer of acetyl groups from acetyl-coenzyme A to CMP-activated sialic acid and formation of a covalent acetyl-enzyme intermediate. Our study provides direct evidence that CASD1 is a sialate O-acetyltransferase and serves as key enzyme in the biosynthesis of 9-O-acetylated sialoglycans. PMID:26169044

  20. Acetylation of Mammalian ADA3 Is Required for Its Functional Roles in Histone Acetylation and Cell Proliferation.

    PubMed

    Mohibi, Shakur; Srivastava, Shashank; Bele, Aditya; Mirza, Sameer; Band, Hamid; Band, Vimla

    2016-10-01

    Alteration/deficiency in activation 3 (ADA3) is an essential component of specific histone acetyltransferase (HAT) complexes. We have previously shown that ADA3 is required for establishing global histone acetylation patterns and for normal cell cycle progression (S. Mohibi et al., J Biol Chem 287:29442-29456, 2012, http://dx.doi.org/10.1074/jbc.M112.378901). Here, we report that these functional roles of ADA3 require its acetylation. We show that ADA3 acetylation, which is dynamically regulated in a cell cycle-dependent manner, reflects a balance of coordinated actions of its associated HATs, GCN5, PCAF, and p300, and a new partner that we define, the deacetylase SIRT1. We use mass spectrometry and site-directed mutagenesis to identify major sites of ADA3 acetylated by GCN5 and p300. Acetylation-defective mutants are capable of interacting with HATs and other components of HAT complexes but are deficient in their ability to restore ADA3-dependent global or locus-specific histone acetylation marks and cell proliferation in Ada3-deleted murine embryonic fibroblasts (MEFs). Given the key importance of ADA3-containing HAT complexes in the regulation of various biological processes, including the cell cycle, our study presents a novel mechanism to regulate the function of these complexes through dynamic ADA3 acetylation. PMID:27402865

  1. Platelet-activating factor (PAF) stimulates the PAF-synthesizing enzyme acetyl-CoA:1-alkyl-sn-glycero-3-phosphocholine O2-acetyltransferase and PAF synthesis in neutrophils.

    PubMed Central

    Doebber, T W; Wu, M S

    1987-01-01

    Platelet activating factor (1-alkyl-2-acetyl-sn-glycero-3-phosphocholine; PAF) induced in isolated rat peritoneal and human peripheral neutrophils a rapid and potent activation of the PAF biosynthetic enzyme acetyl-CoA:1-alkyl-sn-glycero-3-phosphocholine O2-acetyltransferase (EC 2.3.1.67). The PAF-induced activation of the neutrophil acetyltransferase (8-10 times basal neutrophil activity) was maximal within 30 sec after PAF addition, as was the PAF-stimulated degranulation. After 1 min of PAF stimulation, the elevated acetyltransferase activity steadily decreased. Within 2 min of stimulation of neutrophils with 10(-6) M PAF, the 7-fold increase in acetyltransferase activity was coincident with substantial PAF synthesis (as measured by [3H]acetate incorporation into PAF), which was 14% of the PAF synthesis induced by the Ca2+ ionophore A23187 at 10(-5) M. PAF activation of the acetyltransferase and PAF synthesis required intact neutrophils as they did not occur in cells broken by sonication. The neutrophil acetyltransferase was 10-30 times more sensitive to activation by PAF than was degranulation as the acetyltransferase activation was evident with 10(-9) M PAF and was about maximal with 3 x 10(-8) M PAF. The unstimulated and PAF-induced acetyltransferase exhibited the same Km for acetyl-CoA (67 microM), but the Vmax for the PAF-induced enzyme (1667 pmol/min per 10(7) cells) was 10 times that of the unstimulated enzyme (175 pmol/min per 10(7) cells). The PAF induction of the acetyltransferase was less sensitive to inhibition by the specific PAF receptor antagonist L-652,731 than was PAF-induced degranulation. This, along with the differing sensitivities to PAF, suggests that acetyltransferase activation and degranulation induced by PAF either involve two different PAF receptors or involve one receptor type with different receptor occupancy requirements. Escherichia coli alkaline phosphatase, which greatly decreased the activity of the acetyltransferase in spleen

  2. Acetylator phenotype in diabetic neuropathy.

    PubMed

    McLaren, E H; Burden, A C; Moorhead, P J

    1977-07-30

    The proportions of slow and fast acetylators in a group of diabetics with symptomatic peripheral neuropathy were compared with those in a group of diabetics who had had the disease for at least 10 years without developing neuropathy. There was a significantly higher proportion of fast acetylators in the group of diabetics without neuropathy than in those with neuropathy or in the normal population. Hence genetic factors separate from the diabetic diathesis may determine the development of neuropathy in any particular diabetic.

  3. Hepatic cholinesterase of laying hens naturally infected by Salmonella Gallinarum (fowl typhoid).

    PubMed

    Da Silva, Aleksandro S; Boiago, Marcel M; Bottari, Nathieli B; do Carmo, Guilherme M; Alves, Mariana Sauzen; Boscato, Carla; Morsch, Vera M; Schetinger, Maria Rosa C; Casagrande, Renata A; Stefani, Lenita M

    2016-09-01

    Salmonella is a facultative intracellular pathogen that may cause foodborne gastroenteritis in humans and animals consisting of over 2000 serovars. The serovar Salmonella Gallinarum is an important worldwide pathogen of poultry. However, little is known on the mechanisms of pathogenesis of Salmonella in chickens. The aim of this study was to evaluate cholinesterase and myeloperoxidase activities in hepatic tissue of laying hens naturally infected by S. Gallinarum. Twenty positive liver samples for S. Gallinarum were collected, in addition to seven liver samples from healthy uninfected laying hens (control group). The right liver lobe was homogenized for analysis of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and myeloperoxidase (MPO), and the left lobe was divided into two fragments, one for histopathology and the other for Salmonella isolation. The results showed changes in AChE and BchE activity in the liver of infected laying hens compared to the control group (P < 0.05), i.e. reduced AChE and increased BChE activities in liver samples. Infected animals showed increased MPO activity compared to healthy animals (P < 0.05). Furthermore, the histopathological findings showed fibrinoid necrosis associated to the infiltration of lymphocytes, plasma cells, macrophages,heterophils in the liver of infected hens. These findings suggest that the inflammatory process was attenuated providing a pro-inflammatory action of both enzyme analyzed in order to reduce the free ACh, a molecule which has an anti-inflammatory action. Therefore, our results lead to the hypothesis that cholinesterase plays an important role on the modulation of immune response against S. Gallinarum with an inflammatory effect, contributing to the response against this bacterium. This study should contribute to a better understanding on the pathogenic mechanisms involved in laying hens infected by S. Gallinarum.

  4. Histone acetylation dependent energy landscapes in tri-nucleosome revealed by residue-resolved molecular simulations

    PubMed Central

    Chang, Le; Takada, Shoji

    2016-01-01

    Histone tail acetylation is a key epigenetic marker that tends to open chromatin folding and activate transcription. Despite intensive studies, precise roles of individual lysine acetylation in chromatin folding have only been poorly understood. Here, we revealed structural dynamics of tri-nucleosomes with several histone tail acetylation states and analyzed histone tail interactions with DNA by performing molecular simulations at an unprecedentedly high resolution. We found versatile acetylation-dependent landscapes of tri-nucleosome. The H4 and H2A tail acetylation reduced the contact between the first and third nucleosomes mediated by the histone tails. The H3 tail acetylation reduced its interaction with neighboring linker DNAs resulting in increase of the distance between consecutive nucleosomes. Notably, two copies of the same histone in a single nucleosome have markedly asymmetric interactions with DNAs, suggesting specific pattern of nucleosome docking albeit high inherent flexibility. Estimated transcription factor accessibility was significantly high for the H4 tail acetylated structures. PMID:27698366

  5. Regional inhibition of cholinesterase in free-ranging western pond turtles (Emys marmorata) occupying California mountain streams.

    PubMed

    Meyer, Erik; Sparling, Donald; Blumenshine, Steve

    2013-03-01

    The present study investigated the potential effects of cholinesterase (ChE)-inhibiting pesticides on western pond turtles (Emys marmorata) occupying streams in two regions of California, USA. The southern region was suspected of having increased exposure to atmospheric deposition of contaminants originating from Central Valley agriculture. The northern region represented reference ChE activities because this area was located outside of the prominent wind patterns that deposit pesticides into the southern region. Total ChE activity was measured in plasma from a total of 81 turtles from both regions. Cholinesterase activity of turtles was significantly depressed by 31% (p = 0.005) in the southern region after accounting for additional sources of variation in ChE activity. Male turtles had significantly increased ChE activity compared with females (p = 0.054). Cloaca temperature, length, mass, handling time, body condition, and lymph presence were not significant predictors of turtle ChE activity. In the southern region, 6.3% of the turtles were below the diagnostic threshold of two standard deviations less than the reference site mean ChE activity. Another diagnostic threshold determined that 75% of the turtles from the southern region had ChE activities depressed by 20% of the reference mean. The decrease in ChE activity in the southern region suggests sublethal effects of pesticide exposure, potentially altering neurotransmission, which can result in various deleterious behaviors.

  6. Proteinase-activated receptors induce interleukin-8 expression by intestinal epithelial cells through ERK/RSK90 activation and histone acetylation.

    PubMed

    Wang, Hongying; Moreau, France; Hirota, Christina L; MacNaughton, Wallace K

    2010-06-01

    Proteinase-activated receptors (PARs) are involved in both inflammation and tumorigenesis in epithelial cells. Interleukin (IL)-8 is a potent chemoattractant and is also involved in angiogenesis. The molecular mechanism whereby PARs induce epithelial IL-8 expression is not known. In HT-29 colonic epithelial cells, PAR(1) or PAR(2) agonists stimulated the expression of IL-8 through a NF-kappaB-dependent pathway without inducing IkappaB degradation and disassociation of IkappaB from NF-kappaB. Further studies revealed that PAR activation induced the phosphorylation of p65 at Ser-276 in the nucleus, which increased the recruitment of histone acetyltransferase (HAT) p300 to p50. Inhibition of ERK activation completely blocked PAR-induced IL-8 expression, phosphorylation of p65 and HAT activity. We also demonstrated that RSK p90 was the downstream kinase that mediated ERK-induced nuclear p65 phosphorylation. In conclusion, activation of either PAR(1) or PAR(2) stimulated the transcriptional up-regulation of IL-8 in HT-29 colonic epithelial cells through a pathway that involved ERK/RSK p90, NF-kappaB phosphorylation, and HAT activity. These studies provide evidence of a new role for serine proteinases and PARs in the regulation of gene expression in colonic inflammation and tumorigenesis.

  7. Acetylation of C/EBPα inhibits its granulopoietic function

    PubMed Central

    Bararia, Deepak; Kwok, Hui Si; Welner, Robert S.; Numata, Akihiko; Sárosi, Menyhárt B.; Yang, Henry; Wee, Sheena; Tschuri, Sebastian; Ray, Debleena; Weigert, Oliver; Levantini, Elena; Ebralidze, Alexander K.; Gunaratne, Jayantha; Tenen, Daniel G.

    2016-01-01

    CCAAT/enhancer-binding protein alpha (C/EBPα) is an essential transcription factor for myeloid lineage commitment. Here we demonstrate that acetylation of C/EBPα at lysine residues K298 and K302, mediated at least in part by general control non-derepressible 5 (GCN5), impairs C/EBPα DNA-binding ability and modulates C/EBPα transcriptional activity. Acetylated C/EBPα is enriched in human myeloid leukaemia cell lines and acute myeloid leukaemia (AML) samples, and downregulated upon granulocyte-colony stimulating factor (G-CSF)- mediated granulocytic differentiation of 32Dcl3 cells. C/EBPα mutants that mimic acetylation failed to induce granulocytic differentiation in C/EBPα-dependent assays, in both cell lines and in primary hematopoietic cells. Our data uncover GCN5 as a negative regulator of C/EBPα and demonstrate the importance of C/EBPα acetylation in myeloid differentiation. PMID:27005833

  8. Acetylation of banana fibre to improve oil absorbency.

    PubMed

    Teli, M D; Valia, Sanket P

    2013-01-30

    Oil spill leaves detrimental effects on the environment, living organisms and economy. In the present work, an attempt is made to provide an efficient, easily deployable method of cleaning up oil spills and recovering of the oil. The work reports the use of banana fibres which were acetylated for oil spill recovery. The product so formed was characterized by FT-IR, TG, SEM and its degree of acetylation was also evaluated. The extent of acetylation was measured by weight percent gain. The oil sorption capacity of the acetylated fibre was higher than that of the commercial synthetic oil sorbents such as polypropylene fibres as well as un-modified fibre. Therefore, these oil sorption-active materials which are also biodegradable can be used to substitute non-biodegradable synthetic materials in oil spill cleanup. PMID:23218302

  9. Histone Acetylation and Chromatin Remodeling Are Required for UV-B–Dependent Transcriptional Activation of Regulated Genes in Maize[W

    PubMed Central

    Casati, Paula; Campi, Mabel; Chu, Feixia; Suzuki, Nagi; Maltby, David; Guan, Shenheng; Burlingame, Alma L.; Walbot, Virginia

    2008-01-01

    The nuclear proteomes of maize (Zea mays) lines that differ in UV-B tolerance were compared by two-dimensional gel electrophoresis after UV light treatment. Differential accumulation of chromatin proteins, particularly histones, constituted the largest class identified by mass spectrometry. UV-B–tolerant landraces and the B73 inbred line show twice as many protein changes as the UV-B–sensitive b, pl W23 inbred line and transgenic maize expressing RNA interference constructs directed against chromatin factors. Mass spectrometic analysis of posttranslational modifications on histone proteins demonstrates that UV-B–tolerant lines exhibit greater acetylation on N-terminal tails of histones H3 and H4 after irradiation. These acetylated histones are enriched in the promoter and transcribed regions of the two UV-B–upregulated genes examined; radiation-sensitive lines lack this enrichment. DNase I and micrococcal nuclease hypersensitivity assays indicate that chromatin adopts looser structures around the selected genes in the UV-B–tolerant samples. Chromatin immunoprecipitation experiments identified additional chromatin factor changes associated with the nfc102 test gene after UV-B treatment in radiation-tolerant lines. Chromatin remodeling is thus shown to be a key process in acclimation to UV-B, and lines deficient in this process are more sensitive to UV-B. PMID:18398050

  10. Weight Loss Associated with Cholinesterase Inhibitors In Patients With Dementia in a National Healthcare System

    PubMed Central

    Sheffrin, Meera; Miao, Yinghui; Boscardin, W. John; Steinman, Michael A.

    2016-01-01

    Background/Objectives Inconsistent data from randomized trials suggest cholinesterase inhibitors may cause weight loss. We sought to determine if the initiation of cholinesterase inhibitors is associated with significant weight loss in a real-word clinical setting. Design Retrospective cohort study from 2007-2010, comparing weight loss in patients with dementia newly prescribed cholinesterase inhibitors and patients newly prescribed other chronic medications Setting National Veterans Affairs (VA) data Participants Patients 65 years or older with a diagnosis of dementia who received a new prescription for a cholinesterase inhibitor or other new other chronic medication. Measurements The primary outcome was time to 10 pound weight loss over 12 months. We used propensity score matching patients to control for the likelihood of receiving a cholinesterase inhibitor based on baseline characteristics. Data were analyzed in a priori defined subgroups by age, comorbid burden, and initial weight. Results Of 6,504 patients that met study criteria, 1188 patients started on cholinesterase inhibitors were matched to 2189 patients started on other medications. The propensity-matched cohorts were well balanced on baseline covariates. Patients initiated on cholinesterase inhibitors had a higher risk of weight loss compared to matched controls at 12 months, HR 1.23 (95% CI 1.07 - 1.41). At twelve months, 29.3% of patients on cholinesterase inhibitors had experienced weight loss compared to 22.8% of non-users, corresponding to a number needed to harm of 21.2 (95% CI 12.5 – 71.4) over one year. There were no significant differences across subgroups. Conclusion Patients with dementia started on cholinesterase inhibitors had a higher risk of clinically significant weight loss over a 12-month period compared to matched controls. These results are consistent with the available data from randomized controlled trials. Clinicians should consider the risk of weight loss when prescribing

  11. Different sensitivities of rat skeletal muscles and brain to novel anti-cholinesterase agents, alkylammonium derivatives of 6-methyluracil (ADEMS)

    PubMed Central

    Petrov, Konstantin A; Yagodina, Lilia O; Valeeva, Guzel R; Lannik, Natalya I; Nikitashina, Alexandra D; Rizvanov, Albert A; Zobov, Vladimir V; Bukharaeva, Ellya A; Reznik, Vladimir S; Nikolsky, Eugeny E; Vyskočil, František

    2011-01-01

    BACKGROUND AND PURPOSE The rat respiratory muscle diaphragm has markedly lower sensitivity than the locomotor muscle extensor digitorum longus (EDL) to the new acetylcholinesterase (AChE) inhibitors, alkylammonium derivatives of 6-methyluracil (ADEMS). This study evaluated several possible reasons for differing sensitivity between the diaphragm and limb muscles and between the muscles and the brain. EXPERIMENTAL APPROACH Increased amplitude and prolonged decay time of miniature endplate currents were used to assess anti-cholinesterase activity in muscles. In hippocampal slices, induction of synchronous network activity was used to follow cholinesterase inhibition. The inhibitor sensitivities of purified AChE from the EDL and brain were also estimated. KEY RESULTS The intermuscular difference in sensitivity to ADEMS is partly explained caused by a higher level of mRNA and activity of 1,3-bis[5(diethyl-o-nitrobenzylammonium)pentyl]-6-methyluracildibromide (C-547)-resistant BuChE in the diaphragm. Moreover, diaphragm AChE was more than 20 times less sensitive to C-547 than that from the EDL. Sensitivity of the EDL to C-547 dramatically decreased after treadmill exercises that increased the amount of PRiMA AChE(G4), but not ColQ AChE(A12) molecular forms. The A12 form present in muscles appeared more sensitive to C-547. The main form of AChE in brain, PRiMA AChE(G4), was apparently less sensitive because brain cholinesterase activity was almost three orders of magnitude more resistant to C-547 than that of the EDL. CONCLUSIONS AND IMPLICATIONS Our findings suggest that ADEMS compounds could be used for the selective inhibition of AChEs and as potential therapeutic tools. PMID:21232040

  12. Synthesis and biological evaluation of salicylic acid and N-acetyl-2-carboxybenzenesulfonamide regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore: dual inhibitors of cyclooxygenases and 5-lipoxygenase with anti-inflammatory activity.

    PubMed

    Chowdhury, Morshed A; Abdellatif, Khaled R A; Dong, Ying; Das, Dipankar; Yu, Gang; Velázquez, Carlos A; Suresh, Mavanur R; Knaus, Edward E

    2009-12-15

    A novel class of salicylic acid and N-acetyl-2-carboxybenzenesulfonamide regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore attached to its C-4 or C-5 position was designed for evaluation as anti-inflammatory (AI) agents. Replacement of the 2,4-difluorophenyl ring in diflunisal by the N-difluoromethyl-1,2-dihydropyrid-2-one moiety provided compounds showing dual selective cyclooxygenase-2 (COX-2)/5-lipoxygenase (5-LOX) inhibitory activities. AI structure-activity studies showed that the C-4 (14a) and C-5 (14b) salicylate regioisomers were 1.4- and 1.6-fold more potent than aspirin, and the C-5 N-acetyl-2-carboxybenzenesulfonamide regioisomer (22b) was 1.3- and 2.8-fold more potent than ibuprofen and aspirin, respectively. In vivo ulcer index (UI) studies showed that the 4- and 5-(N-difluoromethyl-1,2-dihydropyrid-2-one-4-yl)salicylic acids (14a and 14b) were completely non-ulcerogenic since no gastric lesions were present (UI=0) relative to aspirin (UI=57) at an equivalent mumol/kg oral dose. The N-difluoromethyl-1,2-dihydropyridin-2-one moiety provides a novel 5-LOX pharmacophore for the design of cyclic hydroxamic mimetics for exploitation in the development of dual COX-2/5-LOX inhibitory AI drugs.

