Methods for selective targeting

Abstract

A selective targeting method is disclosed comprising contacting a library of ligands, particularly a peptide library, with an anti-target to allow the ligands to bind to the anti-target; separating the non-binding ligands from the anti-target bound ligands, contacting the non-binding anti-target ligands with a target allowing the unbound ligands to bind with the target to form a target-bound ligand complex; separating the target-bound ligand complex from ligands which do not bind to the target, and identifying the target-bound ligands on the target-bound ligand complex wherein the target-bound ligands have a K D in the range of about 10 −7 to 10 −10 M. Additionally claimed are the ligands identified according to the method.

What is claimed:  
     
         1 . A method for screening a peptide library comprising the steps of, 
 (a) contacting the peptide library with an anti-target to allow the peptides to bind with said anti-target;    (b) separating unbound peptides;    (c) contacting the unbound peptides with a selected target to allow said unbound peptides to bind with the target to form a target-bound peptide complex;    (d) separating said target-bound peptide complex from peptides which do not bind to said target; and    (e) identifying the target-bound peptides on the target-bound peptide complex.    
     
     
         2 . The method according to  claim 1 , wherein step (a), (b), (c) or (d) is repeated between 2 to 10 times.  
     
     
         3 . A method for screening a peptide library comprising the steps of, 
 (a) contacting the peptide library with a selected target and an anti-target essentially simultaneously to allow the peptides to bind with said target to form a target-bound peptide complex;    (b) separating the target-bound peptide complex from the anti-target, anti-target bound peptides and free peptides; and    (c) identifying the target-bound peptides on the target-bound peptide complex.    
     
     
         4 . The method according to  claim 3 , wherein said contacting step is in vivo.  
     
     
         5 . The method according to  claim 3 , wherein said contacting step is in vitro.  
     
     
         6 . The method according to  claim 1  or  3 , wherein the target-bound peptides bind with a selectivity corresponding to at least 10:1 and have a K D  in the range of at least about 10 −7  M .  
     
     
         7 . The method according to  claim 1  or  3 , wherein k off  is about 10 −4  sec −1  or less.  
     
     
         8 . The method according to  claim 1  or  3 , wherein the identifying step comprises amplifying a nucleic acid coding for the target-bound peptide in a polymerase chain reaction.  
     
     
         9 . The method according to  claim 3 , wherein the target-bound peptide is not released from the target during the identifying step.  
     
     
         10 . The method according to  claim 1  or  3 , wherein the peptides are fused to a phage coat protein.  
     
     
         11 . The method according to  claim 1  or  3 , wherein separating said target-bound peptide further includes an acid elution step.  
     
     
         12 . The method according to  claim 1  or  3 , wherein the identified target-bound peptides are less than 25 amino acids in length.  
     
     
         13 . The method according to  claim 1  or  3 , wherein the selectivity of the peptide binding affinity to the target compared to the peptide binding affinity to the anti-target is at least 20:1.  
     
     
         14 . The method according to  claim 1  or  3 , wherein the anti-target is skin or hair.  
     
     
         15 . The method according to  claim 1  or  3 , wherein the target is a cytokine selected from the group consisting of TNF and VEGF.  
     
     
         16 . The method according to  claim 1  or  3 , wherein the target is a stain.  
     
     
         17 . The method according to  claim 1  or  3 , wherein the target is a cell surface receptor.  
     
     
         18 . The method according to  claim 1  or  3 , wherein the target is a hematopoietic cell.  
     
     
         19 . The method according to  claim 1  or  3 , wherein the target is a protease enzyme and the anti-target is a different protease enzyme.  
     
     
         20 . A peptide identified according to the method of  claim 1  or  3 .  
     
     
         21 . A peptide identified according to the method of  claim 15 , wherein said peptide has the amino acid sequence of any one sequence of SEQ ID NOS:3-17 or 79-102, or an amino acid sequence having at least 85% sequence identity thereto.  
     
     
         22 . A method for identifying peptides useful in a cleaning composition comprising the steps of, 
 (a) contacting a peptide library with an anti-target to allow said peptides to bind with the anti-target, wherein the anti-target is selected from the group consisting of fabric, ceramic, glass, stainless steel and plastic;    (b) separating unbound anti-target peptides;    (c) contacting said unbound anti-target peptides with a target, wherein the target is a stain selected from the group consisting of porphyrin derived stains, tannin derived stains, carotenoid pigment derived stains, anthocyanin pigment derived stains, soil-based stains, oil-based stains, and human body soil stains to allow said unbound peptides to bind with the stain to form a stain-bound peptide complex; and    (d) identifying the stain-bound peptides on the stain-bound peptide complex.    
     
     
         23 . The method according to  claim 22 , wherein the cleaning composition is a detergent composition.  
     
     
         24 . A cleaning composition comprising a peptide identified according to  claim 22  and one or more surfactants.  
     
     
         25 . The method according to  claim 22 , wherein the fabric is selected from the group consisting of cotton, wool, silk, polyester, rayon, linen, nylon and blends thereof.  
     
     
         26 . The method according to  claim 22 , wherein the stain is selected from the group consisting of blood, chlorophyll, bilirubin, tea, wine, tomato, and berries.  
     
     
         27 . A peptide identified according to the method of  claim 22 , wherein said peptide can bind to the target stain with a K D  in the range of about 10 −7  M to 10 −10  M.  
     
     
         28 . A peptide identified according to the method of  claim 22 , wherein said peptide has the amino acid sequence of any one sequence of SEQ ID NOs: 18-26, or an amino acid sequence having at least 85% sequence identity to any one sequence of SEQ ID NOs: 18-26.  
     
     
         29 . A peptide identified according to the method of  claim 22 , wherein said peptide has the amino acid sequence of any one sequence of SEQ ID NOs: 50-63, or an amino acid sequence having at least 85% sequence identity to any one sequence of SEQ ID NOs: 50-63.  
     
     
         30 . A peptide identified according to the method of  claim 22 , wherein said peptide has the amino acid sequence of any one sequence of SEQ ID NOs: 64-77, or an amino acid sequence having at least 85% sequence identity to any one sequence of SEQ ID NOs: 64-77.  
     
     
         31 . A peptide identified according to the method of  claim 22 , wherein said peptide has the amino acid sequence of any one sequence of SEQ ID NOs: 29-49, or an amino acid sequence having at least 85% sequence identity to any one sequence of SEQ ID NOs: 29-49.  
     
     
         32 . A peptide comprising the amino acid sequence of any one sequence of SEQ ID NOs: 103-113, or an amino acid sequence having at least 90% sequence identity to any one sequence of SEQ ID NOs: 103-113.