ELECTROPHORETIC CHARACTERIZATION OF BOVINE LIPOPROTEIN SUBFRACTIONS ISOLATED BY AGAROSE-GEL CHROMATOGRAPHY

Lipoproteins isolated from whole bovine serum were applied to agarose gel columns and fractionated by molecular size. Three distinct lipoprotein absorbance peaks (280 nm) emerged from the columns (Peaks I, II, and III). A typical elution profile exhibited lipoprotein distribution of approximately 11% Peak I, 6% Peak II, and 83% Peak III. Characterization of Peak I lipoproteins on agarose gel electrophoresis and polyacrylamide gel electrophoresis suggested that Peak I consisted of very low density lipoproteins. Comparison of polyacrylamide gel electrophoresis patterns of successive tube fractions in Peak II demonstrated the progressive emergence of three bands. The slowest migrating band appeared in fractions from the ascending portion of Peak II. Two additional bands progressively emerged from fractions in the central portion of the peak. These bands may represert low density lipoprotein and its metabolic precursors (intermediate density lipoproteins). Successive tube fractions in the area between Peaks II and III displayed a progressive change from β to α migration on both polyacrylamide gel electrophoresis and paper electrophoresis. This heterogeneous group of lipoproteins is probably equivalent to high density lipoprotein-subfraction 1. Lipoproteins from the center of Peak III demonstrated a electrophoretic migration patterns. © 1979, American Dairy Science Association. All rights reserved.