Patent Evaluation: Protein Fragments as Antibacterial Agents

Summary

Novelty: Methods for neutralizing lipopolysaccharide (LPS) in a mammal suffering from an infection caused by Gram-negative bacteria are disclosed. These consist of administering an amount of bactericidal/permeability-increasing protein (BPI) sufficient to neutralize the LPS. Purified isolated proteins consisting of amino acid residues 1-199 and 1-203 of BPI are fully described.

Biology: The antibacterial effects of the 25 kDa human BPI fragment were compared with the known activities of the holoprotein. The isolated 25 kDa fragment killed E.coli J5, a strain of bacteria highly sensitive to the holoprotein, in a dose-dependent manner. The fragment was found to be about twice as potent as the holoprotein on a mass basis. The effectiveness of the 25 kDa fragment towards a smooth E.coli strain O111:B4 was compared with that of the holoprotein. The 25 kDa fragment was about five times more potent than the holoprotein toward E. coli O111:B4.