Synthetic peptides with bactericidal activity and endotoxin neutralizing activity for gram negative bacteria and methods for their use

DETAILED DESCRIPTION OF THE INVENTION The invention provides for peptides derived from a neutrophil bacterial permeability protein (B/PI).
The peptides are those that are biologically active for bacterial killing or endotoxin neutralization or both.
Preferably, the peptides are about 10 to about 100 amino acids long and contain hydrophilic regions based upon the hydropathy plot of B/PI of Table 1.
The peptides can be modified in many ways including by addition of N- and/or C-terminal cysteine residues.
The peptides are useful in pharmaceutical compositions to treat and prevent bacterial infections and endotoxin shock.
The peptides may also be useful to prevent the growth of bacteria on surfaces.
The invention, therefore, also provides for methods of using the peptides to treat and prevent bacterial infection and endotoxin shock.
A.
Isolation of Bacteria Permeability Protein from Neutrophils and Selection of Biologically Active PePtides A bactericidal protein (B/PI) having a molecular weight of 55,000 daltons as determined by SDS-PAGE can be isolated from human neutrophils.
Briefly, a granular extract from human neutrophils can be separated by Orange A (Amicon Corp.
, Beverly, Mass.
) column chromatography.
Fractions having bactericidal activity for P.
aeruginosa can be pooled and separated by cation exchange chromatography.
Fractions having bactericidal activity can be pooled and further separated by molecular-sieving chromatography.
Fractions having bactericidal activity can be pooled and characterized by SDS-PAGE.
The B/PI protein can be further characterized by its amino acid sequence.
A cDNA sequence coding for B/PI generated by standard methods provides the predicted amino acid sequence for B/PI as shown in FIG.
4 and FIG.
8.
Isolated native B/PI has the N-terminal amino acid sequence of: VNPGVVVRISQKGLDYASQQG (SEQ ID NO:5) which is in agreement with the predicted amino acid sequence for the N-terminal region of B/PI shown in FIG.
4 and FIG.
8.
Once the predicted amino acid sequence of B/PI is known, biologically active peptides having an amino acid sequence derived from or corresponding to that of B/PI can be selected and/or modified