  13. Autoimmune regulator is acetylated by transcription coactivator CBP/p300

    SciTech Connect

    Saare, Mario; Rebane, Ana; Rajashekar, Balaji; Vilo, Jaak; Peterson, Paert

    2012-08-15

    The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations that mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes. -- Highlights: Black-Right-Pointing-Pointer AIRE is acetylated by the acetyltransferases p300 and CBP. Black-Right-Pointing-Pointer Acetylation occurs between CARD and SAND domains and within the SAND domain. Black-Right-Pointing-Pointer Acetylation increases the size of AIRE nuclear dots. Black-Right-Pointing-Pointer Acetylation increases AIRE protein stability. Black-Right-Pointing-Pointer AIRE acetylation mimic regulates a different set of AIRE

  14. Expression of mung bean pectin acetyl esterase in potato tubers: effect on acetylation of cell wall polymers and tuber mechanical properties.

    PubMed

    Orfila, Caroline; Dal Degan, Florence; Jørgensen, Bodil; Scheller, Henrik Vibe; Ray, Peter M; Ulvskov, Peter

    2012-07-01

    A mung bean (Vigna radiata) pectin acetyl esterase (CAA67728) was heterologously expressed in tubers of potato (Solanum tuberosum) under the control of the granule-bound starch synthase promoter or the patatin promoter in order to probe the significance of O-acetylation on cell wall and tissue properties. The recombinant tubers showed no apparent macroscopic phenotype. The enzyme was recovered from transgenic tubers using a high ionic strength buffer and the extract was active against a range of pectic substrates. Partial in vivo de-acetylation of cell wall polysaccharides occurred in the transformants, as shown by a 39% decrease in the degree of acetylation (DA) of tuber cell wall material (CWM). Treatment of CWM using a combination of endo-polygalacturonase and pectin methyl esterase extracted more pectin polymers from the transformed tissue compared to wild type. The largest effect of the pectin acetyl esterase (68% decrease in DA) was seen in the residue from this extraction, suggesting that the enzyme is preferentially active on acetylated pectin that is tightly bound to the cell wall. The effects of acetylation on tuber mechanical properties were investigated by tests of failure under compression and by determination of viscoelastic relaxation spectra. These tests suggested that de-acetylation resulted in a stiffer tuber tissue and a stronger cell wall matrix, as a result of changes to a rapidly relaxing viscoelastic component. These results are discussed in relation to the role of pectin acetylation in primary cell walls and its implications for industrial uses of potato fibres.

  15. System-wide Studies of N-Lysine Acetylation in Rhodopseudomonas palustris Reveals Substrate Specificity of Protein Acetyltransferases

    SciTech Connect

    Crosby, Heidi A; Pelletier, Dale A; Hurst, Gregory {Greg} B; Escalante-Semerena, Jorge C

    2012-01-01

    Background: Protein acetylation is widespread in prokaryotes. Results: Six new acyl-CoA synthetases whose activities are controlled by acetylation were identified, and their substrate preference established. A new protein acetyltransferase was also identified and its substrate specificity determined. Conclusion: Protein acetyltransferases acetylate a conserved lysine residue in protein substrates. Significance: The R. palustris Pat enzyme specifically acetylates AMP-forming acyl-CoA synthetases and regulates fatty acid metabolism.

  16. Pharmacoeconomics of cholinesterase inhibitors in the treatment of Alzheimer's disease.

    PubMed

    Jönsson, Linus

    2003-01-01

    Cholinesterase inhibitors constitute one of few treatment options available for Alzheimer's disease, the most common cause of dementia. The modest effects and relatively high acquisition costs of these drugs make the health economics of dementia an important subject of study. Simulation models can be used to bring together existing data and make predictions of the long-term cost effectiveness of treatment. Most models have been built around cognitive function as a key parameter based on the observed relationship between cognitive function and costs of care. Patients with more severe disease attain higher total costs of care. Also, these patients have a higher share of formal care costs than do patients with mild disease, who are usually looked after by informal caregivers. The valuation of unpaid care is controversial, and the choice of method may affect results considerably. Another important issue is the measurement of health-related QOL in patients with Alzheimer's disease. The few existing studies have used proxy respondents to elicit utility weights in different disease states; however, this methodology has not been validated. It is likely that the increased drug costs incurred by the use of cholinesterase inhibitors will be offset (at least partly) by savings in other healthcare costs. However, these results should be viewed as preliminary, since we are still awaiting data from long-term follow-up studies. Also, the value of treatment for patients and caregivers in terms of QOL improvements has yet to be established. PMID:13129415

  17. A review on cholinesterase inhibitors for Alzheimer's disease.

    PubMed

    Anand, Preet; Singh, Baldev

    2013-04-01

    Alzheimer's disease (AD), a progressive neurodegenerative disorder, is characterized by the deficits in the cholinergic system and deposition of beta amyloid (Aβ) in the form of neurofibrillary tangles and amyloid plaques. Since the cholinergic system plays an important role in the regulation of learning and memory processes, it has been targetted for the design of anti-Alzheimer's drugs. Cholinesterase inhibitors enhance cholinergic transmission directly by inhibiting the enzyme acetylcholinesterase (AChE) which hydrolyses acetylcholine. Furthermore, it has been also demonstrated that both acetylcholinesterase and butrylcholinesterase (BuChE) play an important role in Aβ-aggregation during the early stages of senile plaque formation. Therefore, AChE and BuChE inhibition have been documented as critical targets for the effective management of AD by an increase in the availability of acetylcholine in the brain regions and decrease in the Aβ deposition. This review discusses the different classes of cholinesterase inhibitors including tacrine, donepezil, rivastigmine, galantamine, xanthostigmine, para-aminobenzoic acid, coumarin, flavonoid, and pyrrolo-isoxazole analogues developed for the treatment of AD.

  18. Regulation of S-Adenosylhomocysteine Hydrolase by Lysine Acetylation*

    PubMed Central

    Wang, Yun; Kavran, Jennifer M.; Chen, Zan; Karukurichi, Kannan R.; Leahy, Daniel J.; Cole, Philip A.

    2014-01-01

    S-Adenosylhomocysteine hydrolase (SAHH) is an NAD+-dependent tetrameric enzyme that catalyzes the breakdown of S-adenosylhomocysteine to adenosine and homocysteine and is important in cell growth and the regulation of gene expression. Loss of SAHH function can result in global inhibition of cellular methyltransferase enzymes because of high levels of S-adenosylhomocysteine. Prior proteomics studies have identified two SAHH acetylation sites at Lys401 and Lys408 but the impact of these post-translational modifications has not yet been determined. Here we use expressed protein ligation to produce semisynthetic SAHH acetylated at Lys401 and Lys408 and show that modification of either position negatively impacts the catalytic activity of SAHH. X-ray crystal structures of 408-acetylated SAHH and dually acetylated SAHH have been determined and reveal perturbations in the C-terminal hydrogen bonding patterns, a region of the protein important for NAD+ binding. These crystal structures along with mutagenesis data suggest that such hydrogen bond perturbations are responsible for SAHH catalytic inhibition by acetylation. These results suggest how increased acetylation of SAHH may globally influence cellular methylation patterns. PMID:25248746

  19. Occupational determinants of serum cholinesterase inhibition among organophosphate-exposed agricultural pesticide handlers in Washington State

    PubMed Central

    Hofmann, Jonathan N; Keifer, Matthew C; De Roos, Anneclaire J; Fenske, Richard A; Furlong, Clement E; van Belle, Gerald; Checkoway, Harvey

    2010-01-01

    Objective To identify potential risk factors for serum cholinesterase (BuChE) inhibition among agricultural pesticide handlers exposed to organophosphate (OP) and N-methyl-carbamate (CB) insecticides. Methods We conducted a longitudinal study among 154 agricultural pesticide handlers who participated in the Washington State cholinesterase monitoring program in 2006 and 2007. BuChE inhibition was analyzed in relation to reported exposures before and after adjustment for potential confounders using linear regression. Odds ratios estimating the risk of ‘BuChE depression’ (>20% from baseline) were also calculated for selected exposures based on unconditional logistic regression analyses. Results An overall decrease in mean BuChE activity was observed among study participants at the time of follow-up testing during the OP/CB spray season relative to pre-season baseline levels (mean decrease of 5.6%, P < 0.001). Score for estimated cumulative exposure to OP/CB insecticides in the past 30 days was a significant predictor of BuChE inhibition (β = −1.74, P < 0.001). Several specific work practices and workplace conditions were associated with greater BuChE inhibition, including mixing/loading pesticides and cleaning spray equipment. Factors that were protective against BuChE inhibition included full-face respirator use, wearing chemical-resistant boots, and storing personal protective equipment in a locker at work. Conclusions Despite existing regulations, agricultural pesticide handlers continue to be exposed to OP/CB insecticides at levels resulting in BuChE inhibition. These findings suggest that modifying certain work practices could potentially reduce BuChE inhibition. Replication from other studies will be valuable. PMID:19819864

  20. Do cholinesterase inhibitors act primarily on attention deficit? A naturalistic study in Alzheimer's disease patients.

    PubMed

    Bracco, Laura; Bessi, Valentina; Padiglioni, Sonia; Marini, Sandro; Pepeu, Giancarlo

    2014-01-01

    Attention is the first non-memory domain affected in Alzheimer's disease (AD), before deficits in language and visuo-spatial function, and it is claimed that attention deficits are responsible for the difficulties with daily living in early demented patients. The aim of this longitudinal study in a group of 121 Caucasian, community-dwelling, mild-to-moderate AD patients (Mini-Mental State Examination (MMSE) score >17) was to detect which cognitive domains were most affected by the disease and whether one year treatment with cholinesterase inhibitors was more effective in preserving attention than memory. All subjects were evaluated by a neuropsychological battery including global measurements (MMSE, Information-Memory-Concentration Test) and tasks exploring verbal long-term memory, language, attention, and executive functions. The comparison between two evaluations, made 12 months apart, shows statistically significant differences, indicating deterioration compared to baseline, in the following tests: MMSE (with no gender differences), Composite Memory Score, Short Story Delayed Recall, Trail-Making Test A, Semantic Fluency Test, and Token Test. Conversely, there were no differences in the two evaluations of the Digit Span, Corsi Tapping Test, Short Story Immediate Recall, and Phonemic Fluency Tests. It appears that the treatment specifically attenuated the decline in tests assessing attention and executive functions. A stabilization of the ability to pay attention, with the ensuing positive effects on executive functions, recent memory, and information acquisition which depend on attention, appears to be the main neuropsychological mechanism through which the activation of the cholinergic system, resulting from cholinesterase inhibition, exerts its effect on cognition. PMID:24577458

  1. New Cholinesterase Inhibitory Constituents from Lonicera quinquelocularis

    PubMed Central

    Khan, Dilfaraz; Khan, Hidayat Ullah; Khan, Farmanullah; Khan, Shafiullah; Badshah, Syed; Khan, Abdul Samad; Samad, Abdul; Ali, Farman; Khan, Ihsanullah; Muhammad, Nawshad

    2014-01-01

    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1–5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile. PMID:24733024

  2. New cholinesterase inhibitory constituents from Lonicera quinquelocularis.

    PubMed

    Khan, Dilfaraz; Khan, Hidayat Ullah; Khan, Farmanullah; Khan, Shafiullah; Badshah, Syed; Khan, Abdul Samad; Samad, Abdul; Ali, Farman; Khan, Ihsanullah; Muhammad, Nawshad

    2014-01-01

    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1-5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.

  3. Acetylator phenotype in diabetic neuropathy.

    PubMed Central

    McLaren, E H; Burden, A C; Moorhead, P J

    1977-01-01

    The proportions of slow and fast acetylators in a group of diabetics with symptomatic peripheral neuropathy were compared with those in a group of diabetics who had had the disease for at least 10 years without developing neuropathy. There was a significantly higher proportion of fast acetylators in the group of diabetics without neuropathy than in those with neuropathy or in the normal population. Hence genetic factors separate from the diabetic diathesis may determine the development of neuropathy in any particular diabetic. PMID:871863

  4. Lysine Acetylation of CREBH Regulates Fasting-Induced Hepatic Lipid Metabolism.

    PubMed

    Kim, Hyunbae; Mendez, Roberto; Chen, Xuequn; Fang, Deyu; Zhang, Kezhong

    2015-12-01

    Cyclic AMP-responsive element-binding protein 3-like 3, hepatocyte specific (CREBH), is a hepatic transcription factor that functions as a key regulator of energy homeostasis. Here, we defined a regulatory CREBH posttranslational modification process, namely, lysine-specific acetylation, and its functional involvement in fasting-induced hepatic lipid metabolism. Fasting induces CREBH acetylation in mouse livers in a time-dependent manner, and this event is critical for CREBH transcriptional activity in regulating hepatic lipid homeostasis. The histone acetyltransferase PCAF-mediated acetylation and the deacetylase sirtuin-1-mediated deacetylation coexist to maintain CREBH acetylation states under fasting conditions. Site-directed mutagenesis and functional analyses revealed that the lysine (K) residue at position 294 (K294) within the bZIP domain of the CREBH protein is the site where fasting-induced acetylation/deacetylation occurs. Introduction of the acetylation-deficient (K294R) or acetylation-mimicking (K294Q) mutation inhibited or enhanced CREBH transcriptional activity, respectively. Importantly, CREBH acetylation at lysine 294 was required for the interaction and synergy between CREBH and peroxisome proliferator-activated receptor α (PPARα) in activating their target genes upon fasting or glucagon stimulation. Introduction of the CREBH lysine 294 mutation in the liver leads to hepatic steatosis and hyperlipidemia in animals under prolonged fasting. In summary, our study reveals a molecular mechanism by which fasting or glucagon stimulation modulates lipid homeostasis through acetylation of CREBH.

  5. Acetylation of cyclin-dependent kinase 5 is mediated by GCN5

    SciTech Connect

    Lee, Juhyung; Yun, Nuri; Kim, Chiho; Song, Min-Young; Park, Kang-Sik; Oh, Young J.

    2014-04-25

    Highlights: • Cyclin-dependent kinase 5 (CDK5) is present as an acetylated form. • CDK5 is acetylated by GCN5. • CDK5’s acetylation site is mapped at Lys33. • Its acetylation may affect CDK5’s kinase activity. - Abstract: Cyclin-dependent kinase 5 (CDK5), a member of atypical serine/threonine cyclin-dependent kinase family, plays a crucial role in pathophysiology of neurodegenerative disorders. Its kinase activity and substrate specificity are regulated by several independent pathways including binding with its activator, phosphorylation and S-nitrosylation. In the present study, we report that acetylation of CDK5 comprises an additional posttranslational modification within the cells. Among many candidates, we confirmed that its acetylation is enhanced by GCN5, a member of the GCN5-related N-acetyl-transferase family of histone acetyltransferase. Co-immunoprecipitation assay and fluorescent localization study indicated that GCN5 physically interacts with CDK5 and they are co-localized at the specific nuclear foci. Furthermore, liquid chromatography in conjunction with a mass spectrometry indicated that CDK5 is acetylated at Lys33 residue of ATP binding domain. Considering this lysine site is conserved among a wide range of species and other related cyclin-dependent kinases, therefore, we speculate that acetylation may alter the kinase activity of CDK5 via affecting efficacy of ATP coordination.

  6. Lysine Acetylation of CREBH Regulates Fasting-Induced Hepatic Lipid Metabolism

    PubMed Central

    Kim, Hyunbae; Mendez, Roberto; Chen, Xuequn; Fang, Deyu

    2015-01-01

    Cyclic AMP-responsive element-binding protein 3-like 3, hepatocyte specific (CREBH), is a hepatic transcription factor that functions as a key regulator of energy homeostasis. Here, we defined a regulatory CREBH posttranslational modification process, namely, lysine-specific acetylation, and its functional involvement in fasting-induced hepatic lipid metabolism. Fasting induces CREBH acetylation in mouse livers in a time-dependent manner, and this event is critical for CREBH transcriptional activity in regulating hepatic lipid homeostasis. The histone acetyltransferase PCAF-mediated acetylation and the deacetylase sirtuin-1-mediated deacetylation coexist to maintain CREBH acetylation states under fasting conditions. Site-directed mutagenesis and functional analyses revealed that the lysine (K) residue at position 294 (K294) within the bZIP domain of the CREBH protein is the site where fasting-induced acetylation/deacetylation occurs. Introduction of the acetylation-deficient (K294R) or acetylation-mimicking (K294Q) mutation inhibited or enhanced CREBH transcriptional activity, respectively. Importantly, CREBH acetylation at lysine 294 was required for the interaction and synergy between CREBH and peroxisome proliferator-activated receptor α (PPARα) in activating their target genes upon fasting or glucagon stimulation. Introduction of the CREBH lysine 294 mutation in the liver leads to hepatic steatosis and hyperlipidemia in animals under prolonged fasting. In summary, our study reveals a molecular mechanism by which fasting or glucagon stimulation modulates lipid homeostasis through acetylation of CREBH. PMID:26438600

  7. Regulation of platelet activating factor synthesis: modulation of 1-alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase by phosphorylation and dephosphorylation in rat spleen microsomes

    SciTech Connect

    Lenihan, D.J.; Lee, T.C.

    1984-05-16

    1-Alkyl-2-lyso-sn-glycero-3-phosphocholine:acetyl-CoA acetyltransferase plays an important regulatory role in the biosynthesis of platelet activating factor, a potent bioactive mediator. The authors tested the hypothesis that the activity of acetyltransferase may be modulated by enzymatic phosphorylation and dephosphorylation. The results showed that acetyltransferase activity in rat spleens was 2- to 3-fold higher in microsomes isolated in the presence of F/sup -/ than in those isolated in the presence of Cl/sup -/. The microsomal acetyltransferase could be activated by preincubation of microsomes, isolated in the presence of Cl/sup -/, with ATP, Mg/sup 2 +/, and the soluble fraction from rat spleen. Addition of phosphatidylserine, diacylglycerols, plus Ca/sup 2 +/ further enhanced the activity. The increase in the activity of acetyltranferase was abolished by treatment of the activated microsomes with alkaline phosphatase. Conversely, the activity of acetyltransferase can be reactivated in the alkaline phosphatase-treated microsomes with incubation conditions that favor phosphorylation. Therefore, the findings suggest that acetyltransferase activity is regulated by reversible activation/inactivation through phosphorylation/dephosphorylation.

  8. Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

    PubMed

    Rodríguez, Yeray A; Gutiérrez, Margarita; Ramírez, David; Alzate-Morales, Jans; Bernal, Cristian C; Güiza, Fausto M; Romero Bohórquez, Arnold R

    2016-10-01

    New N-allyl/propargyl 4-substituted 1,2,3,4-tetrahydroquinolines derivatives were efficiently synthesized using acid-catalyzed three components cationic imino Diels-Alder reaction (70-95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl-cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC50 = 72 μm) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl-cholinesterase was exhibited by compound 4ae (IC50 = 25.58 μm) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl-cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets. PMID:27085663

  9. Synthesis and evaluation of in vivo antioxidant, in vitro antibacterial, MRSA and antifungal activity of novel substituted isatin N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)thiosemicarbazones.

