Cloning and expression of lipopolysaccharide elimination protein (LEP) in lactic acid bacteria

Abstract

Lipopolysaccharide (LPS) is related to human inflammation. Therefore, in the probiotics research field, controlling the mechanisms of LPS neutralization and elimination of inflammation of human intestines are important. This chapter presents a description of the identification of LPS elimination protein (LEP) in lactic acid bacteria (LAB), cloning of its protein, and its expression. First, LEP is extracted from the LAB cell wall digestion fraction using Blue Native PAGE. Then LEP is identified by the elimination activity of LPS on gel pieces. Results show that the LEP is an approx. 200 kDa protein part of heat shock protein in lactic acid bacteria. After sequencing amino acids of LEP, LEP cloning is done using a Brevibacillus sp. expression system without a general transformation system but with Gram-negative Escherichia coli having LPS. Results presented in this chapter demonstrate the elimination activity of recombinant LEP.