Investigation of pesticides on honey bee carbonic anhydrase inhibition

Abstract

Carbonic anhydrase (CA, EC 4.2.1.1) plays crucial physiological roles in many different organisms, such as in pH regulation, ion transport, and metabolic processes. CA was isolated from the European bee Apis mellifera (AmCA) spermatheca and inhibitory effects of pesticides belonging to various classes, such as carbamates, thiophosphates, and pyrethroids, were investigated herein. The inhibitory effects of methomyl, oxamyl, deltamethrin, cypermethrin, dichlorodiphenyltrichloroethane (DDT) and diazinon on AmCA were analysed. These pesticides showed effective in vitro inhibition of the enzyme, at sub-micromolar levels. The IC 50 values for these pesticides ranged between of 0.0023 and 0.0385 lM. The CA inhibition mechanism with these compounds is unknown at the moment, but most of them contain ester functionalities which may be hydrolysed by the enzyme with the formation of intermediates that can either react with amino acid residues or bid to the zinc ion from the active site.

Investigation of the effects of some pesticides on carbonic anhydrase isoenzymes

“…The carbamates and organophosphates investigated here possess ester bonds, which can be hydrolysed by the esterase activity of the a‐CAs. In fact, it has been thoroughly documented that these enzymes are esterases/thioesterases/selenoestearses with carboxylic, phosphoric, thiocarboxylic, and even selenol esters 53 . It was reported that carbamates bind to the CA active site through their deprotonate carbamate nitrogen, which coordinates the catalytic metal ion.…”

“…In fact, it has been thoroughly documented that these enzymes are esterases/thioesterases/selenoestearses with carboxylic, phosphoric, thiocarboxylic, and even selenol esters. 53 It was reported that carbamates bind to the CA active site through their deprotonate carbamate nitrogen, which coordinates the catalytic metal ion. In this study, X-ray crystallography of the CA-carbamate interaction showed the direct binding of these compounds to a metal ion.…”

Proteinaceous Venom Expression of the Yellow Meadow Ant, Lasius flavus (Hymenoptera: Formicidae)

“…It is involved in diverse and important processes in insects, such as aging and longevity, insecticide susceptibility, food intake, and courtship [ 44 , 45 , 46 ]. Carbonic anhydrases are involved in pH regulation, ion transport, metabolic processes, and insecticides resistance [ 47 , 48 ]. In insects, nose resistant to fluoxetine protein has only been characterized in the fruit fly, Drosophila melanogaster , which participates in oogenesis and embryogenesis and neurodegeneration [ 49 , 50 ].…”