Acetylthiocholine: An agent used as a substrate in assays for cholinesterases, especially to discriminate among enzyme types.Acetylcholinesterase: An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.CholinesterasesTetraisopropylpyrophosphamide: N,N',N'',N'''-Tetraisopropylpyrophosphamide. A specific inhibitor of pseudocholinesterases. It is commonly used experimentally to determine whether pseudo- or acetylcholinesterases are involved in an enzymatic process.Cholinesterase Inhibitors: Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.Thiocholine: A mercaptocholine used as a reagent for the determination of CHOLINESTERASES. It also serves as a highly selective nerve stain.Butyrylcholinesterase: An aspect of cholinesterase (EC 3.1.1.8).Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Kinetics: The rate dynamics in chemical or physical systems.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
(1/38) Histochemically distinct compartments in the striatum of human, monkeys, and cat demonstrated by acetylthiocholinesterase staining.

We here report observations on the distribution of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) in the striatum of the adult human, the rhesus monkey, and the cat. By the histochemical staining methods of Geneser-Jensen and Blackstad and of Karnovsky and Roots, compartments of low cholinesterase activity were identified in parts of the striatum in all three species. In frontal sections, these enzyme-poor zones appeared as a variable number of weakly stained approximately 0.5-mm-wide zones embedded in a darkly stained background. The zones varied in cross-sectional shape from round to elongated and were sometimes branched. They were most prominent in the head of the caudate nucleus. Three-dimensional reconstructions of serial sections through the caudate nucleus in the human and cat suggest that over distances of at least several millimeters, the zones of low enzyme activity form nearly continuous labyrinths.  (+info)

(2/38) Determinants of substrate specificity of a second non-neuronal secreted acetylcholinesterase from the parasitic nematode Nippostrongylus brasiliensis.

We recently reported on a non-neuronal secreted acetylcholinesterase (AChE B) from the nematode parasite Nippostrongylus brasiliensis. Here we describe the primary structure and enzymatic properties of a second secreted variant, termed AChE C after the designation of native AChE isoforms from this parasite. As for the former enzyme, AChE C is truncated at the carboxyl terminus in comparison with the Torpedo AChE, and three of the 14 aromatic residues that line the active site gorge are substituted by nonaromatic residues, corresponding to Tyr70 (Ser), Trp279 (Asn) and Phe288 (Met). A recombinant form of AChE C was highly expressed by Pichia pastoris. The enzyme was monomeric and hydrophilic, and displayed a marked preference for acetylthiocholine as substrate. A double mutation (W302F/W345F, corresponding to positions 290 and 331 in Torpedo) rendered the enzyme 10-fold less sensitive to excess substrate inhibition and two times less susceptible to the bis quaternary inhibitor BW284C51, but did not radically affect substrate specificity or sensitivity to the 'peripheral site' inhibitor propidium iodide. In contrast, a triple mutant (M300G/W302F/W345F) efficiently hydrolysed propionylthiocholine and butyrylthiocholine in addition to acetylthiocholine, while remaining insensitive to the butyrylcholinesterase-specific inhibitor iso-OMPA and displaying a similar profile of excess substrate inhibition as the double mutant. These data highlight a conserved pattern of active site architecture for nematode secreted AChEs characterized to date, and provide an explanation for the substrate specificity that might otherwise appear inconsistent with the primary structure in comparison to other invertebrate AChEs.  (+info)

(3/38) High-resolution optical mapping of the right bundle branch in connexin40 knockout mice reveals slow conduction in the specialized conduction system.

Connexin40 (Cx40) is a major gap junction protein that is expressed in the His-Purkinje system and thought to be a critical determinant of cell-to-cell communication and conduction of electrical impulses. Video maps of the ventricular epicardium and the proximal segment of the right bundle branch (RBB) were obtained using a high-speed CCD camera while simultaneously recording volume-conducted ECGs. In Cx40(-/-) mice, the PR interval was prolonged (47.4+/-1.4 in wild-type [WT] [n=6] and 57.5+/-2.8 in Cx40(-/-) [n=6]; P<0.01). WT ventricular epicardial activation was characterized by focused breakthroughs that originated first on the right ventricle (RV) and then the left ventricle (LV). In Cx40(-/-) hearts, the RV breakthrough occurred after the LV breakthrough. Additionally, Cx40(-/-) mice showed RV breakthrough times that were significantly delayed with respect to QRS complex onset (3.7+/-0.7 ms in WT [n=6] and 6.5+/-0.7 ms in Cx40(-/-) [n=6]; P<0.01), whereas LV breakthrough times did not change. Conduction velocity measurements from optical mapping of the RBB revealed slow conduction in Cx40(-/-) mice (74.5+/-3 cm/s in WT [n=7] and 43.7+/-6 cm/s in Cx40(-/-) [n=7]; P<0.01). In addition, simultaneous ECG records demonstrated significant delays in Cx40(-/-) RBB activation time with respect to P time (P-RBB time; 41.6+/-1.9 ms in WT [n=7] and 55.1+/-1.3 ms in [n=7]; P<0.01). These data represent the first direct demonstration of conduction defects in the specialized conduction system of Cx40(-/-) mice and provide new insight into the role of gap junctions in cardiac impulse propagation.  (+info)

