title: Acetylcholine-hydrolyzing activities in soluble brain fraction: Characterization with reversible and irreversible inhibitors.
abstract: Some effects of organophosphorus compounds (OPs) esters cannot be explained through actions on currently recognized targets acetylcholinesterase or neuropathy target esterase (NTE). In soluble chicken brain fraction, three components (Eα, Eβ and Eγ) of pheny lvalerate esterase activity (PVase) were kinetically discriminated and their relationship with acetylcholine-hydrolyzing activity (cholinesterase activity) were studied in previous works. In this work, four enzymatic components (CS1, CS2, CS3 and CS4) of cholinesterase activity have been discriminated in soluble fraction, according to their sensitivity to irreversible inhibitors mipafox, paraoxon, PMSF and iso-OMPA and to reversible inhibitors ethopropazine and BW284C51. Cholinesterase component CS1 can be related to the Eα component of PVase activity and identified as butyrylcholinesterase (BuChE). No association and similarities can be stablished among the other PVase component (Eβ and Eγ) with the other cholinesterase components (CS2, CS3, CS4). The kinetic analysis has allowed us to stablish a method for discriminating the enzymatic component based on a simple test with two inhibitors. It can be used as biomarker in toxicological studies and for monitoring these cholinesterase components during isolation and molecular identification processes, which will allow OP toxicity to be understood by a multi-target approach.
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain. Electronic address: jorge.estevez@umh.es.
authors: Jorge
authors: J
authors: Estévez
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain.
authors: Verónica
authors: V
authors: Selva
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain.
authors: Mónica
authors: M
authors: Benabent
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain.
authors: Iris
authors: I
authors: Mangas
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain.
authors: Miguel Ángel
authors: MÁ
authors: Sogorb
authors: University "Miguel Hernández", Institute of Bioengineering, Unit of Toxicology, Elche, Spain.
authors: Eugenio
authors: E
authors: Vilanova
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000378:metabolism*; D000122:Acetylthiocholine / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002645:Chickens; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D006868:Hydrolysis / Q000187:drug effects; D010640:Phenothiazines / Q000494:pharmacology; D063088:Phosphoramides / Q000494:pharmacology; D012995:Solubility; D013347:Subcellular Fractions / Q000201:enzymology; D013997:Time Factors; D014105:Tosyl Compounds / Q000494:pharmacology
chemical_list: D002800:Cholinesterase Inhibitors; D010640:Phenothiazines; D063088:Phosphoramides; D014105:Tosyl Compounds; D000122:Acetylthiocholine; C003614:4-toluenesulfonyl fluoride; C084820:profenamine; D002265:Carboxylic Ester Hydrolases; C021859:neurotoxic esterase; D000110:Acetylcholinesterase; D000109:Acetylcholine
keywords: BW284C51; Cholinesterase; Ethopropazine; Iso-OMPA; Mipafox; Organophosphorus; PMSF; Paraoxon; Phenyl valerate esterase