Patent ID: 6080844
Filing Date: 2000-06-27
Classification: C07K

Abstract:
A process of purifying and recovering recombinant beta-casein from a cell comprising the steps of:extracting recombinant beta-casein from a concentrated suspension of cells using a water-miscible organic solvent selected from the group consisting of acetone, isopropanol, ethanol and methanol, said solvent containing from about 50% volume to about 95% volume organic solvent and from about 50% volume to about 5% volume water at a pH of from about 6.5 to about 8.5 and at a temperature of from about 30.degree. C. to about 50.degree. C., the molar ratio of suspension of cells to water miscible organic solvent being from about 1:1 to about 1:5;isolating the recombinant beta-casein from the suspension of cells;concentrating the recombinant beta-casein to remove the organic solvent;cooling the recombinant beta-casein to a temperature of about 5.degree. C. to separate solids from the recombinant beta-casein;isolating the recombinant beta-casein from the solids;treating the recombinant beta-casein with a water-soluble calcium salt, the molar ratio. of water-soluble calcium salt to recombinant beta-casein being from about 1:1 to 1:5;precipitating the recombinant beta-casein using an acid;washing the recombinant beta-casein with sodium acetate or acetic acid; andrecovering the recombinant beta-casein.