Purification Of Lactoferrin And IgG From Bovine Colostrum

Bovine colostrums is produced by female mammals during the first 7 days after giving birth.Chemically colostrums is a very complex fluid rich in nutrients and natural bio-activity merterials. It has great value to develop a simple separation process to obtain natural bio-activity protein from it. We mainly focoused on Lactoferrin (Lf) and Immunoglobulin G (IgG) purification in this article. The main research work we had done were simple ion exchange purification of Lf from colostrums, a multi-ion exchange purification of Lf and IgG from colostrums, Simulated Moving Bed (SMB) system design and optimizing operation parameters. To purify Lf from skimmed bovine colostrums, the skimmed bovine collstrums merterial was applied to ion exchange column that was packed with CM-Sepharose Fast How, Lf was adsorbed on the column, then with the NaCl gradient elution of 1.6% and 5.0% on cation exchange column. Lf of 96.6%(HPLC) purity was obtained.To purify Lf and IgG from bovine colostrums whey, a process of cation exchange and anion exchange in tandem combined with ultra filtration to separate the two proteins from bovine colostrum was developed. The pH of the skimmed bovine colostrums was adjusted to 4.0 with slow addition of 6mol/L HC1. Casein was removed by centrifugation at 5000 r/min for 20 min. Then obtained whey was adjusted to pH 6.8 with slow addition of 1mol/L NaOH. The treated whey was diluted by ultra filtration with a membrane with molecular weight cut-off of 50,000. After a continuous chromatography of cation exchange and anion exchange in tandem Lactoferrin (Lf) was adsorbed on CM-Sepharose Fast How and Immunoglobulin G (IgG) was adsorbed on DEAE-Sepharose Fast How. With the NaCl gradient elution of C(NaCl)=0.27moVL and 0.85mol/L on cation exchange column, Lf of 96.6% (HPLC) purity was obtained and IgG of 95%(HPLC) purity was obtained with NaCl gradient elution of C(NaCl)=17mmol/L and 51 mmol/L on anion exchange column.A SMB system was designed and we preceded continuous Lf purification on it. Comparing with normal ion exchange operations, its efficiency doubled.