(4/38) Action potential characteristics and arrhythmogenic properties of the cardiac conduction system of the murine heart.

Studies have characterized conduction velocity in the right and left bundle branches (RBB, LBB) of normal and genetically engineered mice. However, no information is available on the action potential characteristics of the specialized conduction system (SCS). We have used microelectrode techniques to characterize action potential properties of the murine SCS, as well as epicardial and endocardial muscle preparations for comparison. In the RBB, action potential duration at 50%, 70%, and 90% repolarization (APD(50,70,90)) was 6+/-0.7, 35+/-6, and 90+/-7 ms, respectively. Maximum upstroke velocity (dV/dt(max)) was 153+/-14 V/s, and conduction velocity averaged 0.85+/-0.2 m/s. APD(90) was longer in the Purkinje network of fibers (web) than in the RBB (P<0.01). Web APD(50) was longer in the left than in the right ventricle (P<0.05). Yet, web APD(90) was longer in the right than in the left ventricle (P<0.001). APD(50,70) was significantly longer in the endocardial than in the epicardial (P<0.001; P<0.003). APD(90) in the epicardial and endocardial was shorter than in the RBB ( approximately 36 ms versus approximately 100 ms). Spontaneous electrical oscillations in phase 2 of the SCS occasionally resulted in early afterdepolarizations. These results demonstrate that APDs in the murine SCS are significantly ( approximately 2-fold) longer than in the myocardium and implicate the role of the murine SCS in arrhythmias. The differences should have important implications in the use of the mouse heart to study excitation, propagation, and arrhythmias.  (+info)

(5/38) Reversibly bound and covalently attached ligands induce conformational changes in the omega loop, Cys69-Cys96, of mouse acetylcholinesterase.

We have used a combination of cysteine substitution mutagenesis and site-specific labeling to characterize the structural dynamics of mouse acetylcholinesterase (mAChE). Six cysteine-substituted sites of mAChE (Leu(76), Glu(81), Glu(84), Tyr(124), Ala(262), and His(287)) were labeled with the environmentally sensitive fluorophore, acrylodan, and the kinetics of substrate hydrolysis and inhibitor association were examined along with spectroscopic characteristics of the acrylodan-conjugated, cysteine-substituted enzymes. Residue 262, being well removed from the active center, appears unaffected by inhibitor binding. Following the binding of ligand, hypsochromic shifts in emission of acrylodan at residues 124 and 287, located near the perimeter of the gorge, reflect the exclusion of solvent and a hydrophobic environment created by the associated ligand. By contrast, the bathochromic shifts upon inhibitor binding seen for acrylodan conjugated to three omega loop (Omega loop) residues 76, 81, and 84 reveal that the acrylodan side chains at these positions are displaced from a hydrophobic environment and become exposed to solvent. The magnitude of fluorescence emission shift is largest at position 84 and smallest at position 76, indicating that a concerted movement of residues on the Omega loop accompanies gorge closure upon ligand binding. Acrylodan modification of substituted cysteine at position 84 reduces ligand binding and steady-state kinetic parameters between 1 and 2 orders of magnitude, but a similar substitution at position 81 only minimally alters the kinetics. Thus, combined kinetic and spectroscopic analyses provide strong evidence that conformational changes of the Omega loop accompany ligand binding.  (+info)

(6/38) Asymmetric distribution of acetylcholinesterase in gravistimulated maize seedlings.

