Determination of the DNA sequences of acetylcholinesterase and butyrylcholinesterase from cat and demonstration of the existence of both in cat plasma

Bartels, Cynthia F.; Xie, Weihua; Miller-Lindholm, Amanda K.; Schopfer, Lawrence M.; Lockridge, Oksana

doi:10.1016/s0006-2952(00)00365-8

Cited by 31 publications

(25 citation statements)

References 38 publications

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“…[35–37] For example, the BChE concentration in human plasma should be ~5 mg/L according to Bartels et al . [36] and ~7 mg/L according to Polhuijs et al .,[35] giving an average value of ~6 mg/L or ~0.07 μM in terms of the total BChE protein concentration. Further, both native acetylcholinesterase (AChE) and BChE exist in tetramer.…”

Section: Resultsmentioning

confidence: 99%

Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine

Zhan

Hou

Chen

et al. 2013

Biochemical Journal

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It has been known that cocaine produces the toxic and physiological effects through not only cocaine itself but also norcocaine formed from cocaine oxidation catalyzed by microsomal cytochrome P450 3A4 in the human liver. The catalytic parameters (kcat and KM) of human butyrylcholinesterase (BChE) and its three mutants (i.e. the A199S/S287G/A328W/Y332G, A199S/F227A/S287G/A328W/E441D, and A199S/F227A/S287G/A328W/Y332G mutants) for norcocaine have been characterized in the present study, for the first time, in comparison with those for cocaine. Based on the obtained kinetic data, wild-type human BChE has a significantly lower catalytic activity for norcocaine (kcat = 2.8 min−1, KM = 15 μM, and kcat/KM = 1.87 × 105 M−1 min−1) compared to its catalytic activity for (−)-cocaine. The BChE mutants examined in this study have considerably improved catalytic activities against both cocaine and norcocaine compared to the wild-type enzyme. Within the enzymes examined in this study, the A199S/F227A/S287G/A328W/Y332G mutant (CocH3) is identified as the most efficient enzyme for hydrolyzing both cocaine and norcocaine. CocH3 has a 1080-fold improved catalytic efficiency for norcocaine (kcat = 2610 min−1, KM = 13 μM, and kcat/KM = 2.01 × 108 M−1 min−1) and a 2020-fold improved catalytic efficiency for cocaine. It has been demonstrated that CocH3 as an exogenous enzyme can rapidly metabolize norcocaine, in addition to cocaine, in rats. Further kinetic modeling has suggested that CocH3 with an identical concentration as that of the endogenous BChE in human plasma can effectively eliminate both cocaine and norcocaine in a simplified kinetic model of cocaine abuse.

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Section: Resultsmentioning

confidence: 99%

Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine

Zhan

Hou

Chen

et al. 2013

Biochemical Journal

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“…It is striking that mouse BChE hydrolyzes this peptide so much better than human BChE, which is ~80% homologous and shares similar catalytic efficiency for butyrylthiocholine, acetylcholine, and cocaine [24, 32, 33]. Because mouse BChE exhibits a 10-fold lower K m and 3-fold higher k cat than human BChE we conclude that ghrelin docking in the active site must differ widely across species.…”

Section: Discussionmentioning

confidence: 96%

Radiometric assay of ghrelin hydrolase activity and 3H-ghrelin distribution into mouse tissues

Chen

Gao

Geng

et al. 2015

Biochemical Pharmacology

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A high-throughput radiometric assay was developed to characterize enzymatic hydrolysis of ghrelin and to track the peptide's fate in vivo. The assay is based on solvent partitioning of [3H]-octanoic acid liberated from [3H]-octanoyl ghrelin during enzymatic hydrolysis. This simple and cost-effective method facilitates kinetic analysis of ghrelin hydrolase activity of native and mutated butyrylcholinesterases or carboxylesterases from multiple species. In addition, the assay's high sensitivity facilitates ready evaluation of ghrelin's pharmacokinetics and tissue distribution in mice after i.v. bolus administration of radiolabeled peptide.

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“…(Enghild et al, 1989). Fourteen micromolar 417 a-2-macroglobulin was incubated with 0.12 lM BChE for 30 min 418 before initiating the ghrelin hydrolysis reaction by addition of butyrylthiocholine (Bartels et al, 2000). However, it is equivalent 508 to the turnover numbers for the well-recognized P450 enzymes, 509 e.g., P450 2B4 oxidizes 9-cis-retinal with a turnover number of 510 3.7 min À1 (Raner et al, 1996); and P450 2G1 oxidizes estradiol at 511 0.66 min À1 , testosterone at 1.58 min À1 , and progesterone at 512 1.66 min À1 (Ding and Coon, 1994 directly (Chen et al, 2015).…”

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confidence: 99%

Pure human butyrylcholinesterase hydrolyzes octanoyl ghrelin to desacyl ghrelin

Schopfer

Lockridge

Brimijoin

2015

General and Comparative Endocrinology

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Determination of the DNA sequences of acetylcholinesterase and butyrylcholinesterase from cat and demonstration of the existence of both in cat plasma

Cited by 31 publications

References 38 publications

Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine

Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine

Radiometric assay of ghrelin hydrolase activity and 3H-ghrelin distribution into mouse tissues

Pure human butyrylcholinesterase hydrolyzes octanoyl ghrelin to desacyl ghrelin

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