A sulfur-containing analog of butyrylcholine which is hydrolyzed by butyrylcholinesterase to butyrate and thiocholine. It is used as a reagent in the determination of butyrylcholinesterase activity.
An aspect of cholinesterase (EC 3.1.1.8).
A mercaptocholine used as a reagent for the determination of CHOLINESTERASES. It also serves as a highly selective nerve stain.
The benzoic acid ester of choline.
An agent used as a substrate in assays for cholinesterases, especially to discriminate among enzyme types.
Cholinesterases are a group of enzymes that catalyze the hydrolysis of acetylcholine and other choline esters, playing crucial roles in the termination of impulse transmission at cholinergic synapses and neuro-muscular junctions, and in the metabolism of certain drugs and toxic substances.
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.
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.
The rate dynamics in chemical or physical systems.

Interaction between the peripheral site residues of human butyrylcholinesterase, D70 and Y332, in binding and hydrolysis of substrates. (1/19)

Human butyrylcholinesterase displays substrate activation with positively charged butyrylthiocholine (BTC) as the substrate. Peripheral anionic site (PAS) residues D70 and Y332 appear to be involved in the initial binding of charged substrates and in activation control. To determine the contribution of PAS residues to binding and hydrolysis of quaternary substrates and activation control, the single mutants D70G/Y and Y332F/A/D and the double mutants Y332A/D70G and Y332D/D70Y were studied. Steady-state hydrolysis of the charged substrates, BTC and succinyldithiocholine, and the neutral ester o-nitrophenyl butyrate was measured. In addition, inhibition of wild-type and mutant enzymes by tetramethylammonium was investigated, at low concentrations of BTC. Single and double mutants of D70 and Y332 showed little or no substrate activation, suggesting that both residues were important for activation control. The effects of double mutations on D70 and Y332 were complex. Double-mutant cycle analysis provided evidence for interaction between these residues. The category of interaction (either synergistic, additive, partially additive or antagonistic) was found to depend on the nature of the substrate and on measured binding or kinetic parameters. This complexity reflects both the cross-talk between residues involved in the sequential formation of productive Michaelian complexes and the effect of peripheral site residues on catalysis. It is concluded that double mutations on the PAS induce a conformational change in the active site gorge of butyrylcholinesterase that can alter both substrate binding and enzyme acylation.  (+info)

Differential effect of pressure and temperature on the catalytic behaviour of wild-type human butyrylcholinesterase and its D70G mutant. (2/19)

The combined action of temperature (10-35 degrees C) and pressure (0. 001-2 kbar) on the catalytic activity of wild-type human butyrylcholinesterase (BuChE) and its D70G mutant was investigated at pH 7.0 using butyrylthiocholine as the substrate. The residue D70, located at the mouth of the active site gorge, is an essential component of the peripheral substrate binding site of BuChE. Results showed a break in Arrhenius plots of wild-type BuChE (at Tt approximately 22 degrees C) whatever the pressure (dTt/dP = 1.6 +/- 1.5 degrees C.kbar-1), whereas no break was observed in Arrhenius plots of the D70G mutant. These results suggested a temperature-induced conformational change of the wild-type BuChE which did not occur for the D70G mutant. For the wild-type BuChE, at around a pressure of 1 kbar, an intermediate state, whose affinity for substrate was increased, appeared. This intermediate state was not seen for the mutant enzyme. The wild-type BuChE remained active up to a pressure of 2 kbar whatever the temperature, whereas the D70G mutant was found to be more sensitive to pressure inactivation (at pressures higher than 1.5 kbar the mutant enzyme lost its activity at temperatures lower than 25 degrees C). The results indicate that the residue D70 controls the conformational plasticity of the active site gorge of BuChE, and is involved in regulation of the catalytic activity as a function of temperature.  (+info)

Concentration-dependent reversible activation-inhibition of human butyrylcholinesterase by tetraethylammonium ion. (3/19)

