[Objective] This study aimed to explore the effects of cysteine （Cys58） on the characteristics of PlxyCSP1 in P. Iostella combined with pesticide compounds. [Method] Cys58 of PlxyCSP1 was mutated into Trp58 by using overlap extension PCR method, and PlxyCSP1-M2 mutant was obtained. Expression vector was con- structed and the protein was detected by western blot. [Result] Expression vector pET32a-PlxyCSP1-M2 was constructed to express the 35kDa weight protein. [Conclusion] PlxyCSP1 mutant protein has been expressed successfully in prokaryotic ex- pression system.