    PubMed

    Thanh, Nguyen Dinh; Giang, Nguyen Thi Kim; Quyen, Tran Ha; Huong, Doan Thi; Toan, Vu Ngoc

    2016-11-10

    Some new isatin N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)thiosemicarbazones 4a-t with different substituents at 1-, 5- and 7-positions of isatin ring have been synthesized by reaction of N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)thiosemicarbazide 2 with corresponding isatins 3a-t. Compounds 4a-t were evaluated in vivo for antioxidant activity and in vitro for anti-microorganism activities. The MIC values were found for Gram positive bacteria (MIC = 1.56-6.25 μM), for Gram negative bacteria (MIC = 12.5 μM), and for fungi Aspergillus niger (MIC = 3.12-12.5 μM), Fusarium oxysporum (MIC = 6.25-12.5 μM) and Saccharomyces cerevisiae (MIC = 6.25-12.5 μM). Regarding the antioxidant activity, the SOD, GHS-Px and catalase activities of 4c-i and 4m-r were MIC = 10.57-10.85, 0.27-0.93 and 345.45-399.75 unit/mg protein, respectively. Compounds 4e-h had MIC values of 0.78, 1.56, and 3.12 μM for three clinical MRSA isolates. Compound 4e showed the selective cytotoxic effects against some cancer (LU-1, HepG2, MCF7, P338, SW480, KB) cell lines and normal fibroblast cell line NIH/3T3. PMID:27517802

  10. Biological Activities and Composition of Ferulago carduchorum Essential Oil

    PubMed Central

    Golfakhrabadi, Fereshteh; Khanavi, Mahnaz; Ostad, Seyed Nasser; Saeidnia, Soodabeh; Vatandoost, Hassan; Abai, Mohammad Reza; Hafizi, Mitra; Yousefbeyk, Fatemeh; Rad, Yaghoob Razzaghi; Baghenegadian, Ameneh; Ardekani, Mohammad Reza Shams

    2015-01-01

    Background: Ferulago carduchorum Boiss and Hausskn belongs to the Apiaceae family. This plant grows in west part of Iran that local people added it to dairy and oil ghee to delay expiration date and give them a pleasant taste. The aim of this study was to investigate the antioxidant, antimicrobial, acetyl cholinesterase inhibition, cytotoxic, larvicidal activities and composition of essential oil of F. carduchorum. Methods: Acetyl cholinesterase (AChE) inhibitory, larvicidal activities and chemical composition of essential oil of F. carduchorum were investigated. Besides, antioxidant, antimicrobial and cytotoxic activities of essential oil were tested using DPPH, microdilution method and MTT assay, respectively. Results: The major components of essential oil were (z)-β-ocimene (43.3%), α-pinene (18.23%) and bornyl acetate (3.98%). Among 43 identified components, monoterpenes were the most compounds (84.63%). The essential oil had noticeable efficiency against Candida albicans (MIC= 2340 μg ml−1) and it was effective against Anopheles stephensi with LC50 and LC90 values of 12.78 and 47.43 ppm, respectively. The essential oil could inhibit AChE (IC50= 23.6 μl ml−1). The essential oil showed high cytotoxicity on T47D, HEP-G2 and HT-29 cell lines (IC50< 2 μg ml−1). Conclusion: The essential oil of F. carduchorum collected from west of Iran had anti-Candida, larvicidal and cytotoxicity effects and should be further investigated in others in vitro and in vivo experimental models. PMID:26114148

  11. Plasma cholinesterase inhibition in the clay-colored robin (Turdus grayi) exposed to diazinon in maradol papaya crops in Yucatan, Mexico

    USGS Publications Warehouse

    Cobos, V.M.; Mora, M.A.; Escalona, G.

    2006-01-01

    The use of organophosphorous pesticides in agriculture can result in intoxication of birds foraging in sprayed crops. Effects on birds resulting from pesticide intoxication are varied and include behavioral and reproductive effects, including death. One widely used insecticide in Maradol papaya crops is diazinon which has been associated with various incidents of intoxication and death of wild birds. The objective of this study was to evaluate the impact of diazinon application to papaya crops on plasma cholinesterase activity of the clay-colored robin (Turdus grayi). We captured clay-colored robins foraging in a papaya crop the following day after the field had been sprayed with diazinon at a dose of 1.5 kg/ha during March and May, respectively. We took a blood sample from the brachialis vein of the birds captured and measured plasma enzymatic activity. The plasma samples from birds used as controls were taken during the same time period and were analyzed in a similar way. Enzymatic activity of males was greater than that of females (53,52%) and mean cholinesterase inhibition was 49.43%. Cholinesterase inhibition was greater during May than in March probably due to more continuous exposure and ingestion of the insecticide through food and possible absorption through the skin. This degree of enzymatic inhibition is possibly affecting the behavior of the clay-colored robin and could result in death in severe cases.

  12. Transitions in histone acetylation reveal boundaries of three separately regulated neighboring loci

    PubMed Central

    Litt, Michael D.; Simpson, Melanie; Recillas-Targa, Félix; Prioleau, Marie-Noëlle; Felsenfeld, Gary

    2001-01-01

    We have studied developmentally regulated patterns of histone acetylation at high resolution across ∼54 kb of DNA containing three independently regulated but neighboring genetic loci. These include a folate receptor gene, a 16 kb condensed chromatin region, the chicken β-globin domain and an adjacent olfactory receptor gene. Within these regions the relative levels of acetylation appear to fall into three classes. The condensed chromatin region maintains the lowest acetylation at every developmental stage. Genes that are inactive show similarly low levels, but activation results in a dramatic increase in acetylation. The highest levels of acetylation are seen at regulatory sites upstream of the genes. These patterns imply the action of more than one class of acetylation. Notably, there is a very strong constitutive focus of hyperacetylation at the 5′ insulator element separating the globin locus from the folate receptor region, which suggests that this insulator element may harbor a high concentration of histone acetylases. PMID:11331588

  13. Residues in the acetyl CoA binding site of pyruvate carboxylase involved in allosteric regulation.

    PubMed

    Choosangtong, Kamonman; Sirithanakorn, Chaiyos; Adina-Zada, Abdul; Wallace, John C; Jitrapakdee, Sarawut; Attwood, Paul V

    2015-07-22

    We have examined the roles of Asp1018, Glu1027, Arg469 and Asp471 in the allosteric domain of Rhizobium etli pyruvate carboxylase. Arg469 and Asp471 interact directly with the allosteric activator acetyl coenzyme A (acetyl CoA) and the R469S and R469K mutants showed increased enzymic activity in the presence and absence of acetyl CoA, whilst the D471A mutant exhibited no acetyl CoA-activation. E1027A, E1027R and D1018A mutants had increased activity in the absence of acetyl CoA, but not in its presence. These results suggest that most of these residues impose restrictions on the structure and/or dynamics of the enzyme to affect activity. PMID:26149215

  14. The forced swimming-induced behavioural immobility response involves histone H3 phospho-acetylation and c-Fos induction in dentate gyrus granule neurons via activation of the N-methyl-D-aspartate/extracellular signal-regulated kinase/mitogen- and stress-activated kinase signalling pathway.

    PubMed

    Chandramohan, Yalini; Droste, Susanne K; Arthur, J Simon C; Reul, Johannes M H M

    2008-05-01

    The hippocampus is involved in learning and memory. Previously, we have shown that the acquisition of the behavioural immobility response after a forced swim experience is associated with chromatin modifications and transcriptional induction in dentate gyrus granule neurons. Given that both N-methyl-D-aspartate (NMDA) receptors and the extracellular signal-regulated kinases (ERK) 1/2 signalling pathway are involved in neuroplasticity processes underlying learning and memory, we investigated in rats and mice whether these signalling pathways regulate chromatin modifications and transcriptional events participating in the acquisition of the immobility response. We found that: (i) forced swimming evoked a transient increase in the number of phospho-acetylated histone H3-positive [P(Ser10)-Ac(Lys14)-H3(+)] neurons specifically in the middle and superficial aspects of the dentate gyrus granule cell layer; (ii) antagonism of NMDA receptors and inhibition of ERK1/2 signalling blocked forced swimming-induced histone H3 phospho-acetylation and the acquisition of the behavioural immobility response; (iii) double knockout (DKO) of the histone H3 kinase mitogen- and stress-activated kinases (MSK) 1/2 in mice completely abolished the forced swimming-induced increases in histone H3 phospho-acetylation and c-Fos induction in dentate granule neurons and the behavioural immobility response; (iv) blocking mineralocorticoid receptors, known not to be involved in behavioural immobility in the forced swim test, did not affect forced swimming-evoked histone H3 phospho-acetylation in dentate neurons; and (v) the pharmacological manipulations and gene deletions did not affect behaviour in the initial forced swim test. We conclude that the forced swimming-induced behavioural immobility response requires histone H3 phospho-acetylation and c-Fos induction in distinct dentate granule neurons through recruitment of the NMDA/ERK/MSK 1/2 pathway.

  15. 9-O-acetylated sialic acids differentiating normal haematopoietic precursors from leukemic stem cells with high aldehyde dehydrogenase activity in children with acute lymphoblastic leukaemia.

    PubMed

    Chowdhury, Suchandra; Chandra, Sarmila; Mandal, Chitra

    2014-10-01

    Childhood acute lymphoblastic leukaemia (ALL) originates from mutations in haematopoietic progenitor cells (HPCs). For high-risk patients, treated with intensified post-remission chemotherapy, haematopoietic stem cell (HSC) transplantation is considered. Autologous HSC transplantation needs improvisation till date. Previous studies established enhanced disease-associated expression of 9-O-acetylated sialoglycoproteins (Neu5,9Ac2-GPs) on lymphoblasts of these patients at diagnosis, followed by its decrease with clinical remission and reappearance with relapse. Based on this differential expression of Neu5,9Ac2-GPs, identification of a normal HPC population was targeted from patients at diagnosis. This study identifies two distinct haematopoietic progenitor populations from bone marrow of diagnostic ALL patients, exploring the differential expression of Neu5,9Ac2-GPs with stem cell (CD34, CD90, CD117, CD133), haematopoietic (CD45), lineage-commitment (CD38) antigens and cytosolic aldehyde dehydrogenase (ALDH). Normal haematopoietic progenitor cells (ALDH(+)SSC(lo)CD45(hi)Neu5,9Ac2 -GPs(lo)CD34(+)CD38(-)CD90(+)CD117(+)CD133(+)) differentiated into morphologically different, lineage-specific colonies, being crucial for autologous HSC transplantation while leukemic stem cells (ALDH(+)SSC(lo)CD45(lo)Neu5,9Ac2 -GPs(hi)CD34(+)CD38(+)CD90(-)CD117(-)CD133(-)) lacking this ability can be potential targets for minimal residual disease detection and drug-targeted immunotherapy.

  16. Mapping sugar beet pectin acetylation pattern.

    PubMed

    Ralet, Marie-Christine; Cabrera, Juan Carlos; Bonnin, Estelle; Quéméner, Bernard; Hellìn, Pilar; Thibault, Jean-François

    2005-08-01

    Homogalacturonan-derived partly methylated and/or acetylated oligogalacturonates were recovered after enzymatic hydrolysis (endo-polygalacturonase+pectin methyl esterase+side-chain degrading enzymes) of sugar beet pectin followed by anion-exchange and size exclusion chromatography. Around 90% of the GalA and 75% of the acetyl groups present in the initial sugar beet pectin were recovered as homogalacturonan-derived oligogalacturonates, the remaining GalA and acetyl belonging to rhamnogalacturonic regions. Around 50% of the acetyl groups present in sugar beet homogalacturonans were recovered as partly methylated and/or acetylated oligogalacturonates of degree of polymerisation 5 whose structures were determined by electrospray ionization ion trap mass spectrometry (ESI-IT-MSn). 2-O-acetyl- and 3-O-acetyl-GalA were detected in roughly similar amounts but 2,3-di-O-acetylation was absent. Methyl-esterified GalA residues occurred mainly upstream 2-O-acetyl GalA. Oligogalacturonates containing GalA residues that are at once methyl- and acetyl-esterified were recovered in very limited amounts. A tentative mapping of the distribution of acetyl and methyl esters within sugar beet homogalacturonans is proposed. Unsubstituted GalA residues are likely to be present in limited amounts (approximately 10% of total GalA residues), due to the fact that methyl and acetyl groups are assumed to be most often not carried by the same residues.

  17. Protein acetylation in archaea, bacteria, and eukaryotes.

    PubMed

    Soppa, Jörg

    2010-09-16

    Proteins can be acetylated at the alpha-amino group of the N-terminal amino acid (methionine or the penultimate amino acid after methionine removal) or at the epsilon-amino group of internal lysines. In eukaryotes the majority of proteins are N-terminally acetylated, while this is extremely rare in bacteria. A variety of studies about N-terminal acetylation in archaea have been reported recently, and it was revealed that a considerable fraction of proteins is N-terminally acetylated in haloarchaea and Sulfolobus, while this does not seem to apply for methanogenic archaea. Many eukaryotic proteins are modified by differential internal acetylation, which is important for a variety of processes. Until very recently, only two bacterial proteins were known to be acetylation targets, but now 125 acetylation sites are known for E. coli. Knowledge about internal acetylation in archaea is extremely limited; only two target proteins are known, only one of which--Alba--was used to study differential acetylation. However, indications accumulate that the degree of internal acetylation of archaeal proteins might be underestimated, and differential acetylation has been shown to be essential for the viability of haloarchaea. Focused proteomic approaches are needed to get an overview of the extent of internal protein acetylation in archaea.

  18. Carbofuran poisoning in herons: diagnosis using cholinesterase reactivation techniques.

    PubMed

    Hunt, K A; Hooper, M J; Littrell, E E

    1995-04-01

    Exposure to the carbamate insecticide carbofuran was detected using brain cholinesterase (ChE) reactivation techniques in heron carcasses collected from a potential pesticide exposure incident. Great egrets (Nycticorax nycticorax), great blue herons (Ardea herodias), and black-crowned night herons (Casmerodius albus) were exposed to carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) either by dermal exposure while wading or through ingestion of contaminated food items. Carcasses may have been in the field up to 5 days prior to collection. Brain ChE, substantially inhibited in most samples, increased 7.9-208% in the reactivation assay after 4 to 96 hours at 37 C, providing evidence of exposure to a carbamate pesticide. Crayfish (Procambarus clarkii) identified in the crops of some herons contained carbofuran residues of up to 0.6 parts per million wet weight, providing additional evidence of exposure. Reactivated brain ChE in several samples approached the range of control values.

  19. Metabolism of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine in the human neutrophil

    SciTech Connect

    Triggiani, M.; D'Souza, D.M.; Chilton, F.H. )

    1991-04-15

    The biosynthesis of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (1-acyl-2-acetyl-GPC) together with that of 1-alkyl-2-acetyl-GPC (platelet-activating factor) has been demonstrated in a variety of inflammatory cells and tissues. It has been hypothesized that the relative proportion of these phospholipids produced upon cell activation may be influenced by their rates of catabolism. We studied the catabolism of 1-acyl-2-acetyl-GPC in resting and activated human neutrophils and compared it to that of 1-alkyl-2-acetyl-GPC. Neutrophils rapidly catabolize both 1-alkyl-2-acetyl-GPC and 1-acyl-2-acetyl-GPC; however, the rate of catabolism of 1-acyl-2-acetyl-GPC is approximately 2-fold higher than that of 1-alkyl-2-acetyl-GPC. In addition, most of 1-acyl-2-acetyl-GPC is catabolized through a pathway different from that of 1-alkyl-2-acetyl-GPC. The main step in the catabolism of 1-acyl-2-acetyl-GPC is the removal of the long chain at the sn-1 position; the long chain residue is subsequently incorporated either into triglycerides or into phosphatidylcholine. The 1-lyso-2-acetyl-GPC formed in this reaction is then further degraded to glycerophosphocholine, choline, or phosphocholine. 1-Acyl-2-acetyl-GPC is also catabolized, to a lesser extent, through deacetylation at the sn-2 position and reacylation with a long chain fatty acid. Stimulation of neutrophils by A23187 results in a higher rate of catabolism of 1-acyl-2-acetyl-GPC by increasing both the removal of the long chain at the sn-1 position and the deacetylation-reacylation at the sn-2 position. In a broken cell preparation, the cytosolic fraction of the neutrophil was shown to contain an enzyme activity which cleaved the sn-1 position of 1-acyl-2-acetyl-GPC and 1-acyl-2-lyso-GPC but not of 1,2-diacyl-GPC.

  20. BRAIN CHOLINESTERASE INHIBITION AND DEPRESSION OF THE PHOTIC AFTER DISCHARGE (PHAD) OF FLASH EVOKED POTENTIALS (FEPS) IN LONG EVANS RATS FOLLOWING ACUTE OR REPEATED EXPOSURES TO A MIXTURE OF CARBARYL AND PROPOXUR.

    EPA Science Inventory

    Carbaryl and propoxur are N-methyl carbamate pesticides (NMCs) which are part of the EPA’s cumulative risk assessments for NMCs. These NMCs inhibit cholinesterase (ChE) activity and may lead to cholinergic disruption of CNS function. We used decreases in the PhAD of FEPs to indic...

  1. Extensive lysine acetylation occurs in evolutionarily conserved metabolic pathways and parasite-specific functions during Plasmodium falciparum intraerythrocytic development

    PubMed Central

    Miao, Jun; Lawrence, Matthew; Jeffers, Victoria; Zhao, Fangqing; Parker, Daniel; Ge, Ying; Sullivan, William J.; Cui, Liwang

    2013-01-01

    Summary Lysine acetylation has emerged as a major posttranslational modification involved in diverse cellular functions. Using a combination of immunoisolation and liquid chromatography coupled to accurate mass spectrometry, we determined the first acetylome of the human malaria parasite Plasmodium falciparum during its active proliferation in erythrocytes with 421 acetylation sites identified in 230 proteins. Lysine-acetylated proteins are distributed in the nucleus, cytoplasm, mitochondrion, and apicoplast. Whereas occurrence of lysine acetylation in a similarly wide range of cellular functions suggests conservation of lysine acetylation through evolution, the Plasmodium acetylome also revealed significant divergence from those of other eukaryotes and even the closely-related parasite Toxoplasma. This divergence is reflected in the acetylation of a large number of Plasmodium-specific proteins and different acetylation sites in evolutionarily conserved acetylated proteins. A prominent example is the abundant acetylation of proteins in the glycolysis pathway but relatively deficient acetylation of enzymes in the citrate cycle. Using specific transgenic lines and inhibitors, we determined that the acetyltransferase PfMYST and lysine deacetylases play important roles in regulating the dynamics of cytoplasmic protein acetylation. The Plasmodium acetylome provides an exciting start point for further exploration of functions of acetylation in the biology of malaria parasites. PMID:23796209

  2. Association of chronic pesticide exposure with serum cholinesterase levels and pulmonary functions.

    PubMed

    Sutoluk, Zeynel; Kekec, Zeynep; Daglioglu, Nebile; Hant, Ismail

    2011-01-01

    The present study focused on the analysis of serum cholinesterase levels and the pulmonary function tests in seasonal farm workers who were chronically exposed to pesticides, mostly organophosphorus, in comparison with non-farm workers in the farming areas of Cukurova region, Turkey. Serum cholinesterase levels and pulmonary function tests using spyrometer in 50 male seasonal farm workers (study group) were compared to 50 male non-farm workers (control group) in this cross-sectional study. The mean serum cholinesterase enzyme level in the farm worker group (7095.5 ± 1699.4 U/L) was significantly lower than those of the control group (9716.4 ± 1484.4 U/L) (p < .001). There was no significant difference between pulmonary function tests of 2 groups (p > .05). These results show that chronic environmental organophosphorus exposure caused a decrease in the serum cholinesterase enzyme levels in farm workers, emphasizing the importance of primary prevention. PMID:24484366

  3. Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism.

    PubMed

    You, Di; Yin, Bin-Cheng; Li, Zhi-Hai; Zhou, Ying; Yu, Wen-Bang; Zuo, Peng; Ye, Bang-Ce

    2016-06-14

    In cells of all domains of life, reversible lysine acetylation modulates the function of proteins involved in central cellular processes such as metabolism. In this study, we demonstrate that the nitrogen regulator GlnR of the actinomycete Saccharopolyspora erythraea directly regulates transcription of the acuA gene (SACE_5148), which encodes a Gcn5-type lysine acetyltransferase. We found that AcuA acetylates two glutamine synthetases (GlnA1 and GlnA4) and that this lysine acetylation inactivated GlnA4 (GSII) but had no significant effect on GlnA1 (GSI-β) activity under the conditions tested. Instead, acetylation of GlnA1 led to a gain-of-function that modulated its interaction with the GlnR regulator and enhanced GlnR-DNA binding. It was observed that this regulatory function of acetylated GSI-β enzymes is highly conserved across actinomycetes. In turn, GlnR controls the catalytic and regulatory activities (intracellular acetylation levels) of glutamine synthetases at the transcriptional and posttranslational levels, indicating an autofeedback loop that regulates nitrogen metabolism in response to environmental change. Thus, this GlnR-mediated acetylation pathway provides a signaling cascade that acts from nutrient sensing to acetylation of proteins to feedback regulation. This work presents significant new insights at the molecular level into the mechanisms underlying the regulation of protein acetylation and nitrogen metabolism in actinomycetes. PMID:27247389

  4. Studies on combined effects of organophosphates and heavy metals in birds. I. Plasma and brain cholinesterase in Coturnix quail fed methyl mercury and orally dosed with parathion

    USGS Publications Warehouse

    Dieter, M.P.; Ludke, J.L.

