Modulation of complement activity

1. A polypeptide of the formula R1-Xaa0-Xaa1-Xaa2-Xaa3-Xaa4-Xaa5-Xaa6-Xaa7-Xaa8-Xaa9-Xaa10-Xaa11-Xaa12-Xaa13-Xaa14-Xaa15-Xaa16-R 2 , wherein:

R 1 is selected from the group consisting of an acetyl group, H, an acyl group, a heptanoyl group, an amide, a carbamate, urea, polyethylene glycol (PEG), hydroxyalkyl starch and chloroacetic acid, or is absent;

Xaa0 is absent or Met;

Xaa1 is selected from the group consisting of Cys, Lys, (S)-2-amino-5-azidopentanoic acid, and 3-thiopropionic acid, or is absent;

Xaa2 is selected from the group consisting of Val, Ala, and D-Ala, or is absent;

Xaa3 is selected from the group consisting of Glu, norvaline, and Ala, or is absent;

Xaa4 is selected from the group consisting of Arg, Cys, Ala, Ser, and norvaline, or is absent;

Xaa5 is selected from the group consisting of Phe, Tyr, N-methyl-tyrosine, and Ala, or is absent;

Xaa6 is selected from the group consisting of Cys, Glu, N-methyl-glutamic acid, Asp, (S)-2-aminopent-4-ynoic acid, and Ala;

Xaa7 is selected from the group consisting of Asp, Asn, N-methyl-asparagine, alpha-methyl L-aspartic acid, (S)-2-amino-3-(1H-tetrazol-5-yl)propanoic acid, N-methyl-aspartic acid, cycloleucine, 4-amino-tetrahydro-pyran-4-carboxylic acid, and Ala;

Xaa8 is selected from the group consisting of tert-butylglycine, Val and Ala;

Xaa9 is Tyr;

Xaa10 is selected from the group consisting of 7-azatryptophan, Trp, 3-aminomethyl-L-phenyalanine, N-methyl-tryptophan, and 1-methyl-tryptophan;

Xaa11 is Glu;

Xaa12 is Tyr;

Xaa13 is Pro;

Xaa14 is selected from the group consisting of cyclohexylglycine, phenylglycine, D-phenylglycine, N-methyl-phenylglycine, amino isobutyric acid, and Ala, or is absent;

Xaa15 is selected from the group consisting of norvaline, Lys, and Pro, or is absent;

Xaa16 is absent or selected from the group consisting of N-ε-palmitoyl lysine, N-ε-lauryl lysine, N-ε-capryl lysine, N-ε-caprylic lysine, B20, B28, K14, Cys, and Lys; and

R 2 is —NH 2 or is absent.

2. The polypeptide of claim 1 , further comprising a bridging moiety between two amino acids.

3. The polypeptide of claim 2 , wherein said bridging moiety comprises a structure selected from the group consisting of structures I-XIX;

wherein each X is independently N or CH, such that no ring contains more than 2 N; each Z is independently a bond, NR, O, S, CH 2 , C(O)NR, NRC(O), S(O) v NR, NRS(O) v ; each m is independently selected from 0, 1, 2, and 3; each v is independently selected from 1 and 2; each R is independently selected from H and C 1 -C 6 ; and each bridging moiety is connected to the polypeptide by independently selected C 0 -C 6 spacers.

4. The polypeptide of claim 2 , wherein the bridging moiety comprises a feature selected from the group consisting of a disulfide bond, an amide bond (lactam), a thioether bond an aromatic ring, an unsaturated aliphatic hydrocarbon chain, a saturated aliphatic hydrocarbon chain and a triazole ring.

5. The polypeptide of any of claim 1 , wherein the peptide comprises a cyclic loop, wherein the cyclic loop is of a length selected from the group consisting of 1 amino acid, 2 amino acids, 3 amino acids, 4 amino acids, 5 amino acids, 6 amino acids, 7 amino acids, 8 amino acids, 9, amino acids, 10 amino acids, 11 amino acids, 12 amino acids, 13 amino acids, 14 amino acids, 15 amino acids and 16 amino acids.

6. The polypeptide of claim 2 , wherein residue Xaa1 is cysteine and wherein the bridging moiety joins residue Xaa1 and Xaa6.

7. The polypeptide of claim 4 , wherein said feature comprises an aromatic ring and wherein said bridging moiety is formed by reaction with a poly(bromomethyl)benzene.

8. The polypeptide of claim 7 , wherein the poly(bromomethyl)benzene is selected from the group consisting of 1,2-bis(bromomethyl)benzene, 1,3-bis(bromomethyl)benzene and 1,4-bis(bromomethyl)benzene.

9. The polypeptide of claim 8 wherein the reagent is 1,3-bis(bromomethyl)benzene.

10. The polypeptide of claim 4 , wherein said feature comprises a disulfide bond between two cysteine residues.

11. The polypeptide of claim 4 , wherein said feature comprises an aromatic ring and wherein said bridging moiety is produced by reaction with a compound selected from the group consisting of 2,6-bis(bromomethyl)pyridine, (E)-1,4-dibromobut-2-ene and 1,2-bis(bromomethyl)-4-alkylbenzene.

12. The polypeptide of claim 1 , wherein said polypeptide is conjugated to a hydrophilic polymer.

13. The polypeptide of claim 12 , wherein the hydrophilic polymer is selected from the group consisting of polyalkylene oxide homopolymers, polypropylene glycols, polyoxyethylenated polyols and copolymers thereof.

14. The polypeptide of claim 12 , wherein the hydrophilic polymer comprises polyethylene glycol (PEG).

15. The polypeptide of claim 14 comprising a polypeptide-PEG conjugate.

16. The polypeptide of claim 14 comprising at least one lipid moiety.

17. The polypeptide of claim 1 , wherein said polypeptide is conjugated to an albumin-binding polypeptide, wherein the albumin-binding polypeptide comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 202-204.

18. The polypeptide of claim 1 , wherein said polypeptide is conjugated to a cell penetrating polypeptide, wherein the cell penetrating polypeptide comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 205-210.

19. A method for treating a complement-related disease, disorder, or condition in a subject, the method comprising administering the polypeptide of claim 1 , wherein the polypeptide inhibits C5 cleavage.

20. The method of claim 19 , wherein the complement-related disease, disorder, or condition comprises hemolysis.

21. The method of claim 20 , wherein the hemolysis is caused by thrombin-induced complement activation.