Details

Autor(en) / Beteiligte

• Lopes, Vanessa F
• Cabral, Hamilton
• Machado, Luciana PB
• Mateus, Rogério P

Titel

Purification and Characterization of a Specific Late-Larval Esterase from Two Species of the Drosophila repleta Group: Contributions to Understand Its Evolution

Ist Teil von

• Zoological Studies, 2014-01, Vol.53 (1), p.6-6, Article 6

Ort / Verlag

Berlin/Heidelberg: 中央研究院生物多樣性研究中心

Erscheinungsjahr

2014

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Background After duplication, one copy of an original gene can become redundant and decay toward a pseudogene status or functionally diverge. Here, we performed the purification and biochemical characterization of EST-4 (a late larval β-esterase) from two Drosophila repleta group species, Drosophila mulleri and Drosophila arizonae , in order to establish comparative parameters between these enzymes in these species and to contribute to better understand their evolution. Results In D. mulleri , EST-4 had an optimal activity in temperatures ranging from 40° to 45°C and at pH 7.5, maintaining stability in alkaline pH (8.0 to 10.0). It was classified as serine esterase as its activity was inhibited by PMSF. No ion negatively modulated EST-4 activity, and iron had the most positive modulating effect. In D. arizonae , it showed similar optimum temperature (40°C), pH (8.0), and was also classified as a serine esterase, but the enzymatic stability was maintained in an acidic pH (5.5 to 6.5). Fe +2 had the opposite effect found in D. mulleri , that is, negative modulation. Al +3 almost totally inhibited the EST-4 activity, and Na + and Cu +2 had a positive modulation effect. Kinetic studies, using ρ-nitrophenyl acetate as substrate, showed that EST-4 from D. mulleri had higher affinity, while in D. arizonae , it showed higher V max and catalytic efficiency in optimal reaction conditions. Conclusions EST-4 from D. mulleri and D. arizonae are very closely related and still maintain several similar features; however, they show some degree of differentiation. Considering that EST-4 from D. mulleri has more conspicuous gel mobility difference among all EST-4 studied so far and a lower catalytic efficiency was observed here, we proposed that after duplication, this new copy of the original gene became redundant and started to decay toward a pseudogene status in this species, which probably is not occurring in D. arizonae .