Recombinant Mouse Lipopolysaccarid Binding Protein

Source : Chinese Hamster Ovarian Cells (CHO). LBP is produced from mouse LBP transfected CHO-cells in serum free medium. For transfection we have cloned complete mouse LBP cDNA into expression vector pPOL-DHFR. Before transfection the complete mouse LBP cDNA was amplified by PCR and cloned into expression vector p-POL-DHFR. RmLBP was produced by his-tag by means of metal affinity purification with Talon and controlled by SDS page. Attention: His-tag at the c-terminal end of the LBP has no protease site and is not to split off. Up to 2µg/ml LBP mediates binding of FITC-LPS (0.5µg/ml) to CD14+CHO transfectants (2 x 106/ml). Lipopolysaccharides (LPS) are a type of glycolipids on the outer cell wall of Gram-negative bacteria. Lipopolysaccharide binding protein (aka LBP) is a plasma protein which facilitates the diffusion of bacterial LPS (endotoxin). LBP is involved in the acute-phase immunologic response to gram-negative bacterial infections. In cooperation with bactericidal permeability-increasing protein (BPI), LBP binds LPS and interacts with the CD14 receptor, most likely playing a role in regulating LPS-dependent monocyte responses. LBP belongs to a family of structurally and functionally related proteins, including BPI, plasma cholesteryl ester transfer protein (CETP), and phospholipid transfer protein (PLTP). The LBP gene is found on chromosome 20, directly downstream of the BPI gene. LBP catalyzes the transfer of LPS monomers from LPS aggregates to HDL particles, to phospholipid bilayers, and to a binding site on soluble CD14 (sCD14). sCD14 is capable of speeding up the transfer by receiving an LPS monomer from an LPS aggregate, and then yielding it to an HDL particle, therefore acting as a soluble 'shuttle' for an insoluble lipid.