High-Performance Gel-Permeation Chromatography of Bovine Skim Milk Proteins

Abstract

The separation of bovine skim milk proteins by gel-permeation high-performance liquid chromatography was examined. Toya-Soda TSK-GEL (Type SW) columns were used with an eluent of 0.05 M phosphate buffer (ph 6.80) containing 0.1 M sodium sulfate at 0.5 ml/min. Bovine whole milk was centrifuged to remove lipids and the resultant skim milk directly injected. A 2000SW column yielded 3 protein peaks: 1 = casein, IgG and BSA [bovine serum albumin]; 2 = .beta.-lactoglobulins and BSA; and 3 = .alpha.-lactalbumin and BSA. A 3000SW plus 2000SW column system with a 30 .mu.l injection volume yielded 4 protein peaks: 1 = minor amounts of .alpha. - and .beta.-casein; 2 = casein, BSA and IgG; 3 = .beta.-lactoglobulins; and 4 = .**GRAPHIC**. A 3000SW plus 2000SW column system with a 10 .mu.l injection volume yielded 5 protein peaks: 1 = casein; 2 = IgG; 3 = BSA; 4 = .beta.-lactoglobulins; and 5 = .alpha.-lactalbumin. Both the single column and dual column applications yielded 3 nonprotein peaks, which were dialyzed from solution. A high speed analytical separation of milk proteins was achieved according to molecular size, but this application is highly dependent on sample size.