Stable factor VIII/vWF-complex
There are disclosed a stable factor VIII/vWF-complex, particularly comprising high-molecular vWF multimers, being free from low-molecular vWF molecules and from proteolytic vWF degradation products, as well as a method of producing this complex.
1. A method of recovering stable Factor VIII/von Willebrand Factor (vWF)-complex from a protein solution contaminated with other proteins, wherein the method comprises
binding the Factor VIII/vWF-complex contained in the protein solution to an anion exchanger;
selectively eluting the other proteins with an eluting agent containing a calcium salt and an elution salt, wherein the elution salt is present at a concentration of no more than 200 mM, and
subsequently recovering Factor VIII/vWF-complex from the anion exchanger using a buffer having an elution salt at a concentration of 200 to 400 mM, wherein the buffer is without a calcium salt.
2. The method according to claim 1 , wherein the other proteins are plasma proteins.
3. The method according to claim 2 , wherein the plasma proteins are selected from the group consisting of Vitamin K-dependent Factors, plasma proteases, fibronectin and fibrinogen.
4. The method according to claim 1 , wherein the calcium salt is CaCl 2 and is contained in the eluting agent at a concentration of 1 mM to 15 mM.
5. The method according to claim 4 , wherein the CaCl 2 is contained in the eluting agent at a concentration of 10 mM.
6. The method according to claim 1 , wherein the eluting is carried out at a pH of 6.0 to 8.5.
7. The method according to claim 1 , wherein the eluting is carried out at a pH of 7.4.
8. The method according to claim 1 , wherein the elution salt contained in the eluting agent is NaCl.
9. The method according to claim 1 , wherein a Factor VIII/vWF-complex containing high-molecular vWF multimers is obtained, and the Factor VIII/vWF-complex is free from low-molecular vWF molecules and from vWF degradation products.
10. The method according to claim 1 , further comprising subjecting the Factor VIII/vWF-complex recovered from said anion exchanger to a further chromatographic step.
11. The method according to claim 10 , wherein the further chromatographic step is affinity chromatography.
12. The method according to claim 11 , wherein the affinity chromatography is heparin chromatography carried out with a heparin affinity carrier by binding the Factor VIII/vWF-complex from the protein solution to the heparin affinity carrier in a buffer system and recovering the Factor VIII/vWF-complex at an elution salt concentration of 200 to 300 mM.
13. The method according to claim 12 , wherein the heparin affinity carrier is selected from the group consisting of AF-HEPARIN TOYOPEARL® (synthetic, hydrophilic polymer of large pore size based on methacrylate), HEPARIN EMD-FRACTOGEL® (synthetic, hydrophilic polymer based on ethylene glycol, methacrylate and dimethyl acrylate) and HEPARIN-SEPHAROSE FAST FLOW® (containing natural dextran and agarose derivatives).