›› 2006, Vol. 49 ›› Issue (5): 733-739.

• RESEARCH PAPERS • Previous Articles     Next Articles

Cloning and sequencing of cDNA encoding pheromone binding protein 3 from the Helicoverpa assulta (Guenée) and its expression in Escherichia coli

LIU Xiao-Guang, AN Shi-Heng, LUO Mei-Hao, GUO Xian-Ru, YUAN Guo-Hui   

  1. (College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China)
  • Online:2006-11-07 Published:2006-10-20
  • Contact: LUO Mei-Hao

Abstract:

A cDNA clone encoding a pheromone binding protein 3 from antenna of Helicoverpa assulta (named HassPBP3) was isolated by reverse transcription polymerase chain reaction (RT-PCR). The cloning and sequencing results showed that the full length of HassPBP3 open reading frame (ORF) was 495 bp, encoding 164 amino acid residues, and the predicted molecular weight (MW) was 18.5 kD. The N-terminus hydrophobic region predicted containing of 22 amino acid residues within the HassPBP3 displayed the characteristic features of a signal peptide. Thus, the mature protein should consist of 142 amino acids with a calculated molecular weight (MW) of 16.1 kD and isoelectric point (IP) of 5.44. The gene was then constructed into expression vector pGEX-4T-2 for over expression in prokaryotic cells. The SDS-PAGE and Western blot analysis showed that induced by IPTG, the PBP3 proteins in H. assultawas expressed in Escherichia coli BL21, and its MW was found to be about 42 kD by checking with SDS-PAGE, nearly equal to the predicted.

Key words: Helicoverpa assulta, pheromone binding protein, gene clone, prokaryotic expression