AFFINITIES OF PEPTIDE (BNEP) MIMICKING BACTERICIDALITY/PERMEABILITY-INCREASING PROTEIN FOR LIPOPOLYSACCHARIDE AND Lipid A BY BIOSENSOR TECHNOLOGY / 解放军医学杂志

ABSTRACT

To explore the mechamisms of bactericidal neutralizing endotoxin peptide(BNEP), a synthetic peptide mimicking bactericidality/permeability-increasing protein (BPI). The affinities of BNEP for LPS and Lipid A were determined with biosensor technology, and the ability of BNEP neutralizing LPS in vitro was tested by quantitative limulus amoebocyte lysate assay. The results showed that BNEP had high affinities for both LPS and Lipid A. The Kd value for LPS was at the level between 25.8 and 48.8nmol/L and for Lipid A from 11.8 to 21.8nmol/L. When 8?g/ml of BNEP was used, it could completely neutralize the concentration of 2ng/ml of LPS in vitro. It is concluded that BNEP has high binding affinities for both LPS and Lipid A. Our results also suggest that the binding site of LPS is at the glucosaminyl-?1'-6-glucosamine disaccharide of Lipid A. The binding activity of BNEP for LPS is in accord with its neutralizing activity for LPS.