Title:  Biologically active peptides from functional domains of bactericidal/permeability-increasing protein and uses thereof

United States Patent:  6,228,834

Assignee:  Xoma Corporation (Berkeley, CA)

Filed:  June 8, 1998

The present invention provides peptides having an amino acid sequence that is the amino acid sequence of a human bactericidal/permeability-increasing protein (BPI) functional domain or a subsequence thereof, and variants of the sequence or subsequence thereof, having at least one of the BPI biological activities, such as heparin binding, heparin neutralization, LPS binding, LPS neutralization or bactericidal activity. The invention provides peptides and pharmaceutical compositions of such peptides for a variety of therapeutic uses.

SUMMARY OF THE INVENTION

This invention provides small, readily-produced peptides having an amino acid sequence that is the amino acid sequence of a BPI functional domain or a subsequence thereof and variants of the sequence or subsequence having at least one of the biological activities of BPI, such as heparin binding, heparin neutralization, LPS binding, LPS neutralization or bactericidal activity. The functional domains of BPI discovered and described herein include: domain I, encompassing the amino acid sequence of BPI from about amino acid 17 to about amino acid 45; domain II, encompassing the amino acid sequence of BPI from about amino acid 65 to about amino acid 99; and domain III, encompassing the amino acid sequence of BPI from about amino acid 142 to about amino acid 169. Thus, the BPI functional domain peptides are based on the amino-terminal portion of human BPI.

The peptides of the invention include linear and cyclized peptides, and peptides that are linear, cyclized and branched-chain combinations of particular BPI functional domain amino acid sequences or subsequences thereof and variants of the sequence or subsequence. Combination peptides include peptides having the sequence or subsequence and variants of the sequence or subsequence of the same or different functional domains of BPI that are covalently linked together. Specifically included are combinations from two to about 10 peptides of any particular sequence or subsequence thereof and variants of that sequence or subsequence. The invention also provides peptides having additional biological activities distinct from the known biological activities of BPI, including but not limited to bactericidal activity having an altered target cell species specificity. Peptides having particular biological properties of BPI that are enhanced or decreased compared with the biological properties of BPI are also provided.

The peptides of the invention include linear and cyclized peptides, and peptides that are linear, cyclized and branched-chain amino acid substitution and additional variants of particular BPI functional domain amino acid sequences or subsequences thereof. For the substitution variants, amino acid residues at one or more positions in each of the peptides are replaced with a different amino acid residue (including atypical amino acid residues) from that found in the corresponding position of the BPI functional domain from which the specific peptide is derived. For the addition variants, peptides may include up to about a total of 10 additional amino acids, covalently linked to either the amino-terminal or carboxyl-terminal extent, or both, of the BPI functional domain peptides herein described. Such additional amino acids may duplicate amino acids in BPI contiguous to a functional domain or may be unrelated to BPI amino acid sequences and may include atypical amino acids. Linear, cyclized, and branched-chain combination embodiments of the amino acid substitution and addition variant peptides are also provided as peptides of the invention, as are cyclized embodiments of each of the aforementioned BPI functional domain peptides. In addition, peptides of the invention may be provided as fusion proteins with other functional targeting agents, such as immunoglobulin fragments. Addition variants include derivatives and modifications of amino acid side chain chemical groups such as amines, carboxylic acids, alkyl and phenyl groups.

The invention provides pharmaceutical compositions for use in treating mammals for neutralizing endotoxin, killing Gram-negative and Gram-positive bacteria and fungi, neutralizing the anticoagulant properties of heparin, inhibiting angiogenesis, inhibiting tumor and endothelial cell proliferation, and treating chronic inflammatory disease states. The pharmaceutical compositions comprise unit dosages of the BPI peptides of this invention in solid, semi-solid and liquid dosage forms such as tablet pills, powder, liquid solution or suspensions and injectable and infusible solutions.

