Resolution Of Lipoproteins Research Articles

Electrophoretic separation of LDL and HDL subclasses.

An extensive literature supports the hypothesis that measurements of lipoprotein subclasses provide a more detailed reflection of lipoprotein metabolism and a more accurate prediction for risk of cardiovascular disease. Lipoprotein subclasses have been resolved on the basis of density fractionation, gel filtration, and immunological and electrophoretic procedures. Perhaps one of the most widely used methods has been the resolution of lipoproteins on the basis of particle size using nondenaturing pore gradient gel electrophoresis (GGE). GGE procedures have been based on highly reliable gradient gels supplied in two formats: PAA2/16 for resolving low-density lipoproteins (LDLs) and PAA4/30 for resolving high-density lipoprotems (HDLs) (Pharmacia, Piscataway, NJ). These gel formats produce repeatable and detailed separations of the two major classes of lipoprotein particles, appropriate for quantitative analyses of lipoprotein phenotypes.

Heterogeneity of HDL in crossed immunoelectrophoresis with continuous gradient polyacrylamide gel in the first dimension and one or two antibody layers in the second dimension

We describe a new method of immunoelectrophoresis with a continuous gradient polyacrylamide gel in the first dimension and an agarose-dextran gel in the second dimension with one or two layers of antibody. The use of a polyacrylamide gel in the first dimension allows better resolution of lipoproteins than with crossed immunoelectrophoresis using agarose gel in both dimensions. The use of two layers of antibody in the second dimension also enhances the specificity of characterization and the resolution of the separation. Thus, using a layer of anti-apo A-I combined with a layer of anti-apo A-II, three particles containing only apo A-I and three containing both apo A-I and A-II could be separated.

Fractionation of bovine serum lipoproteins and their characterization by gradient gel electrophoresis

SummaryBovine serum lipoproteins were fractionated by precipitation with dextran sulphate followed by ultracentrifugation and were examined by paper electrophoresis and by disk electophoresis in acrylamide gels. Gels containing concentration gradients of both sucrose and acrylamide gave better resolution of lipoproteins than did gels of uniform composition or gels with a concentration gradient of sucrose and a uniform concentration of acrylamide.The densities of the lipoprotein classes isolated (listed in order of increasing mobility on electrophoresis in acrylamide gels) were as follows:I,d< 1·019; II, 1·039 <d<1·050;III, 1·019 <d<1·039; IVa and IVb,d> 1·050.Lipoproteins of classes I, II and III were precipitated by dextran sulphate. On paper electrophoresis, lipoproteins of class II had β mobility and lipoproteins of classes IVa and IVb had α mobility. Lipoproteins of class I remained at the origin.The lipoprotein classes of bovine sera resembled those of sheep and goat sera in that class IV predominated. In contrast, the sera of several non-ruminant species showed a predominance of lipoprotein classes of low electrophoretic mobility.

Polyacrylamide gels of increasing concentration gradient for the electrophoresis of lipoproteins

A method for the preparation of polyacrylamide gels having a concentration gradient in polyacrylamide is described. Such gels have been used to resolve blood plasma high molecular weight lipoproteins into multiple components on the basis of molecular diameter. The resolution of lipoproteins using this method is superior to that using conventional electrophoretic and ultra-centrifuge methods. Qualitative differences among normal and among pathological plasmas have been demonstrated. The validity of the lipoprotein prestaining procedure and of the results obtained have been tested in a number of independent ways. Some tentative conclusions have been drawn concerning the molecular diameter distribution of high molecular weight lipoprotein.