title: Characterization of acetylcholinesterase from the brain of the Amazonian tambaqui (Colossoma macropomum) and in vitro effect of organophosphorus and carbamate pesticides.
abstract: In the present study, acetylcholinesterase (AChE) from the brain of the Amazonian fish tambaqui (Colossoma macropomum) was partially characterized and its activity was assayed in the presence of five organophosphates (dichlorvos, diazinon, chlorpyrifos, and tetraethyl pyrophosphate [TEPP]) and two carbamates (carbaryl and carbofuran) insecticides. Optimal pH and temperature were 7.0 to 8.0 and 45°C, respectively. The enzyme retained approximately 70% of activity after incubation at 50°C for 30 min. The insecticide concentration capable of inhibiting half of the enzyme activity (IC50) for dichlorvos, chlorpyrifos, and TEPP were calculated as 0.04 µmol/L, 7.6 µmol/L, and 3.7 µmol/L, respectively. Diazinon and temephos did not inhibit the enzyme. The IC50 values for carbaryl and carbofuran were estimated as 33.8 µmol/L and 0.92 µmol/L, respectively. These results suggest that AChE from the juvenile C. macropomum brain could be used as an alternative biocomponent of organophosphorus and carbamate biosensors in routine pesticide screening in the environment.
authors.affiliation: Laboratório de Enzimologia, LABENZ, Departamento de Bioquímica and Laboratório de Imunopatologia Keizo Asami, Universidade Federal de Pernambuco, Pernambuco, Brazil.
authors.forename: Caio Rodrigo Dias
authors.initials: CR
authors.lastname: Assis
authors.forename: Patrícia Fernandes
authors.initials: PF
authors.lastname: Castro
authors.forename: Ian Porto Gurgel
authors.initials: IP
authors.lastname: Amaral
authors.forename: Elba Verônica Matoso Maciel
authors.initials: EV
authors.lastname: Carvalho
authors.forename: Luiz Bezerra
authors.initials: LB
authors.lastname: Carvalho
authors.forename: Ranilson Souza
authors.initials: RS
authors.lastname: Bezerra
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002219:Carbamates / Q000378:metabolism / Q000633:toxicity*; D002800:Cholinesterase Inhibitors / Q000378:metabolism / Q000633:toxicity; D005399:Fishes; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009943:Organophosphorus Compounds / Q000378:metabolism / Q000633:toxicity*; D010575:Pesticides / Q000378:metabolism / Q000633:toxicity*; D013045:Species Specificity; D013696:Temperature
chemical_list: D002219:Carbamates; D002800:Cholinesterase Inhibitors; D009943:Organophosphorus Compounds; D010575:Pesticides; D000110:Acetylcholinesterase