Abstract:

Objective　To evaluate the expression of recombinant plasmid pcDNA3·1/GBD of glucan binding protein ofStrepto- coccus mutansin mammalian cells COS-7.Methods　Eukaryotic plasmid carrying encoding gene of GBD ofStreptococcus mutans gbpAwas constructed and the plasmid was introduced into COS-7 cells by Lipofectamine reagent. The transient expressed protein in COS-7 cells was detected by immunochemistry technique.Results　The positive expression was detected in plasma of the cells which were transfected with recombinant plasmid pcDNA3·1/GBD. The cells which were transfected with pcDNA3·1 were nega- tive.Conclusion　GBD can translate and express in COS-7 cells aftertransfectedwith recombinant plasmid pcDNA3·1/GBD. The expressed protein locates in the plasma and the protein is able to combine with anti-GbpA antibody. The expressed protein has the antigenicity and is a candidate gene vaccine.

Key words: Streptococcus mutans, glucan-binding protein, mammalian cells, gene expression