Comparative Isolation of Serum \beta + pre- \beta Lipoproteins of Human and Various Domestic Animal Species by Dextran Sulfate/MnCl_2 and Sodium Phosphotungstate/MgCl_2 Precipitation Methods


Abstract: Lipoproteins are water-soluble complexes through which various lipids are transported between the various tissues for storage and utilization. Association of lipoproteins with risk of coronary heart disease and various types of dyslipoproteinemias necessitate the quantification of the individual lipoprotein classes. The study was undertaken to compare the concentrations of precipitation reagents (dextran sulfate/MnCl_2, sodium phosphotungstate/MgCl_2) necessary in order to precipitate \beta + pre- \beta lipoproteins in human and various animal sera. To this end, the serum \beta + pre- \beta lipoproteins of human and various animal species were precipitated using various methods. The lipoproteins precipitated were separated and identified by agarose gel electrophoresis. Dextran sulfate/MnCl_2 at the concentration used for human serum resulted in complete precipitation of \beta + pre- \beta lipoprotein of sera from all animal species. In the sodium phosphotungstate/MgCl_2 precipitation method, \beta + pre- \beta lipoproteins of goat and sheep were precipitated by two times more sodium phosphotungstate/MgCl_2 than that required for human serum \beta + pre- \beta lipoproteins. Also in other animal species \beta + pre- \beta lipoproteins were precipitated by the same sodium phosphotungstate/MgCl_2 concentration. It was concluded that the concentrations of polyanion/divalent cation used for the precipitations of serum \beta + pre- \beta lipoproteins differ between human and several animal species. The existing differences might be attributed to the variations in charge densities of lipoproteins' surfaces as well as to dissimilarities in lipid compositions of the lipoproteins between species.

Keywords: Lipoprotein isolation, precipitation, polyanion, divalent cation, serum.

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