Purification of VWF for increased removal of non-lipid enveloped viruses
View Patent ↗The present invention provides methods for purifying Von Willebrand factor (VWF) for increased removal of non-lipid enveloped viruses.
1. A method for removing a non-lipid enveloped virus from a protein-containing solution comprising:
applying the protein-containing solution to a cation exchange resin at a pH of 1.6 pH units or more above the isoelectric point of a protein in the protein-containing solution; and
washing the cation exchange resin with a wash buffer to form an eluate, said wash buffer having a pH that is lower than the pH of the protein-containing solution applied to the cation exchange resin, wherein the protein has a molecular mass of at least about 150 kilodaltons, and whereby the non-lipid enveloped virus is removed from the protein-containing solution.
2. The method of claim 1 , wherein the solution applied to the cation exchange resin is at least 1.8 pH units above the isoelectric point of VWF.
3. The method of claim 1 , wherein the pH of the solution applied to the cation exchange resin is greater than 7.0.
4. The method of claim 1 , wherein the cation exchange resin has a negatively charged group selected from the group consisting of carboxymethyl (CM), sulfoalkyl, sulfated esters of cellulose, heparin and methylsulfonate (S).
5. The method of claim 4 , wherein the negatively charged sulfoalkyl group is sulfopropyl (SP) or sulfoethyl (SE).
6. The method of claim 1 , wherein the pH of the wash buffer is greater than the isoelectric point of the VWF applied to the cation exchange resin.
7. A method for removing a non-lipid enveloped virus from a VWF-containing solution comprising:
applying the solution to a cation exchange resin, wherein the pH of the solution is 2.0 pH units or more above the isoelectric point of VWF; and
washing the cation exchange resin with a wash buffer to form an eluate, said wash buffer having a pH that is equal to or lower than the pH of the solution applied to the cation exchange resin, and whereby the non-lipid enveloped virus is removed from the VWF-containing solution.
8. The method of claim 7 , wherein the pH of the VWF-containing solution and the wash buffer is about 9.0.
9. The method of claim 1 , wherein the VWF-containing solution applied to the cation exchange resin is at least 2.0 pH units above the isoelectric point of the VWF.