Removal of serine proteases by treatment with finely divided silicon dioxide
View Patent ↗The present invention provides novel methods for reducing the serine protease and/or serine protease zymogen content of a plasma-derived protein composition. Also provided are methods for manufacturing plasma-derived protein compositions having reduced serine protease and\or serine protease zymogen content. Among yet other aspects, the present invention provides aqueous and lyophilized compositions of plasma-derived proteins having reduced serine protease and/or serine protease zymogen content. Yet other aspects include methods for treating, managing, and/or preventing a disease comprising the administration of a plasma-derived protein composition having a reduced serine protease or serine protease zymogen content.
1. A method for preparing a Factor H composition, the method comprising the steps of:
(a) contacting a first composition containing Factor H and at least one serine protease or serine protease zymogen with finely divided silicon dioxide (SiO 2 ) under conditions suitable to bind the Factor H;
(b) washing the SiO 2 with a solution comprising a pH between 5.0 and 7.0 and a conductivity of less than 4 mS/cm;
(c) eluting Factor H from the SiO 2 with a solution comprising a pH between 7.0 and 8.0 and a conductivity greater than 10 mS/cm, thereby forming a first Factor H eluate.
2. The method of claim 1 , wherein the first composition containing Factor H is selected from the group consisting of a suspended Cohn fraction I precipitate, a suspended Cohn fraction II+III precipitate, a suspended Cohn fraction I+II+III precipitate, a suspended Kistler/Nitschmann Precipitate A, a suspended Kistler/Nitschmann Precipitate B and equivalent fraction thereof.
3. The method of claim 1 , wherein the solution used to wash the SiO 2 in step (b) has a pH of from 5.5 to 6.5.
4. The method of claim 1 , wherein the solution used to wash the SiO 2 in step (b) has a pH of 6.0±0.2.
5. The method of claim 1 , wherein the solution used to elute the SiO 2 in step (c) has a conductivity of at least 20 mS/cm.
6. The method of claim 1 , wherein the solution to elute the SiO 2 in step (b) has a conductivity of from 25 mS/cm to 40 mS/cm.
7. The method of claim 1 , wherein the first composition containing Factor H is selected from the group consisting of a Cohn fraction I precipitate, a Cohn fraction II+III precipitate, a Cohn fraction I+II+III precipitate, a Kistler/Nitschmann Precipitate A, a Kistler/Nitschmann Precipitate B, and an equivalent fraction thereof.
8. The method of claim 1 , wherein the first composition containing Factor H is a Cohn fraction I precipitate or a suspended Cohn fraction I precipitate.
9. The method of claim 1 , wherein the first composition containing Factor H is a Cohn fraction II+III precipitate or a suspended Cohn fraction II+III precipitate.
10. The method of claim 1 , further comprising a step of:
(d) precipitating at least one impurity from the first Factor H eluate, thereby forming an enriched Factor H supernatant.
11. The method of claim 10 , wherein precipitating (d) the at least one impurity from the first Factor H eluate is performed by the addition of PEG 4000 to the first Factor H eluate at a final concentration of from 3% to 7% (w/v).
12. The method of claim 10 , wherein precipitating (d) the at least one impurity from the first Factor H eluate is performed by the addition of PEG 4000 to the first Factor H eluate at a final concentration of 5±0.5% (w/v).
13. The method of claim 1 , further comprising a step of:
(e) precipitating Factor H from an enriched Factor H composition, thereby forming an enriched Factor H precipitate.
14. The method of claim 13 , wherein precipitating (e) the Factor H from the enriched Factor H composition is performed by the addition of PEG 4000 to the enriched Factor H composition at a final concentration of from 10% to 15% (w/v).
15. The method of claim 13 , wherein precipitating (e) the Factor H from the enriched Factor H composition is performed by the addition of PEG 4000 to the enriched Factor H composition at a final concentration of 12±0.5% (w/v).
16. The method of claim 10 , further comprising a step of:
(e) precipitating Factor H from an enriched Factor H composition, thereby forming an enriched Factor H precipitate, wherein the enriched Factor H composition is the enriched Factor H supernatant formed in step (d).
17. The method of claim 16 , wherein precipitating (e) the Factor H from the enriched Factor H supernatant is performed by the addition of PEG 4000 to the enriched Factor H supernatant at a final concentration of from 10% to 15% (w/v).
18. The method of claim 13 , wherein precipitating (e) the Factor H from the enriched Factor H supernatant is performed by the addition of PEG 4000 to the enriched Factor H supernatant at a final concentration of 12±0.5% (w/v).
19. The method of claim 1 , further comprising a step of:
(f) enriching Factor H by anion exchange chromatography.
20. The method of claim 1 , further comprising a step of:
(g) enriching Factor H by heparin affinity chromatography.
21. The method of claim 19 , further comprising a step of:
(g) enriching Factor H by heparin affinity chromatography.