    1975-01-01

    We found that mercury potentiated the toxicity and biochemical effects of parathion. Male Coturnix quail (Coturnix coturnix japonica) were fed a sublethal concentration of morsodren (4 ppm as methyl mercury) for 18 weeks. This resulted in an accumulation of 21.0 ppm of mercury in the liver and 8.4 ppm in the carcass. Birds fed clean feed and those fed morsodren-treated feed were orally dosed with 2, 4, 6, 8,and 10 mg/kg parathion, and their 48-h survival times compared. The computed LD50 was 5.86mg/kg in birds not fed morsodren and 4.24 in those fed the heavy metal. When challenged with a sublethal, oral dose of parathion (1.0 mg/kg), morsodren-fed birds exhibited significantly greater inhibition of plasma and brain cholinesterase activity than controls dosed with parathion. Brain cholinesterase activity was inhibited 41% in morsodren-fed birds and 26in clean-fed birds dosed with parathion, which suggested that the increase in parathion toxicity in the presence of morsodren was directly related to the inhibitation of brain cholinesterase.

  5. CSF monoamine metabolites, cholinesterases and lactate in the adult hydrocephalus syndrome (normal pressure hydrocephalus) related to CSF hydrodynamic parameters.

    PubMed Central

    Malm, J; Kristensen, B; Ekstedt, J; Adolfsson, R; Wester, P

    1991-01-01

    Monoamine metabolites, cholinesterases and lactic acid in lumbar cerebrospinal fluid (CSF) were investigated on patients with the adult hydrocephalus syndrome (idiopathic normal pressure syndrome; AHS, n = 15), Alzheimer's disease (AD, n = 14), multi-infarct dementia (MID, n = 13) and controls (n = 21). Patients had clinical and CSF hydrodynamic investigations. Monoamine concentrations were determined by reversed-phase liquid chromatography, cholinesterases and lactate were determined photometrically. In the AHS patients, CSF monoamine concentrations were not significantly different compared with controls, AD or MID patients. AHS and AD patients showed a similar reduction of CSF acetylcholinesterase activity compared with controls. Positive correlations were found in concentrations of CSF homovanillic acid, CSF 5-hydroxyindoleacetic acid and CSF lactic acid versus CSF outflow conductance (that is, resistance against CSF outflow) in the AHS patients. A similar pattern was observed in a subgroup of MID patients characterised by dilated ventricles and disturbed CSF hydrodynamics. These data suggest that a low CSF outflow conductance may facilitate the clearance of acidic substances from the arachnoid space at the probenecid sensitive active transport site. Alternative explanations would be that a pathologically low CSF outflow conductance is accompanied by an inverse caudorostral flow of CSF or a compromised trans-ependymal diffusion. PMID:1709421

  6. Phytochemical profile of a blend of black chokeberry and lemon juice with cholinesterase inhibitory effect and antioxidant potential.

    PubMed

    Gironés-Vilaplana, Amadeo; Valentão, Patrícia; Andrade, Paula B; Ferreres, Federico; Moreno, Diego A; García-Viguera, Cristina

    2012-10-15

    In this study, black chokeberry concentrate was added (5% w/v) to lemon juice, since previous reports suggested potential health benefits of this blend. The phytochemical composition, antioxidant capacity (scavenging of DPPH, superoxide and hydroxyl radicals, and hypochlorous acid), and inhibitory activity against cholinesterase of the new blend were determined and compared with those of lemon juice and chokeberry in citric acid (5%). The chokeberry concentrate, rich in cyanidin-glycosides, quercetin derivatives, and 3-O-caffeoylquinic acid, and lemon juice, possessing flavones, flavanones, quercetin derivates, and hydroxycinnamic acids, were characterised. The new drink showed a higher antioxidant effect than the chokeberry or lemon controls for all the tested methods, except for hypochlorous acid, in which lemon juice displayed higher activity. Both the lemon juice and chokeberry controls inhibited acetylcholinesterase and butyrylcholinesterase, and this effect was increased in the new mixtures. The results of the different radical scavenging assays indicate that the lemon-black chokeberry (5% w/v) mixture was more antioxidative than the respective controls separately. Moreover, their inhibition of cholinesterase is of interest regarding neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, or senile dementia.

  7. Identification of cellular factors binding to acetylated HIV-1 integrase.

    PubMed

    Allouch, Awatef; Cereseto, Anna

    2011-11-01

    The viral protein integrase (IN) catalyzes the integration of the HIV-1 cDNA into the host cellular genome. We have recently demonstrated that IN is acetylated by a cellular histone acetyltransferase, p300, which modifies three lysines located in the C-terminus of the viral factor (Cereseto et al. in EMBO J 24:3070-3081, 2005). This modification enhances IN catalytic activity, as demonstrated by in vitro assays. Consistently, mutations introduced in the targeted lysines greatly decrease the efficiency of HIV-1 integration. Acetylation was proven to regulate protein functions by modulating protein-protein interactions. HIV-1 to efficiently complete its replication steps, including the integration reaction, requires interacting with numerous cellular factors. Therefore, we sought to investigate whether acetylation might modulate the interaction between IN and the cellular factors. To this aim we performed a yeast two-hybrid screening that differs from the screenings so far performed (Rain et al. in Methods 47:291-297, 2009; Studamire and Goff in Retrovirology 5:48, 2008) for using as bait IN constitutively acetylated. From this analysis we have identified thirteen cellular factors involved in transcription, chromatin remodeling, nuclear transport, RNA binding, protein synthesis regulation and microtubule organization. To validate these interactions, binding assays were performed showing that acetylation increases the affinity of IN with specific factors. Nevertheless, few two-hybrid hits bind with the same affinity the acetylated and the unmodified IN. These results further underlie the relevance of IN post-translational modification by acetylation in HIV-1 replication cycle.

  8. [Study of the interaction of main potato glycoalkaloids in inhibition of immobilized butyryl cholinesterase].

    PubMed

    Arkhypova, V M; Dziadevych, S V; Jaffrezic-Renault, N; Martelet, C; Soldatkin, O P

    2006-01-01

    The interaction of main potato glycoalkaloids alpha-solanine and alpha-chaconine in inhibition of horse serum butyryl cholinesterases immobilized on the pH-sensitive field-effect transistors has been investigated. The method of isobol diagram of Loewe and Muishnek has been used for interpretation of results. It has been shown the alpha-chaconine inhibits the immobilized bytyryl cholinesterases more strongly than alpha-solanine, and their mixture has the addition effect.

  9. Influence of clitoria ternatea extracts on memory and central cholinergic activity in rats.

    PubMed

    Taranalli, A D; Cheeramkuzhy, T C

    2000-01-01

    Clitoria ternatea , commonly known as Shankpushpi, is widely used in the traditional Indian system of medicine as a brain tonic and is believed to promote memory and intelligence. We examined the effectiveness of alcoholic extracts of aerial and root parts of C. ternatea at 300 and 500 mg/kg doses orally in rats in attenuating electroshock-induced amnesia. Extracts at 300 mg/kg dose produced significant memory retention, and the root parts were found to be more effective. In order to delineate the possible mechanism through which C. ternatea elicits the anti-amnesic effects, we studied its influence on central cholinergic activity by estimating the acetylcholine content of the whole brain and acetylcholinesterase activity at different regions of the rat brain, viz., cerebral cortex, midbrain, medulla oblongata and cerebellum. Our results suggest that C. ternatea extracts increase rat brain acetylcholine content and acetyl cholinesterase a ctivity in a similar fashion to the standard cerebro protective drug Pyritinol. PMID:21214440

  10. Identification and Characterization of Mitochondrial Acetyl-Coenzyme A Hydrolase from Pisum sativum L. Seedlings 1

    PubMed Central

    Zeiher, Carolyn A.; Randall, Douglas D.

    1990-01-01

    Mitochondria from Pisum sativum seedlings purified free of peroxisomal and chlorophyll contamination were examined for acetyl-coenzyme A (CoA) hydrolase activity. Acetyl-CoA hydrolase activity was latent when assayed in isotonic media. The majority of the enzyme activity was found in the soluble matrix of the mitochondria. The products, acetate and CoA, were quantified by two independent methods and verified that the observed activity was an acetyl-CoA hydrolase. The pea mitochondrial acetyl-CoA hydrolase showed a Km for acetyl-CoA of 74 micromolar and a Vmax of 6.1 nanomoles per minute per milligram protein. CoA was a linear competitive inhibitor of the enzyme with a Kis of 16 micromolar. The sensitivity of the enzyme to changes in mole fraction of acetyl-CoA suggested that the changes in the intramitochondrial acetyl-CoA/CoA ratio may be an effective mechanism of control. The widespread distribution of mitochondrial acetyl-CoA hydrolase activity among different plant species indicated that this may be a general mechanism in plants for synthesizing acetate. PMID:16667687

  11. Leucine-684: A conserved residue of an AMP-acetyl CoA synthetase (AceCS) from Leishmania donovani is involved in substrate recognition, catalysis and acetylation.

    PubMed

    Soumya, Neelagiri; Tandan, Hitendra; Damre, Mangesh V; Gangwal, Rahul P; Sangamwar, Abhay T; Singh, Sushma

    2016-04-15

    AMP-acetyl CoA synthetase (AMP-AceCS) is a key enzyme which catalyzes the activation of acetate to acetyl CoA, an important intermediate at the cross roads of various anabolic and catabolic pathways. Multiple sequence alignment of Leishmania donovani AceCS with other organisms revealed the presence of a highly conserved leucine residue at 684 position which is known to be crucial for acetylation by protein acetyl transferases in other organisms. In an attempt to understand the role of leucine residue at 684 position in L. donovani acetyl CoA synthetase (LdAceCS), it was mutated to proline (P) by site directed mutagenesis. Kinetic analysis of the L684P-LdAceCS mutant revealed approximately two fold increased binding affinity with acetate, whereas fivefold decreased affinity was observed with ATP. There was insignificant change in secondary structure as revealed by CD however, two fold decreased fluorescence intensity was observed at an emission maxima of 340 nm. Interestingly, L684P mutation abolished the acetylation of the mutant enzyme indicating the importance of L684 in acetylation of the enzyme. Changes in biochemical parameters of the mutant protein were validated by homology modeling of the wild type and mutant LdAceCS enzyme using Salmonella enterica AceCS crystal structure as template. Our data provides evidence for the role of leucine 684 residue in substrate recognition, catalysis and acetylation of the AceCS enzyme.

  12. Flow properties of acetylated chickpea protein dispersions.

    PubMed

    Liu, Li H; Hung, Tran V

    2010-06-01

    Chickpea protein concentrate was acetylated with acetic anhydride at 5 levels. Acetylated chickpea protein (ACP) dispersions at 3 levels (6%, 45%, and 49%) were chosen for this flow property study. Effects of protein concentration, temperature, concentrations of salt addition and particularly, degree of acetylation on these properties were examined. Compared with native chickpea proteins, the ACP dispersions exhibited a strong shear thinning behavior. Within measured temperature range (15 to 55 degrees C), the apparent viscosities of native chickpea protein dispersions were temperature independent; those of ACP dispersions were thermally affected. The flow index (n), consistency coefficient (m), apparent yield stress, and apparent viscosities of ACP dispersions increased progressively up to 45% acetylation but decreased at 49% acetylation level. Conformational studies by gel filtration suggested that chickpea proteins were associated or polymerized at up to 45% acetylation but the associated subunits gradually dissociated to smaller units at higher levels (49%) of acetylation.

  13. Kinetic analysis of histone acetylation turnover and Trichostatin A induced hyper- and hypoacetylation in alfalfa.

    PubMed

    Waterborg, Jakob H; Kapros, Tamás

    2002-01-01

    Dynamic histone acetylation is a characteristic of chromatin transcription. The first estimates for the rate of acetylation turnover of plants are reported, measured in alfalfa cells by pulse, pulse-chase, and steady-state acetylation labeling. Acetylation turnover half-lives of about 0.5 h were observed by all methods used for histones H3, H4, and H2B. This is consistent with the rate at which changes in gene expression occur in plants. Treatment with histone deacetylase inhibitor Trichostatin A (TSA) induced hyperacetylation at a similar rate. Replacement histone variant H3.2, preferentially localized in highly acetylated chromatin, displayed faster acetyl turnover. Histone H2A with a low level of acetylation was not subject to rapid turnover or hyperacetylation. Patterns of acetate labeling revealed fundamental differences between histone H3 versus histones H4 and H2B. In H3, acetylation of all molecules, limited by lysine methylation, had similar rates, independent of the level of lysine acetylation. Acetylation of histones H4 and H2B was seen in only a fraction of all molecules and involved multiacetylation. Acetylation turnover rates increased from mono- to penta- and hexaacetylated forms, respectively. TSA was an effective inhibitor of alfalfa histone deacetylases in vivo and caused a doubling in steady-state acetylation levels by 4-6 h after addition. However, hyperacetylation was transient due to loss of TSA inhibition. TSA-induced overexpression of cellular deacetylase activity produced hypoacetylation by 18 h treatment with enhanced acetate turnover labeling of alfalfa histones. Thus, application of TSA to change gene expression in vivo in plants may have unexpected consequences. PMID:12123281

  14. Ionizing radiation induces immediate protein acetylation changes in human cardiac microvascular endothelial cells

    PubMed Central

    Barjaktarovic, Zarko; Kempf, Stefan J.; Sriharshan, Arundhathi; Merl-Pham, Juliane; Atkinson, Michael J.; Tapio, Soile

    2015-01-01

    Reversible lysine acetylation is a highly regulated post-translational protein modification that is known to regulate several signaling pathways. However, little is known about the radiation-induced changes in the acetylome. In this study, we analyzed the acute post-translational acetylation changes in primary human cardiac microvascular endothelial cells 4 h after a gamma radiation dose of 2 Gy. The acetylated peptides were enriched using anti-acetyl conjugated agarose beads. A total of 54 proteins were found to be altered in their acetylation status, 23 of which were deacetylated and 31 acetylated. Pathway analyses showed three protein categories particularly affected by radiation-induced changes in the acetylation status: the proteins involved in the translation process, the proteins of stress response, and mitochondrial proteins. The activation of the canonical and non-canonical Wnt signaling pathways affecting actin cytoskeleton signaling and cell cycle progression was predicted. The protein expression levels of two nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, sirtuin 1 and sirtuin 3, were significantly but transiently upregulated 4 but not 24 h after irradiation. The status of the p53 protein, a target of sirtuin 1, was found to be rapidly stabilized by acetylation after radiation exposure. These findings indicate that post-translational modification of proteins by acetylation and deacetylation is essentially affecting the radiation response of the endothelium. PMID:25840449

  15. Crystal structure, phytochemical study and enzyme inhibition activity of Ajaconine and Delectinine

    NASA Astrophysics Data System (ADS)

    Ahmad, Shujaat; Ahmad, Hanif; Khan, Hidayat Ullah; Shahzad, Adnan; Khan, Ezzat; Ali Shah, Syed Adnan; Ali, Mumtaz; Wadud, Abdul; Ghufran, Mehreen; Naz, Humera; Ahmad, Manzoor

    2016-11-01

    The Crystal structure, comparative DFT study and phytochemical investigation of atisine type C-20 diterpenoid alkaloid ajaconine (1) and lycoctonine type C-19 diterpenoid alkaloid delectinine (2) is reported here. These compounds were isolated from Delphinium chitralense. Both the natural products 1 and 2 crystallize in orthorhombic crystal system with identical space group of P212121. The geometric parameters of both compounds were calculated with the help of DFT using B3LYP/6-31+G (p) basis set and HOMO-LUMO energies, optimized band gaps, global hardness, ionization potential, electron affinity and global electrophilicity are calculated. The compounds 1 and 2 were screened for acetyl cholinesterase and butyryl cholinesterase inhibition activities in a dose dependent manner followed by molecular docking to explore the possible inhibitory mechanism of ajaconine (1) and delectinine (2). The IC50 values of tested compounds against AChE were observed as 12.61 μM (compound 1) and 5.04 μM (compound 2). The same experiments were performed for inhibition of BChE and IC50 was observed to be 10.18 μM (1) and 9.21 μM (2). Promising inhibition activity was shown by both the compounds against AChE and BChE in comparison with standard drugs available in the market such as allanzanthane and galanthamine. The inhibition efficiency of both the natural products was determined in a dose dependent manner.

  16. Acetylation mediates Cx43 reduction caused by electrical stimulation

    PubMed Central

    Meraviglia, Viviana; Azzimato, Valerio; Colussi, Claudia; Florio, Maria Cristina; Binda, Anna; Panariti, Alice; Qanud, Khaled; Suffredini, Silvia; Gennaccaro, Laura; Miragoli, Michele; Barbuti, Andrea; Lampe, Paul D.; Gaetano, Carlo; Pramstaller, Peter P.; Capogrossi, Maurizio C.; Recchia, Fabio A.; Pompilio, Giulio; Rivolta, Ilaria; Rossini, Alessandra

    2015-01-01

    Communication between cardiomyocytes depends upon Gap Junctions (GJ). Previous studies have demonstrated that electrical stimulation induces GJ remodeling and modifies histone acetylases (HAT) and deacetylases (HDAC) activities, although these two results have not been linked. The aim of this work was to establish whether electrical stimulation modulates GJ-mediated cardiac cell-cell communication by acetylation-dependent mechanisms. Field stimulation of HL-1 cardiomyocytes at 0.5 Hz for 24 hours significantly reduced Connexin43 (Cx43) expression and cell-cell communication. HDAC activity was down-regulated whereas HAT activity was not modified resulting in increased acetylation of Cx43. Consistent with a post-translational mechanism, we did not observe a reduction in Cx43 mRNA in electrically stimulated cells, while the proteasomal inhibitor MG132 maintained Cx43 expression. Further, the treatment of paced cells with the HAT inhibitor Anacardic Acid maintained both the levels of Cx43 and cell-cell communication. Finally, we observed increased acetylation of Cx43 in the left ventricles of dogs subjected to chronic tachypacing as a model of abnormal ventricular activation. In conclusion, our findings suggest that altered electrical activity can regulate cardiomyocyte communication by influencing the acetylation status of Cx43. PMID:26264759

  17. Dynamic changes in histone acetylation regulate origins of DNA replication

    PubMed Central

    Unnikrishnan, Ashwin; Gafken, Philip R.; Tsukiyama, Toshio

    2011-01-01

    While histone modifications have been implicated in many DNA-dependent processes, their precise role in DNA replication remains largely unknown. Here, we describe a very efficient, single-step method to specifically purify histones located around an origin of replication from S. cerevisiae. Using high-resolution mass spectrometry, we have obtained a comprehensive view of the histone modifications surrounding the origin of replication throughout the cell cycle. We have discovered that histone H3 and H4 acetylation is dynamically regulated around an origin of replication, at the level of multiply-acetylated histones. Furthermore, we find that this acetylation is required for efficient origin activation during S-phase. PMID:20228802

  18. An acetylation rheostat for the control of muscle energy homeostasis

    PubMed Central

    Menzies, Keir; Auwerx, Johan

    2013-01-01

    In recent years the role of acetylation has gained ground as an essential modulator of intermediary metabolism in skeletal muscle. Imbalance in energy homeostasis or chronic cellular stress, due to diet, aging or disease, translate into alterations in the acetylation levels of key proteins which governs bioenergetics, cellular substrate use and/or changes in mitochondrial content and function. For example, cellular stress induced by exercise or caloric restriction can alter the coordinated activity of acetyltransferases and deacetylases to increase mitochondrial biogenesis and function in order to adapt to low energetic levels. The natural duality of these enzymes, as metabolic sensors and effector proteins, have helped biologists understand how the body can integrate seemingly distinct signaling pathways to control mitochondrial biogenesis, insulin sensitivity, glucose transport, reactive oxygen species handling, angiogenesis and muscle satellite cell proliferation/differentiation. Our review will summarize the recent developments related to acetylation dependent responses following metabolic stress in skeletal muscle. PMID:23999889

  19. An acetylation rheostat for the control of muscle energy homeostasis.

    PubMed

    Menzies, Keir; Auwerx, Johan

    2013-12-01

    In recent years, the role of acetylation has gained ground as an essential modulator of intermediary metabolism in skeletal muscle. Imbalance in energy homeostasis or chronic cellular stress, due to diet, aging, or disease, translate into alterations in the acetylation levels of key proteins which govern bioenergetics, cellular substrate use, and/or changes in mitochondrial content and function. For example, cellular stress induced by exercise or caloric restriction can alter the coordinated activity of acetyltransferases and deacetylases to increase mitochondrial biogenesis and function in order to adapt to low energetic levels. The natural duality of these enzymes, as metabolic sensors and effector proteins, has helped biologists to understand how the body can integrate seemingly distinct signaling pathways to control mitochondrial biogenesis, insulin sensitivity, glucose transport, reactive oxygen species handling, angiogenesis, and muscle satellite cell proliferation/differentiation. Our review will summarize the recent developments related to acetylation-dependent responses following metabolic stress in skeletal muscle. PMID:23999889

  20. Characterization of catalytic efficiency parameters of brain cholinesterases in tropical fish.

    PubMed

    de Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Santos, Juliana Ferreira; Marcuschi, Marina; Carvalho, Elba Verônica Matoso Maciel; Bezerra, Ranilson Souza; Carvalho, Luiz Bezerra

    2014-12-01

    Brain cholinesterases from four fish (Arapaima gigas, Colossoma macropomum, Rachycentron canadum and Oreochromis niloticus) were characterized using specific substrates and selective inhibitors. Parameters of catalytic efficiency such as activation energy (AE), k(cat) and k(cat)/k(m) as well as rate enhancements produced by these enzymes were estimated by a method using crude extracts described here. Despite the BChE-like activity, specific substrate kinetic analysis pointed to the existence of only acetylcholinesterase (AChE) in brain of the species studied. Selective inhibition suggests that C. macropomum brain AChE presents atypical activity regarding its behavior in the presence of selective inhibitors. AE data showed that the enzymes increased the rate of reactions up to 10(12) in relation to the uncatalyzed reactions. Zymograms showed the presence of AChE isoforms with molecular weights ranging from 202 to 299 kDa. Values of k(cat) and k(cat)/k(m) were similar to those found in the literature.