Tetraalkylammonium (TAA) salts are well known reversible inhibitors of cholinesterases. However, at concentrations around 10 mm, they have been found to activate the hydrolysis of positively charged substrates, catalyzed by wild-type human butyrylcholinesterase (EC 3.1.1.8) [Erdoes, E.G., Foldes, F.F., Zsigmond, E.K., Baart, N. & Zwartz, J.A. (1958) Science 128, 92]. The present study was undertaken to determine whether the peripheral anionic site (PAS) of human BuChE (Y332, D70) and/or the catalytic substrate binding site (CS) (W82, A328) are involved in this phenomenon. For this purpose, the kinetics of butyrylthiocholine (BTC) hydrolysis by wild-type human BuChE, by selected mutants and by horse BuChE was carried out at 25 degreeC and pH 7.0 in the presence of tetraethylammonium (TEA). It appears that human enzymes with more intact structure of the PAS show more prominent activation phenomenon. The following explanation has been put forward: TEA competes with the substrate at the peripheral site thus inhibiting the substrate hydrolysis at the CS. As the inhibition by TEA is less effective than the substrate inhibition itself, it mimics activation. At the concentrations around 40 mm, well within the range of TEA competition at both substrate binding sites, it lowers the activity of all tested enzymes.  (+info)

High activity of human butyrylcholinesterase at low pH in the presence of excess butyrylthiocholine. (4/19)

Butyrylcholinesterase is a serine esterase, closely related to acetylcholinesterase. Both enzymes employ a catalytic triad mechanism for catalysis, similar to that used by serine proteases such as alpha-chymotrypsin. Enzymes of this type are generally considered to be inactive at pH values below 5, because the histidine member of the catalytic triad becomes protonated. We have found that butyrylcholinesterase retains activity at pH +info)

An evaluation of the inhibition of human butyrylcholinesterase and acetylcholinesterase by the organophosphate chlorpyrifos oxon. (5/19)

 (+info)

ENZO: a web tool for derivation and evaluation of kinetic models of enzyme catalyzed reactions. (6/19)

 (+info)

The proline-rich tetramerization peptides in equine serum butyrylcholinesterase. (7/19)

 (+info)

Molecular and kinetic properties of two acetylcholinesterases from the western honey bee, Apis mellifera. (8/19)

 (+info)

Butyrylthiocholine is a synthetic chemical compound that is often used in scientific research, particularly in the study of enzymes and neurotransmitters. It is the substrate for the enzyme butyrylcholinesterase, which is found in the blood and helps to break down certain types of drugs and neurotransmitters.

In biochemical terms, butyrylthiocholine is a choline ester of butyric acid, with a thio (sulfur) group replacing one of the oxygen atoms in the ester linkage. This structural feature makes it an excellent substrate for butyrylcholinesterase, as the sulfur atom can form a covalent bond with the enzyme's active site, leading to rapid and specific catalysis.

It is important to note that butyrylthiocholine itself does not have any direct medical relevance, but rather serves as a tool for studying the mechanisms of enzymes and other biological processes.

Butyrylcholinesterase (BChE) is an enzyme that catalyzes the hydrolysis of esters of choline, including butyrylcholine and acetylcholine. It is found in various tissues throughout the body, including the liver, brain, and plasma. BChE plays a role in the metabolism of certain drugs and neurotransmitters, and its activity can be inhibited by certain chemicals, such as organophosphate pesticides and nerve agents. Elevated levels of BChE have been found in some neurological disorders, while decreased levels have been associated with genetic deficiencies and liver disease.

Thiocholine is not a medical term per se, but it is a chemical compound that has applications in the medical and biological fields. Thiocholine is the reduced form of thiochrome, which is a derivative of vitamin B1 (thiamine). It is often used as a reagent in biochemical assays to measure the activity of acetylcholinesterase, an enzyme that breaks down the neurotransmitter acetylcholine.

In this context, thiocholine iodide (S-[2-(hydroxyethyl)thio]ethan-1-oniuim iodide) is commonly used as a substrate for acetylcholinesterase. When the enzyme hydrolyzes thiocholine iodide, it produces thiocholine, which can be detected and quantified through its reaction with ferric chloride to form a colored complex. This assay is useful in diagnosing certain neurological conditions or monitoring the effectiveness of treatments that target the cholinergic system.

Benzoylcholine, also known as benzoylcholine or physostigmine salicylate, is not a medical term commonly used to define a specific medical condition or disease. Instead, it is a chemical compound that has been used in medical research and some therapeutic applications.

Benzoylcholine is a synthetic derivative of physostigmine, a natural alkaloid found in the Calabar bean. Physostigmine is an inhibitor of acetylcholinesterase, an enzyme that breaks down the neurotransmitter acetylcholine in the body. Benzoylcholine also acts as an inhibitor of acetylcholinesterase and has been used in research to study the cholinergic system, which is involved in various physiological processes such as memory, attention, and muscle contraction.

