At present, it is believed that after LPS enters the host blood, it mainly combines with the lipopolysaccharide binding protein (LBP) of the host blood. The main function of LBP is to dissociate the LPS aggregation in the blood into LPS monomers, accelerate the combination of the monomer LPS and CD14, play the role of lipid shuttle and presentation, and have a catalytic function.

LBP has a high affinity for free rough LPS, smooth LPS, and LPS on the cell membrane of gram-negative bacteria. It is easy to bind with LPS and participate in the activation effect of LPS, so it is named. LBP can regulate particles containing LPS and complete gram-negative bacteria, and mediate the attachment of coated particles to macrophages, which is conducive to phagocytosis of macrophages. The negatively charged phosphate radical of the LPS molecule can combine with the related domains of positively charged proteins in LBP and BPI (bactericidal/permeability-enhancing protein), and has the compatibility of spatial conformation. LBP was first discovered and isolated by American scholar Tobias in 1986 from rabbit serum during the acute reaction period of endotoxemia. Lei et al. also isolated LBP from rats in 1988; The next year Robert et al. isolated and obtained LBP molecules from humans and other animals.