RESUMO
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 IC50 values for these pesticides ranged between of 0.0023 and 0.0385 µM. 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.
Assuntos
Inibidores da Anidrase Carbônica/química , Anidrases Carbônicas/metabolismo , Praguicidas/química , Animais , Abelhas , Carbamatos/química , Carbamatos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Domínio Catalítico , DDT/química , DDT/farmacologia , Diazinon/química , Diazinon/farmacologia , Ésteres/química , Metomil/química , Metomil/farmacologia , Nitrilas/química , Nitrilas/farmacologia , Praguicidas/farmacologia , Fosfatos/química , Fosfatos/farmacologia , Ligação Proteica , Piretrinas/química , Piretrinas/farmacologia , Relação Estrutura-Atividade , Zinco/químicaRESUMO
A widely used approach for assessing genome instability in plants makes use of somatic homologous recombination (SHR) reporter lines. Here, we review the published characteristics and uses of SHR lines. We found a lack of detailed information on these lines and a lack of sufficient evidence that they report only homologous recombination. We postulate that instead of SHR, these lines might be reporting a number of alternative stress-induced stochastic events known to occur at transcriptional, posttranscriptional, and posttranslational levels. We conclude that the reliability and usefulness of the somatic homologous recombination reporter lines requires revision. Thus, more detailed information about these reporter lines is needed before they can be used with confidence to measure genome instability, including the complete sequences of SHR constructs, the genomic location of reporter genes and, importantly, molecular evidence that reconstituted gene expression in these lines is indeed a result of somatic recombination.