In clinical settings, benzoylcholine has been used as a diagnostic tool to test for myasthenia gravis, a neuromuscular disorder characterized by weakness and fatigue of the skeletal muscles. The administration of benzoylcholine in patients with myasthenia gravis can cause a transient worsening of symptoms due to the accumulation of acetylcholine at the neuromuscular junction.

It is important to note that benzoylcholine should only be used under medical supervision and its use is generally limited to research or diagnostic settings.

Acetylthiocholine is a synthetic chemical compound that is widely used in scientific research, particularly in the field of neuroscience. It is the acetylated form of thiocholine, which is a choline ester. Acetylthiocholine is often used as a substrate for enzymes called cholinesterases, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE).

When Acetylthiocholine is hydrolyzed by AChE, it produces choline and thioacetic acid. This reaction is important because it terminates the signal transduction of the neurotransmitter acetylcholine at the synapse between neurons. Inhibition of AChE can lead to an accumulation of Acetylthiocholine and acetylcholine, which can have various effects on the nervous system, depending on the dose and duration of inhibition.

Acetylthiocholine is also used as a reagent in the Ellman's assay, a colorimetric method for measuring AChE activity. In this assay, Acetylthiocholine is hydrolyzed by AChE, releasing thiocholine, which then reacts with dithiobisnitrobenzoic acid (DTNB) to produce a yellow color. The intensity of the color is proportional to the amount of thiocholine produced and can be used to quantify AChE activity.

Cholinesterases are a group of enzymes that play an essential role in the nervous system by regulating the transmission of nerve impulses. They work by breaking down a type of chemical messenger called acetylcholine, which is released by nerves to transmit signals to other nerves or muscles.

There are two main types of cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). AChE is found primarily in the nervous system, where it rapidly breaks down acetylcholine to terminate nerve impulses. BChE, on the other hand, is found in various tissues throughout the body, including the liver and plasma, and plays a less specific role in breaking down various substances, including some drugs and toxins.

Inhibition of cholinesterases can lead to an accumulation of acetylcholine in the synaptic cleft, which can result in excessive stimulation of nerve impulses and muscle contractions. This effect is exploited by certain medications used to treat conditions such as myasthenia gravis, Alzheimer's disease, and glaucoma, but can also be caused by exposure to certain chemicals or toxins, such as organophosphate pesticides and nerve agents.

Acetylcholinesterase (AChE) is an enzyme that catalyzes the hydrolysis of acetylcholine (ACh), a neurotransmitter, into choline and acetic acid. This enzyme plays a crucial role in regulating the transmission of nerve impulses across the synapse, the junction between two neurons or between a neuron and a muscle fiber.

Acetylcholinesterase is located in the synaptic cleft, the narrow gap between the presynaptic and postsynaptic membranes. When ACh is released from the presynaptic membrane and binds to receptors on the postsynaptic membrane, it triggers a response in the target cell. Acetylcholinesterase rapidly breaks down ACh, terminating its action and allowing for rapid cycling of neurotransmission.

Inhibition of acetylcholinesterase leads to an accumulation of ACh in the synaptic cleft, prolonging its effects on the postsynaptic membrane. This can result in excessive stimulation of cholinergic receptors and overactivation of the cholinergic system, which may cause a range of symptoms, including muscle weakness, fasciculations, sweating, salivation, lacrimation, urination, defecation, bradycardia, and bronchoconstriction.

Acetylcholinesterase inhibitors are used in the treatment of various medical conditions, such as Alzheimer's disease, myasthenia gravis, and glaucoma. However, they can also be used as chemical weapons, such as nerve agents, due to their ability to disrupt the nervous system and cause severe toxicity.

Cholinesterase inhibitors are a class of drugs that work by blocking the action of cholinesterase, an enzyme that breaks down the neurotransmitter acetylcholine in the body. By inhibiting this enzyme, the levels of acetylcholine in the brain increase, which can help to improve symptoms of cognitive decline and memory loss associated with conditions such as Alzheimer's disease and other forms of dementia.

Cholinesterase inhibitors are also used to treat other medical conditions, including myasthenia gravis, a neuromuscular disorder that causes muscle weakness, and glaucoma, a condition that affects the optic nerve and can lead to vision loss. Some examples of cholinesterase inhibitors include donepezil (Aricept), galantamine (Razadyne), and rivastigmine (Exelon).

