Abstract
Although recent works have suggested that plant has the innate immunity system to Lipopolysaccharide (LPS), a major constituent of outer membrane of gram-negative bacteria, the interaction molecules consisting of the system have not been identified. In this study, we focused on LPS-binding protein (LBP) which is an about 50kD serum glycoprotein produced principally by hepatocytes in mammal and is known to bind and transfer LPS to LPS receptor expressing on the surface of macrophage or as a soluble form in the serum.
Arabidopsis genome contains two LBP genes (AtLBP1 and AtLBP2). We expressed each AtLBPs in E.coli and analyzed their binding ability to LPS biochemically. These analyses show the specific binding of AtLBPs to LPS, which is similar to that of human LBP. Furthermore, these results raised the possibility that AtLBPs are involved in innate immunity system to LPS in Arabidopsis.
