Labeled protein and its producing method, labeling compound to be used in the method, and method for analyzing function of genes

Abstract

A protein having a labeling compound attached to its C-terminal, in which the compound comprises a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in a cell-free protein synthesis system or in a living cell is provided. Also, a method for producing the protein comprising the step of performing synthesis of a protein in a cell-free protein synthesis system or in a living cell in the presence of a labeling compound comprising a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in the cell-free protein synthesis system or in the living cell, the labeling compound being present at a concentration effective for the labeling compound to bind to the C-terminal of the synthesized protein is provided. Also, the labeling compound and a method for analyzing a function of a gene are further provided.

What is claimed is:  
     
         1 . A protein having a labeling compound attached to its C-terminal, in which said compound comprises a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in a cell-free protein synthesis system or in a living cell.  
     
     
         2 . The protein according to    claim 1   , wherein said label portion comprises a radioactive substance or a non-radioactive label substance.  
     
     
         3 . The protein according to    claim 1   , wherein said acceptor portion comprises a nucleic acid derivative.  
     
     
         4 . The protein according to    claim 1   , wherein said acceptor portion comprises a compound in which a nucleic acid and an amino acid or an amino acid derivative are bound to each other.  
     
     
         5 . The protein according to    claim 1   , wherein said acceptor portion comprises a compound in which 2′- or 3′-aminoadenosine or its derivative and an amino acid or an amino acid derivative are bound to each other.  
     
     
         6 . The protein according to    claim 1   , wherein said acceptor portion comprises puromycin or its derivative.  
     
     
         7 . A method for producing the protein as defined in    claim 1   , comprising the step of carrying out synthesis of a protein in a cell-free protein synthesis system or in a living cell in the presence of a labeling compound comprising a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in the cell-free protein synthesis system or in the living cell, said labeling compound being present at a concentration effective for said labeling compound to bind to the C-terminal of the synthesized protein.  
     
     
         8 . A labeling compound for labeling a protein, comprising a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in a cell-free protein synthesis system or in a living cell.  
     
     
         9 . A method for analyzing a function of a gene, comprising the steps of: 
 adding a nucleic acid containing the gene to a cell-free protein synthesis system as a template; and    carrying out protein synthesis in the presence of a labeling compound comprising a label portion comprising a label substance and an acceptor portion comprising a compound having an ability of binding to a C-terminal of a synthesized protein when protein synthesis is carried out in a cell-free protein synthesis system or in a living cell to obtain a protein having the labeling compound attached to the C-terminal of the protein, said labeling compound being present at a concentration effective for said labeling compound to bind to the C-terminal of the synthesized protein; and    analyzing a function of the labeled protein.    
     
     
         10 . The method according to    claim 9   , wherein said analysis of the function of protein comprises determination of a protein-protein interaction.  
     
     
         11 . The method according to    claim 9   , wherein said analysis of the function of protein comprises determination of a protein-nucleic acid interaction.  
     
     
         12 . The method according to    claim 9   , wherein said analysis of the function of protein comprises determination of an interaction between a protein and a ligand capable of specifically binding to the protein.