It's important to note that while cholinesterase inhibitors can help to improve symptoms in some people with dementia, they do not cure the underlying condition or stop its progression. Side effects of these drugs may include nausea, vomiting, diarrhea, and increased salivation. In rare cases, they may also cause seizures, fainting, or cardiac arrhythmias.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

... butyrylthiocholine MeSH D02.092.877.883.555 - methacholine compounds MeSH D02.092.877.883.555.500 - methacholine chloride MeSH ... butyrylthiocholine MeSH D02.675.276.352 - edrophonium MeSH D02.675.276.370 - emepronium MeSH D02.675.276.400 - gallamine ...
... butyrylthiocholine iodide, 5,5-dithiobis-[2-nitrobenzoic acid] (DTNB) and eserine had been purchased from Sigma-Aldrich Co. ... butyrylthiocholine iodide, 5,5-dithiobis-[2-nitrobenzoic acid] (DTNB) and eserineSerum, acetylthiocholine iodide, ... Serum, acetylthiocholine iodide, butyrylthiocholine iodide, 5,5-dithiobis-[2-nitrobenzoic acid] (DTNB) and eserine had been ... Serum, acetylthiocholine iodide, butyrylthiocholine iodide, 5,5-dithiobis-[2-nitrobenzoic acid] (DTNB) and eserineSerum, ...
Substrates for the assay included acetylthiocholine (ATC) and butyrylthiocholine (BTC). The lung homogenates were then ...
... butyrylthiocholine MeSH D02.092.877.883.555 - methacholine compounds MeSH D02.092.877.883.555.500 - methacholine chloride MeSH ... butyrylthiocholine MeSH D02.675.276.352 - edrophonium MeSH D02.675.276.370 - emepronium MeSH D02.675.276.400 - gallamine ...
Butyrylthiocholine D2.886.489.789.200. CADASIL C14.907.253.337.187 C10.228.140.380.230.124. Caffeine D3.132.960.175. ...
Butyrylthiocholine D2.886.489.789.200. CADASIL C14.907.253.337.187 C10.228.140.380.230.124. Caffeine D3.132.960.175. ...
The normal range for propionylthiocholine is 1700-4100 U/L and for butyrylthiocholine iodide is 3500-8500 U/L. All the school ... Assay methods used for plasma cholinesterase activity are the use of propionylthiocholine or butyrylthiocholine iodide as ... When the normal assay methods for plasma cholinesterase activity using propionylthiocholine (PTC) and butyrylthiocholine iodide ... and butyrylthiocholine iodide (BTCI) methods had whole blood cholinesterase activity between 0.013?pH/min and 0.020?pH/min when ...
Development of a thin film assay for serum cholinesterase using butyrylthiocholine as substrate Clinical Chemistry 37(6): 966. ...
including acetylcholine (ACh) and butyrylthiocholine (BTC), are close Vactosertib ic50 to those of the corresponding wild-type ...
... butyrylthiocholine, propionylthiocholine) on cholinesterase activity and determine the kinetic parameters (Vmax and Km ). The ...
Goat Purified Anti-serum to Human Apolipoprotein A2 specific. Preservative: 0.09% Sodium Azide.The serum is polyclonal, delipidated and monospecific by immunoelectrophoresis.. ...
S-Butyrylthiocholine Iodide crystallizate Use S-Butyrylthiocholine Iodide in diagnostic tests for the determination of ...
Butyrylthiocholine D2.886.489.789.200. CADASIL C14.907.253.337.187 C10.228.140.380.230.124. Caffeine D3.132.960.175. ...
... using butyrylthiocholine -BuChE- and benzoylcholine -BeChE- as substrates. The study population consisted of intensive ...
Substrates for the assay included acetylthiocholine (ATC) and butyrylthiocholine (BTC). The lung homogenates were then ...
A sample of the patients plasma is incubated with the substrate butyrylthiocholine, along with the indicator chemical 5,5- ...
3. [Cholinesterase (EC 3.1.1.8) with butyrylthiocholine-iodide as substrate: references depending on age and sex with special ...
S-Butyrylthiocholine Iodide Narrower Concept UI. M0003117. Registry Number. 0. Terms. S-Butyrylthiocholine Iodide Preferred ... Butyrylthiocholine Preferred Term Term UI T005940. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1975). ... Butyrylthiocholine Preferred Concept UI. M0003116. Registry Number. 4555-00-4. Scope Note. A sulfur-containing analog of ... Butyrylthiocholine. Tree Number(s). D02.092.877.883.333.800.200. D02.675.276.232.800.200. D02.886.489.789.200. Unique ID. ...
