Method for purifying or detecting a target protein

Abstract

The invention relates to a method for purifying or detecting a target protein present in a solution, wherein said method comprises, before carrying out the purification or detection step itself, the step of contacting said solution with an aptamer binding specifically to said target protein, wherein said aptamer does not bind to any protein homologous to said target protein that could also be present in the solution.

1 .- 27 . (canceled) 
     
     
         28 . A method for purifying a target protein present in a biological solution, comprising:
 contacting the biological solution with a single stranded DNA aptamer immobilized onto a solid support through a spacer, wherein the immobilized aptamer binds specifically to the target protein but not to any protein homologous to the target protein; and then   purifying the target protein,   wherein the target protein is obtained from a non-human transgenic animal, and the target protein is Factor IX, Factor X, Factor XIII, antithrombin III, protein C, or protein S.   
     
     
         29 . A method according to  claim 28 , wherein the biological solution is a non-human transgenic mammal's milk, a non-human transgenic mammal's milk-derived product, or a non-human transgenic mammal's clarified milk. 
     
     
         30 . A method according to  claim 28 , wherein the target protein has an amino-acid sequence identity of more than 50% with the homologous protein. 
     
     
         31 . A method according to  claim 28 , wherein the target protein has a glycosylation homology with said homologous protein. 
     
     
         32 . A method according to  claim 28 , wherein the solid support is a chip, an affinity chromatography column, a magnetic or para-magnetic bead, or a membrane. 
     
     
         33 . A method according to  claim 28 , wherein said spacer is a non specific oligonucleotide sequence or a sequence of the polyethylene glycol (PEG) type. 
     
     
         34 . A method for purifying specifically a target protein from a solution which contains the target protein and which may contain a protein homologous to the target protein, comprising:
 a) providing a solid support comprising a DNA aptamer immobilized onto the solid support through a spacer, wherein the immobilized aptamer specifically binds to the target protein but not to a protein homologous to the target protein,   b) contacting the solid support with the solution, and   c) recovering the target protein bound to the aptamer,   wherein the target protein is obtained from a non-human transgenic animal, and the target protein is Factor IX, Factor X, Factor XIII, antithrombin III, protein C, or protein S.   
     
     
         35 . A method according to  claim 34 , wherein the biological solution is a non-human transgenic mammal's milk, a non-human transgenic mammal's milk-derived product, or a non-human transgenic mammal's clarified milk. 
     
     
         36 . A method according to  claim 34 , wherein the target protein has an amino-acid sequence identity of more than 50% with the homologous protein. 
     
     
         37 . A method according to  claim 34 , wherein the solid support is a chip, an affinity chromatography column, a magnetic or para-magnetic bead, or a membrane. 
     
     
         38 . A method according to  claim 34 , wherein the spacer is a non specific oligonucleotide sequence or a sequence of the polyethylene glycol (PEG) type.