Brain acetylcholinesterase of jaguar cichlid (Parachromis managuensis): From physicochemical and kinetic properties to its potential as biomarker of pesticides and metal ions.
This contribution aimed to characterize physicochemical and kinetic parameters of the brain cholinesterases (ChEs) from Parachromis managuensis and investigate the in vitro effects of pesticides and metal ions on its activity intending to propose as biomarker. This species is suitable for this investigation because (1) it was recently introduced in Brazil becoming invasive (no restrictions on capture) and (2) occupies the top of the food chain (being subject to bioaccumulation). The enzyme extract was exposed to 10 metal ions (Al(3+), Ba(2+), Cd(2+), Cu(2+), Hg(2+), Mg(2+), Mn(2+), Pb(2+), Fe(2+) and Zn(2+)) and ChEs selective inhibitors (BW284c51, Iso-OMPA, neostigmine and serine). The extract was also incubated with organophosphate (dichlorvos) and carbamate pesticides (carbaryl and carbofuran). Inhibition parameters (IC20, IC50 and ki) were determined. Selective inhibitors and kinetic parameters confirmed acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) -like as responsible for the ChE activities, most AChE. The IC50 values for pesticides were: 1.68μM (dichlorvos); 4.35μM (carbaryl) and 0.28μM (carbofuran). Most of the analyzed ions did not show significant effect at 1mM (p=0.05), whereas the following ions inhibited the enzyme activity in the order: Hg(2+)>Cu(2+)>Cd(2+)>Zn(2+). Mercury ion strongly inhibited the enzyme activity (IC20=0.7μM). The results about allow to conclude that P. managuensis brain AChE is a potential biomarker for heavy metals and pesticides under study, mainly for the carbamate carbofuran once it was capable to detect 6-fold lower levels than the limit concentration internationally recommended.
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Marlyete Chagas de
MC
Araújo
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil. Electronic address: caiodias2@hotmail.com.
Caio Rodrigo Dias
CR
Assis
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil; Laboratório de Fisiologia Comparada e Comportamental, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Luciano Clemente
LC
Silva
Laboratório de Fisiologia Comparada e Comportamental, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Dijanah Cota
DC
Machado
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Kaline Catiely Campos
KC
Silva
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Ana Vitória Araújo
AV
Lima
Laboratório de Imunopatologia Keizo Asami-LIKA, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Luiz Bezerra
LB
Carvalho
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Ranilson de Souza
Rde S
Bezerra
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brazil.
Maria Betânia Melo de
MB
Oliveira
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000201:enzymology*; D002800:Cholinesterase Inhibitors / Q000378:metabolism; D023681:Cichlids / Q000378:metabolism*; D020128:Inhibitory Concentration 50; D007477:Ions / Q000378:metabolism; D007700:Kinetics; D019216:Metals, Heavy / Q000378:metabolism / Q000633:toxicity*; D010575:Pesticides / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
D015415:Biomarkers; D002800:Cholinesterase Inhibitors; D007477:Ions; D019216:Metals, Heavy; D010575:Pesticides; D014874:Water Pollutants, Chemical; D000110:Acetylcholinesterase
Biomarker; Cholinesterase; Environment; Heavy metals; Parachromis managuensis; Pesticides