  1. Fish cholinesterases as biomarkers of sublethal effects of organophosphorus and carbamates in tissues of Labeo rohita.

    PubMed

    Ghazala; Mahboob, Shahid; Ahmad, L; Sultana, S; Alghanim, K; Al-Misned, F; Ahmad, Z

    2014-03-01

    Organophosphates and carbamates are major agrochemicals that strongly affect different neuroenzymes and the growth of various fish species. Here, we study the effect of sublethal concentrations of profenofos and carbofuran on the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and the associated health risk in fish. Labeo rohita fingerlings were exposed to three sublethal concentrations of profenofos and carbofuran. The minimum cholinesterase activities in the brain, gills, muscle, kidney, liver, and blood were after exposure to profenofos (0.06 mg/L). The minimum AChE and BuChE activities in the brain, gills, muscle, kidney, liver, and blood were after exposure to carbofuran (0.28 and 0.198 mg/L). Exposure to both types of pesticides affected the functions of these organs, including metabolism and neurotransmission, to various extents at different exposure concentrations. These findings suggest that they are required to be properly monitored in the environment, to reduce their toxic effects on nontarget organisms. PMID:24357265

  2. Insights into K-Ras 4B regulation by post-translational lysine acetylation.

    PubMed

    Knyphausen, Philipp; Lang, Franziska; Baldus, Linda; Extra, Antje; Lammers, Michael

    2016-10-01

    Ras is a molecular switch cycling between an active, GTP-bound and an inactive, GDP-bound state. Mutations in Ras, mostly affecting the off-switch, are found in many human tumours. Recently, it has been shown that K-Ras 4B is targeted by lysine acetylation at K104. Based on results obtained for an acetylation mimetic Ras mutant (K104Q), it was hypothesised that K104-acetylation might interfere with its oncogenicity by impairing SOS-catalysed guanine-nucleotide exchange. We prepared site-specifically K104-acetylated K-Ras 4B and the corresponding oncogenic mutant protein G12V using the genetic-code expansion concept. We found that SOS-catalysed nucleotide exchange, also of allosterically activated SOS, was neither affected by acetylation of K104 in wildtype K-Ras 4B nor in the G12V mutant, suggesting that glutamine is a poor mimetic for acetylation at this site. In vitro, the lysine-acetyltransferases CBP and p300 were able to acetylate both, wildtype and G12V K-Ras 4B. In addition to K104 we identified further acetylation sites in K-Ras 4B, including K147, within the important G5/SAK-motif. However, the intrinsic and the SOS-catalysed nucleotide exchange was not affected by K147-acetylation of K-Ras 4B. Finally, we show that Sirt2 and HDAC6 do neither deacetylate K-Ras 4B if acetylated at K104 nor if acetylated at K147 in vitro.

  3. Investigating Histone Acetylation Stoichiometry and Turnover Rate.

    PubMed

    Fan, J; Baeza, J; Denu, J M

    2016-01-01

    Histone acetylation is a dynamic epigenetic modification that functions in the regulation of DNA-templated reactions, such as transcription. This lysine modification is reversibly controlled by histone (lysine) acetyltransferases and deacetylases. Here, we present methods employing isotopic labeling and mass spectrometry (MS) to comprehensively investigate histone acetylation dynamics. Turnover rates of histone acetylation are determined by measuring the kinetics of labeling from (13)C-labeled precursors of acetyl-CoA, which incorporates (13)C-carbon onto histones via the acetyltransferase reaction. Overall histone acetylation states are assessed from complete protease digestion to single amino acids, which is followed by MS analysis. Determination of site-specific acetylation stoichiometry is achieved by chemically acetylating endogenous histones with isotopic acetic anhydride, followed by trypsin digestion and LC-MS analysis. Combining metabolic labeling with stoichiometric analysis permits determination of both acetylation level and acetylation dynamics. When comparing genetic, diet, or environmental perturbations, these methods permit both a global and site-specific evaluation of how histone acetylation is dynamically regulated.

  4. Investigating Histone Acetylation Stoichiometry and Turnover Rate.

    PubMed

    Fan, J; Baeza, J; Denu, J M

    2016-01-01

    Histone acetylation is a dynamic epigenetic modification that functions in the regulation of DNA-templated reactions, such as transcription. This lysine modification is reversibly controlled by histone (lysine) acetyltransferases and deacetylases. Here, we present methods employing isotopic labeling and mass spectrometry (MS) to comprehensively investigate histone acetylation dynamics. Turnover rates of histone acetylation are determined by measuring the kinetics of labeling from (13)C-labeled precursors of acetyl-CoA, which incorporates (13)C-carbon onto histones via the acetyltransferase reaction. Overall histone acetylation states are assessed from complete protease digestion to single amino acids, which is followed by MS analysis. Determination of site-specific acetylation stoichiometry is achieved by chemically acetylating endogenous histones with isotopic acetic anhydride, followed by trypsin digestion and LC-MS analysis. Combining metabolic labeling with stoichiometric analysis permits determination of both acetylation level and acetylation dynamics. When comparing genetic, diet, or environmental perturbations, these methods permit both a global and site-specific evaluation of how histone acetylation is dynamically regulated. PMID:27423860

  5. Characterization of plasma cholinesterase from the White stork (Ciconia ciconia) and its in vitro inhibition by anticholinesterase pesticides.

    PubMed

    Oropesa, Ana-Lourdes; Gravato, Carlos; Sánchez, Susana; Soler, Francisco

    2013-11-01

    Blood plasma cholinesterase (ChE) activity is a sensitive biomarker of exposure to organophosphorus (OP) and carbamate (CB) insecticides in vertebrates. Several studies indicate that more than one ChE form may be present in blood of birds. In this study the predominant ChE activity (acetylcholinesterase - AChE- or butyrylcholinesterase - BChE-), the range of ChE activity as well as ChE age-dependent changes in non-exposed individuals of White stork (Ciconia ciconia) have been established. The in vitro sensitivity of ChE to OP and CB insecticides such as paraoxon-methyl, carbofuran and carbaryl was also investigated. Plasma ChE was characterised using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51 and iso-OMPA). The results indicated that propionylthiocholine was the preferred substrate by plasma cholinesterase followed by acetylcholine and butyrylcholine and the predominant enzymatic activity in plasma of White storks was BChE. Normal plasma BChE activity in White stork was 0.32±0.01μmol/min/ml for adults and 0.28±0.03μmol/min/ml for juveniles. So, the age had no significant effect on the range of BChE activity. The study on the in vitro inhibitory potential of tested anticholinesterase pesticides on plasma ChE activity revealed that paraoxon-methyl is the most potent inhibitor followed by carbofuran and finally by carbaryl. The percentage of in vitro plasma ChE inhibition was observed to be similar between adults and juveniles.

  6. Blockade of histone deacetylase inhibitor-induced RelA/p65 acetylation and NF-kappaB activation potentiates apoptosis in leukemia cells through a process mediated by oxidative damage, XIAP downregulation, and c-Jun N-terminal kinase 1 activation.

    PubMed

    Dai, Yun; Rahmani, Mohamed; Dent, Paul; Grant, Steven

    2005-07-01

    NF-kappaB activation is reciprocally regulated by RelA/p65 acetylation and deacetylation, which are mediated by histone acetyltransferases (HATs) and deacetylases (HDACs). Here we demonstrate that in leukemia cells, NF-kappaB activation by the HDAC inhibitors (HDACIs) MS-275 and suberoylanilide hydroxamic acid was associated with hyperacetylation and nuclear translocation of RelA/p65. The latter events, as well as the association of RelA/p65 with IkappaBalpha, were strikingly diminished by either coadministration of the IkappaBalpha phosphorylation inhibitor Bay 11-7082 (Bay) or transfection with an IkappaBalpha superrepressor. Inhibition of NF-kappaB by pharmacological inhibitors or genetic strategies markedly potentiated apoptosis induced by HDACIs, and this was accompanied by enhanced reactive oxygen species (ROS) generation, downregulation of Mn-superoxide dismutase and XIAP, and c-Jun N-terminal kinase 1 (JNK1) activation. Conversely, N-acetyl L-cysteine blocked apoptosis induced by Bay/HDACIs by abrogating ROS generation. Inhibition of JNK1 activation attenuated Bay/HDACI lethality without affecting NF-kappaB inactivation and ROS generation. Finally, XIAP overexpression dramatically protected cells against the Bay/HDACI regimen but failed to prevent ROS production and JNK1 activation. Together, these data suggest that HDACIs promote the accumulation of acetylated RelA/p65 in the nucleus, leading to NF-kappaB activation. Moreover, interference with these events by either pharmacological or genetic means leads to a dramatic increase in HDACI-mediated lethality through enhanced oxidative damage, downregulation of NF-kappaB-dependent antiapoptotic proteins, and stress-related JNK1 activation.

  7. Treatment with endotracheal therapeutics after sarin microinstillation inhalation exposure increases blood cholinesterase levels in guinea pigs.

    PubMed

    Che, Magnus M; Song, Jian; Oguntayo, Samuel; Doctor, Bhupendra P; Rezk, Peter; Perkins, Michael W; Sciuto, Alfred M; Nambiar, Madhusoodana P

    2012-05-01

    Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were measured in the blood and tissues of animals that are treated with a number of endotracheally aerosolized therapeutics for protection against inhalation toxicity to sarin. Therapeutics included, aerosolized atropine methyl bromide (AMB), scopolamine or combination of AMB with salbutamol, sphingosine 1-phosphate, keratinocyte growth factor, adenosine A1 receptor antisense oligonucleotide (EPI2010), 2,3-diacetyloxybenzoic acid (2,3 DABA), oxycyte, and survanta. Guinea pigs exposed to 677.4 mg/m(3) or 846.5 mg/m(3) (1.2 LCt(50)) sarin for 4 min using a microinstillation inhalation exposure technique and treated 1 min later with the aerosolized therapeutics. Treatment with all therapeutics significantly increased the survival rate with no convulsions throughout the 24 h study period. Blood AChE activity determined using acetylthiocholine as substrate showed 20% activity remaining in sarin-exposed animals compare to controls. In aerosolized AMB and scopolamine-treated animals the remaining AChE activity was significantly higher (45-60%) compared to sarin-exposed animals (p < 0.05). Similarly, treatment with all the combination therapeutics resulted in significant increase in blood AChE activity in comparison to sarin-exposed animals although the increases varied between treatments (p < 0.05). BChE activity was increased after treatment with aerosolized therapeutics but was lesser in magnitude compared to AChE activity changes. Various tissues showed elevated AChE activity after therapeutic treatment of sarin-exposed animals. Increased AChE and BChE activities in animals treated with nasal therapeutics suggest that enhanced breathing and reduced respiratory toxicity/lung injury possibly contribute to rapid normalization of chemical warfare nerve agent inhibited cholinesterases.

  8. Plasma cholinesterase levels of mountain plovers (Charadrius montanus) wintering in central California, USA.

    PubMed

    Iko, William M; Archuleta, Andrew S; Knopf, Fritz L

    2003-01-01

    Declines of over 60% in mountain plover (Charadrius montanus) populations over the past 30 years have made it a species of concern throughout its current range and a proposed species for listing under the U.S. Endangered Species Act. Wintering mountain plovers spend considerable time on freshly plowed agricultural fields where they may potentially be exposed to anticholinesterase pesticides. Because of the population status and wintering ecology of plovers, the objectives of our study were to use nondestructive methods to report baseline plasma cholinesterase (ChE) levels in free-ranging mountain plovers wintering in California, USA, and to assess whether sampled birds showed signs of ChE inhibition related to anticholinesterase chemical exposure. We compared plasma ChE activity for mountain plovers sampled from the Carrizo Plain (an area relatively free of anticholinesterase pesticide use) with similar measures for plovers from the Central Valley (where anticholinesterase pesticides are widely used). Analyses for ChE inhibition indicated that none of the plovers had been recently exposed to these chemicals. However, mean ChE levels of plovers from the Central Valley were significantly higher (32%) than levels reported for plovers from the Carrizo Plain. This result differs from our original assumption of higher exposure risk to mountain plovers in the Central Valley but does suggest that some effect is occurring in the ChE activity of mountain plovers wintering in California.

  9. Neuroactive Multifunctional Tacrine Congeners with Cholinesterase, Anti-Amyloid Aggregation and Neuroprotective Properties

    PubMed Central

    Kozurkova, Maria; Hamulakova, Slavka; Gazova, Zuzana; Paulikova, Helena; Kristian, Pavol

    2011-01-01

    The review summarizes research into the highly relevant topics of cholinesterase and amyloid aggregation inhibitors connected to tacrine congeners, both of which are associated with neurogenerative diseases. Various opinions will be discussed regarding the dual binding site inhibitors which are characterized by increased inhibitor potency against acetylcholin/butyrylcholine esterase and amyloid formation. It is suggested that these compounds can both raise levels of acetylcholine by binding to the active site, and also prevent amyloid aggregation. In connection with this problem, the mono/dual binding of the multifunctional derivatives of tacrine, their mode of action and their neuroprotective activities are reported. The influence of low molecular compounds on protein amyloid aggregation, which might be considered as a potential therapeutic strategy in the treatment of Alzheimer's disease is also reported. Finally, attention is paid to some physico-chemical factors, such as desolvation energies describing the transfer of the substrate solvated by water, the metal-chelating properties of biometals reacting with amyloid precursor protein, amyloid beta peptide and tau protein.

  10. Protective Effects of Acetylation on the Pathological Reactions of the Lens Crystallins with Homocysteine Thiolactone

    PubMed Central

    Moafian, Zeinab; Khoshaman, Kazem; Oryan, Ahmad; Kurganov, Boris I.; Yousefi, Reza

    2016-01-01

    Various post-translational lens crystallins modifications result in structural and functional insults, contributing to the development of lens opacity and cataract disorders. Lens crystallins are potential targets of homocysteinylation, particularly under hyperhomocysteinemia which has been indicated in various eye diseases. Since both homocysteinylation and acetylation primarily occur on protein free amino groups, we applied different spectroscopic methods and gel mobility shift analysis to examine the possible preventive role of acetylation against homocysteinylation. Lens crystallins were extensively acetylated in the presence of acetic anhydride and then subjected to homocysteinylation in the presence of homocysteine thiolactone (HCTL). Extensive acetylation of the lens crystallins results in partial structural alteration and enhancement of their stability, as well as improvement of α-crystallin chaperone-like activity. In addition, acetylation partially prevents HCTL-induced structural alteration and aggregation of lens crystallins. Also, acetylation protects against HCTL-induced loss of α-crystallin chaperone activity. Additionally, subsequent acetylation and homocysteinylation cause significant proteolytic degradation of crystallins. Therefore, further experimentation is required in order to judge effectively the preventative role of acetylation on the structural and functional insults induced by homocysteinylation of lens crystallins. PMID:27706231

  11. Protein acetylation affects acetate metabolism, motility and acid stress response in Escherichia coli

    PubMed Central

    Castaño-Cerezo, Sara; Bernal, Vicente; Post, Harm; Fuhrer, Tobias; Cappadona, Salvatore; Sánchez-Díaz, Nerea C; Sauer, Uwe; Heck, Albert JR; Altelaar, AF Maarten; Cánovas, Manuel

    2014-01-01

    Although protein acetylation is widely observed, it has been associated with few specific regulatory functions making it poorly understood. To interrogate its functionality, we analyzed the acetylome in Escherichia coli knockout mutants of cobB, the only known sirtuin-like deacetylase, and patZ, the best-known protein acetyltransferase. For four growth conditions, more than 2,000 unique acetylated peptides, belonging to 809 proteins, were identified and differentially quantified. Nearly 65% of these proteins are related to metabolism. The global activity of CobB contributes to the deacetylation of a large number of substrates and has a major impact on physiology. Apart from the regulation of acetyl-CoA synthetase, we found that CobB-controlled acetylation of isocitrate lyase contributes to the fine-tuning of the glyoxylate shunt. Acetylation of the transcription factor RcsB prevents DNA binding, activating flagella biosynthesis and motility, and increases acid stress susceptibility. Surprisingly, deletion of patZ increased acetylation in acetate cultures, which suggests that it regulates the levels of acetylating agents. The results presented offer new insights into functional roles of protein acetylation in metabolic fitness and global cell regulation. PMID:25518064

  12. A dysregulated acetyl/SUMO switch of FXR promotes hepatic inflammation in obesity

    PubMed Central

    Kim, Dong-Hyun; Xiao, Zhen; Kwon, Sanghoon; Sun, Xiaoxiao; Ryerson, Daniel; Tkac, David; Ma, Ping; Wu, Shwu-Yuan; Chiang, Cheng-Ming; Zhou, Edward; Xu, H Eric; Palvimo, Jorma J; Chen, Lin-Feng; Kemper, Byron; Kemper, Jongsook Kim

    2015-01-01

    Acetylation of transcriptional regulators is normally dynamically regulated by nutrient status but is often persistently elevated in nutrient-excessive obesity conditions. We investigated the functional consequences of such aberrantly elevated acetylation of the nuclear receptor FXR as a model. Proteomic studies identified K217 as the FXR acetylation site in diet-induced obese mice. In vivo studies utilizing acetylation-mimic and acetylation-defective K217 mutants and gene expression profiling revealed that FXR acetylation increased proinflammatory gene expression, macrophage infiltration, and liver cytokine and triglyceride levels, impaired insulin signaling, and increased glucose intolerance. Mechanistically, acetylation of FXR blocked its interaction with the SUMO ligase PIASy and inhibited SUMO2 modification at K277, resulting in activation of inflammatory genes. SUMOylation of agonist-activated FXR increased its interaction with NF-κB but blocked that with RXRα, so that SUMO2-modified FXR was selectively recruited to and trans-repressed inflammatory genes without affecting FXR/RXRα target genes. A dysregulated acetyl/SUMO switch of FXR in obesity may serve as a general mechanism for diminished anti-inflammatory response of other transcriptional regulators and provide potential therapeutic and diagnostic targets for obesity-related metabolic disorders. PMID:25425577

  13. Analysis of acetylation stoichiometry suggests that SIRT3 repairs nonenzymatic acetylation lesions.

    PubMed

    Weinert, Brian T; Moustafa, Tarek; Iesmantavicius, Vytautas; Zechner, Rudolf; Choudhary, Chunaram

    2015-11-01

    Acetylation is frequently detected on mitochondrial enzymes, and the sirtuin deacetylase SIRT3 is thought to regulate metabolism by deacetylating mitochondrial proteins. However, the stoichiometry of acetylation has not been studied and is important for understanding whether SIRT3 regulates or suppresses acetylation. Using quantitative mass spectrometry, we measured acetylation stoichiometry in mouse liver tissue and found that SIRT3 suppressed acetylation to a very low stoichiometry at its target sites. By examining acetylation changes in the liver, heart, brain, and brown adipose tissue of fasted mice, we found that SIRT3-targeted sites were mostly unaffected by fasting, a dietary manipulation that is thought to regulate metabolism through SIRT3-dependent deacetylation. Globally increased mitochondrial acetylation in fasted liver tissue, higher stoichiometry at mitochondrial acetylation sites, and greater sensitivity of SIRT3-targeted sites to chemical acetylation in vitro and fasting-induced acetylation in vivo, suggest a nonenzymatic mechanism of acetylation. Our data indicate that most mitochondrial acetylation occurs as a low-level nonenzymatic protein lesion and that SIRT3 functions as a protein repair factor that removes acetylation lesions from lysine residues.