Acetylcholinesterase (AChE) activity has previously been studied by this laboratory and shown to occur at the interface between the stele and cortex of the mesocotyl of maize (Zea mays L.) seedlings. In this work we studied the distribution of AChE activity in 5-d-old maize seedlings following a gravity stimulus. After the stimulus, we found an asymmetric distribution of the enzyme in the coleoptile, the coleoptile node, and the mesocotyl of the stimulated seedlings using both histochemical and colorimetric methods for measuring the hydrolysis of acetylthiocholine. The hydrolytic capability of the esterase was greater on the lower side of the horizontally placed seedlings. Using the histochemical method, we localized the hydrolytic capability in the cortical cells around the vascular stele of the tissues. The hydrolytic activity was inhibited 80 to 90% by neostigmine, an inhibitor of AChE. When neostigmine was applied to the corn kernel, the gravity response of the seedling was inhibited and no enzyme-positive spots appeared in the gravity-stimulated seedlings. We believe these results indicate a role for AChE in the gravity response of maize seedlings.  (+info)

(7/38) Studies of the acetylcholinesterase from houseflies (Musca domestica L.) resistant and susceptible to organophosphorus insecticides.

Acetylcholinesterase from the heads of insecticide-resistant and -susceptible houseflies (Musca domestica L.) was studied in vitro. The enzymes could not be distinguished electrophoretically, and their behaviour on polyacrylamide-disc-gel electrophoresis was influenced by the presence of Triton X-100 in both the homogenate and the gels. In the absence of detergent, the acetylcholinesterase was heterogeneous, but behaved as a single enzyme when it was present. By analogy with studies of acetylcholinesterase from other sources, these observations were attributed to aggregation of the enzyme when not bound by membranes. The enzyme from resistant flies was more slowly inhibited than the susceptible enzyme, bimolecular rate constants (ki) differing by approx. 4-20-fold for a range of organophosphorus compounds. The kinetics of inhibition of acetylcholinesterase were consistent with the results of electrophoresis, i.e. they corresponded to those of a single enzyme in the presence of Triton X-100, but a mixture of enzymes in its absence. The susceptibility of the more sensitive components in these mixtures was determined.  (+info)

(8/38) Substrate activation in acetylcholinesterase induced by low pH or mutation in the pi-cation subsite.

Substrate inhibition is considered a defining property of acetylcholinesterase (AChE), whereas substrate activation is characteristic of butyrylcholinesterase (BuChE). To understand the mechanism of substrate inhibition, the pH dependence of acetylthiocholine hydrolysis by AChE was studied between pH 5 and 8. Wild-type human AChE and its mutants Y337G and Y337W, as well as wild-type Bungarus fasciatus AChE and its mutants Y333G, Y333A and Y333W were studied. The pH profile results were unexpected. Instead of substrate inhibition, wild-type AChE and all mutants showed substrate activation at low pH. At high pH, there was substrate inhibition for wild-type AChE and for the mutant with tryptophan in the pi-cation subsite, but substrate activation for mutants containing small residues, glycine or alanine. This is particularly apparent in the B. fasciatus AChE. Thus a single amino acid substitution in the pi-cation site, from the aromatic tyrosine of B. fasciatus AChE to the alanine of BuChE, caused AChE to behave like BuChE. Excess substrate binds to the peripheral anionic site (PAS) of AChE. The finding that AChE is activated by excess substrate supports the idea that binding of a second substrate molecule to the PAS induces a conformational change that reorganizes the active site.  (+info)

