Motif-grafted hybrid polypeptides and uses thereof
Provided herein are hybrid polypeptides that specifically bind to a disease-associated isoform of a polypeptide involved in diseases of protein aggregation. The hybrid polypeptides can be used for diagnosis and treatment of such diseases. In a particular embodiment, a hybrid protein that specifically binds to the infectious form of a prion (PrP Sc ) is provided.
1. A hybrid immunoglobulin or a Fab fragment of the hybrid immunoglobulin that specifically binds to the infectious form of a prion protein, comprising antibody b12 or a fragment thereof, wherein:
residues 119-131 of antibody b12 whose sequence is set forth in SEQ ID NO:4 or corresponding residues in a fragment thereof are replaced with residues 121-158 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species or a portion of residues 121-158 or the corresponding residues that binds to the infectious form of a prion protein.
2. The hybrid immunoglobulin or the Fab fragment of claim 1 that comprises the heavy and light chains of antibody b12, wherein the heavy chain comprises the sequence of amino acids set forth in SEQ ID NO: 4, and the light chain comprises the sequence of amino acids set forth in SEQ ID NO: 2.
3. A hybrid immunoglobulin or a Fab fragment of the hybrid immunoglobulin that specifically binds to the infectious form of a prion protein, comprising antibody b12 or a fragment thereof, wherein:
residues 119-131 of antibody b12 whose sequence is set forth in SEQ ID NO:4 or corresponding residues in a fragment thereof are replaced with residues 87-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues from prion polypeptides of another species or a portion of residues 87-112 or the corresponding residues that binds to the infectious form of a prion protein.
4. A hybrid immunoglobulin polypeptide or a fragment of the hybrid immunoglobulin, wherein:
a polypeptide motif is inserted within a complementarity-determining region (CDR) of the immunoglobulin molecule or fragment thereof, said polypeptide motif consisting of a sufficient number of contiguous amino acid residues from residues 136-158, 89 105, 89-112 or 95-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO:5 or the corresponding residues of a prion polypeptide from another species so that the resulting fragment or hybrid immunoglobulin preferentially binds to the infectious PrP Sc form of the prion compared to the PrP c form; and
the fragment is a Fab, an F(ab)2 or single chain Fv.
5. The hybrid immunoglobulin or the fragment of claim 4 that is a Fab, an F(ab)2 or single chain Fv fragment.
6. A hybrid immunoglobulin or a Fab fragment of the hybrid immunoglobulin, wherein:
a polypeptide motif is inserted within the third complementarity-determining region (CDR) of an immunoglobulin molecule or a Fab fragment of the immunoglobulin molecule, said polypeptide motif consisting of a sufficient number of contiguous amino acid residues from residues 87-169 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species so that the resulting Fab fragment or hybrid immunoglobulin preferentially binds to the infectious PrP Sc form of the prion compared to the PrP c form.
7. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif consists of at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80 residues or up to all of residues 87-169 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species presented in its native non-infectious conformation.
8. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif consists of residues from a portion of a PrP that corresponds to residues 87-169 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
9. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif consists of 10, 15, 20, 25, 30 or 35 contiguous residues that include residues 121-131, 121-141, 121-136, 121-144, 121-158, 87-112, 87-118, 87-130, 126-158, 131-158, 136-158 or 141-158 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
10. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the prion from which the polypeptide motif is derived is an animal prion selected from among prions of humans, hamster, mice, rats, deer, sheep, goats, elk, kudu, horses, dogs, cats, camels and pigs.
11. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif includes at least residues 136-158, 89-105, 89-112 or 95-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
12. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif contains only residues 136-158, 89-105, 89-112 or 95-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
13. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif includes at least residues 145-155 from the PrPc form of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
14. The hybrid immunoglobulin polypeptide or the Fab fragment of claim 6 , wherein the motif contains at least 5, 10, 15, 20, 25, 30 or 35 contiguous residues from the region of residues 119-158 of the prion polypeptide, wherein:
residues from the region are the only prion-derived residues in the polypeptide; and
the residues correspond upon alignment of the prion sequence with the Syrian hamster prion sequence to residues 119-158 of the prion polypeptide whose sequence is set forth in SEQ ID NO: 5 or the corresponding residues from prion polypeptides of other species.
