A protein phosphatase 2A (PP2A) inhibition assay using a recombinant enzyme for rapid detection of microcystins

Ikehara, Tsuyoshi; Imamura, Shihoko; Oshiro, Naomasa; Ikehara, Satsuki; Shinjo, Fukiko; Yasumoto, Takeshi

doi:10.1016/j.toxicon.2008.03.003

Cited by 39 publications

(33 citation statements)

References 16 publications

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“…The PP2A assay, which used rhPP2Ac, was performed as previously described (Ikehara et al, 2008). In brief, the assay was performed in 96-well plates.…”

Section: Pp2a Inhibition Assaymentioning

confidence: 99%

Different responses of primary normal human hepatocytes and human hepatoma cells toward cyanobacterial hepatotoxin microcystin-LR

Ikehara

Nakashima

et al. 2015

Toxicon

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“…The PP2A assay, which used rhPP2Ac, was performed as previously described (Ikehara et al, 2008). In brief, the assay was performed in 96-well plates.…”

Section: Pp2a Inhibition Assaymentioning

confidence: 99%

Different responses of primary normal human hepatocytes and human hepatoma cells toward cyanobacterial hepatotoxin microcystin-LR

Ikehara

Nakashima

et al. 2015

Toxicon

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“…[ 12 ] The development of reliable methods for monitoring MC-LR in water resources is of great interest to determine the occurrence and to prevent exposure to the toxin. Several methods have been developed to detect MC-LR, such as high-performance liquid chromatography/mass spectrometry (LC/MS), [ 9 , 13 ] bioassays, [ 14 ] biochemical assays, [ 15 ] and immunoassays, [ 13 ] which require long processing times, sophisticated instruments, complex procedures, or high processing cost [16][17][18][19] and are in general used in the laboratory, not in situ. A sensitive, specifi c, simple, and rapid method for monitoring MC-LR could help to prevent exposure to the toxin.…”

Section: A Multiwalled-carbon-nanotube-based Biosensor For Monitoringmentioning

confidence: 99%

A Multiwalled‐Carbon‐Nanotube‐Based Biosensor for Monitoring Microcystin‐LR in Sources of Drinking Water Supplies

Cui

Doepke

Cho

et al. 2013

Adv Funct Materials

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A multiwalled carbon nanotube (MWCNT)‐based electrochemical biosensor is developed for monitoring microcystin‐LR (MC‐LR), a toxic cyanobacterial toxin, in sources of drinking water supplies. The biosensor electrodes are fabricated using vertically well‐aligned, dense, millimeter‐long MWCNT arrays with a narrow size distribution, grown on patterned Si substrates by water‐assisted chemical vapor deposition. High temperature thermal treatment (2500 °C) in an Ar atmosphere is used to enhance the crystallinity of the pristine materials, followed by electrochemical functionalization in alkaline solution to produce oxygen‐containing functional groups on the MWCNT surface, thus providing the anchoring sites for linking molecules that allow the immobilization of MC‐LR onto the MWCNT array electrodes. Addition of the monoclonal antibodies specific to MC‐LR in the incubation solutions offers the required sensor specificity for toxin detection. The performance of the MWCNT array biosensor is evaluated using micro‐Raman spectroscopy, including polarized Raman measurements, X‐ray photoelectron spectroscopy, cyclic voltammetry, optical microscopy, and Faradaic electrochemical impedance spectroscopy. A linear dependence of the electron‐transfer resistance on the MC‐LR concentration is observed in the range of 0.05 to 20 μg L−1, which enables cyanotoxin monitoring well below the World Health Organization (WHO) provisional concentration limit of 1 μg L−1 for MC‐LR in drinking water.

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“…Previous research has shown that MCs display a potent and specific inhibition of serine/threonine protein phosphatases such as protein phosphatases 1 (PP1) and 2A (PP2A) [17,18]. Bioassays based on the protein phosphatase inhibition have been developed, which provide an attractive way to carry out MCs screening and indicate the toxicity of the sample.…”

Section: Introductionmentioning

confidence: 99%

Pulsed galvanostatic control of a solid-contact ion-selective electrode for potentiometric biosensing of microcystin-LR

Ding

Wang

et al. 2016

Sensors and Actuators B: Chemical

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a b s t r a c tWe report here on the development of a chronopotentiometric assay for microcystin-LR based on enzymatic inhibition. The inhibition of protein phosphatase by microcystin-LR can be sensed potentiometrically by using 4-nitrophenyl phosphate as an enzyme substrate. A solid-contact ion-selective electrode (ISE) with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) as a transduction layer has been designed for potentiometric biosensing using the pulsed galvanastatic technique. By applying an anodic current, the enzymatic generated p-nitrophenol can be extracted into the polymeric membrane with tetradodecylammonium tetrakis(4-chlorophenyl)-borate to produce the chronopotentiometric signal. Meanwhile, a controlled voltage was applied to refresh the membrane for multiple consecutive measurements. The proposed potentiometric assay showed a linear response for microcystin-LR in the range 1-100 g/L with a detection limit of 0.5 g/L (3 ). We believe that the proposed method can be employed for sensitive, rapid and reliable determination of analytes involved in enzyme inhibition.

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A protein phosphatase 2A (PP2A) inhibition assay using a recombinant enzyme for rapid detection of microcystins

Cited by 39 publications

References 16 publications

Different responses of primary normal human hepatocytes and human hepatoma cells toward cyanobacterial hepatotoxin microcystin-LR

Different responses of primary normal human hepatocytes and human hepatoma cells toward cyanobacterial hepatotoxin microcystin-LR

A Multiwalled‐Carbon‐Nanotube‐Based Biosensor for Monitoring Microcystin‐LR in Sources of Drinking Water Supplies

Pulsed galvanostatic control of a solid-contact ion-selective electrode for potentiometric biosensing of microcystin-LR

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