Abstract:【Objective】 To analyze the application of recombinant gp125 proteins in serological diagnosis of nasopharyngeal carcinoma (NPC). 【Methods】 DNA was extracted from the B95-8 cells was used as the templates in a polymerase chain reaction (PCR). gp125 gene (2574 bp) was generated and inserted into pPIC9 vector. The recombinant plasmids were transformed into GS115 yeast by electroporation. The yeast transformants induced by methanol expressed recombinant proteins. The recombinant proteins synthesized were coated to microplate for detection of EBV-IgA antibody in NPC patients by ELISA. 【Results】 We have successfully secretly expressed the recombinant gp125 protein in the Pichia pastoris. The molecular weight of product was approximately 110 000. The recombinant protein gp125 in the culture supernatant showed good immunoreactivity with IgA antibodies to EBV by Western blot. A novel ELISA was established using Pichia pastoris-expressed gp125 proteins. Serum samples were collected from patients with NPC and healthy controls and using this ELISA tested. The sensitivity and the specificity of gp125 tests in the NPC sera were 78.0% and 92.0%

separately. 【Conclusion】 The recombinant proteins gp125 were highly secretly expressed in pichia pastoris

the diagnostic value of the recombinant protein in screening for NPC patients was primary evaluated and the valuable pPIC9-gp125 yeast strain was obtained.