*  List of MeSH codes (D02)
... acetylthiocholine MeSH D02.675.276.232.800.200 --- butyrylthiocholine MeSH D02.675.276.352 --- edrophonium MeSH D02.675.276.370 ... acetylthiocholine MeSH D02.092.877.883.333.800.200 --- butyrylthiocholine MeSH D02.092.877.883.555 --- methacholine compounds ...
Sensors | Free Full-Text | Critical Evaluation of Acetylthiocholine Iodide and Acetylthiocholine Chloride as Substrates for...  Sensors | Free Full-Text | Critical Evaluation of Acetylthiocholine Iodide and Acetylthiocholine Chloride as Substrates for...
We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our ... is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine ... investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be ... Keywords: acetylthiocholine iodide; acetylthiocholine chloride; amperometry; acetylcholinesterase acetylthiocholine iodide; ...
more infohttp://mdpi.com/1424-8220/13/2/1603/xml
Immunodetection of Serum Albumin Adducts as Biomarkers for Organophosphorus Exposure | Journal of Pharmacology and Experimental...  Immunodetection of Serum Albumin Adducts as Biomarkers for Organophosphorus Exposure | Journal of Pharmacology and Experimental...
1 mM acetylthiocholine, 1 mM 5,5′-dithiobis-(2-nitrobenzoic acid) in 50 mM PBS buffer, pH 7.4]. Absorbance change of 5,5′- ...
more infohttp://jpet.aspetjournals.org/content/344/2/531.long
Preliminary investigation on cholinesterase activity in Adamussium colbecki from Terra Nova Bay: field and laboratory study |...  Preliminary investigation on cholinesterase activity in Adamussium colbecki from Terra Nova Bay: field and laboratory study |...
Characterization of various ChE enzymes using specific substrates including an acetylthiocholine iodide (ASCh) and a ... Characterization of various ChE enzymes using specific substrates including an acetylthiocholine iodide (ASCh) and a ...
more infohttps://iris.unige.it/handle/11567/213053
Acetylthiocholine chloride ≥99% (TLC), powder | Sigma-Aldrich  Acetylthiocholine chloride ≥99% (TLC), powder | Sigma-Aldrich
Acetylthiocholine chloride for your research needs. Find product specific information including CAS, MSDS, protocols and ...
more infohttps://www.sigmaaldrich.com/catalog/product/sigma/a5626?lang=en®ion=US
AID 1097367 - Inhibition of AChE in po dosed Charles Foster albino Rattus norvegicus (rat) assessed as hydrolysis of...  AID 1097367 - Inhibition of AChE in po dosed Charles Foster albino Rattus norvegicus (rat) assessed as hydrolysis of...
... assessed as hydrolysis of acetylthiocholine iodide per mg of protein in hypothalamus administered qd for 7 days measured 1 hr ...
more infohttps://pubchem.ncbi.nlm.nih.gov/bioassay/1097367
AID 1070082 - Inhibition of human erythrocyte acetylcholinesterase using acetylthiocholine chloride as substrate preincubated...  AID 1070082 - Inhibition of human erythrocyte acetylcholinesterase using acetylthiocholine chloride as substrate preincubated...
Inhibition of human erythrocyte acetylcholinesterase using acetylthiocholine chloride as substrate preincubated for 15 mins ...
more infohttps://pubchem.ncbi.nlm.nih.gov/bioassay/1070082
RCSB PDB - AT3 Ligand Summary Page  RCSB PDB - AT3 Ligand Summary Page
ACETYLTHIOCHOLINE. AT3 as a free ligand exists in 3 entries. Examples include: 2HA5 2C58 2C4H ...
more infohttp://www.rcsb.org/ligand/AT3
RCSB PDB - Launch Viewer 









