Comparison of ultracentrifugation and gel filtration for the isolation of bovine lipoproteins

Abstract

Lipoproteins from the plasma of three nonlactating Holstein cows were isolated using either preparative ultracentrifugation or gel filtration chromatography. Lipoprotein classes obtained by ultracentrifugation were very low density plus chylomicra, less than 1.006 g/ml; low density, 1.007-1.039 g/ml; high density1, 1.040-1.063 g/ml; and high density, 1.064-1.22 g/ml. These lipoprotein classes were individually applied to an agarose gel column to determine at what volume they eluted in comparison to lipoproteins that were separated after applying total bovine lipoproteins to the column. Three major peaks corresponding to very low density lipoproteins plus chylomicra, low density, and high density lipoproteins resulted after gel filtration of total lipoproteins. Very low density lipoproteins plus chylomicra, obtained by ultracentrifugation, eluted as a single peak, as did low density and high density lipoproteins. However, high density1 lipoproteins eluted as two peaks. The first peak eluted at the same volume as low density lipoproteins, and the second peak eluted at a volume similar to that of the ascending slope of the high density lipoprotein peak. Results from disc polyacrylamide gel electrophoresis, immunoelectrophoresis and double immunodiffusion of lipoprotein fractions, and SDS polyacrylamide gel electrophoresis of their apoproteins, similarly indicated that the lipoproteins present in the 1.040-1.063 g/ml density interval are a mixture of low and high density lipoproteins rather than a unique class of lipoproteins.

Utilization of Intestinal Triglyceride-rich Lipoproteins in Mammary Gland of Cows

“…Among these techniques, gel permeation chromatography is useful for both the analysis and preparation of bovine lipoproteins. Grummer et al [9] reported that three major peaks (TRL, LDL, and HDL) were observed on the elution profiles of TLP in both lactating and non-lactating cows by gel permeation chromatography, however, only two peaks (TRL and HDL) were observed in lactating cows in this study. Ferreri and Gleockler [6] also detected two peaks in lactating cows and speculated that the lack of LDL peak was resulted from large HDL particles eluted broadly at the same position in LDL.…”

Progesterone production by cultured luteal cells in the presence of bovine low- and high-density lipoproteins purified by heparin affinity chromatography2

“…The LDL and HDL from that study (Pate and Condon, 19821 were separated by preparative ultracentrifugation using 1.064 g/mL density cutoff but were not characterized. The LDL was most likely con- taminated with HDL (Grummer et al, 1983). A second report comparing the ability of LDL or HDL to stimulate bovine luteal cell progesterone production reported that LDL was the preferred lipoprotein, but both LDL and HDL may be important in vivo (O'Shaugnessy and Wathes, 19851. Luteal cells were cultured in 10% bovine serum with cyclic adenosine monophosphate.…”

Bovine lipoprotein and apolipoprotein profiles as influenced by sex and growth

“…They showed no clear-cut division in this density interval (1.006 to 1.063 dml ) where these lipoproteins could be separated. Gnunmer et al (1983) found that LDL, HDL1, and HDL had two proteins with molecular weights of 40,OOO to 55,000 D a In either case, the identity of these proteins in these fractions is really unknown, however, their presence in all three fractions suggests that they may be apolipoproteins rather than contaminating proteins.…”