Choline esterases

Johnson has described a method for the estimation of physostigmine in the salicylate for the determination of minute amounts of the alkaloid Ellis, Plaehte and Straus have devised processes depending on (a) inhibition of serum choline-esterase by the alkaloid, or (b) measurement of the colour intensity produced by the conversion of physostigmine to rubreserine in an alkaline medium. i ... 

Ellis, Krayer and Plachte have shown that the degradation products of physostigmine, eseroline and eserine-brown do not inhibit choline-esterase, but rubreserine and eserine-blue are inhibitors in vitro, having... 

Ph. C CH. C(CH,. N(Br)Mc3) C(0. CO. NMca). CH CH, an analogue of prostigmine, shows marked inhibition for i/i-choline-esterase, but is only slightly active towards true choline-esterase. 

Choline, 413, 773 Choline-esterase, 262 Choline-esterases, inhibition by... 

Clinical observations of such inherited differences in drug effects were first documented in the 1950s, as shown by the relationship between prolonged muscle relaxation after suxamethonium and an inherited deficiency of plasma choline esterase [2]. Some psychiatric patients were found to be unusually susceptible to suxametho-... 

The physiological significance of mucoproteins in serum is unknown but it is tempting to speculate that they may simply be intermediate stages in the synthesis of albumins and globulins. However, it will be seen below that mucoproteins with hormone properties can be isolated from serum of pregnant mares, and that the enzyme choline esterase, is probably a serum mucoprotein. 

By a careful fractionation of normal horse serum, involving as an essential part of the process a separation of closely related substances by the Schtitz168 foam technique, Bader, Schiitz and Stacey16 obtained a crystalline mucoprotein with high choline esterase activity. This appears to be the first mucoprotein obtained without the use of heat or alcohol, and while it is not yet claimed that the crystalline material is indeed the enzyme itself, arguments are advanced to show that the enzymic activity is closely bound up with mucoprotein structure. 

Keywords Barbus graellsii, Biomarkers, Choline esterases, Cyprinus carpio, Daphnia magna, Dreissena polymorpha, EROD, Metallothionein, qRT-PCR, Xenobiotics... 

Acid- and base-sensitive lipidated peptides can be selectively deprotected by enzymatic hydrolysis of choline esters.[13al Choline esters of simple peptides, but also of sensitive peptide conjugates like phos-phorylated and glycosylated peptides,1141 nucleopep-tides1151 and lipidated peptides,113,1631 can be cleaved with acetyl choline esterase (AChE) and butyryl choline esterase (BChE) under virtually neutral conditions with complete chemoselectivity. Acid-labile farnesyl groups and base-sensitive thioesters are not attacked. 

For instance, in a synthesis of N-Ras lipopeptide 8, the choline ester in the palmitoylated tripeptide 5 was removed selectively and in high yield by means of the butyryl choline esterase (BChE). Efficient cou-... 

There is some confusion in the literature regarding the substances designated as anti-choline-esterases (usually shortened to anticholinesterases). The term cholinesterase was first used1 in connexion with an enzyme present in the blood serum of the horse which catalysed the hydrolysis of acetylcholine and of butyrylcholine, but exhibited little activity towards methyl butyrate,... 

Protection against benzoylcholine by injection of psevdo cholin esterase... 

Fig. 9.8 Examples of rule-of-three compliant molecules that have biological activity better than 10 nM. Under each molecule, the following information is included molecule name, MW, ClogP, the biological activity type, value and target. Target names are as follows D3 and D4 - dopaminergic receptor types 2 and 3 AChE and BChE - acetyl- and butyryl-choline esterases PRa and PRb - progesterone receptor types A and B H] and H3, histamine receptor types 1 and 3 5-HT2a, 5-HT2b, 5-HT2c, 5-HT3, 5-HT4 - serotonin receptor subtypes 2A, 2B, 2C, and types 3 and 4 DAT, NET, 5-HTT - dopamine, norepinephrine and serotonin transporter proteins /X], /x.2, S, ki, ks - opioid receptor types mu-1, mu-2, delta, kappa-1 and kappa-3 5a-Rl and 5o -R2 - 5-alpha-reductase isozymes 1 and 2 Flt-1-fms-like tyrosine kinase receptor.

Houghton PJ, Agbedahunsi JM, Adegbulugbe A, Choline esterase inhibitory properties of alkaloids from two Nigerian Crinum species. Phytochemistry 65 2893-2896, 2004. 

This enzyme [EC 3.1.1.7], also known as true cholinesterase, choline esterase I, and cholinesterase, catalyzes the hydrolysis of acetylcholine to produce choline and acetate. The enzyme will also act on a number of acetate esters as well as catalyze some transacetylations. 

ALKENYLGLYCEROPHOSPHOETHANOL-AMINE HYDROLASE 1-ALKYL-2-ACETYLGLYCEROL CHOLINE PHOSPHOTRANSFERASE 1-ALKYL-2-ACETYLG LYCEROPHOSPHO-CHOLINE ESTERASE Alkylation,... 

Barckow, D., Neuhaus, G., and Erdmann, W.D. Zur Behandlung der schweren Parathion-(E 6050O)-Verglftung mlt dem Cholin-esterase-Reaktivator Obidoxim (Toxogonin )). Arch. Toxikol. 24 133-146, 1969. (English Summary)... 

In 1989, to the best of our knowledge, the first report appeared on the use of an avidin-biotin system for the immobilization of enzymes in the preparation of biosensors. Walt et al. have immobilized biotin-modified enzymes (urease, esterase, and penicillinase) on the surface of biotin-modified optical fiber using avidin as a binder (Figure 5a). They have demonstrated the general use of this procedure in immobilizing several types of enzymes. At nearly the same time, Gunaratna and Wilson used an enzyme column in which choline esterase and choline oxidase were immobilized through avidin-biotin complexation for the determination of acetyl-... 

They did not report the minimum lethal dose or any other quantitative measure of toxicity, but nobody reading their paper would have missed the fact that the compounds are violently poisonous. During World War II, research on the fluorophosphonates was carried on for military purposes, and Adrian and his coworkers in Britain noted the similarity between the physiological action of the fluorophosphonates and that of reversible inhibitors of choline esterase (Adrian et al., 1947). This led to a number of scientific investigations of the action of nerve gases on various esterases. 

Metal ions Choline esterase luciferase invertase... 

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