Methods for removing suspended particles from soluble protein solutions

Abstract

The present invention provides soluble protein solutions, free of suspended particles in high yield. More particularly, the current invention provides a method for removing suspended particles from soluble protein solutions by filtering the soluble protein solution through highly purified diatomaceous earth.

1 - 23 . (canceled)  
     
     
         24 . A method for removing suspended particles from a soluble protein solution comprising the step of: 
 filtering the soluble protein solution through highly purified diatomaceous earth, thereby providing a clarified soluble protein solution;    reducing the amount of DNA and endotoxins, wherein the protein solution is a lysate; and,    purifying the soluble protein solution.    
     
     
         25 . A method for removing suspended particles from a soluble protein solution comprising the step of: 
 filtering the soluble protein solution through highly purified diatomaceous earth, thereby providing a clarified soluble protein solution;    reducing the amount of DNA and endotoxins, wherein the protein solution is a lysate, wherein the soluble protein solution is stirred with a highly purified diatomaceous earth before filtering through a filter press.    
     
     
         30 . The method of one of claims  24  or  25  wherein the protein comprises cysteine residues and those residues are protected by treating the residues with a protecting group selected from the group consisting of disulfides, sulfenyl compounds, thiocarbamates, thioesters, and thioethers.  
     
     
         31 . The method of one of claims  24  or  25  wherein the protein comprises a cysteine residue and the residue is blocked by oxidation.  
     
     
         32 . The method of  claim 24  further comprising the step of removing the protecting group.  
     
     
         33 . The method of  claim 25  further comprising the step of deblocking the residue with a reducing agent.