IgG binding peptides and multifunctional antigen-binding proteins comprising the same
Disclosed herein are multifunctional antigen-binding proteins comprising at least one multifunctional recombinant protein scaffold and at least one antigen-specific binding domain. Polynucleotides encoding the multifunctional antigen-binding proteins, vectors containing the disclosed polynucleotides, and cells that have been genetically engineered to express the polynucleotide are also provided. Methods of using the multifunctional antigen-binding proteins are disclosed.
1. A multifunctional antigen-binding protein comprising, at least one multifunctional recombinant protein scaffold that binds to IgG and at least one antigen-specific binding domain,
wherein the at least one multifunctional recombinant protein scaffold that binds to IgG comprises a human polypeptide that contains mutations that enable the polypeptide to mimic the IgG binding domain of protein A,
wherein the at least one multifunctional recombinant protein scaffold comprises a polypeptide that is:
(a) at east 90% identical to huZZ as set forth in SEQ ID NO:28; or
(b) at least 90% identical to huZZ1 as set forth in SEQ ID NO:29; and
wherein the at least one antigen-specific binding domain comprises an antigen-specific peptide, an antigen-specific antibody or fragment thereof, or a combination thereof.
2. The multifunctional antigen-binding protein of claim 1 , wherein the at least one multifunctional recombinant protein scaffold that binds to IgG comprises a portion of an alpha2-macroglobulin receptor-associated protein.
3. The multifunctional antigen-binding protein of claim 1 , wherein the at least one multifunctional recombinant protein scaffold has the sequence set forth as SEQ ID NO:28 or SEQ ID NO:29.
4. The multifunctional antigen-binding protein of claim 1 , wherein the at least one multifunctional recombinant protein scaffold is linked to said antigen-specific binding domain and is capable of binding to a protein other than an antigen which can be hound by the antigen-specific binding domain.
5. The multifunctional antigen-binding protein of claim 1 , wherein the antigen-specific peptide comprises a polypeptide that is at least 90% identical to any one of SEQ ID NOs:12-24.
6. The multifunctional antigen-binding protein of claim 1 , wherein the antigen-specific antibody comprises a polypeptide that is at least 90% identical to 4D5scFv as set forth in SEQ ID NO:30.
7. The multifunctional antigen-binding protein of claim 6 , said multifunctional antigen-binding protein having an amino acid sequence that is:
(a) at least 90% identical to 4D5scFv-huZZ as set forth in SEQ NO:31; or
(b) at least 90% identical to 4D5scFv-huZZ1 as set forth in SEQ NO:32.
8. The multifunctional antigen-binding protein of claim 1 , further comprising a protein domain that promotes solubility.
9. The multifunctional antigen-binding protein of claim 1 , further comprising an epitope tag, a fluorophore, a radio isotope, an enzyme, or any combination thereof.
10. The multifunctional antigen-binding protein of claim 9 , wherein said epitope tag is a poly-histidine tag.
11. The multifunctional antigen-binding protein of claim 1 , further comprising a linker having one or more glycine residues, wherein said linker connects the at least one multifunctional recombinant protein scaffold to the at least one antigen-specific binding domain.
12. The multifunctional antigen-binding protein of claim 11 , wherein the linker comprises a polypeptide that is at least 90% identical to SEQ ID NO:25 or SEQ ID NO:26.
13. The multifunctional antigen-binding protein of claim 1 , further comprising an interferon (IFN) polypeptide or portion thereof.
14. The multifunctional antigen-binding protein of claim 13 , said multifunctional antigen-binding protein having an amino acid sequence that is:
(a) at least 90% identical to 4D5scFv-huZZ-hIFN as set forth in SEQ ID NO:33;
(b) at least 90% identical to 4D5scFv-huZZ-mIFN as set forth in SEQ ID NO:34;
(c) at least 90% identical to 4D5scFv-huZZ1-hIFN as set forth in SEQ ID NO:35; or
(d) at least 90% identical to 4D5scFv-huZZ1-mIFN as set forth in SEQ NO:36.
15. A polynucleotide encoding the multifunctional antigen-binding protein of claim 1 .
16. A cell that has been genetically engineered to express the polynucleotide of claim 15 .
17. A composition comprising the multifunctional antigen-binding protein of claim 1 and a pharmaceutically acceptable carrier.
18. A polypeptide comprising the sequence as set forth in SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ NO:34, SEQ ID NO:35, or SEQ ID NO:36.
19. A polynucleotide encoding the polypeptide of claim 18 .