Expression of alcohol dehydrogenase gene in Escherichia coli for replacement therapy of dental caries

Objective To express the gene of alcohol dehydrogenase in E. coli. which was obtained from the recombinant vector of pMDLA for the replacement therapy of dental caries. Methods adhB gene was digested by restriction enzymes from the recombinant vector and inserted into the expression vector pET-28a and then expressed in E. coli BL21. Results Expression vector of pET-28a-adhB was successfully constructed. A specific 40,000-protein band could be seen on the SDS-PAGE gel induced by IPTG and positive clones were observed on aldehyde indicator plates. Conclusion It is comfirmed that the ldh gene was replaced perfectly by adhB gene, which is a start for the further study of the constuction of LDH-deficient mutant of S. mutans.