Abstract: γ-Aminobutyric acid receptor (GABAR) is one of the most important insecticide targets. In this study, the fragments of genes of GRD and LCCH3 subunits in Drosophila melanogaster were amplified by RT-PCR and cloned into pET-32a expression vector. Homologous analysis showed that they have more than 99% identity with the published amino acid sequences of the homologous genes in GenBank, without frameshift mutation. The recombinant plasmids were transformed into Escherichia coli and expressed under IPTG induction. LCCH3 gene was expressed successfully, but GRD gene failed. The expressed LCCH3 subunit was purified by the processes of inclusion body washing, denaturation, Ni²⁺ affinity chromatography and renaturation. The secondary structure of LCCH3 subunit was determined by circular dichroism (CD) spectroscopy, the result showed that this subunit was rich in β-strand. The results provide important information for the study of relationship between the structure and function of GABA receptor.

Key words: Drosophila melanogaster, GABA receptor, GRD subunit, LCCH3 subunit, gene cloning, expression, identification