[SPR detection of affinity of antibacterial peptides in bactericidal/permeability-increasing protein domain for endotoxin].
OBJECTIVE
To study the affinity of endotoxin for three antibacterial peptides derived from N-terminal domain of bactericidal/permeability-increasing protein(BPI).


METHODS
To design and synthesize three peptides from N-terminal domain of BPI, BPI22-36, BPI85-99 and BPI147-161.Surface plasmon resonance(SPR) was used to monitor the interaction between LPS/lipid A and the peptides and polymyxin B(PMB) immobilized on CM5 sensor chip.


RESULTS
In three peptides, BPI147-161 was proved to have a best binding capacity with LPS/lipid A, followed by BPI85-99, but BPI22-36 could not interact with LPS/lipid A.The affinity constant K(A) of BPI147-161 with lipid A was 1.12 x 10⁶ L/mol. In contrast, the K(A) of PMB was 5.58 x 10⁶ L/mol.


CONCLUSIONS
The results suggest that the peptide BPI147-161 from BPI effectively neutralize endotoxin and probably provide a novel treatment method for septic shock.
Department of Laboratory Science, Yanjing Medical College, Beijing 101300, China.
Jing-qin
JQ
Li
Qing-li
QL
Kong
Zheng
Z
Fan
D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D001798:Blood Proteins / Q000737:chemistry*; D004731:Endotoxins / Q000737:chemistry*; D008050:Lipid A / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*
D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D004731:Endotoxins; D008050:Lipid A; D008070:Lipopolysaccharides; C021623:bactericidal permeability increasing protein