  14. Cholinesterase inhibition and behavioral toxicity of carbofuran on Oreochromis niloticus early life stages.

    PubMed

    Pessoa, P C; Luchmann, K H; Ribeiro, A B; Veras, M M; Correa, J R M B; Nogueira, A J; Bainy, A C D; Carvalho, P S M

    2011-10-01

    Nile tilapia Oreochromis niloticus at 9 days post-hatch were exposed in semi-static experiments to the carbamate insecticide carbofuran, which is applied in agricultural systems in Brazil. Although the molecular mechanism of carbofuran toxicity is well known, a detailed understanding of the ecological mechanisms through which carbofuran effects can propagate towards higher levels of biological organization in fish is incomplete. Mortality rates were quantified for larvae exposed for 96 h to 8.3, 40.6, 69.9, 140, 297 and 397 μg/L carbofuran, and the LC(50) 96 h was 214.7 μg/L. In addition, the biochemical biomarker cholinesterase inhibition and behavioral biomarkers related to vision, swimming, prey capture and predator avoidance were quantified in individual larvae, as well as their growth in weight. The behavioral parameters were quantified by analysis of digitally recorded videos of individual larvae within appropriate experimental setups. The activity of the enzyme cholinesterase decreased after exposure to carbofuran with a lowest observed effects concentration (LOEC) of 69.9 μg/L. Visual acuity deficits were detected after carbofuran exposure with a LOEC of 40.6 μg/L. Swimming speed decreased with carbofuran exposure, with a LOEC of 397.6 μg/L. The number of attacks to prey (Daphnia magna nauplii) decreased in larvae exposed to carbofuran, with a LOEC of 397.6 μg/L. Growth in weight was significantly reduced in a dose dependent manner, and all carbofuran groups exhibited a statistically significant decrease in growth when compared to controls (p<0.05). The number of predator attacks necessary to capture larvae decreased after exposure to carbofuran, and the LOEC was 69.9 μg/L. These results show that exposure of sensitive early life stages of tilapia O. niloticus to sublethal concentrations of carbofuran can affect fundamental aspects of fish larval ecology that are relevant to recruitment of fish populations, and that can be better understood by the

  15. Simulating cholinesterase inhibition in birds caused by dietary insecticide exposure

    USGS Publications Warehouse

    Corson, M.S.; Mora, M.A.; Grant, W.E.

    1998-01-01

    We describe a stochastic simulation model that simulates avian foraging in an agricultural landscape to evaluate factors affecting dietary insecticide exposure and to predict post-exposure cholinesterase (ChE) inhibition. To evaluate the model, we simulated published field studies and found that model predictions of insecticide decay and ChE inhibition reasonably approximated most observed results. Sensitivity analysis suggested that foraging location usually influenced ChE inhibition more than diet preferences or daily intake rate. Although organophosphorus insecticides usually caused greater inhibition than carbamate insecticides, insecticide toxicity appeared only moderately important. When we simulated impact of heavy insecticide applications during breeding seasons of 15 wild bird species, mean maximum ChE inhibition in most species exceeded 20% at some point. At this level of inhibition, birds may experience nausea and/or may exhibit minor behavioral changes. Simulated risk peaked in April-May and August-September and was lowest in July. ChE inhibition increased with proportion of vegetation in the diet. This model, and ones like it, may help predict insecticide exposure of and sublethal ChE inhibition in grassland animals, thereby reducing dependence of ecological risk assessments on field studies alone.

  16. Toxicological Differences Between NMDA Receptor Antagonists and Cholinesterase Inhibitors.

    PubMed

    Shi, Xiaodong; Lin, Xiaotian; Hu, Rui; Sun, Nan; Hao, Jingru; Gao, Can

    2016-08-01

    Cholinesterase inhibitors (ChEIs), represented by donepezil, rivastigmine, and galantamine, used to be the only approved class of drugs for the treatment of Alzheimer's disease. After the approval of memantine by the Food and Drug Administration (FDA), N-methyl-d-aspartic acid (NMDA) receptor antagonists have been recognized by authorities and broadly used in the treatment of Alzheimer's disease. Along with complementary mechanisms of action, NMDA antagonists and ChEIs differ not only in therapeutic effects but also in adverse reactions, which is an important consideration in clinical drug use. And the number of patients using NMDA antagonists and ChEIs concomitantly has increased, making the matter more complicated. Here we used the FDA Adverse Event Reporting System for statistical analysis , in order to compare the adverse events of memantine and ChEIs. In general, the clinical evidence confirmed the safety advantages of memantine over ChEIs, reiterating the precautions of clinical drug use and the future direction of antidementia drug development. PMID:26769920

  17. Neurobehavioral effects of the pyridinium aldoxime cholinesterase reactivator HI-6.

    PubMed

    Liu, W F; Shih, J H

    1990-01-01

    A series of neurobehavioral testing procedures was used to evaluate the behavioral effects of the pyridinium aldoxime cholinesterase reactivator HI-6 in male Sprague-Dawley rats. These procedures were fixed-ratio (FR) responding, shuttle-box conditioned avoidance response (CAR), conditioned taste aversion (CTA), drinking behavior, open-field exploratory behavior, negative geotaxis, and wire suspension time. Dose-response studies of HI-6 at dose-levels of 25, 50 and 100 mg/kg, or saline (IP) were evaluated. HI-6 disrupted FR responding in a dose-dependent fashion, with significant effects occurring at doses of 50 and 100 mg/kg. The pattern of disruption was characterized by extended periods of nonresponding having an abrupt onset and offset. HI-6 produced CTA in a dose-related manner, with significant effects at doses equal to those that disrupted FR performance. HI-6 did not alter CAR, drinking motivation, exploratory behavior, negative geotaxis, or wire suspension time. These data suggest that there may be a commonality in the underlying mechanism(s) for the disruption in FR performance and the induction of the CTA. This mechanism may relate to the presumed drug-induced adverse internal state inducing the CTA.

  18. 3-Hydroxy-3-methylglutaryl-coenzyme A synthase from ox liver. Properties of its acetyl derivative.

    PubMed Central

    Lowe, D M; Tubbs, P K

    1985-01-01

    Ox liver mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (EC 4.1.3.5) reacts with acetyl-CoA to form a complex in which the acetyl group is covalently bound to the enzyme. This acetyl group can be removed by addition of acetoacetyl-CoA or CoA. The extent of acetylation and release of CoA were found to be highly temperature-dependent. At temperatures above 20 degrees C, a maximum value of 0.85 mol of acetyl group bound/mol of enzyme dimer was observed. Below this temperature the extent of rapid acetylation was significantly lowered. Binding stoichiometries close to 1 mol/mol of enzyme dimer were also observed when the 3-hydroxy-3-methylglutaryl-CoA synthase activity was titrated with methyl methanethiosulphonate or bromoacetyl-CoA. This is taken as evidence for a 'half-of-the-sites' reaction mechanism for the formation of 3-hydroxy-3-methylglutaryl-CoA by 3-hydroxy-3-methylglutaryl-CoA synthase. The Keq. for the acetylation was about 10. Isolated acetyl-enzyme is stable for many hours at 0 degrees C and pH 7, but is hydrolysed at 30 degrees C with a half-life of 7 min. This hydrolysis is stimulated by acetyl-CoA and slightly by succinyl-CoA, but not by desulpho-CoA. The site of acetylation has been identified as the thiol group of a reactive cysteine residue by affinity-labelling with the substrate analogue bromo[1-14C]acetyl-CoA. PMID:2860896

  19. Mutations of Arabidopsis TBL32 and TBL33 affect xylan acetylation and secondary wall deposition

    DOE PAGES

    Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin; Haghighat, Marziyeh; Richardson, Elizabeth A.; Ye, Zheng -Hua; Zhang, Jin -Song

    2016-01-08

    Xylan is a major acetylated polymer in plant lignocellulosic biomass and it can be monoand di-acetylated at O-2 and O-3 as well as mono-acetylated at O-3 of xylosyl residues that is substituted with glucuronic acid (GlcA) at O-2. Based on the finding that ESK1, an Arabidopsis thaliana DUF231 protein, specifically mediates xylan 2-O- and 3-O-monoacetylation, we previously proposed that different acetyltransferase activities are required for regiospecific acetyl substitutions of xylan. Here, we demonstrate the functional roles of TBL32 and TBL33, two ESK1 close homologs, in acetyl substitutions of xylan. Simultaneous mutations of TBL32 and TBL33 resulted in a significant reductionmore » in xylan acetyl content and endoxylanase digestion of the mutant xylan released GlcA-substituted xylooligomers without acetyl groups. Structural analysis of xylan revealed that the tbl32 tbl33 mutant had a nearly complete loss of 3-O-acetylated, 2-O-GlcA-substituted xylosyl residues. A reduction in 3-Omonoacetylated and 2,3-di-O-acetylated xylosyl residues was also observed. Simultaneous mutations of TBL32, TBL33 and ESK1 resulted in a severe reduction in xylan acetyl level down to 15% of that of the wild type, and concomitantly, severely collapsed vessels and stunted plant growth. In particular, the S2 layer of secondary walls in xylem vessels of tbl33 esk1 and tbl32 tbl33 esk1 exhibited an altered structure, indicating abnormal assembly of secondary wall polymers. Furthermore, these results demonstrate that TBL32 and TBL33 play an important role in xylan acetylation and normal deposition of secondary walls.« less

  20. Mutations of Arabidopsis TBL32 and TBL33 Affect Xylan Acetylation and Secondary Wall Deposition

    PubMed Central

    Yuan, Youxi; Teng, Quincy; Zhong, Ruiqin; Haghighat, Marziyeh; Richardson, Elizabeth A.; Ye, Zheng-Hua

    2016-01-01

    Xylan is a major acetylated polymer in plant lignocellulosic biomass and it can be mono- and di-acetylated at O-2 and O-3 as well as mono-acetylated at O-3 of xylosyl residues that is substituted with glucuronic acid (GlcA) at O-2. Based on the finding that ESK1, an Arabidopsis thaliana DUF231 protein, specifically mediates xylan 2-O- and 3-O-monoacetylation, we previously proposed that different acetyltransferase activities are required for regiospecific acetyl substitutions of xylan. Here, we demonstrate the functional roles of TBL32 and TBL33, two ESK1 close homologs, in acetyl substitutions of xylan. Simultaneous mutations of TBL32 and TBL33 resulted in a significant reduction in xylan acetyl content and endoxylanase digestion of the mutant xylan released GlcA-substituted xylooligomers without acetyl groups. Structural analysis of xylan revealed that the tbl32 tbl33 mutant had a nearly complete loss of 3-O-acetylated, 2-O-GlcA-substituted xylosyl residues. A reduction in 3-O-monoacetylated and 2,3-di-O-acetylated xylosyl residues was also observed. Simultaneous mutations of TBL32, TBL33 and ESK1 resulted in a severe reduction in xylan acetyl level down to 15% of that of the wild type, and concomitantly, severely collapsed vessels and stunted plant growth. In particular, the S2 layer of secondary walls in xylem vessels of tbl33 esk1 and tbl32 tbl33 esk1 exhibited an altered structure, indicating abnormal assembly of secondary wall polymers. These results demonstrate that TBL32 and TBL33 play an important role in xylan acetylation and normal deposition of secondary walls. PMID:26745802

  1. Chemical reactivation and aging kinetics of organophosphorus-inhibited cholinesterases from two earthworm species.

    PubMed

    Rodríguez-Castellanos, Laura; Sanchez-Hernandez, Juan C

    2007-09-01

    An in vitro study was conducted to evaluate the ability of pyridine-2-aldoxime methochloride (2-PAM) to recover organophosphorus (OP)-inhibited cholinesterase (ChE) activity of two earthworm species (Eisenia fetida and Lumbricus terrestris). After inhibition of ChE activity by OP pesticides, an alkyl group may be released from the OP-ChE complex. This reaction is termed aging, and the esterase cannot be reactivated either spontaneously or by the action of reactivating agents, such as 2-PAM. We also examined the aging kinetics of OP-inhibited ChE activity to evaluate the suitability of 2-PAM reactivation methodology for field monitoring. A 2-PAM concentration of 5 x 10(-4) M was enough to reactivate the OP-inhibited ChE activity after 60 min of incubation at 25 degrees C. Chemical reactivation kinetics followed an exponential rise to a maximum of 70 to 80% of normal enzyme activity when ChEs were inhibited with methyl paraoxon or dichlorvos and up to 60% for the chlorpyrifos-inhibited ChE of E. fetida. The aging rates (ka) of the inhibited ChEs were strongly affected by the OP type, and these rates decreased for both earthworm species in the following order: Methyl paraoxon (ka = 0.023-0.033/h) > dichlorvos (ka = 0.008-0.009/h) > chlorpyrifos oxon (ka = 0.003-0.006/h). In particular, chlorpyrifos-inhibited ChE activity of L. terrestris aged slowly (median aging time, 190 h), which means that chemical reactivation of esterase activity with 2-PAM seems feasible one week after exposure to OP pesticides. We conclude that reactivation of earthworm ChE activity by treatment with 2-PAM is a complementary and specific methodology for assessing exposure to OP pesticides. PMID:17705652

  2. Synthesis, Biological Evaluation and Molecular Docking Study of Hydrazone-Containing Pyridinium Salts as Cholinesterase Inhibitors.

    PubMed

    Parlar, Sulunay; Bayraktar, Gulsah; Tarikogullari, Ayse Hande; Alptüzün, Vildan; Erciyas, Ercin

    2016-01-01

    A series of pyridinium salts bearing alkylphenyl groups at 1 position and hydrazone structure at 4 position of the pyridinium ring were synthesized and evaluated for the inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. The cholinesterase (ChE) inhibitory activity studies were carried out by using the Ellman's colorimetric method. All compounds displayed considerable AChE and BuChE inhibitory activity and some of the compounds manifested remarkable anti-AChE activity compared to the reference compound, galantamine. Among the title compounds, the series including benzofuran aromatic ring exhibited the best inhibitory activity both on AChE and BuChE enzymes. Compound 3b, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-(3-phenylpropyl)pyridinium bromide, was the most active compound with IC50 value of 0.23 (0.24) µM against enantiomeric excess (ee)AChE (human (h)AChE) while compound 3a, 4-[2-(1-(benzofuran-2-yl)ethylidene)hydrazinyl]-1-phenethylpyridinium bromide, was the most active compound with IC50 value of 0.95 µM against BuChE. Moreover, 3a and b exhibited higher activity than the reference compound galantamine (eeAChE (hAChE) IC50 0.43 (0.52) µM; BuChE IC50 14.92 µM). Molecular docking studies were carried out on 3b having highest inhibitory activity against AChE. PMID:27581632

  3. 2-Acetyl-pyridinium bromanilate.

    PubMed

    Thomas, Lynne H; Boyle, Bryan; Clive, Lesley A; Collins, Anna; Currie, Lynsey D; Gogol, Malgorzata; Hastings, Claire; Jones, Andrew O F; Kennedy, Jennifer L; Kerr, Graham B; Kidd, Alastair; Lawton, Lorreta M; Macintyre, Susan J; Maclean, Niall M; Martin, Alan R G; McGonagle, Kate; Melrose, Samantha; Rew, Gaius A; Robinson, Colin W; Schmidtmann, Marc; Turnbull, Felicity B; Williams, Lewis G; Wiseman, Alan Y; Wocial, Malgorzata H; Wilson, Chick C

    2009-01-01

    In the crystal of the title mol-ecular salt (systematic name: 2-acetyl-pyridinium 2,5-dibromo-4-hydr-oxy-3,6-dioxocyclo-hexa-1,4-dienolate), C(7)H(8)NO(+)·C(6)HBr(2)O(4) (-), centrosymmetric rings consisting of two cations and two anions are formed, with the components linked by alternating O-H⋯O and N-H⋯O hydrogen bonds. Short O⋯Br contacts [3.243 (2) and 3.359 (2) Å] may help to consolidate the packing. PMID:21583087

  4. A Method to determine lysine acetylation stoichiometries

    SciTech Connect

    Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; Shukla, Anil K.; Weitz, Karl K.; Moore, Ronald J.; Hixson, Kim K.; Kim, Jong Seo; Petyuk, Vladislav A.; Monroe, Matthew E.; Pasa-Tolic, Ljiljana; Qian, Weijun; Smith, Richard D.; Adkins, Joshua N.; Ansong, Charles

    2014-07-21

    A major bottleneck to fully understanding the functional aspects of lysine acetylation is the lack of stoichiometry information. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of lysine acetylation on proteins globally. Using this technique, we determined the modification occupancy on hundreds of acetylated peptides from cell lysates and cross-validated the measurements via immunoblotting.

  5. New platinum(II) complexes conjugated at position 7α of 17β-acetyl-testosterone as new combi-molecules against prostate cancer: design, synthesis, structure-activity relationships and biological evaluation.

    PubMed

    Fortin, Sébastien; Brasseur, Kevin; Morin, Nathalie; Asselin, Éric; Bérubé, Gervais

    2013-10-01

    Prostate cancer is a major public health problem worldwide and, more specifically, new treatments for hormone-refractory cancers are highly sought by several research groups. Although platinum(II)-based chemotherapy and other strategies grow in interest to treat castration-resistant prostate cancer (CRPC), they still exhibit modest activity on CRPC and overall patient survival. In this study, we designed and prepared new combi-molecules using 17β-acetyl-testosterone and amino acid platinum(II) complexes linked at the position 7α to target and to improve the antiproliferative activity of platinum(II)-based chemotherapy on prostate cancer cells. Twelve chemical intermediates and six new combi-molecules were prepared and characterized. Structure-activity relationships studies show that the platinum complex moiety is essential for an optimal cytocidal activity. Moreover, stereochemistry of the amino acid involved in the platinum complexes had only minor effects on the antiproliferative activity whereas pyridinyl (10a and b) and thiazolyl (10f) complexes exhibited the highest cytocidal activities that are significantly superior to that of cisplatin used as control on human prostate adenocarcinoma LNCaP (AR+), PC3 (AR-) and DU145 (AR-). Compounds 10a, b and f arrested the cell cycle progression in S-phase and induced double strand breaks as confirmed by the phosphorylation of histone H2AX into γH2AX. Compounds 10a and f showed 33 and 30% inhibition, respectively of the growth of HT-1080 tumors grafted onto chick chorioallantoic membranes. Finally, compounds 10a and 10f exhibited low toxicity on the chick embryos (18 and 21% of death, respectively), indicating that these new combi-molecules might be a promising new class of anticancer agents for prostate cancer.

