LBP (lipopolysaccharide-binding protein) is a glycoprotein with a relative molecular weight of 60000. Its protein structure is a single-chain polypeptide with a relative molecular weight of 5000. It undergoes a glycosylation reaction in the Golgi body and secretes into the blood after maturity to become a glycoprotein. LBP is not heat-resistant, and its activity is usually stable at 50 ℃, and about 50% of its activity is lost between 53 and 56 ℃. When mouse serum or mouse pure LBP was heated to 59 ℃, the activity was completely lost. Human plasma is sensitive to heat. The most common method of inactivating complement (56 ℃, 30 min) can lead to a 70% loss of biological activity of LBP.

At present, it has been clarified that the amino acid sequence of human LBP protein is a mature protein polypeptide chain composed of a signal sequence peptide with 25 amino acid residues and 452 amino acid residues. There are four cysteines and five glycosylation binding sites on the polypeptide chain, which are located at the 275~277, 325~327, 330~332361~363, and 369~371 sites of the polypeptide chain respectively. The protein structure of rabbit LBP is very similar to that of humans. It is also composed of a hydrophobic polypeptide chain composed of 26 amino acid residues and a protein polypeptide chain composed of 456 amino acid residues. Its amino acid sequence is highly homologous with that of humans, with 69% of the same amino acid sequence; The nucleotide sequence is 78% consistent, but only contains 2 cysteines and 3 glycosylation binding sites, which are located at 275~277, 325~327, and 361~363 sites respectively. The chemical spatial conformation of LBP is still unclear, which may be similar to BPI (bactericidal/permeability-enhancing protein).