Polypeptides having a functional domain of interest and methods of identifying and using same

Abstract

Novel polypeptides having functional domains of interest are described, along with DNA sequences that encode the same. A method of identifying these polypeptides by means of a sequence-independent (that is, independent of the primary sequence of the polypeptide sought), recognition unit-based functional screen is also disclosed. Various applications of the method and of the polypeptides identified are described, including their use in assay kits for drug discovery, modification, and refinement.

1 . The method of identifying a polypeptide comprising a functional domain of interest comprising:
 (a) contacting a multivalent recognition unit complex with a plurality of polypeptides; and   (b) identifying a polypeptide having a selective binding affinity for said recognition unit complex.   
     
     
         2 . The method of  claim 1  in which said plurality of polypeptides is from a polypeptide expression library. 
     
     
         3 . The method of  claim 1  in which said plurality of polypeptides is obtained from a virus. 
     
     
         4 . The method of  claim 2  in which said expression library is a cDNA expression library. 
     
     
         5 . The method of  claim 2  in which said expression library is a genomic DNA library. 
     
     
         6 . The method of  claim 2  in which said expression library is a recombinant bacteriophage library. 
     
     
         7 . The method of  claim 6  in which said recombinant bacteriophage library is a recombinant M13 library. 
     
     
         8 . The method of  claim 2  in which said expression library is a recombinant plasmid or cosmid library. 
     
     
         9 . The method of  claim 1  in which the recognition unit is a peptide. 
     
     
         10 . The method of  claim 1  in which said recognition unit is a peptide having less than about 140 amino acid residues. 
     
     
         11 . The method of  claim 1  in which said recognition unit is a peptide having less than about 100 amino acid residues. 
     
     
         12 . The method of  claim 1  in which said recognition unit is a peptide having less than about 70 amino acid residues. 
     
     
         13 . The method of  claim 1  in which said recognition unit is a peptide having about 6 to 60 amino acid residues. 
     
     
         14 . The method of  claim 1  in which said recognition unit is a peptide having 20 to 50 amino acid residues. 
     
     
         15 . The method of  claim 1  in which the valency of the recognition unit in the complex is at least two. 
     
     
         16 . The method of  claim 9  in which the valency of the recognition unit in the complex is at least two. 
     
     
         17 . The method of  claim 1  in which the valency of the recognition unit in the complex is at least four. 
     
     
         18 . The method of  claim 9  in which the valency of the recognition unit in the complex is at least four. 
     
     
         19 . The method of  claim 17  in which the recognition unit complex is a complex comprising (a) avidin or streptavidin, and (b) biotinylated recognition units. 
     
     
         20 . The method of  claim 18  in which the recognition unit complex is a complex comprising (a) avidin or streptavidin, and (b) the biotinylated peptides. 
     
     
         21 - 102 . (canceled)