Target recognizing binding agents

Abstract

The invention is directed to binding agents having binding loops and a stable beta barrel conformation. The binding loops of these agents can easily be altered so that the binding agent can bind any selected target molecule. A variety of methods for generating binding agents with different binding loops are also provided.

1 . An isolated nucleic acid encoding a polypeptide comprising SEQ ID NO:2 or SEQ ID NO:4. 
     
     
         2 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid comprises SEQ ID NO:1 or SEQ ID NO:3. 
     
     
         3 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid is within a replicable vector or a replicable plasmid. 
     
     
         4 . An isolated nucleic acid comprising SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28 or SEQ ID NO:29. 
     
     
         5 . An expression vector comprising a promoter and a nucleic acid encoding a polypeptide comprising SEQ ID NO:2 or SEQ ID NO:4. 
     
     
         6 . The expression vector of  claim 5 , wherein the polypeptide has five binding loops comprising Xaa amino acids, and wherein the Xaa amino acids are genetically encoded L-amino acids, naturally occurring non-genetically encoded L-amino acids, synthetic L-amino acids or D-entantiomers thereof. 
     
     
         7 . The expression vector of  claim 5 , wherein each Xaa amino acid is exchanged for a specific amino acid and the polypeptide can bind to a selected target molecule. 
     
     
         8 . The expression vector of  claim 5 , wherein the nucleic acid comprises SEQ ID NO:1 or SEQ ID NO:3. 
     
     
         9 . A library of binding agents wherein each binding agent in the library comprises a polypeptide with a sequence comprising amino acids 1-26, amino acids 34-53, amino acids 59-74, amino acids 79-101, amino acids 110-116 and amino acids 123-134 of SEQ ID NO:2. 
     
     
         10 - 15 . (canceled)