Dextran sulfate precipitation and ultracentrifugation of lipoproteins from hypercholesterolemic dog serum*

Abstract

Dogs fed a diet containing butter, cholesterol, and thiouracil develop severe hypercholesterolemia. Both α2- and β-lipoprotein cholesterol and phospholipid increase whereas these lipids in the α1 fraction appear to decrease. Comparison of the dextran sulfate-precipitable lipoproteins with lipoprotein fractions obtained by ultracentrifugation at densities 1.019, 1.063, and 1.21 and with paper electrophoretograms reveals that the addition of low molecular weight dextran sulfate and calcium chloride to diluted hypercholesterolemic dog serum quantitatively precipitates low-density lipoproteins. Paper electrophoresis revealed that the dextran sulfate-precipitable fraction contains both α2- and β-lipoproteins.