[Inducible expression of MSP1 gene of Plasmodium falciparum by a tetracycline-controlled promoter].

ABSTRACT

OBJECTIVE: To express the entire MSP1 gene of Plasmodium falciparum and its C-terminal 42 kDa fragment using a tetracycline-controlled PLtetO-1 promoter. METHODS: The entire MSP1 gene and 42 kDa fragment gene were cloned into the plasmid of pZE11, and transformed into E. coli DH5 alpha Z1. Restriction enzyme analysis, SDS-PAGE and Western blotting were used to examine two recombinant plasmids and their expression in E. coli DH5 alpha Z1. RESULTS: The recombinant plasmids of pZE11/MSP1 and pZE11/MSP1-42 were constructed successfully. The expressive products about 190 kDa and 42 kDa of two genes in E. coli DH5 alpha Z1 were identified by SDS-PAGE and Western blotting. CONCLUSION: Tightly controlling expression of the MSP1 gene in E. coli is essential to reduce the toxicity of the product to its host cells as well as to provide a feasibility to construct Salmonella vaccine strain which can inducibly express the important malarial vaccine candidate gene.