High-Density Lipoprotein Isolation

Suenram, A., McConathy, W. J., and Alaupovic, P., Evidence for the lipoprotein heterogeneity of human plasma high density lipoproteins isolated by three different procedures. Lipids 14, 505-510 (1979). 

Soine PJ, Blanke RV, Chinchilli VM, et al. 1984a. High-density lipoproteins decrease the biliary concentration of chlordecone in isolated perfused pig liver. J Toxicol Environ Health 14(2-3) 319-335. 

Chacko, G. K. (1985). Modification of high density lipoprotein (HDL3) with tetranitro-methane and the effect on its binding to isolated rat liver plasma membranes.). Lipid Res. 26, 745-754. 

The third, and perhaps least understood, mechanism regulating contact pheromone production involves its transport to the cuticular surface. The detection of large amounts of hydrocarbons and pheromone internally, within the hemolymph, prompted an examination of lipid transport in B. germanica. Gu et al. (1995) and Sevala etal. (1997) isolated and purified a high density lipoprotein, lipophorin, that carries hydrocarbons, contact pheromone, and JH within the hemolymph. The accumulated evidence supports the idea that the hydrocarbons and contact pheromone components are produced by oenocytes within the abdominal integument, carried by lipophorin, and differentially deposited in the cuticle and ovaries (Fan et al.,... 

To test this hypothesis, very low density lipoprotein (VLDL, d<1.0 gm/ml), low density lipoprotein (LDL, d=l.02-1.063) and high density lipoprotein (HDL, d=l.09-1.21) were isolated from outdated human plasma by ultracentrifugation according to established procedures (27,28), using potassium bromide for density adjustments and stored at -20° C in the presence of 20% sucrose before use. The purity of individual lipoprotein fractions thus obtained was established by polyacrylamide gel electrophoresis in sodium dodecyl buffer system (2 ) and filtration through a Sepha-rose 6B column, equilibrated with 0.2 M potassium bromide in 0.1 M sodium phosphate buffer, pH 7.2. Protein (30) and cholesterol... 

A27. Assmann, G., Herbert, P. N., Fredrickson, D. S., and Forte, T., Isolation and characterization of an abnormal high density lipoprotein in Tangier disease. ]. Clin. Incest. 60, 242-252 (1977). 

B43. Brewer, H. B., Jr., Fairwell, T., Larue, A., Ronan, R., Houser, A., and Bronzert, T., The amino acid sequence of human apoA-1, an apolipoprotein isolated from high density lipoproteins. Biochem. Biophys. Res. Common. 80, 623-630 (1978). 

E8. Eriksen, N., and Benditt, E. P., Isolation and characterization of the amyloid-related apoprotein (SAA) from human high density lipoprotein. Proc. Natl. Acad. Sci. U.S.A. 77, 6860-6864 (1980). 

M24. Malmendier, C. L., Delctoix, C., and Fontaine, M., Effect of sialic acid removal on human low density lipoprotein catabolism in vivo. Atherosclerosis 37, 277-284 (1980). M25. Malmendier, C. L., Paroutaud, P., and Ameryckx, J. P., Partial amino acid sequence of three new apolipoproteins isolated from human high density lipoproteins. FEBS Lett. 109, 43-44 (1980). 

Olofsson, S.-O., Fager, G., and Gustafson, A., Isolation and partial characterization of glycine- and serine-rich polypeptide from human serum high-density lipoproteins (HDL). Scand. J. Clin. Lab. Invest. 37, 749-755 (1977). 

P3. Parks, J. S., and Rudel, L. L., Isolation and characterization of high density lipoprotein... 

Shore, V. G., Shore, B., and Lewis, S. B., Isolation and characterization of two threonine-poor apolipoproteins of human plasma high density lipoproteins. Biochemistry 17, 2174-2179 (1978). 

W8. Weisgraber, K. H., Bersot, T. P., Mahley, R. W., Franceschini, G., and Sirtori, C. R., A-lMilano apoprotein. Isolation and characterization of a cystein-containing variant of the A-I apoprotein from human high density lipoproteins. J. Clin. Invest. 66, 901-907 (1980). 

Blood plasma contains a number of soluble lipoproteins, which are classified, according to their densities, into four major types. These lipid-protein complexes function as a lipid transport system. Isolated lipids are insoluble in blood, but they are rendered soluble, and therefore transportable, by combination with specific proteins, the so-called lipoproteins. There are four basic types in human blood (1) chylomicrons, (2) very low density lipoproteins (VLDL), (3) low-density lipoproteins (LDL). and (4) high-density lipoproteins (HDL). Their properties are summarized in Table 6.2. 

Cholesterol and triacylglycerols are transported in body fluids in the form of lipoprotein particles. Each particle consists of a core of hydrophobic lipids surrounded by a shell of more polar lipids and apoproteins. The protein components of these macromolecular aggregates have two roles they solubilize hydrophobic lipids and contain cell-targeting signals. Lipoprotein particles are classified according to increasing density (Table 26.1) chylomicrons, chylomicron remnants, very low density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Ten principal apoproteins have been isolated and characterized. They are synthesized and secreted by the liver and the intestine. 

The assay used by Pattnaik et al. (1978) to isolate the cholesteryl ester transfer protein in human plasma measured the transfer of 3H-labeled cholesteryl ester from low density to high density lipoprotein. The transfer reaction was terminated by adding MnC and centrifuging to sediment the low density lipoprotein. A heparin, MnCl2 precipitation step may also be used however, in the presence of a phosphate buffer, heparin is not necessary for precipitation of low density lipoprotein. Routine assays were found to be reproducible to within 10%. The increase in high density lipoprotein radioactivity is linear with time until about 25% of the initial low density lipoprotein radioactivity is transferred. The lipoproteins may also be separated by ultracentrifugation. When these two methods were compared, the results agreed within 10%. The precipitation technique is much faster (less than 15 min compared with 18 hr) and simpler. 

Lipoproteins are classified into four major types in human blood, according to their densities chylomicrons, very low density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Isolated lipids are generally insoluble in blood, but lipoproteins allow lipids to be transported in the blood. 

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