[目的]研究半胱氨酸(Cys58)对小菜蛾(Plutella xylostella)化学感受蛋白1(PlxyCSP1)与农药化合物结合特性的影响。[方法]利用重叠延伸PCR法,将PlxyCSP1中Cys58突变成色氨酸(Trp58),获得突变体PlxyCSP1-M2。构建表达载体表达突变蛋白,并进行Western Blot检测。[结果]构建了突变基因的原核蛋白表达载体pET32a-PlxyCSP1-M2,并表达35kDa融合蛋白[结论]利用重叠延伸PCR法成功在原核系统中表达了PlxyC-SP1突变蛋白。 [Objective] The research aimed to study the effect of cysteine ​​(Cys58) on the binding properties of Plutella xylostella chemokine 1 (PlxyCSP1) and pesticide compounds. [Method] Cys58 in PlxyCSP1 was mutated to tryptophan (Trp58) by overlap extension PCR and the mutant PlxyCSP1-M2 was obtained. Construction of expression vector expression of mutant protein, and Western Blot detection. [Result] The prokaryotic expression vector pET32a-PlxyCSP1-M2 with the mutant gene was constructed and the 35kDa fusion protein was expressed. [Conclusion] PlxyC-SP1 mutant protein was successfully expressed in prokaryotic system by overlap extension PCR.