Lipoproteins separation

Lipoproteins are divided into five basic types. The largest particles are the chylomicrons, followed by the very low-density lipoproteins, intermediate lipoproteins, low-density proteins, and finally the smallest— high-density lipoproteins. Separation of the aforementioned cholesterol-containing complexes is accomplished by ultracentrifugation. 

Figure 3.9 UV-detected (280 nm) chromatogram of lipoproteins separated from whole blood serum. The points indicated as T to 8 , show where the flow was stopped so that H NMR spectra could be acquired...

G35. Gustafson, A., Alaupovic, P., and Furman, R. H., Studies of the composition and structure of serum lipoproteins. Separation and characterization of phospholipid-protein residues obtained by partial delipidization of very low density lipoproteins of human serum. Biochemistry 5, 632-640 (1966). 

Lipoproteins, separation of, from somatic antigen, 208 Lysine, 238... 

Lipoprotein Separation by Combined Use of Countercurrent Chromatogr Chromatography... 

Various technologies have been used to measure plasma lipids and lipoproteins and lipoprotein subfractions, including enzymatic, immunochemical, and chemical precipitation reagents, and physical methods, such as ultracentrifugation, electrophoresis, column chromatography, and others. Such methods have been reviewed extensively. As mentioned earlier, however, the cholesterol content of any particular lipoprotein class can vaiy somewhat from individual to individual. Moreover, although different methods of lipoprotein separation may produce similar lipoprotein fractions, they usually do not produce identical fractions, giving rise to systematic biases between methods that purport to measure the same component. The present discussion focuses primarily on methods and procedures commonly used in clinical practice for lipid and lipoprotein measurements. 

Fig. 2. The apoproteins of the major classes of lipoproteins separated on sodium dodecyl-polyacrylamide gels. Reproduced with permission of the authors and publisher, from Mahley and Innerarity [12].

The relevance of the results obtained in vitro, in either liver slices or perfusates, to the general problem of lipoprotein biosynthesis in the intact animal remains to be established. In vivo synthesis of the protein moiety of serum 3-lipoprotein was studied in roosters by administration of S -methionine (Florsheim et al., 1963), followed by measurements of specific radioactivity of plasma 3-lipoprotein separated by dextran sulfate. Under these experimental conditions, enhancement of methionine incorporation was noted after pharmacological doses of ethanol, estrogens, and triiodothyronine. No significant effect was obtained after administration of epinephrine, cortisone, and thyroxine preparations. 

VLDL, LDL and HDL, G3000SW for that of HDL subfractions, G5000PW or G6000PW for that of chylomicrons, VLDL and LDL. The applicable range of human serum lipoproteins separated by each column is presented in Table 2. 

A 0.15 M NaCl solution is usually used as the eluent for lipoprotein separation in this method. However, various aqueous solutions containing appropriate amounts of inorganic salts can be used as an eluent, as long as the pH is less than 8.5. Salt concentration, buffering and pH of the eluent may alter the separation of the lipoproteins, and may improve the resolution of lipoproteins. 

Cholesterol Gas-Liquid Chromatographic Microassay in Serum Lipoproteins Separated by Polyacrylamine Gel Electrophoresis 1349. 

G. J. Hamwi, and J. B. Brown Studies on the characterization of human serum lipoproteins separated by ultracentrifugation in a density gradient. I. Serum lipoproteins in normal, hypothyroid and hypercholesterolemic subjects. Amer. J. din. Nutr. 9,24—40 (1961 a). 

Studies on the characterization of human serum lipoproteins separated by... 

The lipoproteins separated by means of such preparative steps are then subjected to analytical ultracentrifugation, yielding a film record from which a determination can be made of the lipoproteins which are present and their concentrations. 

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