（1Key Laboratory of Microbiology of Heilongjiang Province， College of Life Science， Heilongjiang University，
Harbin 150080， Heilongjiang， China； 2Institute of Vegetables and Flowers， Chinese Academy of Agricultural Sciences，
Beijing 100081， China）
Abstract：In this study，we constructed a recombinant of Plutella xylostella cadherin gene
fragment．In order to enhance its expression in Escherichia coli，we studied the effect of time，
temperature and IPTG concentration on fusion protein expression and its solubility．The results showed
that the fusion protein gave rise to the maximum expression when host cells were cultured in LB at 37 ℃
for 1.5 h and then induced by 0.1 mmol·L-1 IPTG at 25℃ 180 r·min-1 for 36 h．And the temperature
change had little impact on the solubility of fusion proteins. SDS-PAGE test also indicated that the
molecular weight of fusion proteins was the same as expected，wh ich is about 16 kDa.