  6. In the absence of cellular poly (A) binding protein, the glycolytic enzyme GAPDH translocated to the cell nucleus and activated the GAPDH mediated apoptotic pathway by enhancing acetylation and serine 46 phosphorylation of p53

    SciTech Connect

    Thangima Zannat, Mst.; Bhattacharjee, Rumpa B.; Bag, Jnanankur

    2011-06-03

    Highlights: {yields} PABP knock down and cell apoptosis. {yields} Nuclear translocation of GAPDH in PABP depleted cells. {yields} Role of p53 in apoptosis of PABP depleted cells. {yields} Bax translocation and cytochrome C release and caspase 3 activation following PABP depletion. {yields} Association of p53 with Bcl2 and Bax. -- Abstract: The cytoplasmic poly (A) binding protein (PABP) interacts with 3' poly (A) tract of eukaryotic mRNA and is important for both translation and stability of mRNA. Previously, we have shown that depletion of PABP by siRNA prevents protein synthesis and consequently leads to cell death through apoptosis. In the present investigation, we studied the mechanism of cell apoptosis. We show that in the absence of PABP, the glycolytic enzyme GAPDH translocated to the cell nucleus and activated the GAPDH mediated apoptotic pathway by enhancing acetylation and serine 46 phosphorylation of p53. As a result, p53 translocated to the mitochondria to initiate Bax mediated apoptosis.

  7. Acetylation of woody lignocellulose: significance and regulation

    PubMed Central

    Pawar, Prashant Mohan-Anupama; Koutaniemi, Sanna; Tenkanen, Maija; Mellerowicz, Ewa J.

    2013-01-01

    Non-cellulosic cell wall polysaccharides constitute approximately one quarter of usable biomass for human exploitation. In contrast to cellulose, these components are usually substituted by O-acetyl groups, which affect their properties and interactions with other polymers, thus affecting their solubility and extractability. However, details of these interactions are still largely obscure. Moreover, polysaccharide hydrolysis to constituent monosaccharides is hampered by the presence of O-acetyl groups, necessitating either enzymatic (esterase) or chemical de-acetylation, increasing the costs and chemical consumption. Reduction of polysaccharide acetyl content in planta is a way to modify lignocellulose toward improved saccharification. In this review we: (1) summarize literature on lignocellulose acetylation in different tree species, (2) present data and current hypotheses concerning the role of O-acetylation in determining woody lignocellulose properties, (3) describe plant proteins involved in lignocellulose O-acetylation, (4) give examples of microbial enzymes capable to de-acetylate lignocellulose, and (5) discuss prospects for exploiting these enzymes in planta to modify xylan acetylation. PMID:23734153

  8. Acetylation of the response regulator RcsB controls transcription from a small RNA promoter.

    PubMed

    Hu, Linda I; Chi, Bui Khanh; Kuhn, Misty L; Filippova, Ekaterina V; Walker-Peddakotla, Arti J; Bäsell, Katrin; Becher, Dörte; Anderson, Wayne F; Antelmann, Haike; Wolfe, Alan J

    2013-09-01

    Nε-lysine acetylation was recently discovered on many bacterial proteins that function in diverse cellular processes. Thus, many questions remain unanswered. For example, what mechanisms regulate lysine acetylation? Does acetylation affect physiology? To help answer these questions, we studied the Escherichia coli response regulator and transcription factor RcsB, which is reported to be acetylated in vitro. To characterize RcsB acetylation, we monitored transcription from the rprA promoter, which requires RcsB. The conventional view is that RcsB is activated by phosphorylation through either the Rcs phosphorelay or acetyl phosphate. We affirmed that rprA transcription requires phosphorylated RcsB and showed that acetyl-phosphate (AcP) is a phosphoryl group donor to RcsB. However, a mutant that accumulates AcP (ackA) exhibited a reduction in rprA transcription instead of the predicted increase. rprA transcription also diminished in the cobB mutant, which lacks the only known E. coli protein deacetylase. This suggests the existence of an inhibitory mechanism that involves lysine acetylation, a supposition supported by the observation that RcsB isolated from the ackA or cobB mutant was hyperacetylated. Finally, we used a genetic approach to identify an AckA- and CobB-sensitive lysine (Lys-154) that controls RcsB activity. We propose that acetylation inhibits RcsB activity and that some of this inhibition acts through the acetylation of Lys-154. PMID:23852870

  9. Acetylation of the Response Regulator RcsB Controls Transcription from a Small RNA Promoter

    PubMed Central

    Hu, Linda I.; Chi, Bui Khanh; Kuhn, Misty L.; Filippova, Ekaterina V.; Walker-Peddakotla, Arti J.; Bäsell, Katrin; Becher, Dörte; Anderson, Wayne F.; Antelmann, Haike

    2013-01-01

    Nε-lysine acetylation was recently discovered on many bacterial proteins that function in diverse cellular processes. Thus, many questions remain unanswered. For example, what mechanisms regulate lysine acetylation? Does acetylation affect physiology? To help answer these questions, we studied the Escherichia coli response regulator and transcription factor RcsB, which is reported to be acetylated in vitro. To characterize RcsB acetylation, we monitored transcription from the rprA promoter, which requires RcsB. The conventional view is that RcsB is activated by phosphorylation through either the Rcs phosphorelay or acetyl phosphate. We affirmed that rprA transcription requires phosphorylated RcsB and showed that acetyl-phosphate (AcP) is a phosphoryl group donor to RcsB. However, a mutant that accumulates AcP (ackA) exhibited a reduction in rprA transcription instead of the predicted increase. rprA transcription also diminished in the cobB mutant, which lacks the only known E. coli protein deacetylase. This suggests the existence of an inhibitory mechanism that involves lysine acetylation, a supposition supported by the observation that RcsB isolated from the ackA or cobB mutant was hyperacetylated. Finally, we used a genetic approach to identify an AckA- and CobB-sensitive lysine (Lys-154) that controls RcsB activity. We propose that acetylation inhibits RcsB activity and that some of this inhibition acts through the acetylation of Lys-154. PMID:23852870

  10. Synthesis of acetyl coenzyme A by carbon monoxide dehydrogenase complex from acetate-grown Methanosarcina thermophila.

    PubMed Central

    Abbanat, D R; Ferry, J G

    1990-01-01

    The carbon monoxide dehydrogenase (CODH) complex from Methanosarcina thermophila catalyzed the synthesis of acetyl coenzyme A (acetyl-CoA) from CH3I, CO, and coenzyme A (CoA) at a rate of 65 nmol/min/mg at 55 degrees C. The reaction ended after 5 min with the synthesis of 52 nmol of acetyl-CoA per nmol of CODH complex. The optimum temperature for acetyl-CoA synthesis in the assay was between 55 and 60 degrees C; the rate of synthesis at 55 degrees C was not significantly different between pHs 5.5 and 8.0. The rate of acetyl-CoA synthesis was independent of CoA concentrations between 20 microM and 1 mM; however, activity was inhibited 50% with 5 mM CoA. Methylcobalamin did not substitute for CH3I in acetyl-CoA synthesis; no acetyl-CoA or propionyl coenzyme A was detected when sodium acetate or CH3CH2I replaced CH3I in the assay mixture. CO could be replaced with CO2 and titanium(III) citrate. When CO2 and 14CO were present in the assay, the specific activity of the acetyl-CoA synthesized was 87% of the specific activity of 14CO, indicating that CO was preferentially incorporated into acetyl-CoA without prior oxidation to free CO2. Greater than 100 microM potassium cyanide was required to significantly inhibit acetyl-CoA synthesis, and 500 microM was required for 50% inhibition; in contrast, oxidation of CO by the CODH complex was inhibited 50% by approximately 10 microM potassium cyanide. PMID:2123865

  11. Simulating the impact of cholinesterase-inhibiting pesticides on non-target wildlife in irrigated crops

    USGS Publications Warehouse

    Pisani, J.M.; Grant, W.E.; Mora, M.A.

    2008-01-01

    We present a simulation model for risk assessment of the impact of insecticide inhibitors of cholinesterase (ChE) applied in irrigated agricultural fields on non-target wildlife. The model, which we developed as a compartment model based on difference equations (??t = 1 h), consists of six submodels describing the dynamics of (1) insecticide application, (2) insecticide movement into floodable soil, (3) irrigation and rain, (4) insecticide dissolution in water, (5) foraging and insecticide intake from water, and (6) ChE inhibition and recovery. To demonstrate application of the model, we simulated historical and "worst-case" scenarios of the impact of ChE-inhibiting insecticides on white-winged doves (Zenaida asiatica) inhabiting natural brushland adjacent to cotton and sugarcane fields in the Lower Rio Grande Valley of Texas, USA. Only when a rain event occurred just after insecticide application did predicted levels of ChE inhibition surpass the diagnostic level of 20% exposure. The present model should aid in assessing the effect of ChE-inhibiting insecticides on ChE activity of different species that drink contaminated water from irrigated agricultural fields, and in identifying specific situations in which the juxtaposition of environmental conditions and management schemes could result in a high risk to non-target wildlife. ?? 2007 Elsevier B.V. All rights reserved.

  12. An Artificial Reaction Promoter Modulates Mitochondrial Functions via Chemically Promoting Protein Acetylation

    PubMed Central

    Shindo, Yutaka; Komatsu, Hirokazu; Hotta, Kohji; Ariga, Katsuhiko; Oka, Kotaro

    2016-01-01

    Acetylation, which modulates protein function, is an important process in intracellular signalling. In mitochondria, protein acetylation regulates a number of enzymatic activities and, therefore, modulates mitochondrial functions. Our previous report showed that tributylphosphine (PBu3), an artificial reaction promoter that promotes acetylransfer reactions in vitro, also promotes the reaction between acetyl-CoA and an exogenously introduced fluorescent probe in mitochondria. In this study, we demonstrate that PBu3 induces the acetylation of mitochondrial proteins and a decrease in acetyl-CoA concentration in PBu3-treated HeLa cells. This indicates that PBu3 can promote the acetyltransfer reaction between acetyl-CoA and mitochondrial proteins in living cells. PBu3-induced acetylation gradually reduced mitochondrial ATP concentrations in HeLa cells without changing the cytoplasmic ATP concentration, suggesting that PBu3 mainly affects mitochondrial functions. In addition, pyruvate, which is converted into acetyl-CoA in mitochondria and transiently increases ATP concentrations in the absence of PBu3, elicited a further decrease in mitochondrial ATP concentrations in the presence of PBu3. Moreover, the application and removal of PBu3 reversibly alternated mitochondrial fragmentation and elongation. These results indicate that PBu3 enhances acetyltransfer reactions in mitochondria and modulates mitochondrial functions in living cells. PMID:27374857

  13. Mechanism of the lysosomal membrane enzyme acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase

    SciTech Connect

    Bame, K.J.

    1986-01-01

    Acetyl-CoA:..cap alpha..-glucosaminide N-acetyltransferase is a lysosomal membrane enzyme, deficient in the genetic disease Sanfilippo C syndrome. The enzyme catalyzes the transfer of an acetyl group from cytoplasmic acetyl-CoA to terminal ..cap alpha..-glucosamine residues of heparan sulfate within the organelle. The reaction mechanism was examined using high purified lysosomal membranes from rat liver and human fibroblasts. The N-acetyltransferase reaction is optimal above pH 5.5 and a 2-3 fold stimulation of activity is observed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicate that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. The binding of acetyl-CoA to the enzyme is measured by exchange label from (/sup 3/H)CoA to acetyl-CoA, and is optimal at pH's above 7.0. The acetyl-enzyme intermediate is formed by incubating membranes with (/sup 3/H)acetyl-CoA. The acetyl group can be transferred to glucosamine, forming (/sup 3/H)N-acetylglucosamine; the transfer is optimal between pH 4 and 5. Lysosomal membranes from Sanfilippo C fibroblasts confirm that these half reactions carried out by the N-acetyltransferase. The enzyme is inactivated by N-bromosuccinimide and diethylpyrocarbonate, indicating that a histidine is involved in the reaction. These results suggest that the histidine residue is at the active site of the enzyme. The properties of the N-acetyltransferase in the membrane, the characterization of the enzyme kinetics, the chemistry of a histidine mediated acetylation and the pH difference across the lysosomal membrane all support a transmembrane acetylation mechanism.

  14. Synthesis, characterization and anticonvulsant activity evaluation of some 1,4-dihydropyridines and 3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-N-[2-(4-sulfamoylphenylamino)-acetyl]-4-(substituted)pyridines.

    PubMed

    Subudhi, Bharat Bhusan; Panda, Prasanna K; Swain, Sarada P; Sarangi, Priyambada

    2009-01-01

    A series of 3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(substituted)pyridines (1a-j) were synthesized by Hantzsch method for pyridine synthesis. Treatment with chloroacetyl chloride produced N-(2-chloroacetyl)-3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(substituted)pyridines (2a-e), which on further treatment with sulfanilamide resulted in 3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-N-[2-(4-sulfamoylphenylamino)-acetyl]-4-(substituted)pyridines (3a-e). The structures has been established on the basis of spectral (IR, 1H-NMR, mass) and elemental analysis. Compounds 1a-j and 3a-e (5 mg/kg and 10 mg/kg) were evaluated for their anticonvulsant effect against pentylenetetrazole-induced convulsions with diazepam (4 mg/kg) as the reference. Compounds 3a-e exhibited significant (p<0.01) anticonvulsant activity compared to the control. PMID:19719048

  15. Characterization, molecular modeling and antimicrobial activity of metal complexes of tridentate Schiff base derived from 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione and 2-aminophenol.

    PubMed

    Adly, Omima M I

    2012-09-01

    Metal complexes of Ni(II), Co(II), Cd(II), VO(IV) and UO(2)(VI) as well as several Cu(II) salts, including Cl(-),NO(3)(-),AcO(-),ClO(4)(-) and SO(4)(-2) with a tridentate O(2)N donor Schiff base ligand (H(2)L), synthesized by condensation of 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione with 2-aminophenol, were prepared and characterized on the basis of elemental analyses, spectral, magnetic, molar conductance and thermal gravimetric analysis. Square planar, tetrahedral and octahedral geometries have been assigned to the prepared complexes. Molecular parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data, and the changes of bond lengths are linearly correlated with IR data. The antimicrobial activities of the synthesized compounds were tested in vitro against the sensitive organisms Staphylococcus aureus as Gram positive bacteria, Proteus vulgaris as Gram negative bacteria and Candida albicans as fungus strain, and the results are discussed.

  16. Characterization, molecular modeling and antimicrobial activity of metal complexes of tridentate Schiff base derived from 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione and 2-aminophenol

    NASA Astrophysics Data System (ADS)

    Adly, Omima M. I.

    Metal complexes of Ni(II), Co(II), Cd(II), VO(IV) and UO2(VI) as well as several Cu(II) salts, including Cl,NO3-,AcO,ClO4- and SO4-2 with a tridentate O2N donor Schiff base ligand (H2L), synthesized by condensation of 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione with 2-aminophenol, were prepared and characterized on the basis of elemental analyses, spectral, magnetic, molar conductance and thermal gravimetric analysis. Square planar, tetrahedral and octahedral geometries have been assigned to the prepared complexes. Molecular parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data, and the changes of bond lengths are linearly correlated with IR data. The antimicrobial activities of the synthesized compounds were tested in vitro against the sensitive organisms Staphylococcus aureus as Gram positive bacteria, Proteus vulgaris as Gram negative bacteria and Candida albicans as fungus strain, and the results are discussed.

  17. Brain cholinesterase response in the snakehead fish (Channa striata) after field exposure to diazinon.

    PubMed

    Nguyen, Van Cong; Nguyen, Thanh Phuong; Bayley, Mark

    2008-10-01

    The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide.

  18. Brain cholinesterase response in the snakehead fish (Channa striata) after field exposure to diazinon.

    PubMed

    Nguyen, Van Cong; Nguyen, Thanh Phuong; Bayley, Mark

    2008-10-01

    The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide. PMID:18514898

  19. Toluidine blue O is a potent inhibitor of human cholinesterases.

    PubMed

    Biberoglu, Kevser; Tek, Melike Yuksel; Ghasemi, Seyhan Turk; Tacal, Ozden

    2016-08-15

    In this study, the inhibitory effects of three phenothiazines [toluidine blue O (TBO), thionine (TH) and methylene violet (MV)] were tested on human plasma butyrylcholinesterase (BChE) and their inhibitory mechanisms were studied in detail. MV acted as a linear mixed type inhibitor of human BChE with Ki = 0.66 ± 0.06 μM and α = 13.6 ± 3.5. TBO and TH caused nonlinear inhibition of human BChE, compatible to double occupancy. Ki values estimated by nonlinear regression analysis for TBO and TH were 0.008 ± 0.003 μM and 2.1 ± 0.42 μM, respectively. The inhibitory potential of TBO was also tested on human erythrocyte AChE. TBO acted as a linear mixed type inhibitor of human AChE with Ki = 0.041 ± 0.005 μM and α = 1.6 ± 0.007. Using four site-directed BChE mutants, the role of peripheral anionic site residues of human BChE was also investigated in the binding of TBO to BChE. The peripheral anionic site mutants of BChE caused 16-69-fold increase in Ki value of TBO, compared to recombinant wild-type, suggesting that peripheral anionic site residues are involved in the binding of TBO to human BChE. In conclusion, TBO which is a potent inhibitor of human cholinesterases, may be a potential drug candidate for the treatment of Alzheimer's disease. PMID:27296777

  20. A Method to Determine Lysine Acetylation Stoichiometries

    DOE PAGES

    Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; Shukla, Anil K.; Weitz, Karl K.; Moore, Ronald J.; Hixson, Kim K.; Kim, Jong-Seo; Petyuk, Vladislav A.; Monroe, Matthew E.; et al

    2014-01-01

    Lysine acetylation is a common protein posttranslational modification that regulates a variety of biological processes. A major bottleneck to fully understanding the functional aspects of lysine acetylation is the difficulty in measuring the proportion of lysine residues that are acetylated. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of protein lysine acetylation. Using this technique, we determined the modification occupancy for ~750 acetylated peptides from mammalian cell lysates. Furthermore, the acetylation on N-terminal tail of histone H4 was cross-validated by treating cells with sodiummore » butyrate, a potent deacetylase inhibitor, and comparing changes in stoichiometry levels measured by our method with immunoblotting measurements. Of note we observe that acetylation stoichiometry is high in nuclear proteins, but very low in mitochondrial and cytosolic proteins. In summary, our method opens new opportunities to study in detail the relationship of lysine acetylation levels of proteins with their biological functions.« less

  1. 21 CFR 172.828 - Acetylated monoglycerides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.828 Acetylated monoglycerides. The food additive acetylated... of catalytic agents that are not food additives or are authorized by regulation, followed by...

  2. New antimuscarinic agents for improved treatment of poisoning by cholinesterase inhibitors. Annual report, 1 November 1983-1 August 1984

    SciTech Connect

    Stubbins, J.F.

    1984-08-01

    The object of this project is to find a more effective antimuscarinic agent than atropine for use as an antidote for poisoning by organophosphate cholinesterase inhibitors. To start this search, 30 structurally diverse antimuscarinic agents have been selected for initial testing. These compounds are to be evaluated for peripheral and central antimuscarinic activity in a variety of in vitro and in vivo tests in addition to determining their effectiveness as antidotes (in combination with an oxime reactivator) for poisoning by soman. Twenty-two of the compounds have now been evaluated for their ability to block acetylcholine-induced contractions in guinea pig intestinal smooth muscle when compared to atropine. Ability to displace radiolabeled quinuclidinyl benzilate from muscarinic receptors of mouse brain homogenate has been determined for atropine, hyoscine and 26 of the compounds. Only triflupromazine appeared to have a distinctly greater affinity for brain receptors than muscle receptors to atropine. Intestinal smooth muscle blockade; oxotremorine tremor inhibition; muscarinic receptor subtypes.

  3. Ferulic acid-carbazole hybrid compounds: Combination of cholinesterase inhibition, antioxidant and neuroprotection as multifunctional anti-Alzheimer agents.

    PubMed

    Fang, Lei; Chen, Mohao; Liu, Zhikun; Fang, Xubin; Gou, Shaohua; Chen, Li

    2016-02-15

    In order to search for novel multifunctional anti-Alzheimer agents, a series of ferulic acid-carbazole hybrid compounds were designed and synthesized. Ellman's assay revealed that the hybrid compounds showed moderate to potent inhibitory activity against the cholinesterases. Particularly, the AChE inhibition potency of compound 5k (IC50 1.9μM) was even 5-fold higher than that of galantamine. In addition, the target compounds showed pronounced antioxidant ability and neuroprotective property, especially against the ROS-induced toxicity. Notably, the neuroprotective effect of 5k was obviously superior to that of the mixture of ferulic acid and carbazole, indicating the therapeutic effect of the hybrid compound is better than the combination administration of the corresponding mixture.