S-Butyrylthiocholine Iodide Narrower Concept UI. M0003117. Registry Number. 0. Terms. S-Butyrylthiocholine Iodide Preferred ... Butyrylthiocholine Preferred Term Term UI T005940. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1975). ... Butyrylthiocholine Preferred Concept UI. M0003116. Registry Number. 4555-00-4. Scope Note. A sulfur-containing analog of ... Butyrylthiocholine. Tree Number(s). D02.092.877.883.333.800.200. D02.675.276.232.800.200. D02.886.489.789.200. Unique ID. ...
M in the activated higher substrate region with n-butyrylthiocholine iodide as the substrate and chlorpromazine as the ... M for mBuChE II as determined by spectrophotometric assay with n-butyrylthiocholine iodide substrate. Although inhibition of ...
S-Butyrylthiocholine,iodide, s-butyrylthiocholine (Sar1,Val5,Ala8)Angiotensin II,(sar1,val5,ala8)angiotensin ii Hematuria, ...
Butyrylthiocholine D2.886.489.789.200. CADASIL C14.907.253.337.187 C10.228.140.380.230.124. Caffeine D3.132.960.175. ...
Butyrophenones N0000169070 Butyryl-CoA Dehydrogenase N0000167627 Butyrylcholinesterase N0000166505 Butyrylthiocholine ...
Butyrylthiocholine (BTC), a cationic substrate, was biphasically hydrolyzed with substrate activation; a second BTC molecule ...
D4.75.80.875.99.722.900.700.200 Butyrylthiocholine D2.886.489.789.200 CADASIL C14.907.253.337.187 C10.228.140.380.230.124 ...
S-Butyrylthiocholine,Iodide, S-Butyrylthiocholine (Sar1,Val5,Ala8)Angiotensin II,(Sar1,Val5,Ala8)Angiotensin II Hematuria, ...
Custom*: Escolha a quantidade desejada de forma personalizada, desde que seja acima de 250 g. Exemplo: 325 g ...
Butyrylthiocholine Buxaceae Buxus Byssinosis Byssochlamys Bystander Effect Byzantium C-Peptide C-Reactive Protein C2 Domains Ca ...
  • Serum, acetylthiocholine iodide, butyrylthiocholine iodide, 5,5-dithiobis-[2-nitrobenzoic acid] (DTNB) and eserine had been purchased from Sigma-Aldrich Co. Seventeen strains of fungi (Table 1) employed for screening experiments had been obtained from the collection with the Department of Pharmaceutical Biology and Botany of the Wroclaw Healthcare University, Poland. (opioid-receptor.com)
  • Substrates for the assay included acetylthiocholine (ATC) and butyrylthiocholine (BTC). (cdc.gov)
  • A sample of the patient's plasma is incubated with the substrate butyrylthiocholine, along with the indicator chemical 5,5'-dithiobis-(2-nitrobenzoic acid), which produces a colored product that is assayed by spectrophotometry. (medscape.com)
  • 3. [Cholinesterase (EC 3.1.1.8) with butyrylthiocholine-iodide as substrate: references depending on age and sex with special reference to hormonal effects and pregnancy]. (nih.gov)
  • The apparent competitive inhibition constants, Ki with chlorpromazine, are 1.8 x 10(-6) M for mBuChE I and 7.6 x 10(-6) M for mBuChE II, whereas the noncompetitive inhibition constant is 1.1 x 10(-5) M for mBuChE II as determined by spectrophotometric assay with n-butyrylthiocholine iodide substrate. (nih.gov)
  • The competitive inhibition constant for the oBuChE was 5.5 x 10(-7) M in the low substrate region, whereas the apparent noncompetitive binding constant was 1.6 x 10(-5) M in the activated higher substrate region with n-butyrylthiocholine iodide as the substrate and chlorpromazine as the reversible inhibitor. (nih.gov)
  • This study assessed seasonal variations in PON1 activity (using paraoxon -POase-, phenylacetate -AREase-, diazoxon -DZOase- and dihydrocoumarin -DHCase- as substrates), erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (using butyrylthiocholine -BuChE- and benzoylcholine -BeChE- as substrates. (nih.gov)
  • Substrates for the assay included acetylthiocholine (ATC) and butyrylthiocholine (BTC). (cdc.gov)