Production and purification of il-29

Abstract

The expression vectors and methods using an E. coli expression system for the large scale production of IL-29 are described. The vectors utilize the IL-29 coding sequence with specific changes in nucleotides in order to optimize codons and mRNA secondary structure for translation in E. coli . Also included are methods of producing, purifying and pegylating an IL-29 polypeptide.

1 . A method of concentrating IL-29 polypeptide comprising:
 (a) providing a solution of purified IL-29 polypeptide;   (b) adding the solution of IL-29 polypeptide to a tangential flow filtration plate and frame system comprising one or more a 3-10 kDa molecular weight cut-off membrane;   (c) applying a transmembrane pressure of 15-25 psi to the system to ultrafilter the solution to a higher concentration; and   (d) filtering the concentrated IL-29 polypeptide through a 0.2 μm membrane.   
     
     
         2 . The method of  claim 1  wherein the filtered IL-29 polypeptide is at least 98% pure by sodium dodecyl sulfate polyacrylamide gel analysis and aggregates are less than 0.2% by size exclusion HPLC. 
     
     
         3 . The method of  claim 1  wherein the filtered IL-29 polypeptide has an endotoxin level of less than 10 endotoxin units per milligram of IL-29 polypeptide in a  Limulus  amoebocyte lysate assay based on USP <85>.