Fibronectin type III domain-based fusion proteins

Abstract

Provided herein are fusion proteins including at least one binding polypeptide and at least one unstructured polypeptide. The fusion protein may further include at least one linker. Further provided are methods for determining the presence of a target in a sample, methods of treating a disease, methods of diagnosing a disease in a subject, and methods of determining the effectiveness of a treatment for a disease in a subject. The methods may include administering to the subject an effective amount of the fusion protein.

We claim: 
     
       1. A multivalent fusion protein comprising at least one Fibronectin type III (FnIII) domain that binds TNF-related apoptosis-inducing ligand receptor 2 (TRAILR-2) and comprises SEQ ID NO: 1, and at least one elastin-like polypeptide (ELP) comprising (VPGXG) n  (SEQ ID NO: 19), wherein X is any amino acid except proline and n is an integer greater than or equal to 1, and wherein the ELP has a transition temperature (T t ) of about 10° C. to about 50° C. 
     
     
       2. The multivalent fusion protein of  claim 1 , wherein n is 60, 120, or 180. 
     
     
       3. The multivalent fusion protein of claim 1 , wherein X is valine. 
     
     
       4. The multivalent fusion protein of  claim 1 , wherein the multivalent fusion protein comprises a plurality of the FnIII domain. 
     
     
       5. The multivalent fusion protein of  claim 4 , wherein the multivalent fusion protein comprises 2, 4, or 6 FnIII domains. 
     
     
       6. The multivalent fusion protein of  claim 4 , wherein the multivalent fusion protein further comprises a linker positioned between at least two adjacent FnIII domains. 
     
     
       7. The multivalent fusion protein of  claim 6 , wherein the linker comprises at least one glycine and at least one serine. 
     
     
       8. The multivalent fusion protein of  claim 7 , wherein the linker comprises an amino acid sequence consisting of SEQ ID NO: 3 ((Gly 4 Ser) 3 ). 
     
     
       9. The multivalent fusion protein of  claim 6 , wherein the linker comprises an amino acid sequence consisting of SEQ ID NO: 4. 
     
     
       10. A method for treating cancer in a subject in need thereof, the method comprising administering to the subject an effective amount of the multivalent fusion protein of  claim 1 . 
     
     
       11. The method of  claim 10 , wherein the cancer comprises colorectal adenocarcinoma. 
     
     
       12. The method of  claim 10 , wherein the multivalent fusion protein is administered intravenously, intraarterially, or intraperitoneally to the subject. 
     
     
       13. The method of  claim 10 , wherein the multivalent fusion protein is administered intratumorally. 
     
     
       14. The method of  claim 10 , wherein the multivalent fusion protein forms a depot upon administration to the subject. 
     
     
       15. The method of  claim 10 , wherein the multivalent fusion protein is administered in a controlled release formulation.