  4. Ferulic acid-carbazole hybrid compounds: Combination of cholinesterase inhibition, antioxidant and neuroprotection as multifunctional anti-Alzheimer agents.

    PubMed

    Fang, Lei; Chen, Mohao; Liu, Zhikun; Fang, Xubin; Gou, Shaohua; Chen, Li

    2016-02-15

    In order to search for novel multifunctional anti-Alzheimer agents, a series of ferulic acid-carbazole hybrid compounds were designed and synthesized. Ellman's assay revealed that the hybrid compounds showed moderate to potent inhibitory activity against the cholinesterases. Particularly, the AChE inhibition potency of compound 5k (IC50 1.9μM) was even 5-fold higher than that of galantamine. In addition, the target compounds showed pronounced antioxidant ability and neuroprotective property, especially against the ROS-induced toxicity. Notably, the neuroprotective effect of 5k was obviously superior to that of the mixture of ferulic acid and carbazole, indicating the therapeutic effect of the hybrid compound is better than the combination administration of the corresponding mixture. PMID:26795115

  5. Aurora B is regulated by acetylation/deacetylation during mitosis in prostate cancer cells

    PubMed Central

    Fadri-Moskwik, Maria; Weiderhold, Kimberly N.; Deeraksa, Arpaporn; Chuang, Carol; Pan, Jing; Lin, Sue-Hwa; Yu-Lee, Li-Yuan

    2012-01-01

    Protein acetylation has been implicated in playing an important role during mitotic progression. Aurora B kinase is known to play a critical role in mitosis. However, whether Aurora B is regulated by acetylation is not known. Using IP with an anti-acetyl lysine antibody, we identified Aurora B as an acetylated protein in PC3 prostate cancer cells. Knockdown of HDAC3 or inhibiting HDAC3 deacetylase activity led to a significant increase (P<0.01 and P<0.05, respectively) in Aurora B acetylation as compared to siLuc or vehicle-treated controls. Increased Aurora B acetylation is correlated with a 30% reduction in Aurora B kinase activity in vitro and resulted in significant defects in Aurora B-dependent mitotic processes, including kinetochore-microtubule attachment and chromosome congression. Furthermore, Aurora B transiently interacts with HDAC3 at the kinetochore-microtubule interface of congressing chromosomes during prometaphase. This window of interaction corresponded with a transient but significant reduction (P=0.02) in Aurora B acetylation during early mitosis. Together, these results indicate that Aurora B is more active in its deacetylated state and further suggest a new mechanism by which dynamic acetylation/deacetylation acts as a rheostat to fine-tune Aurora B activity during mitotic progression.—Fadri-Moskwik, M., Weiderhold, K. N., Deeraksa, A., Chuang, C., Pan, J., Lin, S.-H., Yu-Lee, L.-Y. Aurora B is regulated by acetylation/deacetylation during mitosis in prostate cancer cells. PMID:22751009

  6. Histone H3 globular domain acetylation identifies a new class of enhancers

    PubMed Central

    Pradeepa, Madapura M; Grimes, Graeme R; Kumar, Yatendra; Olley, Gabrielle; Taylor, Gillian C A; Schneider, Robert; Bickmore, Wendy A

    2016-01-01

    Histone acetylation is generally associated with active chromatin, but most studies have focused on the acetylation of histone tails. Various histone H3 and H4 tail acetylations mark the promoters of active genes1. This includes acetylation of H3 on lysine 27 (H3K27ac), which blocks the deposition of polycomb mediated H3K27me32. H3K27ac is also widely used to identify active enhancers3,4, and the assumption has been that profiling of H3K27ac is a comprehensive way of cataloguing the set of active enhancers in mammalian cell types. Here we show that acetylation of lysine residues in the globular domain of H3 (H3K64ac and H3K122ac) marks active gene promoters and also a subset of active enhancers. Moreover, we find a novel class of active functional enhancers that are marked by H3K122ac but lack H3K27ac. This work suggests that, to identify enhancers, a more comprehensive analysis of histone acetylation is required than was previously considered. PMID:27089178

  7. Histone H3 globular domain acetylation identifies a new class of enhancers.

    PubMed

    Pradeepa, Madapura M; Grimes, Graeme R; Kumar, Yatendra; Olley, Gabrielle; Taylor, Gillian C A; Schneider, Robert; Bickmore, Wendy A

    2016-06-01

    Histone acetylation is generally associated with active chromatin, but most studies have focused on the acetylation of histone tails. Various histone H3 and H4 tail acetylations mark the promoters of active genes. These modifications include acetylation of histone H3 at lysine 27 (H3K27ac), which blocks Polycomb-mediated trimethylation of H3K27 (H3K27me3). H3K27ac is also widely used to identify active enhancers, and the assumption has been that profiling H3K27ac is a comprehensive way of cataloguing the set of active enhancers in mammalian cell types. Here we show that acetylation of lysine residues in the globular domain of histone H3 (lysine 64 (H3K64ac) and lysine 122 (H3K122ac)) marks active gene promoters and also a subset of active enhancers. Moreover, we find a new class of active functional enhancers that is marked by H3K122ac but lacks H3K27ac. This work suggests that, to identify enhancers, a more comprehensive analysis of histone acetylation is required than has previously been considered.

  8. Recovery study of cholinesterases and neurotoxic signs in the non-target freshwater invertebrate Chilina gibbosa after an acute exposure to an environmental concentration of azinphos-methyl.

    PubMed

    Cossi, Paula Fanny; Beverly, Boburg; Carlos, Luquet; Kristoff, Gisela

    2015-10-01

    Azinphos-methyl belongs to the class of organophosphate insecticides which are recognized for their anticholinesterase action. It is one of the most frequently used insecticides in the Upper Valley of Río Negro and Río Neuquén in Argentina, where agriculture represents the second most important economic activity. It has been detected in water from this North Patagonian region throughout the year and the maximum concentration found was 22.48 μg L(-1) during the application period. Chilina gibbosa is a freshwater gastropod widely distributed in South America, particularly in Patagonia, Argentina and in Southern Chile. Toxicological studies performed with C. gibbosa in our laboratory have reported neurotoxicity signs and cholinesterase inhibition after exposure to azinphos-methyl for 48 h. Recovery studies together with characterization of the enzyme and sensitivity of the enzyme to pesticides can improve the toxicological evaluation. However, little is known about recovery patterns in organisms exposed to organophosphates. The aim of the present work was to evaluate the recovery capacity (during 21 days in pesticide-free water) of cholinesterase activity and neurotoxicity in C. gibbosa after 48 h of exposure to azinphos-methyl. Also, lethality and carboxylesterase activity were registered during the recovery period. Regarding enzyme activities, after a 48-h exposure to 20 μg L(-1) of azinphos-methyl, cholinesterases showed an inhibition of 85% with respect to control, while carboxylesterases were not affected. After 21 days in pesticide-free water, cholinesterases continued to be inhibited (70%). Severe neurotoxicity signs were observed after exposure: 82% of the snails presented lack of adherence to vessels, 11% showed weak adherence, and 96% exhibited an abnormal protrusion of the head-foot region from shell. After 21 days in pesticide-free water, only 15% of the snails presented severe signs of neurotoxicity. However, during the recovery period significant

  9. Recovery study of cholinesterases and neurotoxic signs in the non-target freshwater invertebrate Chilina gibbosa after an acute exposure to an environmental concentration of azinphos-methyl.

    PubMed

    Cossi, Paula Fanny; Beverly, Boburg; Carlos, Luquet; Kristoff, Gisela

    2015-10-01

    Azinphos-methyl belongs to the class of organophosphate insecticides which are recognized for their anticholinesterase action. It is one of the most frequently used insecticides in the Upper Valley of Río Negro and Río Neuquén in Argentina, where agriculture represents the second most important economic activity. It has been detected in water from this North Patagonian region throughout the year and the maximum concentration found was 22.48 μg L(-1) during the application period. Chilina gibbosa is a freshwater gastropod widely distributed in South America, particularly in Patagonia, Argentina and in Southern Chile. Toxicological studies performed with C. gibbosa in our laboratory have reported neurotoxicity signs and cholinesterase inhibition after exposure to azinphos-methyl for 48 h. Recovery studies together with characterization of the enzyme and sensitivity of the enzyme to pesticides can improve the toxicological evaluation. However, little is known about recovery patterns in organisms exposed to organophosphates. The aim of the present work was to evaluate the recovery capacity (during 21 days in pesticide-free water) of cholinesterase activity and neurotoxicity in C. gibbosa after 48 h of exposure to azinphos-methyl. Also, lethality and carboxylesterase activity were registered during the recovery period. Regarding enzyme activities, after a 48-h exposure to 20 μg L(-1) of azinphos-methyl, cholinesterases showed an inhibition of 85% with respect to control, while carboxylesterases were not affected. After 21 days in pesticide-free water, cholinesterases continued to be inhibited (70%). Severe neurotoxicity signs were observed after exposure: 82% of the snails presented lack of adherence to vessels, 11% showed weak adherence, and 96% exhibited an abnormal protrusion of the head-foot region from shell. After 21 days in pesticide-free water, only 15% of the snails presented severe signs of neurotoxicity. However, during the recovery period significant

  10. Serum cystatin C, urinary neutrophil gelatinase-associated lipocalin and N-acetyl-beta-D-glucosaminidase in juvenile and adult patients with systemic lupus erythematosus: Correlation with clinical manifestations, disease activity and damage.

    PubMed

    Gheita, Tamer A; Abd El Baky, Abeer M Nour El Din; Assal, Heba S; Farid, Tarek M; Rasheed, Inas A; Thabet, Eman H

    2015-01-01

    Lupus nephritis (LN) is a potentially devastating outcome of systemic lupus erythematosus (SLE). It is important to identify reliable, non-invasive methods to assess the kidneys in patients with SLE. The aim of the study was to measure the level of novel markers of renal involvement in these patients and assess their correlation with disease activity and damage. Sixtyone patients with SLE (33 adults and 28 juvenile) were included in the study. Fifty-two ageand sex-matched healthy individuals served as controls. Full history taking, thorough clinical examination and laboratory investigations were performed and disease activity and damage were assessed for all patients. Renal bio-markers including serum cystatin C, urinary neutrophil gelatinase-associated lipocalin (UNGAL) and N-acetyl-beta-D-glucosaminidase (UNAG) were assessed in patients and controls. There was a significant increase in serum cystatin C, UNGAL and UNAG levels in the adult SLE patients compared with controls (P = 0.000, P = 0.013 and P = 0.018, respectively); serum cystatin C and UNGAL levels were higher in the juvenile patients compared with controls (P = 0.038 and P = 0.000, respectively). Serum cystatin C significantly correlated with the damage index, renal biopsy class and negatively with the serum albumin; UNGAL correlated with albuminuria and the level of nephritis and UNAG negatively correlated with serum albumin level. Our study suggests that serum cystatin C, UNGAL and UNAG are important markers of LN and both cystatin C and UNAG would help in predicting the renal biopsy class.

  11. Standardised extract of Bacopa monniera (CDRI-08) improves contextual fear memory by differentially regulating the activity of histone acetylation and protein phosphatases (PP1α, PP2A) in hippocampus.

    PubMed

    Preethi, Jayakumar; Singh, Hemant K; Venkataraman, Jois Shreyas; Rajan, Koilmani Emmanuvel

    2014-05-01

    Contextual fear conditioning is a paradigm for investigating cellular mechanisms involved in hippocampus-dependent memory. Earlier, we showed that standardised extract of Bacopa monniera (CDRI-08) improves hippocampus-dependent learning in postnatal rats by elevating the level of serotonin (5-hydroxytryptamine, 5-HT), activate 5-HT3A receptors, and cyclic adenosine monophosphate (cAMP) response element binding (CREB) protein. In this study, we have further examined the molecular mechanism of CDRI-08 in hippocampus-dependent memory and compared to the histone deacetylase (HDACs) inhibitor sodium butyrate (NaB). To assess the hippocampus-dependent memory, wistar rat pups were subjected to contextual fear conditioning (CFC) following daily (postnatal days 15-29) administration of vehicle solution (0.5 % gum acacia + 0.9 % saline)/CDRI-08 (80 mg/kg, p.o.)/NaB (1.2 g/kg in PBS, i.p.). CDRI-08/NaB treated group showed enhanced freezing behavior compared to control group when re-exposed to the same context. Administration of CDRI-08/NaB resulted in activation of extracellular signal-regulated kinase ERK/CREB signaling cascade and up-regulation of p300, Ac-H3 and Ac-H4 levels, and down-regulation of HDACs (1, 2) and protein phosphatases (PP1α, PP2A) in hippocampus following CFC. This would subsequently result in an increased brain-derived neurotrophic factor (Bdnf) (exon IV) mRNA in hippocampus. Altogether, our results indicate that CDRI-08 enhances hippocampus-dependent contextual memory by differentially regulating histone acetylation and protein phosphatases in hippocampus.

  12. Standardised extract of Bacopa monniera (CDRI-08) improves contextual fear memory by differentially regulating the activity of histone acetylation and protein phosphatases (PP1α, PP2A) in hippocampus.

    PubMed

    Preethi, Jayakumar; Singh, Hemant K; Venkataraman, Jois Shreyas; Rajan, Koilmani Emmanuvel

    2014-05-01

    Contextual fear conditioning is a paradigm for investigating cellular mechanisms involved in hippocampus-dependent memory. Earlier, we showed that standardised extract of Bacopa monniera (CDRI-08) improves hippocampus-dependent learning in postnatal rats by elevating the level of serotonin (5-hydroxytryptamine, 5-HT), activate 5-HT3A receptors, and cyclic adenosine monophosphate (cAMP) response element binding (CREB) protein. In this study, we have further examined the molecular mechanism of CDRI-08 in hippocampus-dependent memory and compared to the histone deacetylase (HDACs) inhibitor sodium butyrate (NaB). To assess the hippocampus-dependent memory, wistar rat pups were subjected to contextual fear conditioning (CFC) following daily (postnatal days 15-29) administration of vehicle solution (0.5 % gum acacia + 0.9 % saline)/CDRI-08 (80 mg/kg, p.o.)/NaB (1.2 g/kg in PBS, i.p.). CDRI-08/NaB treated group showed enhanced freezing behavior compared to control group when re-exposed to the same context. Administration of CDRI-08/NaB resulted in activation of extracellular signal-regulated kinase ERK/CREB signaling cascade and up-regulation of p300, Ac-H3 and Ac-H4 levels, and down-regulation of HDACs (1, 2) and protein phosphatases (PP1α, PP2A) in hippocampus following CFC. This would subsequently result in an increased brain-derived neurotrophic factor (Bdnf) (exon IV) mRNA in hippocampus. Altogether, our results indicate that CDRI-08 enhances hippocampus-dependent contextual memory by differentially regulating histone acetylation and protein phosphatases in hippocampus. PMID:24610280

  13. The Effect of Part D Coverage Restrictions for Antidepressants, Antipsychotics, and Cholinesterase Inhibitors on Related Nursing Home Resident Outcomes

    PubMed Central

    Stevenson, David G.; O’Malley, A. James; Dusetzina, Stacie B.; Mitchell, Susan L.; Zarowitz, Barbara J.; Chernew, Michael E.; Newhouse, Joseph P.; Huskamp, Haiden A.

    2014-01-01

    Objectives In 2006, Medicare Part D transitioned prescription drug coverage for dual-eligible nursing home residents from Medicaid to Medicare and randomly assigned them to Part D prescription drug plans (PDPs). Because PDPs may differ in coverage, residents’ assigned plans may be relatively more or less restrictive for drugs they take. Taking advantage of the fact that randomization mitigates potential selection bias common in observational studies, this study seeks to assess the impact of PDP coverageon resident outcomes for three medication classes – antidepressants, antipsychotics, and cholinesterase inhibitors. Design, Setting, Participants Using Medicare claims, Minimum Data Set assessments, pharmacy claims, and PDP formulary information, we estimate the impact of coverage restrictions – including non-coverage and coverage with restrictions – on the following outcomes for dual-eligible nursing home residents randomized to PDPs in 2006–2008: depression; hallucinations/delusions; aggressive behaviors; cognitive performance; and activities of daily living. We further adjust for baseline health status to address any residual imbalances in the comparison groups. Results Across 5 outcomes in each of three medication classes of interest, PDP coverage restrictions impacted one resident health outcome: for cholinesterase inhibitor users, coverage restrictions were associated with a 0.04 point lower depression rating score relative to residents facing no restrictions. However, this result was not statistically significant after adjusting for multiple comparisons. Conclusion Our findings suggest that exogenous changes in coverage for three commonly-used medication classes had no detectable impact on nursing home resident health outcomes in 2006–2008. There are several possible explanations for this lack of association, including the role of policy protections for dual-eligible nursing home residents and the possibility that suitable clinical alternatives

  14. Akt-dependent metabolic reprogramming regulates tumor cell histone acetylation

    PubMed Central

    Snyder, Nathaniel W.; Wei, Shuanzeng; Venneti, Sriram; Worth, Andrew J.; Yuan, Zuo-Fei; Lim, Hee-Woong; Liu, Shichong; Jackson, Ellen; Aiello, Nicole M.; Haas, Naomi B.; Rebbeck, Timothy R.; Judkins, Alexander; Won, Kyoung-Jae; Chodosh, Lewis A.; Garcia, Benjamin A.; Stanger, Ben Z.; Feldman, Michael D.; Blair, Ian A.; Wellen, Kathryn E.

    2014-01-01

    SUMMARY Histone acetylation plays important roles in gene regulation, DNA replication, and the response to DNA damage, and it is frequently deregulated in tumors. We postulated that tumor cell histone acetylation levels are determined in part by changes in acetyl-CoA availability mediated by oncogenic metabolic reprogramming. Here, we demonstrate that acetyl-CoA is dynamically regulated by glucose availability in cancer cells and that the ratio of acetyl-CoA: coenzyme A within the nucleus modulates global histone acetylation levels. In vivo, expression of oncogenic Kras or Akt stimulates histone acetylation changes that precede tumor development. Furthermore, we show that Akt's effects on histone acetylation are mediated through the metabolic enzyme ATP-citrate lyase (ACLY), and that pAkt(Ser473) levels correlate significantly with histone acetylation marks in human gliomas and prostate tumors. The data implicate acetyl-CoA metabolism as a key determinant of histone acetylation levels in cancer cells. PMID:24998913

  15. DIFFERENTIAL PROFILES OF CHOLINESTERASE INHIBITION AND NEUROBEHAVIORAL EFFECTS IN RATS EXPOSED TO FENAMIPHOS AND PROFENOPHOS.

    EPA Science Inventory

    The relationship between cholinesterase (ChE) inhibition and neurobehavioral changes was examined using two ChE-inhibiting organophosphorus pesticides, fenamiphos and profenophos. Both pesticides inhibit blood ChE, yet brain ChE is relatively spared (little to no inhibition up t...

  16. Caregiver Acceptance of Adverse Effects and Use of Cholinesterase Inhibitors in Alzheimer's Disease

    ERIC Educational Resources Information Center

    Oremus, Mark; Wolfson, Christina; Vandal, Alain C.; Bergman, Howard; Xie, Qihao

    2007-01-01

    Caregivers play a determining role in choosing treatments for persons with Alzheimer's disease. The objective of this study was to examine caregivers' willingness to have persons with Alzheimer's disease continue taking cholinesterase inhibitors in the event that any 1 of 11 adverse effects was to occur. Data were gathered via postal questionnaire…

  17. Brain cholinesterase inhibition in songbirds from pecan groves sprayed with phosaline and disulfoton

    USGS Publications Warehouse

    White, D.H.; Seginak, J.T.

    1990-01-01

    Disulfoton at 0.83 kg/ha caused moderate to severe brain cholinesterase (ChE) depression in 11 of 15 blue jays collected in pecan groves 6-7 hr after the application. Phosalone at 0.83 kg/ha to pecan groves caused only slight ChE inhibition in a few blue jays and red-bellied