Characterization of catalytic efficiency parameters of brain cholinesterases in tropical fish
| Autor: | Caio Rodrigo Dias de Assis, Luiz B. Carvalho, Marina Marcuschi, Amanda Guedes Linhares, Renata Cristina Penha França, Vagne Melo Oliveira, Elba Verônica Matoso Maciel Carvalho, Ranilson de Souza Bezerra, Juliana Ferreira dos Santos |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Gene isoform
Physiology Aché Aquatic Science Biology Biochemistry chemistry.chemical_compound Species Specificity Animals Catalytic efficiency Butyrylcholinesterase chemistry.chemical_classification Tropical Climate Molecular mass Fishes Brain General Medicine biology.organism_classification Acetylcholinesterase language.human_language Oreochromis Enzyme chemistry language |
| Zdroj: | Fish physiology and biochemistry. 40(6) |
| ISSN: | 1573-5168 |
| Popis: | Brain cholinesterases from four fish (Arapaima gigas, Colossoma macropomum, Rachycentron canadum and Oreochromis niloticus) were characterized using specific substrates and selective inhibitors. Parameters of catalytic efficiency such as activation energy (AE), k cat and k cat/k m as well as rate enhancements produced by these enzymes were estimated by a method using crude extracts described here. Despite the BChE-like activity, specific substrate kinetic analysis pointed to the existence of only acetylcholinesterase (AChE) in brain of the species studied. Selective inhibition suggests that C. macropomum brain AChE presents atypical activity regarding its behavior in the presence of selective inhibitors. AE data showed that the enzymes increased the rate of reactions up to 1012 in relation to the uncatalyzed reactions. Zymograms showed the presence of AChE isoforms with molecular weights ranging from 202 to 299 kDa. Values of k cat and k cat/k m were similar to those found in the literature. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink