Peptide library and use thereof

Abstract

Disclosed are compositions and method related to variants of SPINK2 that bind to targets other than an endogenous target of SPINK2. In one embodiment, a peptide is provided that comprises the amino acid sequence SEQ ID NO: 1. In further embodiments, an amino acid sequences encoded by nucleotide positions 4 to 42 and/or nucleotide positions 94 to 189 in the nucleotide sequence of SEQ ID NO: 14 flank the amino terminus and the carboxyl terminus, respectively, of the amino acid sequence. In another embodiment, a peptide is provided that comprises an amino acid sequence derived from the amino acid sequence of SEQ ID NO: 1 in which a conservative substitution, deletion, addition and/or insertion of 1 to 5 (inclusive) amino acids has occurred at amino acids other than the 1st Xaa to the 12th Xaa counting from the amino terminus.

1 . A peptide selected from the following (i) and (ii):
 (i) a peptide comprising an amino acid sequence encoded by a nucleotide sequence derived from SEQ ID NO: 14 by replacing a nucleotide sequence consisting of the 43rd base thymine to the 93rd base thymine with a nucleotide sequence encoding the amino acid sequence represented by SEQ ID NO: 1; and   (ii) the peptide according to (i) having an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 1 by the amino acid substitution, deletion, addition, and/or insertion of 1 to 5 (inclusive) amino acids except at amino acid positions 2 to 8 and 10 to 14.   
     
     
         2 - 18 . (canceled) 
     
     
         19 . The peptide according to  claim 1 , wherein the peptide comprises the amino acid sequence represented by any one of SEQ ID NOs: 2 to 9. 
     
     
         20 . A derivative of a peptide according to  claim 1 , the derivative being prepared by chemically modifying and/or biologically modifying the peptide. 
     
     
         21 - 29 . (canceled) 
     
     
         30 . A method for identifying a peptide or a peptide derivative that binds to a target molecule, the method comprising the following steps (i) to (iii):
 (i) contacting a plurality of peptides or peptide derivatives with the target molecule, wherein each of the peptides or peptide derivatives has an amino acid sequence encoded by a nucleotide sequence derived from SEQ ID NO: 14 by replacing a nucleotide sequence consisting of the 43rd base thymine to the 93rd base thymine with a nucleotide sequence encoding the amino acid sequence represented by SEQ ID NO: 1;   (ii) the peptides according to (i) having an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 1 by the amino acid substitution, deletion, addition, and/or insertion of 1 to 5 (inclusive) amino acids except at amino acid positions 2 to 8 and 10 to 14; and   (iii) recovering the peptide or the peptide derivative that binds to the target molecule.   
     
     
         31 . A method for producing a peptide or a peptide derivative that binds to a target molecule, the method comprising the following steps (i) to (iv):
 (i) contacting a plurality of peptides or peptide derivatives with the target molecule, wherein each of the peptides or peptide derivatives has an amino acid sequence encoded by a nucleotide sequence derived from SEQ ID NO: 14 by replacing a nucleotide sequence consisting of the 43rd base thymine to the 93rd base thymine with a nucleotide sequence encoding the amino acid sequence represented by SEQ ID NO: 1;   (ii) the peptides according to (i) having an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 1 by the amino acid substitution, deletion, addition, and/or insertion of 1 to 5 (inclusive) amino acids except at amino acid positions 2 to 8 and 10 to 14;   (iii) recovering a peptide or a peptide derivative that binds to the target molecule; and   (iv) preparing, by chemical synthesis, gene recombination, or in vitro translation, a peptide that binds to the target molecule, wherein said peptide corresponds to the peptide or is contained in the peptide derivative recovered in step (iii).   
     
     
         32 . A method for determining whether or not a peptide or a peptide derivative binds to a target molecule, comprising the following steps (i) to (iii):
 (i) contacting test peptides or test peptide derivatives with the target molecule, wherein each of the test peptides or test peptide derivatives has an amino acid sequence encoded by a nucleotide sequence derived from SEQ ID NO: 14 by replacing a nucleotide sequence consisting of the 43rd base thymine to the 93rd base thymine with a nucleotide sequence encoding the amino acid sequence represented by SEQ ID NO: 1;   (ii) the test peptides according to (i) having an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 1 by the amino acid substitution, deletion, addition, and/or insertion of 1 to 5 (inclusive) amino acids except at amino acid positions 2 to 8 and 10 to 14; and   (iii) determining that the test peptide or the test peptide derivative is positive for binding, when the test peptide or the test peptide derivative binds to the target molecule.   
     
     
         33 . A method for producing a peptide or a peptide derivative that binds to a target molecule, comprising the following steps (i) to (iv):
 (i) contacting test peptides or test peptide derivatives with the target molecule, wherein each of the test peptides or test peptide derivatives has an amino acid sequence encoded by a nucleotide sequence derived from SEQ ID NO: 14 by replacing a nucleotide sequence consisting of the 43rd base thymine to the 93rd base thymine with a nucleotide sequence encoding the amino acid sequence represented by SEQ ID NO: 1;   (ii) the test peptides according to (i) having an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 1 by the amino acid substitution, deletion, addition, and/or insertion of 1 to 5 (inclusive) amino acids except at amino acid positions 2 to 8 and 10 to 14;   (iii) determining that the test peptide or the test peptide derivative is positive for binding, when the test peptide or the test peptide derivative binds to the target molecule; and   (iv) when the test peptide or peptide derivative has been determined to be positive in step (iii), preparing a peptide that binds to the target molecule wherein said peptide corresponds to the peptide or is contained in the peptide derivative by gene recombination or in vitro translation.   
     
     
         34 - 55 . (canceled)