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[Expression and characterization of carboxylesterase A2 in E. coli]
Jing Huang1, Chuan Ling Qiao, Qiao Zhao
1The State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, the Chinese Academy of Sciences, Beijing 100080, China.
Shi Yan Sheng Wu Xue Bao
|September 4, 2004
Summary
Insecticide resistance is often linked to increased carboxylesterase activity. This study successfully expressed and purified a functional carboxylesterase A2 enzyme from E. coli, offering a purer source for future applications.
Area of Science:
- Biochemistry
- Molecular Biology
- Entomology
Background:
- Insecticide resistance is a growing agricultural problem.
- Increased carboxylesterase activity is a key mechanism in resistance to organophosphate and carbamate insecticides.
Purpose of the Study:
- To express and characterize carboxylesterase A2 (EstA2) from Culex quinquefasciatus in E. coli.
- To assess the purity and kinetic properties of the recombinant enzyme.
Main Methods:
- Carboxylesterase A2 cDNA was amplified from Culex quinquefasciatus using RT-PCR.
- The cDNA was cloned into a prokaryotic expression plasmid (pET-EstA2) and transformed into E. coli BL21.
- Recombinant protein expression was induced, and the enzyme was purified using affinity chromatography.
Main Results:
- A pure recombinant carboxylesterase A2 protein was successfully obtained from E. coli.
- The recombinant enzyme exhibited similar Michaelis constant (Km) but higher maximum velocity (Vm) compared to the native enzyme.
- The purified recombinant enzyme was purer than the native enzyme isolated from Culex quinquefasciatus.
Conclusions:
- The expression and characterization of carboxylesterase A2 in E. coli provide a valuable and purer source of the enzyme.
- This recombinant enzyme has significant potential for future applications in understanding and combating insecticide resistance.