A conformation‐dependent monoclonal antibody against active chicken acetylcholinesterase

Châtel, Jean-Marc; Vallette, François M.; Massoulié, Jean; Grassi, Jacques

doi:10.1016/0014-5793(93)80027-r

Cited by 11 publications

(5 citation statements)

References 16 publications

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“…The remaining 20 -30% of the enzyme molecules become catalytically active and consist of both stable and unstable forms that transit the secretory pathway to the cell surface where they are inserted into cholinergic synapses such as the neuromuscular junction or nicotinic and muscarinic synapses in the central and peripheral nervous systems. These studies were confirmed by Chatel et al (26) using monoclonal antibodies that could distinguish between catalytically active and inactive AChE, and they showed that in chicken brain at least 30% of the AChE was catalytically inactive, an ER resident, and not trafficked in the Golgi apparatus (27). The mechanisms responsible for the activation and stabilization of AChE subunits into catalytically active oligomers are being elucidated.…”

Section: Discussionmentioning

confidence: 77%

Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits

Ruiz

Rossi

Rotundo

2015

Journal of Biological Chemistry

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Background: Most newly synthesized acetylcholinesterase molecules are catalytically inactive and rapidly degraded intracellularly; how this is regulated is not known. Results: The enzyme is stabilized by noncatalytic subunit-derived peptides and is rescued from ERAD degradation. Conclusion: Binding to noncatalytic subunits stabilizes and prevents degradation of acetylcholinesterase in skeletal muscle. Significance: Peptides that stabilize target proteins can potentially be used to increase their expression in vivo.

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Section: Discussionmentioning

confidence: 77%

Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits

Ruiz

Rossi

Rotundo

2015

Journal of Biological Chemistry

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“…The fact that they react with MTP suggests that inactive molecules possess some catalytic activity, with a slower turnover than regular AcChoEase. It is noteworthy that inactive molecules are not recognized by the monoclonal antibody C-131, which appears to be conformation dependent, since its binding is lost together with activity during heat denaturation (24 cosidase H suggests that they are localized in the endoplasmic reticulum. Rotundo et al (9) reported that in chick muscle cultures most of the newly synthesized AcChoEase polypeptides are inactive, sensitive to endoglycosidase H, do not bind WGA, and are rapidly degraded in a nonlysosomal compartment.…”

Section: Discussionmentioning

confidence: 99%

Existence of an inactive pool of acetylcholinesterase in chicken brain.

Châtel

Grassi

Frobert

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

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We analyzed acetyicholinesterase (AcChoEase; EC 3.1.1.7) activity and AcChoEase immunoreactive protein in chicken brain by using five monoclonal antibodies raised against chicken AcChoEase. Four of them specifically recognized AcChoEase catalytic subunits in Western blots and one, C-131, recognized only enzymaticafly active AcChoEase. We observed considerable differences in the ratio of immunoreactive protein to catalytic activity in various fractions, indicating the existence of inactive AcChoEase protein. This inactive AcChoEase component was more abundant in a low-saltsoluble extract than in a subsequent detergent-soluble extract. On the basis of the ratio between activity and immunoreactivity, we calculated that the inactive component represents about 30% of the total AcChoEase subunits in chicken brain. The immunoreactive AcChoEase protein sedimented in sucrose gradients like the active molecular forms; the G1 and G2 peaks contained inactive molecules, whereas the G4 peak appeared to contain only active AcChoEase. The bulk of inactive AcChoEase reacted with the organophosphate cholinesterase inhibitor O-ethyl S-[2-(diisopropylamino)ethylJmethylphosphonothioate (MTP) but was found to bind the active site affinity ligand N-methylacridinium poorly and was not recognized by the active-form-specific monoclonal antibody, C-131. In addition, most of this fraction is sensitive to endoglycosidase H and binds the lectin wheat germ agglutinin poorly, suggesting that it was not processed in the Golgi apparatus. From these observations, we propose that the active and inactive AcChoEase components are differently folded.Acetylcholinesterase (AcChoEase; EC 3.1.1.7) presents a panoply of molecular forms consisting of monomers (Ga), homo-oligomers (dimers, G2, and tetramers, G4), and heterooligomers which incorporate structural as well as catalytic subunits (collagen-tailed or asymmetric forms and hydrophobic-tailed tetramers) (for review, see ref.

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“…It belongs to carboxyl esterase family of enzymes. It is synthesized in the endoplasmic reticulum and is then exported towards the cellular surface, where its different molecular/globular forms may be anchored in plasma membrane, attached to the basal lamina (asymmetric collagen-tailed forms), or secreted as soluble molecules (nonglobular) forms [ 15 ]. It is reported that dimeric (G) AChE forms are present in the human erythrocytes [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity

et al. 2015

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Lead induced neurotoxicity in the people engaged in different occupations has received wide attention but very little studies have been carried out to monitor occupational neurotoxicity directly due to lead exposure using biochemical methods. In the present paper an endeavour has been made in order to assess the lead mediated neurotoxicity by in vitro assay of the activity of acetylcholinesterase (AChE) from human erythrocytes in presence of different concentrations of lead. The results suggested that the activity of this enzyme was localized in membrane bound fraction and it was found to be highly stable up to 30 days when stored at −20°C in phosphate buffer (50 mM, pH 7.4) containing 0.2% Triton X-100. The erythrocyte's AChE exhibited K m for acetylcholinesterase to be 0.1 mM. Lead caused sharp inhibition of the enzyme and its IC50 value was computed to be 1.34 mM. The inhibition of the enzyme by lead was found to be of uncompetitive type (K i value, 3.6 mM) which negatively influenced both the V max and the enzyme-substrate binding affinity. Taken together, these results indicate that AChE from human erythrocytes could be exploited as a surrogate biomarker of lead induced neurotoxicity particularly in the people occupationally exposed to lead.

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A conformation‐dependent monoclonal antibody against active chicken acetylcholinesterase

Cited by 11 publications

References 16 publications

Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits

Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits

Existence of an inactive pool of acetylcholinesterase in chicken brain.

Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity

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