for 2HA5  RCSB PDB - Launch Viewer for 2HA5
Crystal structure of mutant S203A of acetylcholinesterase complexed with acetylthiocholine. Display Files *FASTA Sequence ...
more infohttp://www.rcsb.org/pdb/explore/viewerLaunch.do?viewerType=SV&structureId=2HA5&unit=bio&unit_id=1
Sensors | Free Full-Text | Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical...  Sensors | Free Full-Text | Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical...
Keywords: acetylcholinesterase; organophosphorus compounds; pesticides; thiocholine; acetylthiocholine; nanomaterials ...
more infohttp://www.mdpi.com/1424-8220/9/6/4034
Neuroprotective Effect of Phyllanthus acidus L. on Learning and Memory Impairment in Scopolamine-Induced Animal Model of...  Neuroprotective Effect of Phyllanthus acidus L. on Learning and Memory Impairment in Scopolamine-Induced Animal Model of...
Acetyl thiocholine iodide (ATCI), 5,5-dithiobis-2-nitrobenzoate ion (DTNB), trisfamino methane hydrochloride (Tris-HCl), bovine ...
more infohttps://www.scirp.org/journal/PaperInformation.aspx?PaperID=67408
Patent US5185350 - Substituted pyridinylamino-1h-indoles,1h-indazoles,2h-indazoles, benzo (b ... - Google Patents  Patent US5185350 - Substituted pyridinylamino-1h-indoles,1h-indazoles,2h-indazoles, benzo (b ... - Google Patents
a) 198 mg acetylthiocholine chloride (10 mM). (b) bring to 100 ml with 0.05M phosphate buffer, pH 7.2 ...
more infohttp://www.google.com/patents/US5185350
AChR Activators | SCBT - Santa Cruz Biotechnology  AChR Activators | SCBT - Santa Cruz Biotechnology
Acetylthiocholine chloride A substrate for acetylcholinesterase 6050-81-3. sc-257066 sc-257066A 1 g. 5 g. $65.00 $245.00 0 ... Acetylthiocholine iodide A nAChR agonist and substrate of acetylcholinesterase 1866-15-5. sc-208323 sc-208323A sc-208323B sc- ...
more infohttps://www.scbt.com/scbt/browse/AChR-Activators/_/N-1emufxw
Plus it  Plus it
... acetylthiocholine (ASCh; □), or choline (chol; ▴). Log EC50 values and Hill coefficients (± S.E.M.) are provided in Table 2, ... and perhaps acetylthiocholine; and very weak potency for choline (Fig. 7, Table 2). Lobeline (not shown) and succinylcholine ... 100 μM acetylthiocholine (75%) » 3.8 mM (estimated) choline (22% at 1 mM). Self-inhibitory IC50 values were also determined for ... 7.1 μM acetylthiocholine » 290 μM choline. Lobeline (IC50 = 76 nM) had ligand binding competition potency greater than any ...
more infohttp://molpharm.aspetjournals.org/content/64/6/1283
Spectral Database Index:
        ATR-IR - Standards 3 - Bio‑Rad Sadtler  Spectral Database Index: ATR-IR - Standards 3 - Bio‑Rad Sadtler
Acetylthiocholine iodide. Adenosine-5'-triphosphoric acid, disodium salt. Allophanic acid amide; Carbamoylurea. ...
more infohttp://www.knowitall.com/literature/indices/Spectral_Index.asp?cc=STW3X
Neuroprotective Effect of Phyllanthus acidus L. on Learning and Memory Impairment in Scopolamine-Induced Animal Model of...  Neuroprotective Effect of Phyllanthus acidus L. on Learning and Memory Impairment in Scopolamine-Induced Animal Model of...
Acetyl thiocholine iodide (ATCI), 5,5-dithiobis-2-nitrobenzoate ion (DTNB), trisfamino methane hydrochloride (Tris-HCl), bovine ...
more infohttps://file.scirp.org/Html/4-2440130_67408.htm
Experimental Applications | Springer for Research & Development  Experimental Applications | Springer for Research & Development
A DNA sequence encoding the brain and muscle form of human AChE (AChE-T) was constructed in our laboratory from cloned cDNA and genomic sequences, and tentatively identified by its homology to known...
more infohttps://rd.springer.com/protocol/10.1385/0-89603-457-7%3A89
SCOPe 2.07: Structural Classification of Proteins - extended  SCOPe 2.07: Structural Classification of Proteins - extended
Description: torpedo californica acetylcholinesterase in complex with 500mm acetylthiocholine. Class: hydrolase. Keywords: ...
more infohttps://scop.berkeley.edu/pdb/code=2c4h
Molecules  | Free Full-Text | Why is Aged Acetylcholinesterase So Difficult to Reactivate? | HTML  Molecules | Free Full-Text | Why is Aged Acetylcholinesterase So Difficult to Reactivate? | HTML
... acetylthio)choline. J. Am. Chem. Soc. 2000, 122, 2981-2987. [Google Scholar] [CrossRef] ... Consider the acylation transition state for AChE catalyzed hydrolysis of acetylthiocholine (ATCh). By measuring β-deuterium ... A secondary isotope effect study of equine serum butyrylcholinesterase-catalyzed hydrolysis of acetylthiocholine. Chem. Biol. ... The reactant state for substrate-activated turnover of acetylthiocholine by butyrylcholinesterase is a tetrahedral intermediate ...
more infohttps://www.mdpi.com/1420-3049/22/9/1464/htm
Products A-Z › Products › SERVA Electrophoresis GmbH  Products A-Z › Products › SERVA Electrophoresis GmbH
Using the Quick Order field, you can add a product to your shopping cart with just one click. All you have to do: enter the Cat.No. as shown in our catalog in the format xxxxx.yy and click the Go!-Button.. ...
more infohttps://www.serva.de/enDE/213_Products_Products_A_Z.html
Hetero compounds with composition C H N O S  Hetero compounds with composition C H N O S
... acetylthiocholine; 2-(((1s)-1-hydroxyethyl)thio)-n,n,n- trimethylethanaminium Get C7 H16 N2 O2 S = bbc = 3-((4-aminobutyl) ...
more infohttp://xray.bmc.uu.se/hicup/comp/C_H_N_O_S_comp.html