This invention provides peptides having an amino acid sequence which is the amino acid sequence of human BPI from about position 17 to about position 45 comprising functional domain I, having the sequence:

Domain I ASQQGTAALQKELKRIKIPDYSDSFKIKH (SEQ ID NO:1);

and subsequences thereof which have biological activity, including but not limited to one or more of the activities of BPI, for example, bactericidal activity, LPS binding, LPS neutralization, heparin binding or heparin neutralization. Also provided in this aspect of the invention are peptides having substantially the same amino acid sequence of the functional domain I peptides having the amino acid sequence of BPI from about position 17 to about position 45 or subsequences thereof. Additionally, the invention provides peptides which contain two or more of the same or different domain I peptides or subsequence peptides covalently linked together.

This invention provides peptides having an amino acid sequence which as is the amino acid sequence of human BPI from about position 65 to about position 99 comprising functional domain II, having the sequence:

Domain II SSQISMVPNVGLKFSISNANJKISGKWKAQKRFLK (SEQ ID NO:6);

and subsequences thereof which have biological activity, including but not limited to one or more of the activities of BPI, for example, bactericidal activity, LPS binding, LPS neutralization, heparin binding or heparin neutralization. Also provided in this aspect of the invention are peptides having substantially the same amino acid sequence of the functional domain II peptides having the amino acid sequence of BPI from about position 65 to about position 99 or subsequences thereof. Additionally, the invention provides peptides which contain two or more of the same or different domain II peptides or subsequence peptides covalently linked together.

The invention also provides peptides having an amino acid sequence which is the amino acid sequence of human BPI from about position 142 to about position 169 comprising functional domain III, having the sequence:

Domain III VHVHISKSKVGWLIQLFHKKIESALRNK (SEQ ID NO: 12);

and subsequences thereof which have biological activity, including but not limited to one or more of the activities of BPI, for example, bactericidal activity, LPS binding, LPS neutralization, heparin binding or heparin neutralization. Also provided in this aspect of the invention are peptides having substantially the same amino acid sequence of the functional domain III peptides having the amino acid sequence of BPI from about position 142 to about position 169 or subsequences thereof. Additionally, the invention provides peptides which contain two or more of the same or different domain III peptides or subsequence peptides covalently linked together.

Also provided by this invention are interdomain combination peptides, wherein two or more peptides from different functional domains or subsequences and variants thereof are covalently linked together. Linear, cyclized and branched-chain embodiments of these interdomain combination peptides are provided.

The peptides of this invention have as one aspect of their utility at least one of the known activities of BPI, including LPS binding, LPS neutralization, heparin binding, heparin neutralization and bactericidal activity against Gram-negative bacteria. Additionally and surprisingly, some of the peptides of this invention have utility as bactericidal agents against Gram-positive bacteria. Another surprising and unexpected utility of some of the peptides of this invention is as fungicidal agents. Peptides of this invention provide a new class of antibiotic molecules with the dual properties of neutralizing endotoxin and killing the endotoxin-producing bacteria, useful in the treatment of mammals suffering from diseases or conditions caused by Gram-negative bacteria. Peptides of this invention that retain this dual activity and additionally have an increased antibiotic spectrum represent an additional new class of antimicrobial agents. In addition, peptides of the invention provide a class of antimicrobial agents useful in the treatment of infections by microbial strains that are resistant to traditional antibiotics but are sensitive to the permeability-increasing antimicrobial activity of peptides of the invention.

The invention also provides pharmaceutical compositions of the peptides of the invention comprising the peptides or combinations of the peptides in a pharmaceutically-acceptable carrier or diluent, both per se and for use in methods of treating pathological or disease states or for other appropriate therapeutic uses. Methods of using these pharmaceutical compositions for the treatment of pathological or disease states in a mammal, including humans, are also provided by the invention. Also provided by the invention are uses of BPI functional domain peptide for the manufacture of medicaments for a variety of therapeutic applications.

Claim 1 of 10 Claims

What is claimed is:

1. A method for treating gram-negative bacterial infection and the sequelae thereof in a subject comprising administering an effective amount of a peptide which has an amino acid sequence of human bactericidal/permeability-increasing protein (BPI) from about position 17 to about position 45 of SEQ ID NO: 69, subsequences thereof and variants of the sequence or subsequence thereof, having a biological activity that is an activity of BPI of LPS binding, LPS neutralization or bactericidal activity.

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