IL-6 receptor IL-6 direct fusion protein

Abstract

The present invention intends to provide an IL-6R•IL-6 fusion protein and the like in which IL-6R and IL-6 are directly linked without a linker. The IL-6 receptor•IL-6 fusion protein of the present invention has a structure in which one amino acid residue constituting IL-6 receptor and one amino acid residue constituting IL-6 are directly bonded.

1 . An IL-6 receptor•IL-6 fusion protein, in which one amino acid residue constituting IL-6 receptor and one amino acid residue constituting IL-6 are directly linked.  
     
     
         2 . An IL-6 receptor•IL-6 fusion protein, in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.  
     
     
         3 . A gene for coding for IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6R and one amino acid residue of IL-6 are linked directly.  
     
     
         4 . The gene according to  claim 3 , wherein the gene codes for IL-6 receptor•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.  
     
     
         5 . A yeast of  Pichia pastoris  species which is transformed by an expression vector containing a gene for coding for IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are linked directly.  
     
     
         6 . The yeast of  Pichia pastoris  species according to  claim 5 , which is transformed by an expression vector containing a gene for coding for IL-6R•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.  
     
     
         7 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising a step of cultivating in a culture medium a yeast of a  Pichia pastoris  species having been transformed by an expression vector containing a gene for coding for an IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are linked directly; and a step of collecting the IL-6 receptor•IL-6 fusion protein as a secretory protein from the culture medium.  
     
     
         8 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising a step of cultivating in a culture medium a yeast of a  Pichia pastoris  species set forth in  claim 5  having been transformed by an expression vector containing a gene for coding for an IL-6 receptor•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6; and a step of collecting the IL-6 receptor•IL-6 fusion protein as a secretory protein from the culture medium.  
     
     
         9 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising a step of cultivating a yeast of a  Pichia pastoris  species having been transformed by an expression vector containing a gene for coding for an IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are linked directly, in a culture medium of natural origin containing a carbon source and no methanol, and adding methanol during progress of the cultivation.  
     
     
         10 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising a step of cultivating a yeast of a  Pichia pastoris  species having been transformed by an expression vector containing a gene for coding for an IL-6 receptor•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.  
     
     
         11 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising collecting the IL-6 receptor•IL-6 fusion protein by treating a solution containing IL-6 receptor•IL-6 fusion protein, in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are linked directly, by three kinds of chromatography including ion-exchange chromatography, hydrophobic chromatography, and gel-filtration chromatography to collect the IL-6 receptor•IL-6 fusion protein.  
     
     
         12 . A process for producing an IL-6 receptor•IL-6 fusion protein, comprising collecting the IL-6 receptor•IL-6 fusion protein by treating a solution containing IL-6 receptor•IL-6 fusion protein, in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6, by three kinds of chromatography including ion-exchange chromatography, hydrophobic chromatography, and gel-filtration chromatography to collect the IL-6 receptor•IL-6 fusion protein.  
     
     
         13 . An ex vivo amplifier for a hematopoietic stem cells, comprising an IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are directly linked.  
     
     
         14 . An ex vivo amplifier for a hematopoietic stem cells, comprising an IL-6 receptor•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.  
     
     
         15 . A blood platelet proliferating agent containing as a main component an IL-6 receptor•IL-6 fusion protein in which one amino acid residue of IL-6 receptor and one amino acid residue of IL-6 are directly linked.  
     
     
         16 . A blood platelet proliferating agent containing as a main component an IL-6 receptor•IL-6 fusion protein in which C-terminal of any one of 39 amino acid residues of from N-terminal 323th alanine residue to N-terminal 361th serine residue of IL-6 receptor is linked to an N-terminal amino acid residue of IL-6.