15. The hybrid immunoglobulin polypeptide or the Fab fragment of claim 14 , wherein the prion is an animal prion selected from the group consisting of humans, hamsters, mice, rats, deer, sheep, goats, elk, kudu, horses, dogs, cats, camels and pigs.
16. A solid support comprising a plurality of the hybrid immunoglobulins or the Fab fragments of claim 1 or claim 6 .
17. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the hybrid immunoglobulin or the Fab fragment is antibody b12 or a Fab fragment of antibody b12.
18. The hybrid immunoglobulin polypeptide or the Fab fragment of claim 6 that is a Fab fragment.
19. The hybrid immunoglobulin molecule or the Fab fragment of claim 17 that is a Fab fragment.
20. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein:
the polypeptide motif consists of at least residues 101-106 or at least residues 136-150 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
21. The hybrid immunoglobulin or the Fab fragment of claim 20 , wherein the other species are selected from among sheep, human and cows.
22. The hybrid immunoglobulin or the Fab fragment of claim 20 , wherein the hybrid immunoglobulin polypeptide or the Fab fragment is antibody b12 or a Fab fragment of antibody b12.
23. The hybrid immunoglobulin or the Fab fragment of claim 17 that is the Fab fragment, wherein the polypeptide motif consists of at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80 residues or up to all of residues 87-169 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species presented in its native non-infectious conformation.
24. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment, consisting of at least residues 121-131, 121-141, 121-136, 121-144, 121-158, 87-112, 87-118, 87-130, 126-158, 131-158, 136-158 or 141-158 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
25. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment, wherein the polypeptide motif contains only residues 121-131, 121-141, 121-136, 121-144, 121-158, 87-112, 87-118, 87-130, 126-158, 131-158, 136-158 or 141-158 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
26. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment and contains at least residues 136-158, 89-105, 89-112 or 95-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
27. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment, wherein the polypeptide motif contains only residues 136-158, 89-105, 89-112 or 95-112 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species.
28. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment and contains residues that include at least one α-helix from the PrPc form of the prion.
29. The hybrid immunoglobulin or the Fab fragment of claim 23 that is the Fab fragment, wherein:
the polypeptide motif consists of at least 5, 10, 15, 20, 25, 30 or 35 contiguous residues from the region of residues 119-158 of the Syrian hamster prion polypeptide having a sequence set forth in SEQ ID NO: 5 or the corresponding residues of a prion polypeptide from another species; and
residues from the region are the only prion-derived residues in the polypeptide.
30. The hybrid immunoglobulin or the Fab fragment of claim 29 that is the Fab fragment, wherein the prion is an animal prion selected from the group consisting of humans, hamsters, mice, rats, deer, sheep, goats, elk, kudu, horses, dogs, cats, camels and pigs.
31. The hybrid immunoglobulin polypeptide or the Fab fragment of any of claims 7 , 8 and 10 that is a Fab fragment of the hybrid immunoglobulin.
32. The hybrid immunoglobulin or the Fab fragment of claim 6 , wherein the polypeptide motif contains one or more of at least residues 89-112, 100-106 or 136-141 of the Syrian hamster prion set forth in SEQ ID NO:5 or corresponding residues from a prion polypeptide of another species.
33. The hybrid immunoglobulin polypeptide or the Fab fragment of claim 31 , wherein;
the Fab fragment is an antibody b12 Fab fragment.
34. The hybrid immunoglobulin of claim 1 or claim 3 that is the Fab fragment.
35. The hybrid immunoglobulin or the Fab fragment of claim 14 that is the Fab fragment.
36. The hybrid immunoglobulin or the Fab fragment of claim 20 that is the Fab fragment.
37. The hybrid immunoglobulin or the Fab fragment of claim 15 that is the Fab fragment.